WO2025072244A1 - Stabilized tissue modification systems - Google Patents

Abstract

The present disclosure relates to stabilized tissue modification systems (200) that can be used to form an opening in a target tissue, such as a host leaflet within which a guest prosthetic valve can be expanded. In an example, a stabilized tissue modification system (200) comprises an anchor device (229) that includes an anchor shaft (230) and a helical anchor (250) coupled to the anchor shaft. The system can further include a hole-dilating balloon (296) mounted on a balloon catheter (290). The hole-dilating balloon (296) is configured to transition between deflated and inflated states thereof. The helical anchor head (250) comprises a helical slot (260) defining one or more helical turns (256) terminating at an anchor tip (254). The anchor shaft (230) is a flexible torque shaft configured to rotate around a central axis thereof, such that when the anchor shaft is rotated, the helical anchor is configured to rotate therewith.

Description

STABILIZED TISSUE MODIFICATION SYSTEMS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63/540,757, filed September 27, 2023, and U.S. Provisional Application No. 63/612,934, filed December 20, 2023, the contents of which are herein incorporated by reference in their entirety.

FIELD

[0002] The present disclosure relates to devices and systems configured to form an opening in the target tissue, and to methods and systems for puncturing through a target tissue that can be a leaflet of an existing valvular structure, in a manner that can modify existing valvular structures (for example, leaflets of a native heart valve or previously-implanted prosthetic valve) prior to implantation of a guest prosthetic valve.

BACKGROUND

[0003] The human heart can suffer from various valvular diseases. These valvular diseases can result in significant malfunctioning of the heart and ultimately require repair of the native valve or replacement of the native valve with an artificial valve. There are a number of known repair devices (for example, stents) and artificial valves, as well as a number of known methods of implanting these devices and valves in humans. Percutaneous and minimally-invasive surgical approaches, such as transcatheter aortic valve replacement (TAVR), are used in various procedures to deliver prosthetic medical devices to locations inside the body that are not readily accessible by surgery or where access without surgery is desirable.

[0004] Transcatheter aortic valve replacement (TAVR) is one example of a minimally-invasive surgical procedure used to replace a native aortic valve. In one specific example of the procedure, an expandable prosthetic heart valve is mounted in a crimped state on the distal end of a delivery apparatus and advanced through the patient’ s vasculature (for example, through a femoral artery and the aorta) to the heart. The prosthetic heart valve is positioned within the native valve and expanded to its functional size.

[0005] A variant of TAVR is valve-in- valve (ViV) TAVR, where a new prosthetic heart valve replaces a previously implanted prosthetic valve. In one specific example of the procedure, a new expandable prosthetic heart valve (“guest valve”) is delivered to the heart in a crimped state, as described above for the “native” TAVR. The guest valve is positioned within the previously implanted prosthetic valve (“host valve”) and then expanded to its functional size. The host valve in a ViV TAVR procedure can be a surgically implanted prosthetic valve or a transcatheter prosthetic valve. The term “host valve” is also used herein to refer to the native aortic valve in a native TAVR procedure.

SUMMARY

[0006] Needles or other perforating tools can be utilized for piercing existing leaflets to form an opening that modifies the existing valvular structure, after which a guest prosthetic valve can be implanted in the modified valvular structure, mitigating the risk of coronary ostial obstruction. The leaflet is a relatively thin tissue having a free edge opposite to attachment on an opposite end to the aortic wall in the case of a native leaflet of an aortic valve, or to a frame of a previously implanted prosthetic valve in the case of ViV procedures. Perforation of the leaflet by pushing a needle or other perforating tool there-against, can move the leaflet to some extent due to the push force applied thereto. Even if the needle or other tool does puncture eventually through the tissue material, such initial movement can lead to the penetration point being in a different region of the leaflet relative to the initial point of contact.

[0007] According to some aspects of the disclosure, there is provided a stabilized tissue modification system, comprising an anchor device comprising: an anchor shaft defining an anchor shaft lumen, and a helical anchor head coupled to the anchor shaft.

[0008] In some examples, the helical anchor defines an anchor channel in fluid communication with the anchor shaft lumen.

[0009] In some examples, the helical anchor head comprises an anchor proximal end and at least one helical slot extending distally from the anchor proximal end, the at least one helical slot defining one or more helical turns, wherein a distal-most helical turn of the one or more helical turns defines a tip portion terminating at an anchor tip.

[0010] In some examples, the system further comprises a balloon catheter defining a balloon catheter lumen, and a hole-dilating balloon mounted on the balloon catheter and in fluid communication with the balloon catheter lumen, the hole-dilating balloon configured to transition between deflated and inflated states thereof.

[0011] In some examples, the anchor shaft is a flexible torque shaft configured to rotate around a central axis thereof, such that when the anchor shaft is rotated, the helical anchor head is configured to rotate therewith.

[0012] In some examples, the anchor tip is a sharp anchor tip, configured to penetrate through a target tissue during rotational movement of the helical anchor head. [0013] In some examples, the helical anchor head defines a non-uniform pitch that gets narrower in a proximal direction.

[0014] In some examples, the helical slot has a width that tapers towards a slot proximal end thereof.

[0015] In some examples, the helical anchor head comprises a thinned wall portion terminating at a slot proximal end of the helical slot.

[0016] In some examples, the tip portion further comprises a cutting edge opposite to an inner side of the tip portion.

[0017] In some examples, the inner side of the tip portion is curved.

[0018] In some examples, a length of the cutting edge spans at least 90° from the anchor tip.

[0019] In some examples, a thickening length of the tip portion spans at least 90° from the anchor tip.

[0020] In some examples, the anchor shaft comprises a helical hollow strand tube.

[0021] In some examples, the helical hollow strand tube is a single layer helical hollow strand tube.

[0022] In some examples, the tip portion comprises three planar facets intersecting with each other.

[0023] In some examples, the system further comprising a needle defining a needle lumen, the needle extending through the anchor shaft lumen.

[0024] In some examples, the needle is axially movable relative to the anchor shaft.

[0025] In some examples, the anchor shaft further comprises a movement limiting segment defining a limiting segment channel which is continuous with the anchor shaft lumen.

[0026] In some examples, the needle comprises a stopper extending radially outward therefrom, the stopper configured to axially translate within the limiting segment channel.

[0027] In some examples, the movement limiting segment comprises a distal inner step.

[0028] In some examples, the needle is configured to move between a first position and a second position, wherein the stopper is in contact with the distal inner step in the second position.

[0029] In some examples, the needle, in the first position, is proximal to the needle in the second position.

[0030] In some examples, the needle is axially immovable relative to the anchor shaft.

[0031] In some examples, the needle and the anchor shaft are configured to simultaneously move in the axial direction. [0032] In some examples, the system further comprises an outer shaft defining an outer shaft lumen, wherein the anchor shaft is axially movable relative to the outer shaft lumen.

[0033] In some examples, the outer shaft is coupled to, and distally extends from a handle of a steerable delivery apparatus.

[0034] In some examples, the handle of the steerable delivery apparatus further comprises a valve assembly proximal to the outer shaft.

[0035] In some examples, the valve assembly comprises a cross-slit valve, a disc valve distal to the cross-slit valve, and a hemostatic valve distal to the disc valve.

[0036] In some examples, the anchor device and the needle extend through a delivery catheter, wherein the delivery catheter is configured to be insertable, through a rear port of the handle of the steerable delivery apparatus, into the handle of the steerable delivery apparatus and the outer shaft lumen.

[0037] In some examples, the delivery catheter, the anchor device, and the needle, are coupled to and extend distally from a handle of a perforation apparatus.

[0038] In some examples, the hole-dilating balloon comprises a first balloon portion and a second balloon portion, each configured to expand to a different maximum diameter.

[0039] According to some aspects of the disclosure, there is provided a method comprising advancing an anchor device of a stabilized tissue modification system, over a guidewire, to a host valvular structure.

[0040] In some examples, the method further comprises securing the helical anchor head to a host leaflet of the host valvular structure.

[0041] In some examples, the method further comprises forming, with a perforating component of the stabilized tissue modification system, a pilot puncture in the host leaflet.

[0042] In some examples, the method further comprises passing the guidewire through the pilot puncture.

[0043] In some examples, the method further comprises releasing the helical anchor head from the host leaflet.

[0044] In some examples, the method further comprises positioning a hole-dilating balloon, mounted on a balloon catheter of the stabilized tissue modification system, inside the pilot puncture, in a radially deflated state of the hole-dilating balloon.

[0045] In some examples, the method further comprises inflating the hole-dilating balloon to expand the pilot puncture and form a leaflet opening within the host leaflet.

[0046] In some examples, the perforating component comprises a cutting edge extending along a tip portion of a distal-most helical turn of the helical anchor head. [0047] In some examples, the forming the pilot puncture comprises forming a cut, through the host leaflet, which gradually increases in length in the circumferential direction, during rotational movement of the helical anchor head.

[0048] In some examples, the formed cut spans less than 360° around a central axis of the helical anchor head.

[0049] In some examples, the stabilized tissue modification system further comprises a needle having a needle head, and wherein the perforating component is a sharp needle tip of the needle head.

[0050] In some examples, the forming the pilot puncture comprises positioning the needle head inside the anchor channel, such that the needle head does not extend distally beyond the helical anchor head.

[0051] In some examples, the forming the pilot puncture comprises moving the needle from a first position, in which the needle head is proximal to the host leaflet, to a second position, in which the needle head is advanced through the host leaflet and the anchor channel.

[0052] In some examples, the moving the needle to the second position comprises advancing a stopper extending radially outward from the needle, to contact with a distal inner step of a movement limiting segment of the anchor shaft.

[0053] In some examples, the method further comprises, subsequent to releasing the helical anchor head from the host leaflet and prior to positioning the hole-dilating balloon in the pilot puncture, retrieving the helical anchor head while maintaining the guidewire extending through the pilot puncture.

[0054] In some examples, the positioning the hole-dilating balloon inside the pilot puncture comprises, subsequent to the retrieving the helical anchor head, advancing the balloon catheter, over the guidewire, towards the host leaflet.

[0055] In some examples, the advancing a helical anchor head towards the host valvular structure comprises advancing an outer shaft, defining an outer shaft lumen through which the anchor shaft extends, towards the host valvular structure.

[0056] In some examples, the retrieving the helical anchor head comprises pulling the helical shaft through the outer shaft lumen, while maintaining the outer shaft in position.

[0057] In some examples, the advancing the balloon catheter towards the host leaflet comprises advancing the balloon catheter through the outer shaft lumen.

[0058] In some examples, the method further comprises, before the advancing the anchor device, advancing an outer shaft of a steerable delivery apparatus of the stabilized tissue modification system towards the host valvular structure, wherein the outer shaft defines an outer shaft lumen and distally extends from a handle of the steerable delivery apparatus, and wherein the handle of the steerable delivery apparatus comprises a rear port.

[0059] In some examples, the advancing the outer shaft comprises adjusting the curvature of a distal section of the outer shaft by a knob of the handle of the steerable delivery apparatus.

[0060] In some examples, the handle of the steerable delivery apparatus further comprises a valve assembly proximal to the outer shaft, the valve assembly comprising a cross-slit valve, a disc valve distal to the cross-slit valve, and a hemostatic valve distal to the disc valve.

[0061] In some examples, the method further comprises, before the advancing the outer shaft, inserting an introducer that includes an introducer shaft and a tapered distal portion, through the rear port of the handle of the steerable delivery apparatus, into the handle of the steerable delivery apparatus and the outer shaft lumen.

[0062] In some examples, the advancing the outer shaft comprises advancing the outer shaft over the introducer, while the tapered distal portion of the introducer distally extends out of the outer shaft.

[0063] In some examples, the method further comprises, after the advancing the outer shaft, retrieving the dilator out of the steerable delivery apparatus while maintaining the outer shaft in situ.

[0064] In some examples, the method further comprises, after the retrieving the dilator, inserting a delivery catheter of a perforation apparatus of the stabilized tissue modification system, through the rear port of the handle of the steerable delivery apparatus, into the handle of the steerable delivery apparatus and the outer shaft lumen, wherein the perforation apparatus comprises the anchor device and the needle extending through the delivery catheter.

[0065] In some examples, the advancing the anchor device comprises advancing the delivery catheter through the outer shaft.

[0066] In some examples, the delivery catheter, the anchor device, and the needle, are coupled to and extend distally from a handle of a perforation apparatus.

[0067] In some examples, the method further comprises, after the releasing the helical anchor head and before the positioning the hole-dilating balloon, retrieving the perforation apparatus out of the steerable delivery apparatus while maintaining the outer shaft in situ.

[0068] In some examples, the method further comprises, after the retrieving the perforation apparatus and before the positioning the hole-dilating balloon, inserting the balloon catheter, comprised in a dilation apparatus of the stabilized tissue modification system, through the rear port of the handle of the steerable delivery apparatus, into the handle of the steerable delivery apparatus and the outer shaft lumen. [0069] In some examples, the positioning the hole-dilating balloon comprises advancing the balloon catheter through the outer shaft.

[0070] In some examples, the handle of the perforation apparatus comprises a first handle portion and a second handle portion releasably coupled to the first handle portion, wherein the delivery catheter is rigidly attached to the first handle portion, and wherein the anchor device and the needle are coupled to the second handle portion.

[0071] In some examples, the method further comprises, after the releasing the helical anchor head and before the positioning the hole-dilating balloon, releasing the second handle portion from the first handle portion, and retrieving the anchor device and the needle out of the delivery catheter while maintaining the delivery catheter in situ.

[0072] In some examples, the method further comprises, after the retrieving the anchor device and the needle and before the positioning the hole-dilating balloon, inserting the balloon catheter, comprised in a dilation apparatus of the stabilized tissue modification system, through the second handle portion, into the delivery catheter.

[0073] In some examples, the positioning the hole-dilating balloon comprises advancing the balloon catheter through the delivery catheter.

[0074] The aspects of this disclosure can be used in combination or separately. This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. The foregoing and other objects, features, and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE FIGURES

[0075] Some examples of the invention are described herein with reference to the accompanying figures. The description, together with the figures, makes apparent to a person having ordinary skill in the art how some examples may be practiced. The figures are for the purpose of illustrative description and no attempt is made to show structural details of an example in more detail than is necessary for a fundamental understanding of the invention. For the sake of clarity, some objects depicted in the figures are not to scale.

In the Figures:

[0076] Fig. 1 is a cross-sectional view of a native aortic valve. [0077] Fig. 2A shows a cross-sectional view of a prosthetic heart valve implanted in the native aortic valve of Fig. 1, according to an example.

[0078] Fig. 2B shows the implanted prosthetic heart valve of Fig. 1A as viewed from the ascending aorta, according to an example.

[0079] Fig. 3 shows a valve-in- valve implantation within the native aortic valve of Fig. 1, according to an example.

[0080] Fig. 4 shows an exemplary stabilized tissue modification system.

[0081] Fig. 5 A is a sectional view in perspective of an exemplary stabilized tissue modification system.

[0082] Fig. 5B is a cross-sectional side view of the stabilized tissue modification system of Fig. 5A.

[0083] Figs. 6A-6K illustrate exemplary steps in a method for utilizing an exemplary stabilized tissue modification system for forming an opening within a host leaflet.

[0084] Fig. 7 A is a perspective view of an exemplary stabilized tissue modification system comprising a movement limiting segment and a needle equipped with a stopper.

[0085] Fig. 7B is a cross-sectional view of the stabilized tissue modification system of Fig. 7A, in a first position of the needle.

[0086] Fig. 7C is a cross-sectional view of the stabilized tissue modification system of Fig. 7A, in a second position of the needle.

[0087] Figs. 7D-7E are cross-sectional view of additional examples of a stabilized tissue modification system.

[0088] Fig. 8A is a sectional view in perspective of an exemplary stabilized tissue modification system comprising a balloon catheter extending through an anchor shaft.

[0089] Fig. 8B is a cross-sectional side view of the stabilized tissue modification system of Fig. 8A.

[0090] Figs. 9A-9K illustrate exemplary steps in an exemplary method for utilizing the stabilized tissue modification system of Figs. 8A-8B for forming an opening within a host leaflet.

[0091] Fig. 9L is a simplified side view of a guest prosthetic valve in a crimped configuration positioned inside the leaflet opening formed in the existing valvular structure.

[0092] Fig. 9M is a simplified side view of the guest prosthetic valve of Fig. 29F expanded inside the existing valvular structure.

[0093] Fig. 10A shows the hole-dilating balloon positioned within a pilot puncture of the host leaflet in a deflated state. [0094] Fig. 10B shows the hole-dilating balloon of Fig. 10A inflated within the host leaflet.

[0095] Fig. 10C shows the guest prosthetic valve positioned in the leaflet opening after removal of the hole-dilating balloon of Fig. 10B.

[0096] Fig. 11 A is a perspective view of a host prosthetic valve subsequent to forming a leaflet opening thereof.

[0097] Fig. 1 IB is a perspective view of a guest prosthetic valve expanded within a leaflet opening of a host prosthetic valve.

[0098] Fig. 12 is a perspective view of an exemplary helical anchor having continuous helical turns with a gradually increasing width.

[0099] Fig. 13 is a perspective view of an exemplary helical anchor having a thinned wall portion at a proximal end of its helical slot.

[0100] Fig. 14 is a perspective view of an exemplary helical anchor having a dual-helical arrangement with two sets of helical turns.

[0101] Fig. 15A is a perspective view of an exemplary tube-cut helical anchor head comprising a cutting edge.

[0102] Fig. 15B is a cross-sectional view taken along line 15B-15B of Fig. 15 A.

[0103] Fig. 16A is a perspective view of an exemplary wire-formed helical anchor head comprising a cutting edge.

[0104] Fig. 16B is a cross-sectional view taken along line 16B-16B of Fig. 16A.

[0105] Fig. 17A and 17B are perspective and front views, respectively, of an exemplary tubecut helical anchor head.

[0106] Figs. 18A and 18B are perspective and cross-sectional side views, respectively, of an exemplary helical anchor head having a tip portion that includes a rounded edge.

[0107] Figs. 19A, 19B and 19C are perspective, side and front views, respectively, of an exemplary wire-formed helical anchor head having a conical tip portion.

[0108] Figs. 20A, 20B and 20C are perspective, side and front views, respectively, of an exemplary wire-formed helical anchor head having a lancet-type tip portion.

[0109] Fig. 21 shows a cross-sectional view of an exemplary steerable delivery apparatus.

[0110] Fig. 22 shows a distal portion of an introducer approximated to a rear port of a handle of a steerable delivery apparatus.

[0111] Fig. 23 shows the introducer of Fig. 22 extending through the steerable delivery apparatus.

[0112] Fig. 24 is a cross-sectional view of a tapered distal portion of the introducer. [0113] Fig. 25 shows an exemplary perforation apparatus extending through the steerable delivery apparatus.

[0114] Fig. 26A shows an exemplary dilation apparatus extending through the steerable delivery apparatus.

[0115] Fig. 26B shows an exemplary dilation apparatus extending through a delivery catheter that extends through the steerable delivery apparatus.

[0116] Fig. 27 is a side view of an exemplary prosthetic valve.

[0117] Figs. 28A-28B show a guest prosthetic valve implanted in various examples of host prosthetic valve.

[0118] Figs. 29A-29Q illustrate exemplary steps in a method for utilizing an exemplary stabilized tissue modification system that includes differently sized hole-dilating balloons for forming a tear in a first host leaflet and a bounded hole in a second host leaflet.

[0119] Figs. 30A-30I illustrate exemplary steps in a method for utilizing an exemplary stabilized tissue modification system that includes a non-uniform hole-dilating balloon for forming a tear in a first host leaflet and a bounded hole in a second host leaflet.

DETAILED DESCRIPTION

[0120] For purposes of this description, certain aspects, advantages, and novel features of the examples of this disclosure are described herein. The disclosed methods, apparatus, and systems should not be construed as being limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed examples, alone and in various combinations and sub-combinations with one another. The methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed examples require that any one or more specific advantages be present, or problems be solved. The technologies from any example can be combined with the technologies described in any one or more of the other examples. In view of the many possible examples to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated examples are only preferred examples and should not be taken as limiting the scope of the disclosed technology.

[0121] Although the operations of some of the disclosed examples are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods can be used in conjunction with other methods. Additionally, the description sometimes uses terms like “provide’' or “achieve” to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms may vary depending on the particular implementation and are readily discernible by one of ordinary skill in the art.

[0122] All features described herein are independent of one another and, except where structurally impossible, can be used in combination with any other feature described herein.

[0123] As used in this application and in the claims, the singular forms “a”, “an”, and “the” include the plural forms unless the context clearly dictates otherwise. Additionally, the terms “have” or “includes” means “comprises”. Further, the terms “coupled”, “connected”, and “attached”, as used herein, are interchangeable and generally mean physically, mechanically, chemically, magnetically, and/or electrically coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language. As used herein, “and/or” means “and” or “or”, as well as “and” and “or”.

[0124] Directions and other relative references may be used to facilitate discussion of the drawings and principles herein, but are not intended to be limiting. For example, certain terms may be used such as “inner”, “outer”, “upper”, “lower”, “inside”, “outside”, “top”, “bottom”, “interior”, “exterior”, “left”, right”, and the like. Such terms are used, where applicable, to provide some clarity of description when dealing with relative relationships, particularly with respect to the illustrated examples. Such terms are not, however, intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an “upper” part can become a “lower” part simply by turning the object over. Nevertheless, it is still the same part and the object remains the same.

[0125] The term “plurality” or “plural” when used together with an element means two or more of the element. Directions and other relative references (for example, inner and outer, upper and lower, above and below, left and right, and proximal and distal) may be used to facilitate discussion of the drawings and principles herein but are not intended to be limiting.

[0126] The terms “proximal” and “distal” are defined relative to the use position of a delivery apparatus. In general, the end of the delivery apparatus closest to the user of the apparatus is the proximal end, and the end of the delivery apparatus farthest from the user (for example, the end that is inserted into a patient’s body) is the distal end. The term “proximal” when used with two spatially separated positions or parts of an object can be understood to mean closer to or oriented towards the proximal end of the delivery apparatus. The term “distal” when used with two spatially separated positions or parts of an object can be understood to mean closer to or oriented towards the distal end of the delivery apparatus. The terms “longitudinal’" and “axial” are interchangeable, and refer to an axis extending in the proximal and distal directions, unless otherwise expressly defined.

[0127] The terms “axial direction”, “radial direction”, and “circumferential direction” have been used herein to describe the arrangement and assembly of components relative to the geometry of the frame of the prosthetic valve, or the geometry of an inflatable balloon that can be used to expand a prosthetic valve. Such terms have been used for convenient description, but the disclosed examples are not strictly limited to the description. In particular, where a component or action is described relative to a particular direction, directions parallel to the specified direction as well as minor deviations therefrom are included. Thus, a description of a component extending along an axial direction of the frame does not require the component to be aligned with a center of the frame; rather, the component can extend substantially along a direction parallel to a central axis of the frame.

[0128] As used herein, the terms “integrally formed” and “unitary” refer to a construction that does not include any welds, fasteners, or other means for securing separately formed pieces of material to each other.

[0129] As used herein, operations that occur “simultaneously” or “concurrently” occur generally at the same time as one another, although delays in the occurrence of operation relative to the other due to, for example, spacing between components, are expressly within the scope of the above terms, absent specific contrary language.

[0130] As used herein, terms such as “first”, “second”, and the like are intended to serve as respective labels of distinct components, steps, etc. and are not intended to connote or imply a specific sequence or priority. For example, unless otherwise stated, a step of performing a second action and/or of forming a second component may be performed prior to a step of performing a first action and/or of forming a first component.

[0131] As used herein, the term “substantially” means the listed value and/or property and any value and/or property that is at least 75% of the listed value and/or property. Equivalently, the term “substantially” means the listed value and/or property and any value and/or property that differs from the listed value and/or property by at most 25%. For example, “at least substantially parallel” refers to directions that are fully parallel, and to directions that diverge by up to 22.5 degrees.

[0132] In the present disclosure, a reference numeral that includes an alphabetic label (for example, “a”, “b”, “c”, etc.) is to be understood as labeling a particular example of the structure or component corresponding to the reference numeral. Accordingly, it is to be understood that components sharing like names and/or like reference numerals (for example, with different alphabetic labels or without alphabetic labels) may share any properties and/or characteristics as disclosed herein even when certain such components are not specifically described and/or addressed herein.

[0133] Throughout the figures of the drawings, different superscripts for the same reference numerals are used to denote different examples of the same elements. Examples of the disclosed devices and systems may include any combination of different examples of the same elements. Specifically, any reference to an element without a superscript may refer to any alternative example of the same element denoted with a superscript. In order to avoid undue clutter from having too many reference numbers and lead lines on a particular drawing, some components will be introduced via one or more drawings and not explicitly identified in every subsequent drawing that contains that component.

[0134] Described herein are devices and methods for implanting prosthetic valves and modifying leaflets of an existing valvular structure in a patient’s heart. Prior to or during implantation of the prosthetic heart valve within the existing valvular structure, each device, such as a delivery apparatus that can optionally carry a prosthetic valve, can be provided in the ascending aorta of a patient and can be used to pierce, lacerate, slice, tear, cut or otherwise modify a leaflet or commissure of the existing valvular structure. In some examples, the existing valvular structure can be a native aortic valve (for example, normal or abnormal, such as bicuspid aortic valve (BAV)) or a prosthetic valve previously implanted in the native aortic valve. The modification can avoid, or at least reduce the likelihood of, issues that leaflets of the existing valvular structure might otherwise cause once the prosthetic heart valve has been fully installed, for example, obstruction of blood flow to the coronary arteries, improper mounting due to a non-circular valve cross-section, and/or restricted access to the coronary arteries if subsequent intervention is required. While described with respect to aortic valve, it should be understood that the disclosed examples can be adapted to deliver devices that can modify existing valvular structure, and in some implementations, implant prosthetic devices, to and/or in any of the native annuluses of the heart (for example, the aortic, pulmonary, mitral, and tricuspid annuluses), and can be used with any of various delivery approaches (for example, retrograde, antegrade, transseptal, transventricular, transatrial, etc.).

[0135] Fig. 1 illustrates an anatomy of the aortic root 22, which is positioned between the left ventricle 32 and the ascending aorta 26. The aortic root 22 includes a native aortic valve 20 having a native valvular structure 29 comprising a plurality of native leaflets 30. Normally, the native aortic valve 20 has three leaflets (only two leaflets are visible in the simplified illustration of Fig. 1), but aortic valves with fewer than three leaflets are possible. The leaflets 30 are supported at native commissures by the aortic annulus 24, which is a ring of fibrous tissue at the transition point between the left ventricle 32 and the aortic root 22. The leaflets 30 can cycle between open and closed positions (the closed position is shown in Fig. 1) to regulate flow of blood from the left ventricle 32 to the ascending aorta 26. Branching off the aortic root 22 are the coronary arteries 34, 36. The coronary artery ostia 42, 44 are the openings that connect the aortic root 22 to the coronary arteries 34, 36.

[0136] Figs. 2A-2B show an exemplary prosthetic valve 100 that can be implanted in a native heart valve, such as the native aortic valve 20 of Fig. 1. The term “prosthetic valve”, as used herein, refers to any type of a prosthetic valve deliverable to a patient’s target site over a catheter, which is radially expandable and compressible between a radially compressed, or crimped, state, and a radially expanded state. Thus, the prosthetic valve can be crimped on or retained by an implant delivery apparatus (not shown) in the radially compressed state during delivery, and then expanded to the radially expanded state once the prosthetic valve reaches the implantation site. The expanded state may include a range of diameters to which the valve may expand, between the compressed state and a maximal diameter reached at a fully expanded state. Thus, a plurality of partially expanded states may relate to any expansion diameter between radially compressed or crimped state, and maximally expanded state. A prosthetic valve of the current disclosure (for example, prosthetic valve 100) may include any prosthetic valve configured to be mounted within the native aortic valve, the native mitral valve, the native pulmonary valve, and the native tricuspid valve.

[0137] It is understood that the prosthetic valves disclosed herein may be used with a variety of implant delivery apparatuses. Balloon expandable valves generally involve a procedure of inflating a balloon within a prosthetic valve, thereby expanding the prosthetic valve within the desired implantation site. Once the valve is sufficiently expanded, the balloon is deflated and retrieved along with a delivery apparatus (not shown). Self-expandable valves include a frame that is shape-set to automatically expand as soon an outer retaining shaft or capsule (not shown) is withdrawn proximally relative to the prosthetic valve. Mechanically expandable valves are a category of prosthetic valves that rely on a mechanical actuation mechanism for expansion. The mechanical actuation mechanism usually includes a plurality of expansion and locking assemblies (such as the prosthetic valves described in U.S. Patent No. 10,603,165, International Application No. PCT/US2021/052745 and U.S. Provisional Application Nos. 63/085,947 and 63/209904, each of which is incorporated herein by reference in its entirety), releasably coupled to respective actuation assemblies of a delivery apparatus, controlled via a handle (not shown) for actuating the expansion and locking assemblies to expand the prosthetic valve to a desired diameter. The expansion and locking assemblies may optionally lock the valve’ s diameter to prevent undesired recompression thereof, and disconnection of the actuation assemblies from the expansion and locking assemblies, to enable retrieval of the delivery apparatus once the prosthetic valve is properly positioned at the desired site of implantation.

[0138] Figs. 2A-2B show an example of a prosthetic valve 100, which can be a balloon expandable valve or any other type of valve, illustrated in an expanded state. The prosthetic valve 100 can comprise an outflow end 106 and an inflow end 104. In some instances, the outflow end 106 is the proximal end of the prosthetic valve 100, and the inflow end 104 is the distal end of the prosthetic valve 100. Alternatively, depending for example on the delivery approach of the valve, the outflow end can be the distal end of the prosthetic valve, and the inflow end can be the proximal end of the prosthetic valve.

[0139] The term “outflow”, as used herein, refers to a region of the prosthetic valve through which the blood flows through and out of the prosthetic valve 100.

[0140] The term “inflow”, as used herein, refers to a region of the prosthetic valve through which the blood flows into the prosthetic valve 100.

[0141] In the context of the present application, the terms “lower” and “upper” are used interchangeably with the terms “inflow” and “outflow”, respectively. Thus, for example, the lower end of the prosthetic valve is its inflow end and the upper end of the prosthetic valve is its outflow end.

[0142] In the context of the present application, the terms “lower” and “upper” are used interchangeably with the terms “distal to” and “proximal to”, respectively. Thus, for example, a lowermost component can refer to a distal-most component, and an uppermost component can similarly refer to a proximal-most component.

[0143] The terms “longitudinal” and “axial”, as used herein, refer to an axis extending in the proximal and distal directions, unless otherwise expressly defined.

[0144] The prosthetic valve 100 comprises an annular frame 102 movable between a radially compressed configuration and a radially expanded configuration, and a valvular structure 113 that comprises prosthetic valve leaflets 114 mounted within the frame 102. The frame 102 can be made of various suitable materials, including plastically-deformable materials such as, but not limited to, stainless steel, a nickel based alloy (for example, a cobalt-chromium or a nickel- cobalt-chromium alloy such as MP35N alloy), polymers, or combinations thereof. When constructed of a plastically-deformable materials, the frame 102 can be crimped to a radially compressed state on a balloon catheter, and then expanded inside a patient by an inflatable balloon or other types of expansion mechanisms, such as an expandable frame described in U.S. Provisional Application No. 63/335,739, which is incorporated by reference herein in its entirety. Alternatively or additionally, the frame 102 can be made of shape-memory materials such as, but not limited to, nickel titanium alloy (for example, Nitinol). When constructed of a shape-memory material, the frame 102 can be crimped to a radially compressed state and restrained in the compressed state by insertion into a shaft or equivalent mechanism of a delivery apparatus.

[0145] In the example illustrated in Figs. 2A-2B, the frame 102 is an annular, stent-like structure comprising a plurality of intersecting struts 108. In this application, the term “strut” encompasses axial struts, angled struts, laterally extendable struts, commissure windows, commissure support struts, support posts, and any similar structures described by U.S. Pat. Nos. 7,993,394 and 9,393,110, which are incorporated herein by reference. A strut 108 may be any elongated member or portion of the frame 102. The frame 102 can include a plurality of strut rungs that can collectively define one or more rows of cells 110. The frame 102 can have a cylindrical or substantially cylindrical shape having a constant diameter from the inflow end 104 to the outflow end 106 as shown, or the frame can vary in diameter along the height of the frame, as disclosed in US Pat. No. 9,155,619, which is incorporated herein by reference.

[0146] The struts 108 can include a plurality of angled struts and vertical or axial struts. At least some of the struts 108 can be pivotable or bendable relative to each other, so as to permit frame expansion or compression. For example, the frame 102 can be formed from a single piece of material, such as a metal tube, via various processes such as, but not limited to, laser cutting, electroforming, and/or physical vapor deposition, while retaining the ability to collapse/expand radially in the absence of hinges and like.

[0147] A valvular structure 113 of the prosthetic valve 100 can include a plurality of prosthetic valve leaflets 114 (for example, three leaflets), positioned at least partially within the frame 102, and configured to regulate flow of blood through the prosthetic valve 100 from the inflow end 104 to the outflow end 106. While three leaflets 114 arranged to collapse in a tricuspid arrangement, are shown in the example illustrated in Figs. 2A-2B, it will be clear that a prosthetic valve 100 can include any other number of leaflets 114. Adjacent leaflets 114 can be arranged together to form prosthetic valve commissures 116 that are coupled (directly or indirectly) to respective portions of the frame 102, thereby securing at least a portion of the valvular structure 113 to the frame 102. The prosthetic valve leaflets 114 can be made from, in whole or part, biological material (for example, pericardium), bio-compatible synthetic materials, or other such materials. Further details regarding transcatheter prosthetic valves, including the manner in which leaflets 114 can be coupled to the frame 102 of the prosthetic valve 100, can be found, for example, in U.S. Patent Nos. 6,730,118, 7,393,360, 7,510,575, 7,993,394, 8,652,202, and 11,135,056, all of which are incorporated herein by reference in their entireties.

[0148] In some examples, the prosthetic valve 100 can comprise at least one skirt or sealing member. For example, the prosthetic valve 100 can include an inner skirt (not shown in Fig. 2A-2B), which can be secured to the inner surface of the frame 102. Such an inner skirt can be configured to function, for example, as a sealing member to prevent or decrease perivalvular leakage. An inner skirt can further function as an anchoring region for leaflets 114 to the frame 102, and/or function to protect the leaflets 114 against damage which may be caused by contact with the frame 102, for example during valve crimping or during working cycles of the prosthetic valve 100. An inner skirt can be disposed around and attached to the inner surface of frame 102, while the leaflets can be sutured to the inner skirt along a scalloped line (not shown). An inner skirt can be coupled to the frame 102 via sutures or another form of coupler. [0149] The prosthetic valve 100 can comprise, in some examples, an outer skirt 118 mounted on the outer surface of frame 102 (as shown in Figs. 2A-2B), configured to function, for example, as a sealing member retained between the frame 102 and the surrounding tissue of the native annulus against which the prosthetic valve is mounted, or against an inner side of a previously implanted valve in the case of ViV procedures (described further below), thereby reducing risk of paravalvular leakage (PVL) past the prosthetic valve 100. The outer skirt 118 can be coupled to the frame 102 via sutures or another form of coupler.

[0150] Any of the inner skirt and/or outer skirt can be made of various suitable biocompatible materials, such as, but not limited to, various synthetic materials (for example, PET) or natural tissue (for example pericardial tissue). In some cases, the inner skirt can be formed of a single sheet of material that extends continuously around the inner surface of frame 102. In some cases, the outer skirt 118 can be formed of a single sheet of material that extends continuously around the outer surface of frame 102.

[0151] The cells 110, defined by interconnected struts 108, define cell openings 112. While some of the cell openings 112 can be covered by the inner skirt and/or the outer skirt, at least a portion of the cell opening 112 can remain uncovered, such as cell openings 112 which are closer to the outflow end 106 of the prosthetic valve.

[0152] Figs. 2A-2B illustrate a hypothetical coronary artery obstruction that could occur in some cases from implantation of a prosthetic valve 100 within the native aortic valve 20. In this example, the prosthetic valve 100 is the guest valve or new valve, and the native aortic valve 20 is the host valve or old valve.

[0153] During implantation of the prosthetic valve 100, the prosthetic valve 100 is positioned within a central region defined between the native leaflets 30, which are also the host leaflets 10 for the example illustrated in Fig. 2A-2B. The prosthetic valve 100 is then radially expanded against the host leaflets 10. As illustrated, the host leaflets 10 form a tube around the frame 102 of the prosthetic valve 100 after the prosthetic valve 100 is radially expanded to the working diameter. As further illustrated, expansion of the prosthetic valve 100 displaces the host leaflets 10 outwards towards the coronary ostia 42, 44 such that the host leaflets 10 contact a portion of the aortic root 22 surrounding the coronary ostia 42, 44, causing coronary artery obstruction. [0154] For an existing implanted prosthetic valve, the valvular structure may naturally degrade over time thereby requiring repair or replacement in order to maintain adequate heart functions. In a Valve-in- Valve (ViV) procedure, a new prosthetic heart valve is mounted within the existing, degrading prosthetic heart valve in order to restore proper function. Fig. 3 illustrates an exemplary hypothetical coronary artery obstruction that could occur in some cases from implantation of a prosthetic valve 100b within a previously implanted prosthetic valve 100a (for example, after a ViV procedure). In this example, the prosthetic valve 100b is the guest valve or new valve, and the prosthetic valve 100a is the host valve or old valve. In this example, the prosthetic valve 100a was previously implanted within the orifice of the native aortic valve 20. Each of the prosthetic valves 100a, 100b can have the general structure of the prosthetic valve 100 described with reference to Figs. 2A-2B, though in some examples, each of the prosthetic valves 100a, 100b can be a different type of prosthetic valve. For example, a balloon expandable guest valve 100b can be implanted inside a previously implanted mechanically expandable or self-expandable host valve 100a.

[0155] During implantation of the prosthetic valve 100b, the prosthetic valve 100b is positioned within a central region defined between the leaflets 114a of the prosthetic valve 100a, which now take the role of host leaflet 10. The prosthetic valve 100b is then radially expanded against the host leaflets 10 (i.e., against the prosthetic valve leaflets 114c). As illustrated, the radial expansion of the prosthetic valve 100a results in outward displacement of the host leaflets 10. As further illustrated, the host leaflets 10 are displaced such that the host leaflets 10 contact the aortic root 22 at positions superior to the coronary artery ostia 42, 44, causing coronary artery ostia obstruction. Alternatively, the guest prosthetic valve 100b can displace the host leaflets 114a outwardly against the frame 102a of the host valve 100a, thereby blocking the flow of blood through the frame 102a to the coronary ostia 42, 44. [0156] In some patient anatomies (for example, when the outflow end 106 of the prosthetic valve 100 is at the STJ level 28 and the diameter of the prosthetic valve 100 is similar to the STJ diameter such that the frame 102 touches or is very close to the aortic wall 38 at the STJ level 28), the host leaflets 10 may compromise the ability for future access into the coronary arteries 34, 36 or perfusion through the frame 102 to the coronary arteries 34, 36 during the diastole phase of the cardiac cycle. Similar problems may occur in some patient anatomies either when a guest prosthetic valve 100b is percutaneously expanded within a previously implanted host prosthetic valve 100a, or when a prosthetic valve 100 is percutaneously expanded within a native valve, displacing the native leaflets 30 outward toward the coronary ostia 42, 44.

[0157] The risk illustrated in Fig. 3 may be higher when the host valve is a bioprosthetic valve without a frame or when the leaflets of the host valve are external to a frame. Risk of coronary artery ostia obstruction can increase in a cramped aortic root or when the coronary artery ostium sits low. In the examples illustrated in Figs. 2A-3, the host leaflets 10 are shown obstructing both coronary artery ostia 42, 44. In some cases, only one host leaflet 10 may obstruct a respective coronary artery ostium. For example, the risk of obstructing the left coronary ostium 42 tends to be greater than obstructing the right coronary ostium 44 because the left coronary ostium 42 typically sits lower than the right coronary ostium 44.

[0158] The term “host valve” as used herein refers to a native heart valve in which a prosthetic valve is implanted or a previously implanted prosthetic valve in which a new prosthetic valve is implanted. Moreover, in any of the examples disclosed herein, when the host valve is a previously implanted prosthetic valve, the host valve can be a surgically implanted prosthetic heart valve (known as a “surgical valve”) or a transcatheter heart valve. The term “guest valve”, as used herein, refers to a prosthetic valve implanted in a host valve, which can be either a native heart valve or a previously implanted prosthetic valve. Similarly, the term “host leaflets 10”, as used herein, refers to native leaflets 30 of a native valve in which a new guest prosthetic valve 100 is implanted, or to prosthetic valve leaflets 114a of a previously implanted host valve 100a in which a new guest prosthetic valve 100b is implanted.

[0159] To avoid obstruction of blood flow to the coronary arteries 34, 36, the valvular structure 12 of the existing host valve (whether a native aortic valve or a previously implanted prosthetic valve) can be modified by components of a delivery apparatus prior to or during implantation of a new prosthetic valve within the existing valvular structure 12. In some examples, the host valvular structure 12 is modified by piercing, lacerating, tearing, slicing, and/or cutting one or more host leaflets 10 (for example, a free end of the host leaflet 10 or a commissure of adjacent host leaflets 10, which can be a native commissure 40 for a native aortic valve 20, or a prosthetic valve commissure 116 for a previously implanted host prosthetic valve 100) using the delivery apparatus. The modification thus disrupts the impermeable tubular structure that would otherwise be formed by the existing host leaflets 10, thereby allowing blood to flow to the coronary arteries 34, 36.

[0160] Fig. 4 illustrates an exemplary stabilized tissue modification system 200, which can include a delivery apparatus adapted to deliver an anchor device 229 having a helical anchor head 250 attached, directly or indirectly, to an anchor shaft 230. The anchor head 250 defines an anchor channel 252 and has a sharp anchor tip 254 configured to allow it to engage and penetrate a target tissue, such as a host leaflet 10 of a host valvular structure. The helical anchor head 250 can be optionally used in combination with a perforation member such as a needle that can extend through the anchor channel 252 towards a target tissue, such as a host leaflet 10, for modifying the host leaflet 10. In some examples, a stabilized tissue modification system 200 can include, or be used in combination with, a handle 204 and an outer shaft 208. The anchor shaft 230 can extend through a lumen 210 of the outer shaft 208.

[0161] The outer shaft 208 and the anchor shaft 230 can be configured to be axially movable relative to each other. For example, a distally oriented movement of the anchor shaft 230 relative to the outer shaft 208, can expose the anchor head 250 from the outer shaft lumen 210. [0162] Various exemplary implementations for systems 200 and/or anchor heads 250 thereof can be referred to, throughout the specification, with superscripts, for ease of explanation of features that refer to such exemplary implementations. It is to be understood, however, that any reference to structural or functional features of any device, system or component, without a superscript, refers to these features being commonly shared by all specific exemplary implementations that can be also indicated by superscripts. In contrast, features emphasized with respect to an exemplary implementation of any device, system or component, referred to with a superscript, may be optionally shared by some but not necessarily all other exemplary implementations. For example, the stabilized tissue modification system 200^a illustrated in Fig. 4 can include both the anchor device 229 and the an outer shaft 208, which can be a steerable catheter, coupled to and controllable by the same handle 204, The proximal ends of the outer shaft 208 and the anchor shaft 230 can be coupled to the handle 204. During delivery through the patient’s vasculature, the handle 204 can be maneuvered by an operator (for example, a clinician or a surgeon) to axially advance or retract components of the stabilized tissue modification system 200^a, such as the outer shaft 208 or any other component passing therethrough, including an anchor shaft 230 which will be described in further detail below. [0163] In some examples, the anchor shaft 230 is a torque shaft, configured to be movable rotatably relative to a central axis CA thereof (indicated, for example, in Fig. 5B), and/or rotatable relative to another shaft of the system 200, such as relative to the outer shaft 208. The anchor head 250 is affixed, directly or via one or more intermediate components, to the anchor shaft 230, such that rotation of the anchor shaft 230 effects rotation of the anchor head 250 therewith.

[0164] The handle 204 can include a steering mechanism configured to adjust the curvature of the distal end portion of the stabilized tissue modification system 200^a. In the illustrated example, the handle 204 can include an adjustment member, such as the illustrated rotatable knob 206a, which in turn is operatively coupled to the proximal end portion of a pull wire. The pull wire can extend distally from the handle 204 through the outer shaft 208 and has a distal end portion affixed to the outer shaft 208 at or near the distal end of the outer shaft 208. Rotating the knob 206a can increase or decrease the tension in the pull wire, thereby adjusting the curvature of the distal end portion of the stabilized tissue modification system 200^a. Further details on steering or flex mechanisms for the handle 204 of system 200 can be similar to those described below with respect to a handle 304 illustrated in Fig. 21.

[0165] The handle 204 can further include a shaft-rotating mechanism which can be optionally operable by a knob of the handle, such as the illustrated rotatable knob 206b. A proximal end of the anchor shaft 230 can be operatively connected to a manually rotatable shaft-rotating mechanism or a motorized shaft-rotating mechanism that allows the operator (such as a clinician) to effect rotation of the anchor shaft 230 and the anchor head 250.

[0166] The handle can include additional adjustment mechanisms controllable by additional knobs to maneuver additional components of the stabilized tissue modification system 200, such as axial movement of a needle 270 (shown, for example, in Figs. 5A-5B) and/or axial movement of a delivery shaft 218 (shown, for example, in Figs. 8A-8B), relative to other shafts of the system 200, as will be elaborated in greater detail below. The terms “stabilized tissue modification system 200” and “system 200”, as used herein, are interchangeable.

[0167] In some examples, a stabilized tissue modification system 200 can include a helical anchor head 250 carried by an anchor shaft 230, and an inflatable balloon 296 (see, for example, Figs. 6G-6J) mounted on a balloon catheter 290. The helical anchor head 250 can be used with or without a separate perforating member, such as a needle 270 (shown for example in Fig. 5A- 5B) axially movable relative to the helical anchor head 250, to form a pilot puncture 50 (see, for example, Fig. 6F) in a target tissue, such as a host leaflet 10. The balloon 296, which can be also referred to as a hole-dilating balloon, is configured to be positioned inside the pilot puncture 50, and expand the pilot puncture to form a tissue opening, such as a leaflet opening 52, as shown for example in Fig. 6J and explained in greater detail below.

[0168] Figs. 5A-5B show a sectional view in perspective and a cross-sectional side view of an exemplary stabilized tissue modification system 200. In some examples, a helical anchor head

250 can be a tube-cut anchor head. Manufacturing of a tube-cut helical anchor head 250 can employ any suitable cutting method, such as, but not limited to, laser cutting, water-jet cutting, plasma cutting, and the like. Sharpening the anchor tip 254 can employ grinding of a tip portion

251 terminating with the sharpened tip 254, or any other suitable sharpening method. The helical anchor head 250 can include at least one helical slot 260 extending distally from a proximal end 266 of the anchor head 250, and defining one or more helical turns 256 continuously extending between the anchor proximal end 266 and the sharp anchor tip 254. The terms “helical anchor head 250” and “anchor head 250”, as used herein, are interchangeable.

[0169] The outer shaft 208 has an outer shaft distal end portion 214 which can be, in some examples, an atraumatic distal end portion 214, such as by being rounded and/or being curved radially inwards, or otherwise formed to include an outer surface tapering in the distal direction. In some examples, the anchor head 250 can be maintained inside the outer shaft lumen 210, axially positioning the sharp anchor tip 254 at or proximal to the outer shaft distal end portion 214, to conceal the sharp anchor tip 254 of the anchor head 250 from the surrounding anatomy during delivery, thereby mitigating the risk of the sharp anchor tip 254 contacting and/or damaging any anatomical structure prior to reaching the site of treatment. In such examples, the diameter of outer shaft lumen 210, at least along the outer shaft distal end portion 214, is greater than an outer diameter of the anchor head 250.

[0170] The anchor shaft 230 defines an anchor shaft lumen 232 which is in fluid communication with the anchor channel 252. In some examples, at least a portion of the anchor shaft 230 is formed as a hypotube, configured to increase flexibility thereof. The anchor shaft 230 can optionally include a plurality of circumferential bands 248 arranged between circumferential slits 246, with axially extending connecting portions 247 connecting adjacent bands 248, as illustrated for example in Figs. 12-14. Two adjacent circumferential bands 248 can be connected by a plurality of angularly spaced connecting portions 247. In such arrangements, the anchor shaft 230 exhibits sufficient flexibility to allow it to flex as it is pushed through a tortuous pathway without kinking or buckling, and/or to bend when another component of the system 200 is implemented as a steerable catheter that can be actively articulated to orient the system 200 in a desired direction. [0171] While a specific pattern is illustrated in Figs. 5A-5B, which can be a laser cut pattern, it is to be understood that the pattern of bands 248 and slits 246 and/or the width of the bands 248 and/or slits 246 can vary along the length of the anchor shaft 230 in order to vary stiffness of the anchor shaft 230 along its length. For example, the width of the bands 248 can decrease from the proximal end to the distal end of the anchor shaft 230 to provide greater stiffness near the proximal end and greater flexibility near the distal end of the anchor shaft 230.

[0172] In some examples, at least a portion of the anchor shaft 230 comprises a helical hollow strand (HHS) tube, as illustrated for example in Figs. 4-5B. While conventional HHS tubes can be manufactured in single, double or triple layers to provide varying flexibility and control, the anchor shaft 230 can be, in some examples, a single layer HHS tube, so as to preserve a smaller radial profile.

[0173] It is to be understood that a reference to a helical anchor head 250 attached to an anchor shaft 230 can refer either to a helical anchor head 250 provided as a separate component coupled, directly or indirectly, to a distal end 244 of an anchor shaft 230, or to a unitary component wherein the helical anchor head 250 is integrally formed with the anchor shaft 230. [0174] An exemplary helical anchor head 250 is shown in Figs. 5A-5B as a separate, optionally tube-cut anchor, coupled to a distal end 244 of an anchor shaft 230. The anchor proximal end 266 can be, in some examples, a portion of the anchor head 250 extending proximally from a proximal end 262 of the helical slot 260, thus forming a ring-like portion devoid of helical turns 256. In some examples, the helical winding of the helical turns 256 is generally continuous and uninterrupted except in a region near the slot proximal end 262, wherein a proximal-most helical turn 256 and the anchor proximal end 266 are joined together by a continuous wall portion 258. In other words, the helical slot 260 does not extend, in such examples, through the anchor proximal end 266. This continuous wall portion 258 can provide a rigid structure by which a separately formed anchor head 250 can be solidly coupled to the anchor shaft 230, such as by welding, gluing, press-fitting, or any other suitable form of coupling.

[0175] While separately formed helical anchor 250 and anchor shaft 230 coupled to each other are illustrated in Figs. 5A-5B and described above, a unitary component formed from a single tube that includes an anchor shaft 230 and a helical anchor head 250 integrally formed from a single tube can be similarly utilized in any exemplary system 200 disclosed herein.

[0176] In some examples, a stabilized tissue modification system 200 can further comprises a hollow needle 270 extendable through the anchor shaft lumen 232 and anchor channel 252, as illustrated for exemplary stabilized tissue modification system 200^a in Figs. 5A-5B. When implemented as part of the stabilized tissue modification system 200^a, the needle 270 can extend distally from the handle 204. Needle 270 is axially movable relative to the helical anchor head 250.

[0177] Needle 270 comprises a needle head 274 and a needle shaft 271 extending proximally from the needle head 274, collectively defining a needle lumen 272. The needle head 274 is configured to pierce a target tissue, such as a host leaflet 10 of a host valvular structure 12, to form a pilot puncture 50 in the host leaflet 10. The needle head 274 can define an angled surface 276 terminating at a sharp needle tip 278 configured to facilitate piercing of a target tissue, such as the host leaflet 10, when the needle 270 is pressed thereagainst. The needle lumen 272 can be sized to allow passage of a guidewire 80 (shown, for example, in Figs. 6A-6K) therethrough.

[0178] In some examples, at least a portion of the needle shaft 271 is formed as a hypotube, configured to increase flexibility thereof. In the example illustrated in Figs. 5A-5B, at least part of the needle shaft 271, such as a distal portion 273 thereof, is shown to include a plurality of circumferential bands 228 arranged between circumferential slits 226, with axially extending connecting portions 227 connecting adjacent bands 228. Two adjacent circumferential bands 228 can be connected by a plurality of angularly spaced connecting portions 227. In such arrangements, the slitted part of needle shaft 271 exhibits sufficient flexibility to allow it to flex as it is pushed through a tortuous pathway without kinking or buckling, and/or to bend when another component of the system 200 is implemented as a steerable catheter that can be actively articulated to orient the system 200 in a desired direction.

[0179] While a specific pattern is illustrated in Figs. 5A-5B, which can be a laser cut pattern, it is to be understood that the pattern of bands 228 and slits 226 and/or the width of the bands 228 and/or slits 226 can vary along the length of the slitted part of needle shaft 271in order to vary stiffness of the needle 270 along its length. For example, the width of the bands 228 can decrease from the proximal end to the slitted part of needle shaft 271 to provide greater stiffness near the proximal end and greater flexibility near the distal end of the slitted part of needle shaft 271.

[0180] In some examples, the slitted part of the needle shaft 271 can extend along the entire length of the needle shaft 271 or at least a significant portion of a length thereof. In some examples, the needle shaft 271 can include a distal portion 273 that includes slits, such as slits 226, and a proximal portion 275 extending proximally from the distal portion 273, which can be devoid of slits, as illustrated in Fig. 5A. In some examples, the distal portion 273 and the proximal portion 275 of the needle shaft 271 are separate components that can be affixed to each other, and may be made from similar or different materials. For example, a laser-cut metallic tube that includes slits 226 can be used to form the distal portion 273, while the proximal portion 275 can be made of a polymeric material. The distal portion 273 can allow for increased flexibility along a distal part of the needle 270, allowing it to be steered towards a target tissue, such as a host leaflet 10, to improve precision of positioning and penetration, while the polymeric proximal portion 275, devoid of such slits, may be less flexible than the distal portion 273, yet flexible enough to allow it to passively bend along curved portions of the patient’s vasculature, for example.

[0181] In some examples, the distal portion 273 extends along less than 50% of the length of the entire needle shaft 271. In some examples, the distal portion 273 extends along less than 30% of the length of the entire needle shaft 271. In some examples, the distal portion 273 extends along less than 25% of the length of the entire needle shaft 271. In some examples, the distal portion 273 extends along less than 20% of the length of the entire needle shaft 271. In some examples, the needle head 274 can be continuous with and/or integrally formed with the distal portion 273 of the needle shaft. For example, when the distal portion 273 is formed from a metallic tube, the needle head 274 can be an integral extension of the tube, together forming a unitary component, while the needle head 274 can be devoid of slits.

[0182] In some implementations of a needle 270, the length of the needle shaft 271 extending through a patient’s vasculature, all the way to a host leaflet 10, such as a leaflet in an aortic valve, can be in the order of more than 2 meters, such as between 2-3 meters or even longer. Laser cutting metallic tubes have such lengths can be costly. Limiting the distal portion 273 of the needle shaft 271 to be formed as a hypotube, while the optionally longer proximal portion 275 is made of a polymeric material, can advantageously reduce manufacturing costs. The proximal portion 275 can be affixed, at its distal end, to a proximal end of the distal portion 273, by any method known in the art such as gluing, overmolding, and the like.

[0183] While the needle shaft 271 is shown in the example illustrated in Fig. 5 A to be formed of a distal portion 273 that includes circumferential slits 226, and a proximal portion 275 devoid of slits, it is to be understood any exemplary needle 270 disclosed herein can be, in some examples, slitted along its entire length, such as by being made of a metallic laser-cut hypotube that defines the entirety of the needle shaft 271.

[0184] As further illustrated in Figs. 5A-5B, the anchor device 229, such as exemplary anchor device 229^a, can be axially extendable through a lumen 210 of outer shaft 208. In some examples, the outer shaft 208 can include an atraumatic distal end portion 214. For example, an exemplary outer shaft 208 is illustrated in Figs. 5A-5B to include a distal end portion 214 that can be bent or curved radially inwards. In some examples, a distal end portion 214 of outer shaft 208 can include a distally tapering outer surface, a rounded distal edge, a chamfered distal edge, and the like.

[0185] Figs. 6A-6K illustrate some steps in a method for utilizing a system 200 for forming an opening within a target tissue. An exemplary implementation of the method is illustrated in Figs. 6A-6K with respect to forming a leaflet hole inside a host leaflet, which can be performed prior to implanting a guest prosthetic valve inside the host valvular structure. The system 200 can be used to perforate a host leaflet 10, such as a native leaflet 30 or a prosthetic valve leaflet 1 14 of a previously implanted prosthetic valve. While a system 200 comprising a hollow needle 270 extendable through anchor channel 252, and balloon 296 carried by a balloon catheter 290 that can be also axially extendable through anchor shaft lumen 232 and/or anchor channel 252, is illustrated throughout Figs. 6A-6K, it is to be understood that other examples of system 200 described in the current specification can be used in a similar manner with some steps modified according to the configuration of the system, as will be further elaborated below.

[0186] The distal end portion of the system 200, which can include a distal end portion 214 of the outer shaft 208 and/or the helical anchor head 250, is configured to be inserted into a patient’s vasculature, such as within an ascending aorta, and to be advanced towards the host leaflet 10. Positioning the distal end portion 214 of the outer shaft 208 and/or the helical anchor head 250 relative to the host leaflet 10 may comprise advancing the outer shaft 208 and/or anchor device 229 toward the leaflet over a guidewire 80. When a system 200 includes an additional lacerating member axially movable through anchor channel 252, such as a hollow needle 270, the needle lumen 272 can be configured to accommodate a guidewire 80 that can extend through the needle lumen 272. In such examples, the guidewire 80 can be inserted into the patient’s vasculature, and then the hollow needle 270 and/or other shafts or tubes of the system 200 may be advanced toward the host leaflet 10 over the guidewire 80.

[0187] When a system 200 includes a helical anchor head 250 configured to form a pilot puncture 50 without the use of an additional lacerating member, as will be described in greater detail below, the anchor shaft lumen 232 and anchor channel 252 can be configured to accommodate a guidewire 80 that can extend through the anchor shaft lumen 232 and anchor channel 252. In such examples, the guidewire 80 can be similarly inserted into the patient’s vasculature, and then the anchor device 229 and/or other shafts of the system 200 may be advanced toward the host leaflet 10 over the guidewire 80.

[0188] As mentioned above, an anchor device 229 is configured to be selectively translated in the proximal or distal directions relative to another component of the system 200, such as outer shaft 208, as well as being rotatable around its central axis CA. In some examples, the anchor shaft 230 can be coupled to the handle 204, which can have one or more actuators (for example, in the form of rotatable knobs 206) that are operatively coupled to the anchor shaft 230 to facilitate axial and/or rotational movement thereof. In some examples, the anchor device 229 and the needle 270 are configured to be movable axially relative to each other in the proximal and distal directions. In some examples, needle shaft 271 can be coupled to the handle 204, which can also have one or more actuators (for example, in the form of rotatable knobs 206) that are operatively coupled to the needle shaft 271 to facilitate axial movement of the needle 270.

[0189] During delivery, the helical anchor head 250 can be retained inside outer shaft lumen 210, such that the sharp anchor tip 254 is at or proximal to the distal end portion 214 of the outer shaft 208, as illustrated in Fig. 6A. This position conceals the sharp tip 254 of the helical anchor head 250 from the surrounding anatomy, to protect the anatomical structures from being engaged or punctured by the sharp anchor tip 254 during advancement towards the site of treatment. When used in combination with a needle 270, the needle head 274 can be retained inside the anchor channel 252 or anchor shaft lumen 232, such that the sharp needle tip 278 is at or proximal to the sharp anchor tip 254, which can be also concealed inside the outer shaft lumen 210, as illustrated in Fig. 6A. This position conceals the sharp tip of the needle 270 from the surrounding anatomy, to similarly protect the anatomical structures from being engaged or punctured by the sharp needle tip 278 during advancement towards the site of treatment.

[0190] The anchor device 229 can be axially translated in a distal direction, so as to expose the helical anchor head 250 out of the outer shaft 208 and position the anchor tip 254 in closer proximity to the host leaflet 10. The anchor shaft 230 is then rotated in a first rotation direction (such as clockwise or counterclockwise) around central axis CA, rotating the helical anchor head 250 therewith, causing it to engage and penetrate the host leaflet 10, thereby securing the helical anchor head 250 to host leaflet 10 as shown in Fig. 6B. The tissue material of host leaflet 10 can be retained within helical slot 260, between successive helical turns 256 of the anchor head 250. The terms “ sharp anchor tip 254” and “anchor tip 254”, as used herein, are interchangeable.

[0191] While Fig. 6B illustrates the anchor device 229 advanced distally relative to the outer shaft 208 prior to and/or during anchoring to the host leaflet 10, in some examples, the outer shaft 208 can be advanced up to contact with the host leaflet 10 prior to anchoring of the anchor into the leaflet 10. The outer shaft 208 can apply a limited extent of a distally oriented pushforce against the host leaflet 10, during extension of the anchor head 250 distally and rotatably into the host leaflet 10 to anchor against the host leaflet 10. The outer shaft 208, in such examples, can provide an external support structure through which the anchor head 250 can be advanced and anchored into the leaflet 10, in a manner that increases stability of the leaflet for improved engagement with the helical anchor head 250 at it is being screwed thereinto.

[0192] A perforating member, such as a needle 270, can be then distally advanced to puncture the host leaflet 10 to form a pilot puncture 50 within host leaflet 10 as shown in Fig. 6C, for example when the needle head 274 is axially translated relative to anchor device 229. An attempt to pass a perforating member, such as needle 270, through a relatively thin and movable tissue component, such as a leaflet, in the absence of an anchor, might push the leaflet to some extent prior to eventually penetrating therethrough, which, even if achieving the goal of eventually puncturing the leaflet, might result in a wrong or somewhat offset position of the puncture hole due to this undesired relative movement. Advantageously, the helical anchor head 250 of systems 200 described herein, captures the host leaflet 10 and stabilizes it during formation of a pilot puncture 50, such as by a needle 270 being pushed against and through the host leaflet 10.

[0193] Once the needle head 274 is positioned, at least partially, past the host leaflet 10, the guidewire 80 can be advanced through the needle lumen 272 to terminate with guidewire tip 82 at a position distal to the pilot puncture 50 of host leaflet 10 as shown in Fig. 6D.

[0194] Subsequent to forming the pilot puncture 50 and optionally advancing the guidewire 80 to extend therethrough, the needle 270 can be optionally retracted, as shown in Fig. 6E, and the anchor shaft can be rotated in a second rotational direction, opposite to the first rotational direction, so as to release the helical anchor head 250 from the host leaflet 10, which can be similarly retracted by being then axially pulled away from the host leaflet 10, as shown in Fig. 6F, leaving the guidewire 80 extending through the pilot puncture 50.

[0195] It is to be understood that the order of procedural steps described above with respect to Figs. 6D-6F is merely shown for illustrative purpose, and that in some examples, reverse rotation of the helical anchor head 250 to release it from the host leaflet 10 and retract it can be performed prior to needle 270 retraction. In some examples, counter-rotation of the helical anchor head 250 to release it from the host leaflet 10 can be performed prior to needle 270 retraction, and axial retraction of the anchor device 229 can be performed subsequent to needle 270 retraction. In some examples, needle 270 retraction can be performed simultaneously with counter-rotation of the helical anchor head 250 to release it from the host leaflet 10 and/or axial retraction of the anchor device 229 from the host leaflet.

[0196] In some examples, the guidewire 80 can be advanced simultaneously with advancement of the needle 270 during formation of the pilot puncture 50. In some examples, the guidewire 80 can be advanced to terminate distal to the host leaflet 10 after formation of the pilot puncture 50 by the needle 270, as illustrated in Fig. 6D. In some examples, the guidewire 80 can be advanced through pilot puncture 50 to terminate distal to the host leaflet 10 after retrieval of the needle 270, optionally prior to release of the anchor head 250 from the host leaflet 10.

[0197] In some examples, advancement of the guidewire 80 to position the guidewire tip 82 distal to the pilot puncture 50 can be performed subsequent to counter-rotation of the helical anchor head 250 to release it from the host leaflet 10 and/or axial retraction of the anchor device 229, while the needle 270 is still positioned inside of pilot puncture 50, after which the needle 270 can be retracted. In some examples, advancement of the guidewire 80 to position the guidewire tip 82 distal to the pilot puncture 50 can be performed after needle 270 retraction while the helical anchor head 250 is still engaged with the host leaflet 10, after which the anchor head 250 can be release and retracted.

[0198] As mentioned above, the system 200 can further comprise, in some examples, an inflatable hole-dilating balloon 296 mounted on a balloon catheter 290. In some examples, a balloon catheter 290 carrying hole-dilating balloon 296 can be advanced over the guidewire 80 towards the pilot puncture 50 formed in host leaflet 10, after retraction of the anchor device 229, optionally along with the needle 270, as shown in Fig. 6G. The hole-dilating balloon 296 is configured to transition between a radially deflated state and a radially inflated state. The balloon catheter 290 can define a balloon catheter lumen 292, through which a guidewire 80, as well as one or more additional shafts , can optionally extend.

[0199] In some examples, the balloon catheter 290 can be part of the system 200. In some examples, the balloon catheter 290 can extend through the handle 204 (or a handle of another system or apparatus) and be fluidly connectable to a fluid source (not shown) for inflating the hole-dilating balloon 296. The fluid source comprises an inflation fluid. The term “inflation fluid’', as used herein, means a fluid (for example, saline, though other liquids or gas can be used) used for inflating the hole-dilating balloon 296. The inflation fluid source is in fluid communication with the balloon catheter lumen 292, such that fluid from the fluid source can flow through the balloon catheter lumen 292 into hole-dilating balloon 296 to inflate it.

[0200] In some examples, an inflatable balloon 296, utilized as a hole-dilating balloon, can be different from a typical balloon used for expanding balloon-expandable prosthetic valves or stents, in that while a typical valve-expanding balloon is inflatable to a diameter that can allow expansion of a prosthetic valve to a functional diameter thereof, which can be similar to, or greater than (for example, in the case of valve over-expansion) the diameter of the native annulus in which the valve is deployed, the maximum diameter of a hole-dilating balloon 296 can be significantly smaller, configured to increase the size of a pilot puncture 50 to form a larger leaflet opening 52, optionally without tearing the host leaflet 10 (though in some examples, the host leaflet 10 may be still tom by a hole-dilating balloon 296).

[0201] In some examples, such as when dilation of a pilot puncture 50 is desired to form a larger leaflet opening 52, without necessarily tearing the leaflet 10, the maximum diameter to which the hole-dilating balloon 296 can be inflated is equal to or less than 12 mm. In some examples, the maximum diameter to which the hole-dilating balloon 296 can be inflated is equal to or less than 10 mm. Nevertheless, as mentioned above, in some examples a holedilating balloon 296 can be configured to tear a host leaflet 10 (as will be described in greater detail below with respect to Figs. 29A-29L, for example), in which case the maximum diameter to which the hole-dilating balloon 296 can be inflated can be greater than 12 mm., such as within the range of 20 to 25 mm.

[0202] In some examples, a dilator 280 (see Figs. 6G and 8 A-8B) can be further provided distal to the hole-dilating balloon 296. Dilator 280 can be conical or frustoconical in shape, and include a dilator tapering portion 284 terminating at a dilator distal end 282, and a dilator proximal portion 286 that can be coupled to a dilator shaft 298 that extends proximally therefrom. A dilator lumen 288 continuously extends through the dilator shaft 298 and the dilator 280, open ended at the dilator distal end 282. Attachment of the dilator shaft 298 to the dilator proximal portion 286 can be achieved by a variety of methods, such as overmolding, radio-frequency welding, through an adhesive, and/or a combination thereof. In some examples (not illustrated), the dilator shaft 298 can extend through the entire length of the dilator 280, such that a distal end of the dilator shaft 298 is aligned with the dilator distal end 282. In some examples (not illustrated), the dilator shaft 298 is coupled to one or more components, such as collars or other connectors, which are in turn attached to the dilator 280.

[0203] In some examples, the hole-dilating balloon 296 is coupled to a distal end portion of the balloon catheter 290 at its proximal end, while the balloon’s distal end can be coupled, directly or indirectly, to a portion of another component , such as the dilator 280 or dilator shaft 298. In the examples illustrated in Figs. 6G and 8A-8B, the hole-dilating balloon 296 is shown to be coupled to the dilator proximal portion 286. The dilator proximal portion 286 can optionally include an outer step configured to accommodate the distal end of the balloon 296, such that the outer surface of the balloon 296 can be flush or otherwise relatively continuous with the outer surface of the dilator 280.

[0204] The outer shaft 208, balloon catheter 290, and/or dilator shaft 298, can be configured to be axially movable relative to each other. For example, a proximally oriented movement of the outer shaft 208 relative to the balloon catheter 290, or a distally oriented movement of the balloon catheter 290 relative to the outer shaft 208, can expose the balloon 296 from the outer shaft 208. Similarly, a proximally oriented movement of the dilator 280 relative to the outer shaft 208, or a distally oriented movement of the outer shaft 208 relative to the dilator 280, can expose the dilator 280 and axially translate it in a desired direction.

[0205] In some examples, such as when the hole-dilating balloon 296 is attached at both ends thereof to the dilator 280 and balloon catheter 290, both the dilator 280 with dilator shaft 298 and the balloon catheter 290 can be configured to move simultaneously in the axial direction, without necessarily being axially movable relative to each other, or while axial movement of one relative to the other is limited. In such examples, a stabilized tissue modification system can be designed such that axial movement of the balloon catheter 290 causes the dilator shaft 298 to move therewith, or such that axial movement of one of the dilator shaft 298 or dilator 280 causes the balloon catheter 290 to move therewith.

[0206] In some examples, a stabilized tissue modification system can include all or some of the outer shaft 208, anchor device 229, needle 270, and/or balloon catheter 290 with dilator shaft 298. In some examples, the proximal ends of various components of system 200, such as any of outer shaft 208, anchor shaft 230, needle shaft 271, balloon catheter 290, and/or dilator shaft 298, can be coupled to the handle 204. During delivery, the handle 204 can be maneuvered by an operator (for example, a clinician or a surgeon) to axially advance or retract components of the system 200, such as outer shaft 208, anchor shaft 230, needle shaft 271, balloon catheter 290, and/or dilator shaft 298, through the patient’s vasculature and/or along the target site of treatment, as well as to rotate the anchor shaft 230 in a desired rotational direction to anchor the anchor head 250 to a host leaflet 10 or release it therefrom, and to inflate the hole-dilating balloon 296 mounted on the balloon catheter 290 so as to enlarge a leaflet opening 52, as will be elaborated in further detail below, and to deflate the balloon 296 and optionally retract it.

[0207] Subsequent to forming the pilot puncture 50 and extending the guidewire 80 therethrough, and optionally after retraction of the anchor device 229 and/or needle 270 as shown in Fig. 6G, a hole-dilating balloon 296 carried over a balloon catheter 290 can be advanced towards the host leaflet 10. In some examples, when a dilator 280 is also provided distal to the hole-dilating balloon 296, as also shown in the example illustrated in Fig. 6G, the dilator 280 can be advanced, optionally along with the balloon catheter 290 and hole-dilating balloon 296, towards the host leaflet 10. When included, the dilator 280 can be inserted into the pilot puncture 50 to expand the pilot puncture 50, as shown in Fig. 6H. As the dilator 280 is inserted into the host leaflet 10, the inherent resiliency of the leaflet 10 may urge the leaflet 10 radially inwardly against the dilator 280. The dilator 280 can have sufficient stiffness to facilitate advancement thereof through the leaflet 10, wherein the gradually tapering shape of the dilator 280 facilitates expanding the pilot puncture 50 to a greater diameter.

[0208] In some examples, the balloon catheter 290 with hole-dilating balloon 296 and/or dilator 280 are advanced towards the pilot puncture 50 of host leaflet 10 over the same guidewire 80 used for advancement of the anchor device 229 and optionally needle 270, towards the host leaflet 10, for formation of the pilot puncture 50. In some examples, the balloon catheter 290 with hole-dilating balloon 296 and/or dilator 280 are advanced towards the pilot puncture 50 of host leaflet 10 through the lumen of the same shaft used for advancement of the anchor device 229 and optionally needle 270, such as lumen 210 of outer shaft 208.

[0209] For example, as illustrated in Figs. 6F-6G, the anchor device 229 and/or needle 270 can be retracted through the outer shaft lumen 210 while the outer shaft 208 remains in position, having its distal end portion 214 facing or in close proximity to the pilot puncture 50 of the host leaflet 10, with the guidewire 80 extending through the outer shaft lumen 210. This allows the balloon catheter 290, and optionally dilator shaft 298, to be advanced towards the pilot puncture 50 of the host leaflet 10 over the guidewire 80, through the lumen 210 of the same outer shaft 208. In some examples, the outer shaft 208 can be retracted along with the anchor device 229 and/or needle 270, and then readvanced towards the host leaflet 10 with the balloon catheter 290 and/or dilator shaft 298 extending therethrough.

[0210] In a subsequent step of the method, illustrated in Fig. 61, the hole-dilating balloon 296 may be inserted within the pilot puncture 50, such as by further advancement of the dilator 280 with dilator shaft 298 and/or balloon catheter 290. With the hole-dilating balloon 296 received within the pilot puncture 50, inflating the balloon 296 to transition it from a radially deflated state (Fig. 61) to a radially inflated state (Fig. 6J) can expand the pilot puncture 50 to form a leaflet opening 52 that is sized to receive the prosthetic valve 100 in the radially compressed or crimped configuration. After the balloon 296 is inflated to form the leaflet opening 52 as shown in Fig. 6J, the balloon 296 is deflated, as shown in Fig. 6K, optionally allowing for insertion of a guest prosthetic valve inside the leaflet opening 52.

[0211] In some examples, inflating the hole-dilating balloon 296 within the host leaflet 10 serves to increase a diameter of the pilot puncture 50 such that the resulting leaflet opening 52 is a hole with an increased diameter relative to the pilot puncture 50. In some examples in which the leaflet opening 52 is a hole, the leaflet opening 52 may be a substantially circular hole. In some examples, the leaflet opening 52 may be non-circular (for example, elliptical or asymmetric). In such examples, the diameter of the leaflet opening 52 may refer to any suitable dimension of the leaflet opening 52, such as a minimum diameter of the leaflet opening 52, a maximum diameter of the leaflet opening 52, and/or an average diameter of the leaflet opening 52.

[0212] In some examples, inflating the hole-dilating balloon 296 within the host leaflet 10 may cause the host leaflet 10 to rip and/or tear such that the leaflet opening 52 is not a bounded hole. Stated differently, in such examples, the leaflet opening 52 may be formed by a tear that extends from the pilot puncture 50 fully to the free edge of the host leaflet 10 (the coaptation edge of the leaflet).

[0213] In some cases, it may be desirable to prevent the needle head 274 from extending past the helical anchor head 250 while forming the pilot puncture 50, to protect the anatomical structures in the vicinity of host leaflet 10 from being engaged or punctured by the sharp needle tip 278. For example, a needle 270 is illustrated in Fig. 6C to form the pilot puncture 50 by extending through host leaflet 10 to a limited distance, with the sharp needle tip 278 positioned at the level of or proximal to the anchor tip 254. In some examples, the length of helical anchor head 250 is selected such that after being anchored to host leaflet 10, a sufficient length of the anchor head 250 extends distally from the leaflet 10 to allow extension of the needle 270 through the anchor channel 252 and leaflet 10 during formation of the pilot puncture 50, without the needle head 274 extending beyond the anchor tip 254.

[0214] Figs. 7A and 7B-7C show a view in perspective and cross-sectional views, respectively, of a distal portion of part of an exemplary stabilized tissue modification system 200^b. System 200^b is an exemplary implementation of system 200, and thus includes all of the features described for system 200 throughout the current disclosure, except that system 200^b further comprises a movement limiting segment 234 configured to prevent axial movement of the needle head 274 beyond the anchor tip 254. A needle 270^b of stabilized tissue modification system 200^b can axially move between a first position and a second position relative the helical anchor head 250, wherein the first position is proximal to the second position, and wherein, in the second position, the needle head 274 extends through the anchor channel 252, without extending past the anchor tip 254. Fig. 7A shows the needle 270 in the first position, and Fig. 7B shows the needle 270 in the second position.

[0215] In some examples, a movement limiting segment 234 can be attached to, or integrally formed with, the anchor shaft 230. Figs. 7A-7C illustrate an example in which a movement limiting segment 234^b is attached to a distal end of the anchor shaft 230^b, and a helical anchor head 250^b can be attached to, or integrally formed with, the movement limiting segment 234^b, having the helical turns 256 distally extending therefrom. While helical anchor head 250^b is illustrated in Figs. 7A-7C to include round wire helical turns 256, which can be also referred to as a wire-formed anchor head, it is to be understood that a helical anchor head 250 of a system 200^b can include any other type of helical anchor head 250 disclosed herein, include a tube-cut helical anchor head 250 that can be similar to anchor head 250' shown in Fig. 7E, or other examples of anchor heads 250 described in greater detail with respect to Figs. 12-20C below.

[0216] Movement limiting segment 234 defines a limiting segment channel 236, which is continuous with the anchor shaft lumen 232 and the anchor channel 252, allowing axial movement of the needle 270 therethrough. Any exemplary anchor device 229 that includes a movement limiting segment 234 disclosed herein, further defines a distal inner step 238 that can be at or proximal to the anchor head 250. The movement limiting segment 234^b of anchor device 229^b is an exemplary implementation of movement limiting segment 234, and thus can include any of the features described for movement limiting segment 234 throughout the current disclosure, except that the except that the further includes a distal inner step 238, extending radially inwards at a distal end portion of the segment 234, wherein the distal inner step 238 can be proximal to the anchor head 250^b.

[0217] In some examples, the movement limiting segment 234 further includes a proximal inner step 240, extending radially inwards at a proximal end portion of the segment 234, and an intermediate portion 242 defined between the distal inner step 238 and the proximal inner step 240. In some examples, the diameter of limiting segment channel 236 along the intermediate portion 242 is greater than that of the anchor shaft lumen 232 and/or the anchor channel 252.

[0218] The needle 270^b can include a stopper 279 extending radially outward from an outer surface of the needle, configured to move along a portion of the movement limiting segment 234 proximal to the distal inner step 238, such as along the intermediate portion 242. In the example illustrated in Fig. 7B, the stopper 279 is shown to abut proximal inner step 240 in the first position of needle 270^b, in a manner that prevents further proximal retraction of the needle 270^b relative to the any of the anchor device 229^b, the movement limiting segment 234^b, and/or helical anchor head 250^b. As shown in Fig. 7C, distal movement of the needle 270^b is allowed up to the second position, in which the stopper 279 is pushed against the distal inner step 238, which prevents the stopper 279 and the needle 270^b to which it is attached, from sliding further in the distal direction. Thus, the movement of the needle 270^b in the example illustrated in Figs. 7A-7C is limited between the first and the second positions of movement of the stopper 279 along the intermediate portion 242.

[0219] The stopper 279 can be shorter in the axial direction than the length of the intermediate portion to allow axial movement thereof within the limiting segment channel 236. The extent to which the needle 270^b can be axially moved is dictated by the axial lengths of the intermediate portion 242 and the stopper 279. While the distal inner step 238 and the proximal inner step 240 are illustrated in Fig. 7A to be formed by a cylindrical narrowing in diameter of the limiting segment channel, it is to be understood that this is shown by way of illustration and not limitation, and that any of the distal inner step 238 and/or proximal inner step 240 can be formed by a protrusion extending radially inwards from an inner wall of the movement limiting segment 234, without necessarily spanning the entire circumference around central axis CA. Similarly, while the stopper 279 is illustrated in Fig. 7A in the form of a ring surrounding the needle 270^b, it is to be understood that in some examples, a stopper 279 can be formed as a protrusion extending radially outwards from the outer surface of the needle, without necessarily extending around entire circumference around.

[0220] When both the stopper 279 is formed as a protrusion that does not surround the entire circumference of the needle, and the distal step 238 and/or proximal step 240 is formed as an inwardly-oriented extension that does not span the entire circumference of the limiting segment channel 236, the stopper 279 is circumferentially aligned with the distal step 238 and/or proximal step 240, to engage the step(s) in the second and/or first position.

[0221] While a movement limiting segment 234^b is disposed in the example illustrated in Figs. 7A-7C between a distal end of the anchor shaft 230 and the proximal end 266 of the helical anchor head 250, it is to be understood that this configuration is shown by way of illustration and not limitation, and that a movement limiting segment 234^b can be similarly positioned at any other portion along the length of the anchor shaft 230, or can be attached to a proximal end of the anchor shaft 230. The stopper 279, in such cases, will be positioned on a corresponding axial portion of the needle 270, proximal to the position of the distal inner step 238.

[0222] While the movement limiting segment 234 is shown in the example illustrated in Figs. 7A-7C to include a proximal inner step 240, it is to be understood that in some examples, any exemplary movement limiting segment 234 disclosed herein can include only a distal inner step 238 without a proximal inner step, so as to limit distal advancement of the needle 270 relative to the anchor head 250, yet allow undisturbed proximal movement of the needle 270.

[0223] The helical anchor head 250 can have a length Ln between the anchor proximal end 266 and the anchor tip 254, and the needle head 274 can have a length LN as indicated in Fig. 7C. The helical anchor head 250 can include a plurality of helical turns 256, configured to capture the host leaflet 10 within the helical slot 260 between successive helical turns 256, such as between proximal turn 256a (which can be a proximal-most helical turn) and successive turn 256b, as illustrated in Figs. 7B-7C. The helical turns 256 extending beyond the leaflet 10 define the length of the anchor head 250 extending past the leaflet 10. When the helical anchor head 250 is engaged with the host leaflet 10, the stopper 279 is positioned inside the limiting segment channel 236 such that in the second position of the needle 270, as the stopper 279 contacts the distal inner step 238 which prevents further advancement thereof, the needle head 274 extends through the host leaflet 10, forming pilot puncture 50, but not beyond the anchor tip 254. In some examples, the length LH of helical anchor head 250 is greater than the length LN of needle head 274.

[0224] In some examples, the needle 270 is axially immovable relative to the anchor device 229, and is configured to simultaneously move along with the anchor device 229 in the axial direction. In such examples, the needle 270 is positioned such that the needle head 274 extends through the anchor channel 252, without extending distally past the anchor tip 254, such that the sharp needle tip 278 can be positioned, at all times, proximal to the anchor tip 254, even when the needle tip 278 is distal to the anchor proximal end 266. The needle can be attached at its proximal end (not shown), such as within the handle 204 or a separate handle that can be used in combination with handle 204, to an axially movable body (not sown) to which the proximal end of the anchor device 229 is also coupled, such that axial movement of this body will result is simultaneous axial movement of both the needle 270 and the anchor shaft 230 therewith in the same axial direction. The anchor shaft 230 is also rotatable around the central axis CA, for example by having its proximal end rotatably coupled to the axially movable body, while the needle 270 is not rotatable around the axis CA, such that the helical anchor head 250 can move both axially and rotatably, while the needle 270 can move only axially but not necessarily rotatably. While axial movement of the axially movable body can simultaneously move both the anchor shaft 230 and the needle 270 therewith, the needle 270 may be also axially movable relative to such a body in a manner that allows the needle 270 to move in an axial direction relative to the anchor shaft 230.

[0225] In use, upon approaching the host leaflet 10 and rotating the helical anchor head 250 to screw it into the host leaflet 10, axial advancement of the anchor head 250 as it is rotatably passed through the leaflet 10 can translates the needle 270 in the same axial direction therewith. As the leaflet 10 is received between helical turns 256 inside the anchor channel 252, the needle head 274 is distally advanced during anchoring of the anchor head 250, so as to contact and pierce through the leaflet 10, forming the pilot puncture 50, without posing a risk of the sharp needle tip 278 being exposed beyond the helical anchor head 250. In some examples, one or more bearings (not shown) can be disposed between the needle 270 and the anchor device 229, to allow rotation of the anchor device 229 around and relative to the non-rotational needle 270. [0226] Fig. 7D is a cross-sectional view of an exemplary anchor device 229¹, which is similar to any example described herein for anchor device 229^b with respect to Figs. 7A-7C, except that the distal inner step 238 is defined by the proximal end 266 of anchor head 250¹, to which the advancement limiting segment 234¹ is attached. As illustrated in Fig. 7D, the advancement limiting segment 234¹ can have a uniformly-sized channel 236 extending along and distally from the intermediate portion 242 up to the distal edge 235 of the intermediate portion 242, at which it is attached to the anchor head 250¹, wherein the anchor proximal end 266 has an anchor proximal surface 263 forming the distal inner step 238. For example, the diameter of anchor channel 252 of anchor head 250¹ can be smaller than the diameter of the limiting segment channel 236 of advancement limiting segment 234^1, such that the proximally-facing surface 263 of the anchor head 250¹ extends radially inwards beyond the segment distal edge 235¹.

[0227] Fig. 7E is a cross-sectional view of an exemplary anchor device 229', which is similar to any example described herein for anchor device 229¹, except that while the anchor device 229¹ is illustrated in Fig. 7D to include a wire-formed helical anchor head 250¹, a tube-cut helical anchor head 250’ is shown in Fig. 7E to define the distal inner step 238 of anchor device 229’. It is to be understood that any reference herein to a tube-cut anchor head 250, refers to an anchor head 250 with helical turns 256 having rectangularly-shaped cross-sections. It is to be understood that any reference herein to a wire-formed anchor head 250, refers to an anchor head 250 with helical turns 256 having round (e.g., circular) cross-sections.

[0228] Figs. 8A and 8B show a view in perspective and a cross-sectional view, respectively, of a distal portion of an exemplary stabilized tissue modification system 2004 System 200^c is an exemplary implementation of system 200, and thus includes all of the features described for system 200 throughout the current disclosure, except that the balloon catheter 290 and balloon 296 are disposed inside of, and are axially movable relative to, the anchor device 229^c of system 200^c. The system 200^c can optionally comprise a dilator 280 attached to a dilator shaft 298, and the hole-dilating balloon 296 can be optionally disposed between a distal end of the balloon catheter 290 and the dilator proximal portion 286 according to any of the examples described above for dilator 280, dilator shaft 298, and/or hole-dilating balloon 296. The system 200^c can also include, in some examples, a hollow needle 270^c, implemented according to any of the examples described above. [0229] When a needle 270^c is included in stabilized tissue modification system 200^c, it can extend through the dilator lumen 288 as illustrated in Figs. 8A-8B, and is configured to be axially movable in the distal and proximal direction relative to any of the dilator shaft 298, the balloon catheter 290, and/or the anchor shaft 230.

[0230] The dilator shaft 298 can extend through the balloon catheter lumen 292, and may be sized to such that an annular space is formed within balloon catheter lumen 292 between an inner surface of the balloon catheter 290 and an outer surface of the dilator shaft 298 along the length of balloon catheter 290. This annular space is in fluid communication with one or more balloon catheter inflation openings 294 exposed to an internal cavity of the balloon 296, which can be in fluid communication with a fluid source (for example, a syringe or a pump) that can inject inflation fluid (for example, saline) into the balloon 296, so as to inflate the hole-dilating balloon 296, for example during formation of leaflet opening 52. The pressure of the inflation fluid within hole-dilating balloon 296 may provide the force that allows it to dilate a leaflet opening 52. Further, the balloon catheter lumen 292 may be configured to withdraw fluid from the balloon 296 through the balloon catheter inflation opening(s) 294, to deflate the balloon 296.

[0231] In the illustrated example, the hole-dilating balloon 296 is shown to be coupled to a distal end portion of the balloon catheter 290 at its proximal end, and to the dilator proximal portion 286 at the balloon’s distal end. The dilator proximal portion 286 can optionally include an outer step configured to accommodate the distal end of the hole-dilating balloon 296, such that the outer surface of the hole-dilating balloon 296 can be flush or otherwise relatively continuous with the outer surface of the dilator 280.

[0232] In some examples, a capsule 212 can be attached to the outer shaft 208, or be integrally formed with the outer shaft 208 along a proximal portion thereof. Figs. 8A-8B show an exemplary capsule 212 attached to the outer shaft 208, wherein the distal end portion 214^c of the capsule 212 can be an atraumatic distal end portion, according to any example described above for a distal end portion 214 of the outer shaft. In some examples, the capsule 212 defines a capsule proximal step 216, defined at a transition from a first diameter of the outer shaft lumen 210 along the length of the outer shaft 208, to a greater diameter extending distally from the capsule proximal step 216 along the remainder of the capsule 212.

[0233] The diameter of the outer shaft lumen 210 along the length of the outer shaft 208 extending proximally from the capsule proximal step 216 can be greater than the outer diameter of the anchor shaft 230^c, but less than the outer diameter of the helical anchor head 250^c, while the inner diameter of the capsule 212 along the portion distal to the capsule proximal step 216 can be greater than the diameter of the helical anchor head 250^c. The length of the portion of the capsule extending distally from the capsule proximal step 216 to the capsule distal end portion 214 can be greater than the length Lu of the helical anchor head 250^c. In this manner, the helical anchor head 250^c can be retained inside the capsule 212 in a manner that conceals its sharp tip 254 to prevent it from contacting and possibly damaging the surrounding anatomical structures, during delivery towards the site of treatment (such as toward host valvular structure 12), or during retraction from the patient’s body. The anchor device 229^c can be proximally pulled relative to the outer shaft 208 until the proximally-facing surface 263 of the anchor proximal end 266 hits against capsule proximal step 216, thereby concealing the helical anchor head 250^c inside the capsule 212 as shown in Figs. 8A-8B.

[0234] While an outer shaft 208^c equipped with a capsule 212 shaped and sized to accommodate a helical anchor head 250^c in a concealed state therein, is illustrated in Figs. 8A- 8B as part of an exemplary system 200^c, it is to be understood that this arrangement is merely optional, and that an outer shaft 208 of a system 200^c that includes a balloon catheter 290 extendable through an anchor shaft 230 does not necessarily need to include such a capsule. Moreover, it is to be understood that other exemplary system 200 disclosed herein, can include a capsule 212.

[0235] In some examples, the system 200^c further comprises a delivery shaft 218 disposed between the anchor device 229 and the balloon catheter 290. The delivery shaft 218 extends through the anchor shaft lumen 232, and defines a delivery shaft lumen 220 through which the balloon 296 and balloon catheter 290 can extend. The delivery shaft 218 can include a distal portion 222 which can have, in some examples, an atraumatic end 224, such as by being rounded and/or being curved radially inwards, or otherwise formed to include an outer surface tapering in the distal direction. The delivery shaft distal portion 222 can be formed as an integral distal portion of the delivery shaft 218, or as a separate component attached to the delivery shaft 218. The delivery shaft 218 can be axially movable in the proximal and distal directions, relative to the anchor device 229 and/or the balloon catheter 290.

[0236] In some examples, at least a portion of the delivery shaft 218 is formed as a hypotube, configured to increase flexibility thereof. The delivery shaft 218 can optionally include a plurality of circumferential bands 268 arranged between circumferential slits 267, with axially extending connecting portions connecting adjacent bands 268. Two adjacent circumferential bands 268 can be connected by a plurality of angularly spaced connecting portions. In such arrangements, the delivery shaft 218 exhibits sufficient flexibility to allow it to flex as it is pushed through a tortuous pathway without kinking or buckling, and/or to bend when another component of the system 200 is implemented as a steerable catheter that can be actively articulated to orient the system 200 in a desired direction.

[0237] While a specific pattern is illustrated in Fig. 8A, which can be a laser cut pattern, it is to be understood that the pattern of bands 268 and slits 267 and/or the width of the bands 268 and/or slits 267 can vary along the length of the delivery shaft 218 in order to vary stiffness of the delivery shaft 218 along its length. For example, the width of the bands 268 can decrease from the proximal end to the distal end of the delivery shaft 218 to provide greater stiffness near the proximal end and greater flexibility near the distal end of the delivery shaft 218.

[0238] When a balloon catheter 290 carrying an inflatable hole-dilating balloon 296 extends through the anchor shaft 230, it may be important to protect the hole-dilating balloon 296 from being accidentally contacted by the sharp anchor tip 254. Thus, a delivery shaft 218 that can be disposed between the helical anchor head 250 and the hole-dilating balloon 296 can advantageously protect the hole-dilating balloon 296 from being punctured by the anchor’s sharp tip 254.

[0239] Figs. 9A-9K illustrate some steps in a method for utilizing a system 200^c for forming an opening within a target tissue. An exemplary implementation of the method is illustrated in Figs. 9A-9K with respect to forming a leaflet hole inside a host leaflet 10, which can be performed prior to implanting a guest prosthetic valve inside the host valvular structure. The system 200^c can be used to perforate a host leaflet 10, such as a native leaflet 30 or a prosthetic valve leaflet 114 of a previously implanted prosthetic valve.

[0240] The distal end portion of the system 200^c is configured to be inserted into a patient’s vasculature, such as within an ascending aorta, and to be advanced towards the host leaflet 10. Positioning the distal end portion 214 of the outer shaft 208 or capsule 212, and/or the helical anchor head 250, and/or the dilator 280, relative to the host leaflet 10, may comprise advancing the outer shaft 208 and/or anchor device 229 and/or dilator shaft 298 toward the leaflet over the guidewire 80 as described above with respect to Fig. 6A for example. When a system 200^c includes an additional lacerating member axially movable through dilator lumen 288, such as a hollow needle 270, the needle lumen 272 can be configured to accommodate a guidewire 80 that can extend through the needle lumen 272. In such examples, the guidewire 80 can be inserted into the patient’s vasculature, and then the hollow needle 270 and/or other shafts or tubes of the system 200^c may be advanced toward the host leaflet 10 over the guidewire 80.

[0241] When a system 200^c includes an anchor device 229 comprising a helical anchor head 250 configured to form a pilot puncture 50 without the use of an additional lacerating member, as will be described in greater detail below, the dilator lumen 288 can be configured to accommodate a guidewire 80 that can extend through the dilator lumen 288. In such examples, the guidewire 80 can be similarly inserted into the patient’s vasculature, and then the dilator shaft 298 and/or other shafts of the system 200^c may be advanced toward the host leaflet 10 over the guidewire 80.

[0242] During delivery, the helical anchor head 250 can be optionally retained inside the capsule 212, such that the sharp anchor tip 254 is at or proximal to the distal end portion 214^c of the capsule 212, as illustrated in Fig. 9A. As explained above, this position conceals the sharp tip of the helical anchor head 250 from the surrounding anatomy, to protect the anatomical structures from being engaged or punctured by the sharp anchor tip 254 during advancement towards the site of treatment. When used in combination with a needle 270, the needle head 274 can be retained inside the dilator lumen 288, such that the sharp needle tip 278 is at or proximal to the dilator distal end 282, as also illustrated in Fig. 9A. This position conceals the sharp tip of the needle 270 from the surrounding anatomy, to similarly protect the anatomical structures from being engaged or punctured by the sharp needle tip 278 during advancement towards the site of treatment.

[0243] The delivery shaft 218 can be mostly or entirely retained inside the outer shaft 208, for example such that the delivery shaft distal portion 222 is retained inside the capsule 212, optionally with the delivery shaft atraumatic end 224 positioned distally to the sharp anchor tip 254 as shown in Fig. 9A. Prior, or simultaneously with, advancement of the helical anchor head 250 towards the host leaflet 10, optionally exposing it out of the capsule 212, the delivery shaft 218 can be distally advanced, relative to the balloon catheter 290, closer to, and optionally up to contact or close proximity with, the host leaflet 10, as shown in Fig. 9B.

[0244] The anchor device 229 can be axially translated in a distal direction, subsequent to or simultaneously with advancement of the delivery shaft 218, for example to expose the helical anchor head 250 out of the capsule 212 and position the anchor tip 254 in closer proximity to the host leaflet 10. The anchor shaft 230 is then rotated in a first rotation direction around central axis CA, rotating the helical anchor head 250 therewith, causing it to engage and penetrate the host leaflet 10, thereby securing the helical anchor head 250 to host leaflet 10 as shown in Fig. 9C. The tissue material of host leaflet 10 can be retained within helical slot 260, between successive helical turns 256 of the anchor head 250.

[0245] While Fig. 9C illustrates the anchor device 229 advanced distally relative to the outer shaft 208 prior to and/or during anchoring to the host leaflet 10, in some examples, the outer shaft 208 and/or capsule 212 thereof can be advanced up to contact with the host leaflet 10 prior to anchoring of the anchor head 250 into the leaflet 10. The outer shaft 208 and/or capsule 212 thereof can apply a limited extent of a distally oriented push-force against the host leaflet 10, during extension of the anchor head 250 distally and rotatably into the host leaflet 10 to anchor against the host leaflet 10. The outer shaft 208 and/or capsule 212 thereof, in such examples, can provide an external support structure through which the anchor head 250 can be advanced and anchored into the leaflet 10, in a manner that increases stability of the leaflet for improved engagement with the helical anchor head 250 as it is being screwed thereinto.

[0246] Nevertheless, for instances in which a delivery shaft 218 is distally advanced up to contact with the host leaflet 10 prior to anchoring of the anchor head 250 into the leaflet 10, as illustrated in Figs. 9B-9C, similar advancement of the outer shaft 208 is not necessarily required, as the delivery shaft 218 can similarly apply a limited extent of a distally oriented push-force against the host leaflet 10, during extension of the anchor head 250 distally and rotatably into the host leaflet 10 to anchor against the host leaflet 10. The delivery shaft 218, in such examples, can provide an internal support structure over which the anchor head 250 can be advanced and anchored into the leaflet 10, in a manner that similarly increases stability of the leaflet for improved engagement with the helical anchor head 250 as it is being screwed thereinto.

[0247] A perforating member, such as a needle 270, can be then distally advanced to puncture the host leaflet 10 to form a pilot puncture 50 within host leaflet 10 as shown in Fig. 9D, for example when the needle head 274 is axially translated relative to anchor device 229 and/or dilator 280, wherein the helical anchor head 250 serves to capture and stabilize the host leaflet 10 during formation of a pilot puncture 50 by the needle 270.

[0248] Once the needle head 274 is positioned, at least partially, past the host leaflet 10, the guidewire 80 can be optionally advanced through the needle lumen 272 to terminate with guidewire tip 82 at a position distal to the pilot puncture 50 of host leaflet 10 as shown in Fig. 9E.

[0249] Subsequent to forming the pilot puncture 50 and optionally advancing the guidewire 80, and as shown in Fig. 9F, the dilator 280 can be inserted into the pilot puncture 50 to expand the pilot puncture 50. As the dilator 280 is inserted into the host leaflet 10, the inherent resiliency of the leaflet 10 may urge the leaflet 10 radially inwardly against the dilator 280. Advantageously, keeping the helical anchor head 250 engaged with the host leaflet 10, while the dilator 280 is passed through the anchor channel 252, provides adequate counter force that facilitates passage of the dilator 280 through the pilot puncture 50, wherein the gradually tapering shape of the dilator 280 can expand the pilot puncture 50 to a greater diameter. [0250] The needle head 274 can be re-concealed within dilator lumen 288, such as due to advancement of dilator 280 in a distal direction over the needle head 274 as shown in Fig. 9F, and/or retraction of needle 270 such that the sharp needle tip 278 is at or proximal to the dilator distal end 282, to avoid damage that may be caused to internal anatomical structures of the patient’s body due to accidental contact with the sharp needle tip 278.

[0251] In some examples, the guidewire 80 can be advanced simultaneously with advancement of the needle 270 during formation of the pilot puncture 50. In some examples, the guidewire 80 can be advanced to terminate distal to the host leaflet 10 after formation of the pilot puncture 50 by the needle 270, as illustrated in Fig. 9E. In some examples, the guidewire 80 can be advanced to terminate distal to the host leaflet 10 prior to advancement of the dilator 280 through the pilot puncture 50. In some examples, the guidewire 80 can be advanced simultaneously with advancement of the dilator 280 into and through the pilot puncture 50 after formation of the pilot puncture 50 by the needle 270.

[0252] In some examples, the needle 270 can be retracted back into dilator lumen 288 prior to advancement of the dilator 280 into pilot puncture 50, in which case the dilator 280 can be guided through the pilot puncture 50 of host leaflet 10 over a guidewire 80 distally advanced into and through pilot puncture 50, optionally prior to retraction of the needle 270.

[0253] Prior to advancement of the balloon catheter 290 to position the hole-dilating balloon 296 inside the pilot puncture 50, the anchor shaft can be rotated in the second rotational direction, so as to release the helical anchor head 250 from the host leaflet 10, which can be then retracted back into the capsule 212 by being axially pulled away from the host leaflet 10, as shown in Fig. 9G. Advantageously, the delivery shaft 218 protects the hole-dilating balloon 296 from being contacted by the sharp anchor tip 254 during retraction of the helical anchor head 250.

[0254] After proximally pulling the helical anchor head 250 to a position proximal to the holedilating balloon 296, optionally inside the capsule 212, such that it no longer poses a risk of engaging with the balloon 296, the delivery shaft 218 is proximally pulled relative to the balloon catheter 290, so as to expose the hole-dilating balloon 296 as shown in Fig. 9H.

[0255] In a subsequent step of the method, illustrated in Fig. 91, the hole-dilating balloon 296 may be inserted within the pilot puncture 50, such as by further advancement of the dilator 280 with dilator shaft 298 and/or balloon catheter 290. With the hole-dilating balloon 296 received within the pilot puncture 50, inflating the hole-dilating balloon 296 to transition it from a radially deflated state (Fig. 91) to a radially inflated state (Fig. 9J) can expand the pilot puncture 50 to form a leaflet opening 52 that is sized to receive the prosthetic valve 100 in the radially compressed or crimped configuration. After the hole-dilating balloon 296 is inflated to form the leaflet opening 52 as shown in Fig. 9J, the balloon 296 is deflated, as shown in Fig. 9K, optionally allowing for insertion of a guest prosthetic valve inside the leaflet opening 52.

[0256] While a system 200, such as system 200^c, is described above and illustrated in Figs. 8A-9K to include the balloon catheter 290 and hole-dilating balloon 296, it is to be understood that any system 200 disclosed herein can be provided without the balloon catheter 290 and hole-dilating balloon 296. For example, a system 200 can include an expansion member, such as a hole-dilating balloon 296 mounted on a balloon catheter 290, provided as a separate apparatus or sub-assembly that can be advanced over the guidewire 80 towards the pilot puncture 50 formed in host leaflet 10.

[0257] While a hole-dilating balloon 296 is described above and illustrated for expanding a pilot puncture 50 to form a leaflet opening 52, it is to be understood that other types of expansion members can be used instead of a balloon in any of the methods and/or systems described herein. For example, U.S. Provisional Application No. 63/335,739, which is incorporated herein by reference in its entirety, describes an expandable frame that can be used as an expansion member 296 instead of a hole-dilating balloon.

[0258] It is to be understood that advancement of the needle 270 through the host leaflet 10 to form a pilot puncture 50, as described above for example with respect to Figs. 6C or 9D, can be performed such that the needle head 274 does not extend distally past the anchor tip 254. In some examples, any of the systems 200^a or 200^c can include a movement limiting segment 234 and the needle 270 can include a stopper 279 as described above with respect to any of the systems 200^h, 200¹ or 200', and the methods described above with respect to Figs. 6A-6K or 9A-9K can include steps of transitioning the needle 270 from a first position to a second position during formation of the pilot puncture, as described above with respect to Figs. 7A- 7E, mutatis mutandis.

[0259] Any exemplary system 200 disclosed herein may be configured to form the leaflet opening 52 in any of a variety of host valvular structures 12. In the examples of Figs. 6A-6K or 9A-9K, the host valvular structure 12 can be the valvular structure 113 of a previously implanted prosthetic valve, such as the prosthetic valve 100a of Fig. 3. In such examples, using the a system 200 as described herein to form the leaflet opening 52 in a previously implanted prosthetic valve may be followed by steps for implanting a guest prosthetic valve 100b within the previously implanted prosthetic valve 100a (for example, via a ViV procedure).

[0260] Similarly, the host valvular structure 12 in the examples of Figs. 6A-6K or 9A-9K can be a valvular structure 29 of a native heart valve, such as the native aortic valve 20 shown in Figs. 2A-2B. In such examples, the system 200 can be configured to puncture a native leaflet 30 of the native aortic valve 20. In some examples, the host valvular structure and/or the native valve may refer to another valve of a patient’s heart, such as a mitral valve, a pulmonary valve, or a tricuspid valve.

[0261] While illustrated and described above with respect to forming a leaflet opening 52 within a host leaflet 10, it is to be understood that any exemplary system 200 disclosed herein may be configured to form a tissue opening through other tissues in a patient’s body. For example, prosthetic devices can be delivered to the left atrium or the left ventricle in a transseptal approach, wherein a system 200 is passed through the vena cava, into the right atrium, and through the interatrial septum tissue. Such delivery approaches require puncturing the interatrial septum. Thus, in some examples, a system 200 may be utilized to form an opening through the interatrial septum, for example at the site of the fossa ovalis, which is a region of the septum containing tissue of lesser thickness than is typical of the rest of the septum. Thus, any example of a system 200 described herein can be utilized in a manner similar to that described with respect to Figs. 6A-6K or 9A-9K, or modifications thereof, to form a tissue opening, equivalent to leaflet opening 52 described with respect to Figs. 6A-6K or 9A- 9K, in a target tissue, equivalent to a host leaflet 10 described with respect to Figs. 6A-6K or 9A-9K.

[0262] In some examples, some or all of the components of any exemplary system 200 described herein can be part of a delivery assembly that includes a delivery apparatus carrying a prosthetic valve (examples not shown explicitly). Similarly, a stabilized tissue modification system 200 according to any example of the current disclosure, can be used for implantation of other prosthetic devices aside from prosthetic valves, such as stents or grafts.

[0263] A stabilized tissue modification system 200 can be part of a delivery apparatus utilized, for example, to deliver a prosthetic aortic valve for mounting against the native aortic annulus or against a prosthetic valve previously implanted in a native aortic valve, to deliver a prosthetic mitral valve for mounting against the native mitral annulus or against a prosthetic valve previously implanted in a native mitral valve, or to deliver a prosthetic valve for mounting against any other native annulus or against a prosthetic valve previously implanted in any other native valve.

[0264] In some examples, after forming the leaflet opening 52, and optionally after deflating the hole-dilating balloon 296, a guest prosthetic valve 100 can be positioned in the valvular structure 12 in a compressed state thereof, and expanded therein to implant the guest prosthetic valve 100 inside the host valvular structure. [0265] In some examples, retraction of the expansion member, such as a hole-dilation balloon 296, after deflation thereof, can be performed while the guidewire 80 may be kept in position, extending through the leaflet opening 52. Subsequent to recompressing the expansion member 296 inside the leaflet opening 52 and retracting it away from the host leaflet 10, the method can further include steps of positioning a guest prosthetic valve 100 inside the leaflet opening 52. A delivery apparatus carrying the guest prosthetic valve 100 can be either part of the system 200, or provided as a separate assembly or apparatus advanced into a leaflet opening 52.

[0266] Fig. 10L shows a guest prosthetic valve 100 positioned, in a radially compressed configuration thereof, inside the leaflet opening 52. As shown in Fig. 10G, the guest prosthetic valve 100 can be mounted on a replacement valve delivery apparatus 402 that can be advanced towards the host leaflet 10 over a guide wire, which can be a separate guide wire (not shown), or can be the same guidewire 80.

[0267] In some examples, the guest prosthetic valve is a balloon expandable valve, and the replacement valve delivery apparatus 402 comprises a balloon catheter 404 carrying a valveexpanding balloon 406. While a replacement valve delivery apparatus 402 equipped with a valve-expanding balloon 406 at a distal end portion of a balloon catheter 404 is illustrated, it is to be understood that this is shown by way of illustration and not limitation, and that a replacement valve delivery apparatus 402 can include other shafts and/or mechanisms, for example when utilized to advance and expand other types of replacement prosthetic heart valves, such as self-expandable prosthetic heart valves or mechanically expandable prosthetic heart valves.

[0268] In some examples, the replacement valve delivery apparatus 402 can further include a nosecone 408 positioned distal to the valve-expanding balloon 406 (or other prosthetic-valve expanding mechanism). The nosecone 408 can be conical or frustoconical in shape. The nosecone 408 can be attached to a distal end of a nosecone shaft 410 extending through the balloon catheter 404, wherein the nosecone 408 and the nosecone shaft 410 can collectively define a lumen through which a guidewire can extend. In some examples, when a nosecone 408 is present at a distal end of the replacement valve delivery apparatus 402 as also shown in the example illustrated in Fig. 10G, the nosecone 408 can be advanced towards the host leaflet 10, and may optionally have a maximal diameter that can be somewhat greater than the diameter of the opening 52, such that as the nosecone 408 is inserted into the leaflet opening 52 it can optionally further expand the leaflet opening 52 to a greater diameter.

[0269] As shown in Fig. 9L, the guest prosthetic valve 100 is placed in the leaflet opening 52 in its radially compressed configuration, optionally positioned over a deflated valve-expanding balloon 406 in the case of a balloon-expandable prosthetic valve. With the prosthetic valve 100 received within the leaflet opening 52, radially expanding the guest prosthetic valve 100, as shown in Fig. 9M, can serve to increase a size of the leaflet opening 52 and/or to tear the leaflet. As a result, and as discussed above, radially expanding the guest prosthetic valve 100 can serve to modify the host leaflet 10 such that the leaflet does not obstruct a cell opening 112 in a frame 102 of the guest prosthetic valve 100 or at least increases the area of the host valve and the guest valve that is not covered or obstructed by the modified host leaflet to permit access and sufficient perfusion to the adjacent coronary artery. For example, radially expanding the guest prosthetic valve within the leaflet opening 52 can operate to push a portion of the leaflet extending radially exterior of the guest prosthetic valve below an upper edge of an outer skirt of the guest prosthetic valve 100 and/or away from one or more cell openings 112 of the guest prosthetic valve 100.

[0270] In some examples, a stabilized tissue modification system 200 is part of a delivery assembly that further includes the guest prosthetic valve 100 carried, in a radially compressed state thereof, over a component of the system 200. Exemplary delivery assemblies that include perforating members that can be implemented in the form of a needle, a first balloon that can be a hole-dilating balloon 296, and a second balloon that can be valve-expanding balloon, are described in U.S. Provisional Application Nos. 63/447,453 and 63/447,457, each of which is incorporated herein by reference in its entirety.

[0271] In some examples, a stabilized tissue modification system 200 can be retracted from the host valvular structure 12 and the patient’s body, optionally subsequent to deflation of balloon 296, while the guidewire 80 remains in position, extending through the leaflet opening 52. Positioning a guest prosthetic valve within the leaflet opening can be performed, in such examples, by advancing the guest prosthetic valve into the leaflet opening via over the same guidewire 80.

[0272] In some examples, more than one guidewire can be utilized in a method that includes forming the leaflet opening 52 by a stabilized tissue modification system 200 and positioning a guest prosthetic valve 100 therein. For example, a first guidewire 80 can be utilized in a method of forming a leaflet opening 52 by the stabilized tissue modification system 200 following the steps described with respect to Figs. 6A-6K or 9A-9K herein, or modifications thereof, after which the system 200 can be retracted along with guidewire 80, and a separate guidewire can be then used for advancing a guest prosthetic valve in the host valvular structure. In some examples, a separate guidewire over which a guest prosthetic valve can be advanced, can extend alongside the guidewire 80 over which the system 200 extends. [0273] In some examples, the guest prosthetic valve can be a mechanically-expandable prosthetic valve and radial expansion thereof can be achieved by actuating a mechanical actuator of the guest prosthetic valve to mechanically expand a frame of the guest prosthetic valve. In some examples, the guest prosthetic valve can be a self-expandable prosthetic valve that can be retained during delivery toward the host valvular structure in a capsule or other restraint disposed therearound, and valve expansion can be achieved by removing the capsule or other restraint from the guest prosthetic valve to allow it to radially self-expand within the host valvular structure.

[0274] With the guest prosthetic valve received within the leaflet opening 52, radial expansion thereof can serve to increase a size of the leaflet opening and/or to tear the leaflet. As a result, the valve’s radial expansion can serve to modify the host leaflet 10 such that the leaflet does not obstruct a cell opening in a frame of the guest prosthetic valve or at least increases the exposed area of the host valvular structure and the guest prosthetic valve that is not covered or obstructed by the modified host leaflet 10 to permit access and sufficient perfusion to the adjacent coronary artery.

[0275] While methods disclosed herein can refer to forming a leaflet opening 52 in a host leaflet 10, prior to positioning and expanding a prosthetic valve 100, it is to be understood that any of the methods can comprise, in some examples, repeating one or more steps disclosed throughout the current specification to form a plurality of openings in the host valvular structure. For example, steps described above with respect to Figs. 6A-6K or 9A-9K, or modifications thereof, as will be described herein below, can be performed for forming a first leaflet opening in a first host leaflet, after which the system 200 can be retracted from the first host leaflet and steered toward another host leaflet, after which the same steps can be repeated to form a second leaflet opening within the second host leaflet. The procedure can be optionally repeated to form further leaflet openings, such as a third leaflet opening in a third host leaflet. [0276] In some examples, forming more than one leaflet opening, such as forming the second leaflet opening, can provide further access and/or fluid paths through the frame of the guest prosthetic valve. For example, radially expanding the guest prosthetic valve 100 within the first leaflet opening may push the second host leaflet against the frame of the guest prosthetic valve such that the second leaflet opening is aligned with cell opening(s) of the frame of the guest prosthetic valve. Thus, the second leaflet opening can provide additional unobstructed paths through the frame of the guest prosthetic valve. Moreover, in an example in which the host valve is a previously implanted prosthetic valve, expanding the guest prosthetic valve within the first leaflet opening can trap the second leaflet opening between the respective frames of the host prosthetic valve and the guest prosthetic valve, thereby providing additional access and/or flow paths through each of the frames.

[0277] Thus, forming the second leaflet opening can ensure that a greater number of cell openings of the frame are uncovered, and/or that a greater proportion of the frame is uncovered, relative to an example in which only one leaflet is punctured to form a leaflet opening. This may be particularly beneficial in examples in which the frame of a host prosthetic valve extends axially in a downstream direction beyond one or both of the coronary arteries when the guest prosthetic valve is implanted within a native heart valve.

[0278] For example, in some patient anatomies, the left coronary artery is positioned lower (that is, proximate to the host valvular structure) than the right coronary artery. In such examples, the right coronary artery may be sufficiently far from the host valvular structure that implanting the guest prosthetic heart valve within the host valvular structure does not limit access and/or perfusion to the right coronary artery. Accordingly, forming a single leaflet opening in the host valvular structure may be sufficient to ensure access and/or perfusion to both coronary arteries, provided that the leaflet opening is formed and/or positioned to ensure access to the left coronary artery.

[0279] In some examples, however, each of the left and right coronary arteries may be positioned sufficiently proximate to the host valvular structure that forming a single leaflet opening in the host valvular structure is insufficient to ensure access to both coronary arteries. In such examples, forming two leaflet openings in respective leaflets of the previously implanted prosthetic heart valve may ensure the ability for future access into both coronary arteries or perfusion through the frame to both coronary arteries during the diastole phase of the cardiac cycle. For example, the host valvular structure can be modified such that the guest prosthetic valve is implanted by being expanded in a leaflet opening of a first host leaflet that faces the left coronary artery, and such that the second leaflet opening is formed in a second host leaflet that faces the right coronary artery (or vice-versa).

[0280] In some examples, forming the first leaflet opening can be performed prior to forming the second leaflet opening. In some examples, forming the second leaflet opening can be performed prior to forming the first leaflet opening. In some examples, the order of forming leaflet openings is chosen such that the final leaflet opening is formed in the host leaflet in which a guest prosthetic valve 100 is to be positioned and expanded.

[0281] It is to be understood that the guest prosthetic valve 100 is not limited to being implanted within an opening 52 of a leaflet. For example, in cases where the system 200 is utilized to form a full tear in a host leaflet that extends to the coaptation edge of the leaflet, the guest prosthetic valve 100 can be positioned at a location between the leaflets of the host valvular structure 12 and then expanded. In such cases, the opening 52 may provide sufficient open space through which blood may flow into the coronary ostia, and/or through which additional access devices, such as coronary catheters, can pass during future interventional procedures.

[0282] Figs. 10A-11B illustrate a sequence of events in which a host valvular structure 12 is modified to receive a guest prosthetic valve 100. Figs. 10A-10B illustrate the hole-dilating balloon 296 utilized to expand the pilot puncture 50 into the leaflet opening 52. Fig. 10A illustrates the hole-dilating balloon 296 in a deflated state within the pilot puncture 50, corresponding to the state described above with respect to Figs. 61 and 91, while Fig. 10B illustrates the hole-dilating balloon 296 in an inflated state such that the pilot puncture 50 has enlarged into the leaflet opening 52, corresponding to the state described above with respect to Figs. 6J and 9J. Fig. 10C illustrates a guest prosthetic valve 100 that can be positioned in the leaflet opening 52 after removal of the hole-dilating balloon 296 therefrom, in a crimped configuration of the prosthetic valve 100, corresponding to the state described above with respect to Fig. 9L, after which the guest prosthetic valve 100 can be expanded, such as by inflating a valve-expanding balloon 406 over which it can be mounted in the case of a balloonexpandable valve, so as to implant the guest prosthetic valve 100 inside the host valvular structure 12.

[0283] As mentioned, any system and method of the current specification can be utilized for forming a leaflet opening 52 in a host leaflet 10 which can be either a native leaflet 30 or a prosthetic valve leaflet 114 of a previously implanted prosthetic valve, such as prosthetic valve 100a of Fig. 3, such as in the case of ViV procedures. Fig. 11A shows a previously implanted prosthetic valve 100a subsequent to forming the leaflet opening 52, for example subsequent to the method described above with respect to Figs. 6A-6K or 9A-9K. Fig. 11B shows a configuration in which a second prosthetic valve 100b has been expanded within the leaflet opening 52 of a host prosthetic valve 100a. In the example of Fig. 11B, the guest prosthetic valve 100b is the same type of valve as the host prosthetic valve 100a. It is to be understood, however, that ViV procedures may be similarly applied to any other suitable valvular structures, such as different prosthetic valves and/or native heart valves. For example, the guest prosthetic valve 100b need not be the same type of valve as the host prosthetic valve 100a.

[0284] In the example of Fig. 11A, when the prosthetic valve leaflets 114a of the previously implanted prosthetic valve 100a are pressed against the frame 102a, the leaflet opening 52 provides a partial access into the frame 102a, but the leaflet opening 52 may not be sufficiently large to completely uncover any of the cell openings 112a of the frame 102a.

[0285] As shown in Fig. 1 IB, however, fully expanding the guest prosthetic valve 100b within the leaflet opening 52 further expands and/or tears the leaflet opening 52 such that several cell openings 112a of the frame 102a of the host prosthetic valve 100a and several cell openings 112b of the frame 102b of the guest prosthetic valve 100b are fully uncovered by the leaflets 114a. In some examples, this may result from the frame 102b of the guest prosthetic valve 100b pushing the leaflet 1 14a comprising the leaflet opening 52 downwardly (toward the inflow ends of the prosthetic valves 100a, 100b) such that one or more cell openings 112a are unobstructed by the leaflet 114a. In some examples, expanding the frame 102b within the leaflet 114a comprising the leaflet opening 52 may rip and/or tear this leaflet 114a such that the leaflet 114a cannot obstruct one or more cell openings 112a.

[0286] In some examples, a helical anchor head 250 of a stabilized tissue modification system 200 can be utilized to form a pilot puncture 50, in addition to, or instead of, a perforating member such as a needle 270. Thus, in some examples, a stabilized tissue modification system 200 can be devoid of a separate perforating member, such as a needle 270, relying on the helical anchor head 250 functioning also as a perforating member that can be utilized to form the pilot puncture or pilot opening 50.

[0287] Fig. 12 shows a view in perspective of an exemplary helical anchor head 250^d. Helical anchor head 250^d is an exemplary implementation of helical anchor head 250, and thus includes all of the features described for helical anchor head 250, except that the helical turns 256 of helical anchor head 250^d have non-equal widths at circumferentially-aligned portions thereof. As shown in Fig. 12, the helical turns 256 can be generally continuous, and may have a turn width WT that can gradually increase from the anchor tip 254 to the anchor proximal end 266. A turn width WT is a dimension of the helical turn 256 in a direction parallel to the central axis CA. Since the width WT can gradually increase in a proximal direction along the circumference of any of the helical turns 256, comparison between turn widths WT of successive helical turns 256 can be performed at circumferentially-aligned position along the circumference of successive helical turns 256.

[0288] In the example illustrated in Fig. 12, a helical anchor head 250^d having three helical turns 256 is shown, including a proximal-most helical turn 256a, an intermediate helical turn 256b, and a distal-most helical turn 256d, wherein the width Wr of the helical turn 256a is greater than the width Wrb of the helical turn 256b, which in turn is greater than the width WTC of the helical turn 256d, measured along circumferentially-aligned portions of the turns 256. It is to be understood that any helical anchor head 250 disclosed herein, including exemplary helical anchor head 250^d, can include any other number of helical turns 256, such as less or more than three.

[0289] As the sharp anchor tip 254 initially penetrates into the tissue, it forms an initial point of entry, which is expanded in size to a larger cut portion as the anchor head 250 is rotated through the tissue, due to the increase in the width WT of the helical turns 256 passing through the tissue, wherein the rate of increase and size of the width WT can be designed to cut through a portion of a circumference of the tissue, sufficient to form a pilot puncture or opening 50, which can be generally sized according to the diameter of anchor channel 252. Thus, a helical anchor head 250^d having a turn width WT gradually increasing from the anchor tip 254 to the anchor proximal end 266, can be utilized for forming a pilot puncture or opening 50, even in the absence of a separate perforation member, such as a needle 270.

[0290] In some examples, any helical anchor head 250 configured to serve as a perforating member by cutting around a circumference of an eventually formed pilot puncture 50, is utilized to form a circumferential cut that does not extend along the entire circumference of the final pilot puncture 50. Rotational movement of the helical anchor head 250 can be controlled to form a cut that spans more than 180° but less than 360° around the central axis CA- Forming a cut spanning 360° may cause the cut circular portion of the tissue to “fall-off’ and be carried by the blood stream, posing a risk of forming clots that can result in adverse clinical outcomes. Forming a cut that spans less than 180° can result in a circumferential cut that allows only a limited portion of the tissue to be movable and allow extension of other components of the system 200, such as dilator 280 and/or hole-dilating balloon 296, to extend therethrough.

[0291] Each helical turn 256 of any helical anchor head 250 disclosed herein, has a turn thickness TT defined in a radial direction, between an outer side 255 and an inner side 253 of the helical turn 256 (the inner side 253 defined as the side facing the the anchor channel 252 and/or central axis CA). A distal-most helical turn 256d can include a tip portion 251 terminating at the sharp anchor tip 254, wherein the tip portion 251 can be defined as the portion of the distal-most helical turn 256d that extends from the anchor tip 254 and increases in thickness, until reaching the maximal turn thickness TT - In some examples, the distal most helical turn 256d, as well as all other helical turns 256, can have a uniform thickness which is equal to the maximal turn thickness TTM along any region past the tip portion 251.

[0292] Fig. 13 shows a view in perspective of an exemplary helical anchor head 250^e. Helical anchor head 250^e is an exemplary implementation of helical anchor head 250, and thus includes all of the features described for helical anchor head 250, except that the helical slot 260 includes a slot proximal end 262 configured to facilitate cutting of the tissue through which the helical anchor head 250 extends.

[0293] A pitch PH of the helical anchor head 250, indicated in Figs. 12 and 13, can be defined as the distance between circumferentially-aligned portions of successive helical turns, or as the width of helical slot 260. In some examples, a helical anchor head 250 can have a non-uniform pitch PH that gets narrower in the proximal direction, in a manner that gradually pinches the tissue between adjacent helical turn 256, facilitating cutting of the tissue at the narrowest region of the slot proximal end 262. In some examples, the pitch PH can be relatively uniform along at least some of the length of helical slot 260 extending proximally from the position of anchor tip 254, yet getting significantly narrower as it approached the slot proximal end 262. In other words, the helical slot 260 can have a width that tapers towards the slot proximal end 262.

[0294] In some examples, the helical anchor head 250 can include a thinned wall portion 259 at the region of slot proximal end 262. The thinned wall portion 259, which can be relatively thinner than the maximal turn thickness TTM, can define a sharp edge of the helical anchor head 250 at the region of slot proximal end 262, configured to cut through the tissue during rotation of the anchor head 250 to extend through the tissue material.

[0295] While an exemplary helical anchor head 250^e is shown to include both a narrower slot proximal end 262 and a thinned wall portion 259 at the region of the slot proximal end 262, it is to be understood that both of these features do not have to coexist, and that a helical anchor head 250 can include a narrower slot proximal end 262 without including a thinned wall portion 259, or it can include a thinned wall portion 259 without defining a narrower slot proximal end 262.

[0296] Fig. 14 shows a view in perspective of an exemplary helical anchor head 250^f. Helical anchor head 250^f is an exemplary implementation of helical anchor head 250, and thus includes all of the features described for helical anchor head 250, except that the helical anchor head 250^f employs a multi-helical arrangement that can be cut from a single tub. In the illustrated example, a dual-helical arrangement is shown, wherein the at least one helical slot 260 comprises two helical slots that define a first set of helical turns 256’ terminating with a first sharp anchor tip 254’, and a second set of helical turns 256’ ’ terminating with a second sharp anchor tip 254’ ’ . The helical turns 256’ of the first set are arranged with the helical turns 256’ ’ of the second set in a staggered or alternating arrangement along the length of helical anchor head 250^f, wherein both sets of helical turns can share a common base or interconnection at the anchor proximal end 266. While a dual-helical arrangement is illustrated in Fig. 14, it is to be understood that a helical anchor head 250^f can include any other multi-helical arrangement is contemplated, including having three, four, or more sets of helical turns that can be arranged in a similar staggered or alternating arrangement along the length of the anchor head 250^f.

[0297] It is to be understood that a slotted anchor shaft 230 that includes circumferential slits 246 is shown in Figs. 12-14 by way of illustration and not limitation, and that any of the anchor heads 250^d, 250^e, or 250^f can be coupled to any other type of anchor shaft 230 disclosed herein, and/or can be coupled to a movement limiting segment 234 according to any example disclosed herein.

[0298] Fig. 15 A is a perspective view of an exemplary helical anchor head 250^g. Helical anchor head 250^g is an exemplary implementation of helical anchor head 250, and thus includes all of the features described for helical anchor head 250, except that the tip portion 25 l^g of anchor head 250^s further defines a cutting edge 261 extending from the anchor tip 254. Fig. 15B is a cross-sectional view of the tip portion 25 l^g taken along line 15B-15B of Fig. 15A. As shown in Figs. 15A-15B, the two axial sides 257^g can angularly extend between the inner side 253^g and the outer side 255^g of the tip portion 25 l^g, forming a tapering frustoconical cross-sectional shape defining a relatively sharp cutting edge 261 at the meeting of both axial sides 257⁸ at the outer side 255^s.

[0299] As mentioned above, the tip portion 251 is defined as the portion of the distal-most helical turn 256d that increases in thickness TT up to the maximal turn thickness TTM- A thickening length LT, indicated for example in Fig. 15A, can be defined as the length of the tip portion 251 between the anchor tip 254 and the point at which it expands to the maximal turn thickness TTM. In some examples, the thickening length LT spans at least 90° from the anchor tip 254 along the distal-most helical turn 256d. In some examples, the thickening length LT spans at least 60° from the anchor tip 254 along the distal-most helical turn 256d. In some examples, the thickening length LT spans at least 180° from the anchor tip 254 along the distal- most helical turn 256d. In some examples, the thickening length LT spans at least 270° from the anchor tip 254 along the distal-most helical turn 256d.

[0300] As shown in Fig. 15B, the inner side 253^g can be a relatively flattened side or surface of the tip portion 25 l^g for a tube-cut anchor head 250^g of the type illustrated in Fig. 15 A. The inner side 253^s can have a width equal to the turn width WT, and widen from the anchor tip 254 along the distal-most helical turn 256d, and optionally increase in width WT according to any example described above with respect to anchor head 250^d, for example. The cutting edge 261 can extend along a length Lc from the anchor tip 254, after which the outer side 255⁸ can gradually widen until it reaches the turn width WT. The inner side 253^g is wider than the outer side 255⁸ along at least part of the tip portion 25 l^g, which can include the length Lc of the cutting edge 261 and a gradually widening portion of the outer side 255^s.

[0301] In some examples, the cutting edge length Lc can be shorter than the thickening length LT. In some examples, the cutting edge length Lc spans at least 90° from the anchor tip 254 along the distal-most helical turn 256d. In some examples, the cutting edge length Lc spans at least 60° from the anchor tip 254 along the distal-most helical turn 256d. In some examples, the cutting edge length Lc spans at least 180° from the anchor tip 254 along the distal-most helical turn 256d. In some examples, the cutting edge length Lc spans at least 270° from the anchor tip 254 along the distal-most helical turn 256d.

[0302] While conventional helical anchor heads can be used in various medical device applications for penetration into relatively smooth and/or soft tissues, a host leaflet of an aortic valve, such as a native aortic valve leaflet, or a leaflet of a prosthetic valve previously implanted in an aortic valve, can include calcific deposits therein that can be accumulated over the years in the tissue material. Penetration of helical anchor heads equipped with conventional pointy anchor tips can pose a challenge with respect to calcified leaflets, and may even pose a risk of releasing calcified debris into the blood streams during an attempt to forcefully penetrate into the tissue. Advantageously, a helical anchor head 250^g can alleviate such risks, by utilizing the sharp anchor tip 254 to form a point of puncture, immediately followed by a relatively elongated cutting edge to facilitate continued penetration through the relatively rigid calcified leaflet, with a tip portion that gradually widens over a relatively elongated portion of the distal- most helical turn, thereby enabling the anchor head 250^s to be passed therethrough at a reduced force, with reduced risk of breaking and releasing calcified debris during the procedure.

[0303] Fig. 16A is a perspective view of an exemplary helical anchor head 250^h, and Fig. 16B is a cross-sectional view taken along line 16B-16B of Fig. 16A. Helical anchor head 250^h is similar to any example described herein for helical anchor head 250^s, except that the anchor head 250^h is a wire formed helical anchor, such that the helical turns 256 define a circular crosssection at any region that excludes the tip portion 25 l^h, instead of a rectangular cross-section of a tube-cut anchor head 250^s of the type illustrated in Fig. 15A for example. Thus, unlike the relatively flattened inner side 253^s of the tip portion 25 I^s shown in Fig. 15B, the inner side 253^h of tip portion 251¹¹ is curved, as shown in Fig. 16B.

[0304] In some examples, an advantage of a tip portion 25 l^h of a wire-formed helical anchor head 250^h, over a tube cut anchor head 250^g, can be that the turn thickness TT can be larger for the tip portion 25 l^h than the m thickness TT of the same angular position of the cross-section of a tip portion 251^s, due to optional added material contributed by the dome-shaped inner side 253^h. In such examples, the added cross-sectional turn thickness TT of the tip portion 25 l^h can increase structural strength of the tip portion 25 l^h and facilitate stable and easier penetration into the calcified tissue material, optionally at lower forces.

[0305] It is to be understood that an anchor shaft 230 in the form of an HHS tube is shown in Figs. 15A and 16A by way of illustration and not limitation, and that any of the anchor heads 250^s or 250^h can be coupled to any other type of anchor shaft 230 disclosed herein, and/or can be coupled to a movement limiting segment 234 according to any example disclosed herein.

[0306] Fig. 17A and 17B are perspective and front views, respectively, of an exemplary tubecut helical anchor head 250^k. A helical anchor head 250 can extend along a length LH between the anchor proximal end 266 and anchor tip 254, and define an anchor inner diameter DAI, which is also the diameter of the anchor channel 252, and an anchor outer diameter DAO, as indicated, for example, in Fig. 17B. It is to be understood that any reference herein to an anchor inner radius RAI refers to half of the anchor inner diameter DAI, and any reference to an anchor outer radius RAO refers to half of the anchor outer diameter DAO.

[0307] In some examples, the length LH of a tube-cut anchor head is within the range of 6 to 8 mm. In some examples, the length LH of a tube-cut anchor head is within the range of 6.5 to 7.5 mm. In some examples, the length LH of a tube-cut anchor head is within the range of 6.85 to 6.95 mm. In some examples, the length LH of a tube-cut anchor head is equal to about 6.9 mm.

[0308] In some examples, the inner diameter DAI of a tube-cut anchor head is within the range of 1.4 to 1.8 mm. In some examples, the inner diameter DAI of a tube-cut anchor head is within the range of 1.5 to 1.7 mm. In some examples, the outer diameter DAO of a tube-cut anchor head is within the range of 2.2 to 2.6 mm. In some examples, the outer diameter DAO of a tubecut anchor head is within the range of 2.3 to 2.5 mm. In some examples, the maximal turn thickness TTM of a tube-cut anchor head is within the range of 0.6 to 0.9 mm. In some examples, the maximal turn thickness TTM of a tube-cut anchor head is within the range of 0.65 to 0.85 mm. In some examples, the inner diameter DAI of a tube-cut anchor head is equal to about 1.6 mm., and the outer diameter DAO is equal to about 2.4 mm. In some examples, the maximal turn thickness TTM of a tube-cut anchor head is equal to about 0.8 mm.

[0309] Helical anchor head 250^k is an exemplary implementation of helical anchor head 250, and thus includes all of the features described for helical anchor head 250, except that the tip portion 25 l^k of a tube-cut anchor head 250^g has an inner side 253 defined along an inner radius of curvature Rci that is greater than the anchor inner radius RAI, and an outer side 255 defined along an outer radius of curvature Rco that is smaller than the anchor outer radius RAO- In some examples, each of the axial sides 257 of tip portion 25 l^k, including a distally -facing axial side 257d and a proximally-facing axial sides 257p, can define a right angle at the edges 265 intersecting with the inner side 253.

[0310] In some examples, the inner radius of curvature Rci is within the range of 1 to 1.4 mm. In some examples, the inner radius of curvature Rci is within the range of 1.1 to 1.3 mm. In some examples, the inner radius of curvature Rci is at least 1.5 times as great as the anchor inner radius RAI. In some examples, the inner radius of curvature Rci is equal to about 1.2 mm and the anchor inner radius RAI is equal to about 0.8 mm.

[0311] In some examples, the outer radius of curvature Rco is within the range of 0.8 to 1.1 mm. In some examples, the outer radius of curvature Rco is within the range of 0.9 to 1 mm. In some examples, the outer radius of curvature Rco is equal to about 0.94 mm and the anchor outer radius RAO is equal to about 1.2 mm.

[0312] Figs. 18A and 18B are perspective and cross-sectional side views, respectively, of an exemplary helical anchor head 250¹. Helical anchor head 250¹ is similar to any example described herein for helical anchor head 250^k, except that the intersection edge 265¹ between the distally -facing axial side 257d and the inner side 253 of the tip portion 251¹ is rounded.

[0313] Figs. 19A, 19B and 19C are perspective, side and front views, respectively, of an exemplary wire-formed helical anchor head 250^m. Helical anchor head 250^m is an exemplary implementation of helical anchor head 250, and thus includes all of the features described for helical anchor head 250, except that the tip portion 25 l^m of the wire-formed anchor head 250^m is conical. In the case to a wire-formed anchor head 250, having round cross-sectional shapes of its helical turns 256, the maximal turn diameter TTM can be also referred to as the wire diameter Dw. A conical tip portion 25 l^m gradually expands from the anchor tip 254 to the wire diameter Dw.

[0314] In some examples, the length LH of a wire-formed anchor head is within the range of 4 to 7 mm. In some examples, the length Ln of a wire-formed anchor head is within the range of 5 to 6 mm. In some examples, the length LH of a wire- formed anchor head is within the range of 5.1 to 5.5 mm. In some examples, the length LH of a wire-formed anchor head is equal to about 5.3 mm.

[0315] In some examples, the outer diameter DAO of a wire-formed anchor head is within the range of 2.4 to 2.8 mm. In some examples, the outer diameter DAO of a wire-formed anchor head is within the range of 2.5 to 2.7 mm. In some examples, the wire diameter Dw is within the range of 0.4 to 0.6 mm. In some examples, the wire diameter Dw is within the range of 0.45 to 0.55 mm. In some examples, the outer diameter DAO of a wire-formed anchor head is equal to about 2.6 mm., and the wire diameter Dw is equal to about 0.5 mm.

[0316] Figs. 20A, 20B and 20C are perspective, side and front views, respectively, of an exemplary wire-formed helical anchor head 250". Helical anchor head 250ⁿ is an exemplary implementation of helical anchor head 250, and thus includes all of the features described for helical anchor head 250, except that the tip portion 25 lⁿ of the wire- formed anchor head 250ⁿ is a lancet-type tip portion that includes three planar facets intersecting with each other, namely a primary facet 243 and two secondary facets 245 which are symmetrically angled relative to the primary facet 243 on opposite sides thereof.

[0317] In some examples, the needle 270 and anchor device 229 can be part of a perforation apparatus that can be used as part of a stabilized tissue modification system 300 having a separate steerable delivery apparatus that includes the steerable outer shaft 208. Fig. 21 shows a cross-sectional view of an exemplary steerable delivery apparatus 302 that includes a steerable outer shaft 208 attached to, and configured to be controllably steered by, a handle 304 of the steerable delivery apparatus 302.

[0318] In some examples, the handle 304 can include a first knob 306a (which may also be referred to as a steering knob) at a distal portion thereof, configured to adjust the curvature of a distal section 213 of the outer shaft 208 to assist in guiding the outer shaft 208 and/or any other devices or shafts extendable through the outer shaft lumen 210, through the patient’s vasculature, including through the curvature of the aortic arch when the target site of treatment is at the aortic valve. In some examples, the handle 304 can include a lead member 310 that can be received within a housing of the handle 304. In some examples, the steering knob 306a can be attached to or integrally formed with the lead member 310 such that rotation of the steering knob 306a results in rotation of the lead member 310.

[0319] A threaded slide nut 312 is disposed inside a bore defines by the lead member 310 and is axially movable relative to the lead member 310. The slide nut 312 is formed with external threads that mate with internal threads of the lead member 310. In some examples, the handle 304 can further include an axial guide (not indicated explicitly in Fig. 21) having two side slots that can slidingly receive portions of the threaded slide nut 312. The axial guides of the handle 304 can prevent rotation of the slide nut 312 relative to the lead member 310. By virtue of this arrangement, rotation of the steering knob 306a (either clockwise or counterclockwise) causes the slide nut 312 to move axially relative to the lead member 310.

[0320] One or more pull wires 314 couple the steering knob 306a to the distal section 213 of the outer shaft 208, to adjust the curvature of the distal section 213 upon rotation of the steering knob 306a. In some examples, the one or more pull wires 314 can extend into handle 304 and can be secured to the slide nut 312. In some examples, the pull wire 314 can extend into handle 304 and can be secured to another component attached to and/or otherwise configured to axially move along with the slide nut 312. The distal end portion of the pull wire 314 is secured to a distal end portion of the distal section 213 of the outer shaft 208, for example at or in close proximity to the distal end portion 214.

[0321] When the steering knob 306a is rotated to move the slide nut 312 in the proximal direction, the movement of the slide nut 312 in the proximal direction can cause the pull wire 314 to also move in the proximal direction. The movement of the pull wire 314 in the proximal direction can pull the distal end 214 of the distal section 213, thereby bending the distal section 213 and reducing its radius of curvature. The friction between the steering knob 306a and the slide nut 312 is sufficient to hold the pull wire 314 taut, thus preserving the shape of the bend in the distal section 213 if the steering knob 306a is released (or no longer rotated). When the steering knob 306a is rotated in the opposite direction to move the slide nut 312 in the distal direction, the distal movement of the slide nut 312 can cause distal movement of the slide nut 312, thereby reducing (or releasing) the tension in the pull wire 314. The resiliency of the distal section 213 causes the distal section 213 to return its normal, non-deflected shape as tension on the pull wire 314 is decreased., which is incorporated by reference herein. Further details on steering or flex mechanisms for the handle 304 can be found, for example, in U.S. Patent Nos. 7,780,723, 8,568,472, and 9,339,384, all of which are incorporated herein by reference in their entireties.

[0322] In some examples, the handle 304 comprises a valve assembly 316 proximal to the outer shaft 208 can aligned therewith. The valve assembly 316 comprises a series of valves 318, 324, 330 for sealing around different sized shafts or devices that can be inserted, through a rear port 308 of the handle 304, into the outer shaft lumen 210. In some examples, the valve assembly 316 comprises a cross-slit valve 318, a disc valve 324, and a hemostatic valve 330, arranged in series such that the hemostatic valve 330 is distal to the disc valve 324, and such that the disc valve 324 is distal to the cross-slit valve 318. The valve assembly 316 is configured to provide a seal when there is no shaft or other instrument extending therethrough, as well as when several different sizes of shafts pass through the handle 304 into the outer shaft lumen 210. For example, the valves 318, 324, 330 can seal against an introducer shaft 352 of an introducer 350 that can extend through the handle 304 and outer shaft 208 as will be described in greater detail below with respect to Figs. 22-23. Additionally, the valves 318, 324, 330 can seal against a delivery catheter 370 of a perforation apparatus 360 that can extend through the handle 304 and outer shaft 208 as will be described in greater detail below with respect to Fig. 25. Additionally, the valves 318, 324, 330 can seal against a balloon catheter 290 of a dilation apparatus 380 that can extend through the handle 304 and outer shaft 208 as will be described in greater detail below with respect to Fig. 26.

[0323] The cross-slit valve 318 can include a generally semi-spherical portion 320, and an aperture 322 extending through an apex of the semi- spherical portion 320. The disc valve 324 can include a body portion 326 having an aperture 328 disposed within and extending through a center thereof. Tn some examples, the body portion 326 can have circular cross-sectional shape, or any other suitable shapes for facilitating insertion of devices (for example, a delivery catheter, a balloon catheter, or an introducer) into the handle 304. In some examples, the hemostatic valve 330 can be similar in structure to a duck bill valve, transitioning in the distal direction into a reduced diameter of a central portion thereof, and include a pair of flaps 332 defining elongated slits 334 extending between distal ends of the flaps 332. The aperture 328 of disc valve 324 is coaxially aligned with the aperture 322 of the cross-slit valve 318 and with the outer shaft lumen 210. In some examples, any of the cross-slit valve 318, the disc valve 324, and the hemostatic valve 330, can comprise or be fabricated from polyisoprene, though other biocompatible resilient materials may be used.

[0324] In some examples, the handle 304 further comprises a rigid inner support member 336 proximal to the cross-slit valve 318. The cross-slit valve 318 can be abutted, in such examples, against the inner support member 336 in a manner that forms a fluid-tight seal therebetween. The inner support member 336 defines a central opening 337 aligned with the aperture 322 of the cross-slit valve 318.

[0325] In some examples, the handle 304 can include a second knob 306b (which may be referred to as a securing knob) housing an inner nut 340, a ring 342 disposed inside the inner nut 340, a biasing member 344 (e.g., a coiled spring), a pusher element 346, and a shaft engagement member 348 (e.g., a collet). The securing knob 306 is configured to restrain movement of a shaft extending through the handle 304 and the outer shaft lumen 210 relative to the outer shaft 208. The shaft extendable through the handle 304 and outer shaft lumen 210 can be, in some examples, an introducer shaft 352 of an introducer 350 as will be described in greater detail below with respect to Figs. 22-23, a delivery catheter 370 of a perforation apparatus 360 as will be described in greater detail below with respect to Fig. 25, and/or a balloon catheter 290 of a dilation apparatus 380 as will be described in greater detail below with respect to Fig. 26. While the biasing member 344 is illustrated as a coiled spring, it is to be understood that it can be replaced and/or additionally accompanied by other biasing members, such as an elastomeric body (e.g., a silicone of polyurethane component) which is compressible under external force application, and returns to its original shape when such force is removed. Any such biasing member may replace a coil compression spring 220 as long as it applies a biasing force sufficient to urge the pusher element 346 against the shaft engagement member 348, as explained in greater detail below.

[0326] The inner nut 340 includes inner threads that engage the external threads of a proximal threaded segment 338 that can be integrally formed with, or affixed to, the inner support member 336. The pusher element 346 includes an enlarged distal end portion that bears against the proximal end portion of the shaft engagement member 348. The spring 344 is disposed on a proximal portion of the pusher element 346 and has a proximal end that bears against the ring 342 and a distal end that bears against the enlarged distal end portion of the pusher element 346.

[0327] The securing knob 306b extends co-axially over the inner nut 340 such that rotation of the knob 306b causes corresponding rotation of the nut 340. When the securing knob 306b is rotated in one direction, which can be either clockwise or counterclockwise, corresponding rotation of the nut 340 can cause it to translate in the distal direction along the external threads on the proximal threaded segment 338 of the inner support member 336. As the nut 340 is moved distally along the external threads on the proximal threaded segment 338, the nut 340 pushes against the ring 342, which in turn pushes against the spring 344. The spring 344 presses against the distal end portion of the pusher element 346, urging the pusher element 346 against the shaft engagement member 348. In some examples, the shaft engagement member 348 includes a plurality of axially extending, circumferentially spaced slots that define a plurality of flexible fingers (not shown) therebetween. When the pusher element 346 is urged distally, a distal inner tapered surface of the pusher element 346 pushes against a corresponding tapered surface of the shaft engagement member 348, which can be in the form of a collet, forcing the collet’s fingers (not shown) radially inward against an outer surface of the shaft extending therethrough. The holding force of the shaft engagement member 348 against the shaft locks the shaft extending through the shaft engagement member 348 (e.g., a balloon catheter shaft) relative to the outer shaft 208, thereby preventing relative movement (e.g., axial) of the shaft extending through the shaft engagement member 348 with respect to the outer shaft 208.

[0328] In some examples, the biasing force of the spring 344 can be sufficient to lock the collet 348 against the shaft with a relatively small degree of rotation of the knob 306b, such as less than 360 degrees rotation of the knob. For example, the knob 306b can be rotated less than 180 degrees from an unlocked position (in which the collet does not retain the shaft) to a locked position (in which the collet frictionally engages and retains the shaft). Conversely, rotating the knob 306b in the opposite direction from the locked position to the unlocked position through the same degree of rotation allows the spring 344 to release the biasing force against the pusher element 346 and the collet 348 so as to permit axial movement of the shaft relative to the collet 348.

[0329] While conventional delivery systems for implantation of prosthetic valves, such as prosthetic valve 100, usually include simultaneous advancement of an outer steerable catheter with the prosthetic valve mounted on an inner catheter, such as a balloon catheter in the case of balloon-expandable valve, and a distal nosecone configured to facilitate advancement of the delivery system’s through the patient’s vasculature, the steerable delivery apparatus 302 of a system 300 includes a steerable outer shaft 208 configured to be advanced through the patient’ s vasculature so as to position its distal end portion at or in close proximity to the site of treatment, prior to advancing a prosthetic valve 100 therethrough, and optionally prior to advancing an anchor device 229 or needle 270 therethrough, such that a nosecone that can be part of any of these separate sub-assemblies is not present during initial advancement of the outer shaft 208.

[0330] In some examples, the stabilized tissue modification system 300 further comprises an introducer 350, shown in Figs. 22-23, which can be used in cooperation with the steerable delivery apparatus 302 to advance the outer shaft 208 through the patient’s vasculature. The introducer 350 includes an introducer shaft 352 having a tapered distal portion 354, configured to be received within the outer shaft lumen 210. The introducer shaft 352 can extend from an introducer adaptor 358 that includes a first adaptor port 359a configured to receive a guidewire therethrough and a second adaptor port 359b configured to serve as a flushing port to flush the introducer lumen 356 around the guidewire. Fig. 24 is a cross-sectional view of the tapered distal portion 354 of the introducer 350, which tapers in the distal direction. The introducer shaft 352 can define an introducer lumen 356 through which a guidewire 80 can extend.

[0331] As shown in Fig. 22, the introducer 350 can be preloaded within the outer shaft 208 by inserting the tapered distal portion 354 and the introducer shaft 352, via rear port 308 of the handle 304, into the handle 304. The introducer shaft 352 is distally passed through the valve assembly 316 of handle 304 and into the outer shaft lumen 210, wherein the cross-slit valve 318 and the disc valve 324 provide fluid-tight seals around introducer shaft 352.

[0332] As shown in Fig. 23, the introducer shaft 352 can be further advanced through the outer shaft lumen 210 until the tapered distal portion 354 extends, at least partially, past and out of the distal end portion 214 of outer shaft 208. In this position, the introducer shaft 352 can be axially locked relative to the outer shaft 208, for example by rotating the securing knob 306b, such that both the outer shaft 208 and introducer 350 can be advanced simultaneously through vasculature. The guidewire 80 (not shown in Figs. 22-23) passes through the introducer lumen 356 when the introducer 350 and the outer shaft 208 are advanced towards the site of treatment. The tapered distal portion 354 of the introducer 350 can be, in some examples, sufficiently soft to be advanced through torturous blood vessels or other anatomical structures without causing undue trauma or perforation thereof.

[0333] When the distal end portion of the outer shaft 208 is appropriately positioned at or in close vicinity to the site of treatment, the introducer 350 can be withdrawn from the steerable delivery apparatus 302, with only the outer shaft 208 and guidewire 80 remaining in situ.

[0334] In some examples, as shown in Fig. 25, the anchor device 229 and needle 270 can be part of a perforation apparatus 360 that can be used in cooperation with the steerable delivery apparatus 302. The perforation apparatus 360 can include a delivery catheter 370 attached to a handle 362 and extending distally therefrom. The proximal ends of the delivery catheter 370, the anchor device 229, and the needle 270 can extend into and coupled to the handle 362 of perforation apparatus 360. During delivery through the patient’s vasculature, the handle 362 can be maneuvered by an operator (for example, a clinician or a surgeon) to control movement of components of the apparatus 360, such as the anchor device 229 and the needle 270.

[0335] The handle 362 can include, in some examples, handle distal portion 364 and a handle proximal portion 366 which are separable from each other. A first knob 368a (which may be referred to as an engagement knob) of the handle 362 can be configured to control a lock and release mechanism that can either maintain the two portions 364 and 366 coupled to each other, such as during utilization of the perforation apparatus 360 for forming a pilot puncture 50 in a target tissue, and to allow separation of the handle proximal portion 366 from the handle distal portion 364 after formation of the pilot puncture 50 is complete and retrieval of the needle 270 and anchor device 229 is desired.

[0336] The handle proximal portion 366 can include a second knob 368b (which may be referred to as an anchor control knob), configured to control rotational movement of the anchor device 329, and a third knob 368c (which may be referred to as a needle advancement knob) configured to control axial movement of the needle 270, wherein proximal portions of the anchor shaft 230 and the needle shaft 271 can be coupled to the handle proximal portion 366, such as to mechanisms of the handle proximal portion 366 controllable by the knobs 368b, 368c. The delivery catheter 370 is attached to the handle distal portion 264, while the anchor device 229 and needle 270 can extend through the handle distal portion 364 to connect with handle proximal portion 366, without being attached to the handle distal portion 364 itself. Thus, when the knob 368a is actuated (e.g., rotated) to allow separation between the handle portions 364 and 366, the anchor device 229 and the needle 270 can be removed, along with the handle proximal portion 366, from the handle distal portion 364.

[0337] As shown in Fig. 25, after retrieval of the introducer 350, the distal portion of the delivery catheter 370 of perforation apparatus 360 can be inserted, via the rear port 308 of the handle 304, into the handle 304. In some examples, the distal portion of the delivery catheter 370 of perforation apparatus 360 can be inserted into the handle 304 via the rear port 308 while the anchor head 250 and needle head 274 remain concealed inside delivery catheter 370. This can prevent any unwanted damage to any of the internal components of the handle 304, the outer shaft 208, and/or the patient vasculature. The delivery catheter 370 is distally passed over the guidewire 80 through the valve assembly 316 of handle 304 and into the outer shaft lumen 210, wherein the cross-slit valve 318 and the disc valve 324 provide fluid-tight seals around delivery catheter 370. The delivery catheter 370 can be further advanced through the outer shaft lumen 210 until a distal end portion thereof extends past and out of the distal end portion 214 of outer shaft 208. In some examples, the distal end portion of the delivery catheter 370, having a smaller diameter extending through the larger outer shaft 208, can be more easily navigated from the exit point out of outer shaft 208 towards the desired region of the target tissue, such as a host leaflet 10, in which a pilot puncture is to be formed.

[0338] The guidewire 80 can have a total length sufficient to extend through the patient’s vasculature, from the entry point into the patient’ s body to the site of treatment (for example, the aortic valve), as well as the lengths of handles 304 and 362.

[0339] In some examples, as shown in Figs. 26A-26B, a balloon catheter 290 equipped with a hole-dilating balloon 296, as well as a dilator 280 at a distal end of a dilator shaft 298, can be part of a dilation apparatus 380 that can be used in cooperation with the steerable delivery apparatus 302. The balloon catheter 290 can extend from a balloon catheter adaptor 382 that includes a first adaptor port 384a configured to receive guidewire 80 therethrough and a second adaptor port 384b configured to receive inflation fluid from a fluid source. After formation of the pilot puncture 50, the needle 270 and the anchor device 229 can be retrieved from the patient’s body, optionally by retraction through the outer shaft 208 and out of the handle 304 of steerable delivery apparatus 302, while leaving the outer shaft 208 in position and the guidewire 80 extending through the pilot puncture 50.

[0340] In some examples, the perforation apparatus 360 can be completely removed from the system 300 after formation of the pilot puncture 50, such that the needle 270 and the anchor device 229 are retracted along with the delivery catheter 370 out of the patient’s body and out of the handle 304 of steerable delivery apparatus 302, after which the balloon catheter 290 of dilation apparatus 380 can be inserted, via rear port 308 of the handle 304, into the handle 304, as shown in Fig 26A. The balloon catheter 290 is distally passed over the guidewire 80 through the valve assembly 316 of handle 304 and into the outer shaft lumen 210, wherein the crossslit valve 318 and the disc valve 324 provide fluid-tight seals around balloon catheter 290. The balloon catheter 290 can be further advanced through the outer shaft lumen 210 to pass the dilator 280 through the pilot puncture 50 as described above, for example, with respect to Fig. 6H, and to position the hole-dilating balloon 296 inside the pilot puncture 50 as described above, for example, with respect to Fig. 61. When a perforation apparatus 360 is configured to be completely removed from the handle 304 of steerable delivery apparatus 302 prior to insertion of dilation apparatus 380, the handle 362 does not necessarily need to include separable portion 364, 366.

[0341] In some examples, such as when the handle 362 of perforation apparatus 360 includes separable portion 364, 366, the knob 368a of handle 362 can be actuated after forming the pilot puncture 50 and rotating the anchor device 229 to release it from engagement with the host leaflet 10, to allow separation of the handle proximal portion 366 from the handle distal portion 364. The handle proximal portion 366 can be then proximally pulled, while the handle distal portion 364 remains in position, such that the anchor device 229 and the needle 270 can be retracted through the outer shaft lumen 210 and out of the handle 304 of steerable delivery apparatus 302, while the delivery catheter 370 can remain in position, extending through the outer catheter 208 towards the host leaflet 10. In such examples, as shown in Fig. 26B, the dilation apparatus 380 can be inserted into the delivery catheter 370 and advanced therethrough, optionally over the guidewire 80, towards the host leaflet 10.

[0342] In some cases, a steerable outer shaft 208 of the steerable delivery apparatus 302 can be steered towards the site of treatment so as to generally face the host valvular structure 12. As mentioned above, the smaller-sized delivery catheter 370 can be then extended out of the outer shaft 208, and may be more easily oriented towards a specific desired host leaflet 10 in which a pilot puncture needs to be formed. In such cases, insertion of the balloon catheter 290 into the delivery catheter 370 as exemplified in Fig. 26B, can facilitate easier navigation thereof towards the specific host leaflet 10 and its pilot puncture 50, compared to direct insertion of the balloon catheter 290 into an outer shaft 208 from which the delivery catheter is removed, as exemplified in Fig. 26A. [0343] While a dilation apparatus 380 is shown in Figs 26A-26B to extend through an outer shaft 208 and over a guidewire 80 that remain in situ after retraction of the anchor device 229 and needle 270, either directly inserted through the handle 304 of apparatus 302 after removal of the delivery catheter 370 as well, as shown in Fig. 26A, or inserted into a delivery catheter 370 that remains in position inside the outer shaft 208, as shown in Fig. 26B, it is to be understood that these configurations are shown by way of illustration and not limitation. In some examples, the guidewire 80 can be retrieved from the patient’ s body while the outer shaft 208 remains in situ, with the delivery catheter 370 either retrieved as well or remaining inside the outer shaft, prior to insertion of the balloon catheter 290. The same guidewire 80 or a different guidewire can be then optionally reinserted, for example through the first adapter port 384a of the balloon catheter adaptor 382, over which the balloon catheter 290 can be guided towards the pilot puncture 50 of the host leaflet 10, through the outer shaft 208 and/or delivery catheter 370.

[0344] In some examples, both the perforation apparatus 360 and the steerable delivery apparatus 302 can be retrieved from the patient’s body, while only the guidewire 80 can remain in situ, optionally extending through the pilot puncture, such that the balloon catheter 290 can be guided over the guide wire 80 towards the host leaflet 10.

[0345] An exemplary prosthetic valve 100^a illustrated in Fig. 2A can be representative of a relatively “short” valve, having a length configured to position the outflow end 106^a at or distal to (e.g., below) the STJ level 28. Fig. 27 is a side view of an exemplary prosthetic valve 100^b, which is an exemplary implementation of prosthetic valve 100, and thus includes all of the features described for prosthetic valve 100 throughout the current disclosure, except that the prosthetic valve 100^b, which can be also referred to as a “long” valve, has a length configured to position the outflow end 106^b proximal to (e.g., above) the STJ level 28.

[0346] In some examples, the prosthetic valve 100^b is a self-expandable valve, having a frame 102^b configured to expand from a compressed state to an expanded state under the inherent resiliency or elastic force of the frame. In some examples, the frame can be formed of a shape memory material (e.g., a nickel titanium alloy, such as Nitinol) such that the frame can be shape-set to a particular configuration and then elastically deformed to one or more other configurations. As one example, the frame 102^b can be formed of Nitinol and shape-set in the radially-expanded state. The frame 102^b can be elastically deformed to the radially-compressed state prior to delivery into the patient’ s body, and allowed to self-expand when an enclosure in which the valve 100^b is retained during delivery, such as a capsule, is removed from the frame upon reaching the site of implantation. [0347] In some examples, the frame 102^b can be formed of a plastically -deformable material (e.g., stainless steel or cobalt chromium alloy) such that the frame 102^b can be formed in a particular configuration and then plastically deformed to one or more configurations which are radially smaller or larger than the configuration in which the frame is formed.

[0348] In the example illustrated in Fig. 27, the frame 102^b is shown to include multiple levels, including an inflow section 120 extending proximally from the inflow end 104, an enlarged or flared outflow section 124 extending distally from the outflow end 106, and a transition section 122 between the inflow section 120 and the outflow sections 124. As shown, the outflow section 124 can have a larger cross-section or diameter than that of the inflow section 120 in the expanded state of the prosthetic valve 100^b, while the transition section 122 may taper outwardly from the inflow section 120 to the outflow section 124.

[0349] Figs. 28A and 28B show a guest prosthetic valve 100^ab implanted in an exemplary “short” host valve 100^aa and in an exemplary “long” host valve 100^ba, respectively. When prosthetic valve 100^b is implanted inside a native aortic valve 20, as illustrated for example in Fig. 28B, the inflow section 120 can extend into and anchor against the aortic annulus 24, and the outflow section 124, which can be also referred to as the aortic section, can be positioned in the ascending aorta 26. In some examples, implantation of the prosthetic valve 100^b can be performed such that a portion of the inflow section 120 extends into the left ventricle 32, while the outflow section 124 is anchored against the ascending aorta 26 above the STJ level 28. The commissures 116 of the valvular structure 113^b can be coupled to attachment features of the frame 102^b, which can be positioned entirely within the inflow section 120 or at the juncture of inflow section 120 and transition section 122.

[0350] In some cases, as illustrated in Figs. 28A-28B, the left coronary ostium 42 may be positioned lower or closer to the aortic annulus 24 than the right coronary ostium 44. In such anatomies, as illustrated in Fig. 28A, using a “short” prosthetic valve 100“ in a valve-in-valve procedures can pose a smaller risk of curtaining the right coronary ostium 42 than the left coronary ostium 44, in which case, formation of a leaflet opening 52 in the left leaflet may be sufficient to mitigate the risk of compromising access or flow to the left coronary ostium 42. In contrast, a “long” prosthetic valve 100^b having a valvular structure 113 which sits relatively higher than (or more distal from) the aortic annulus 24, serving as the host valve as shown in Fig. 28B, can potentially block both coronary ostia 42, 44.

[0351] In such cases, it may be desirable to form a first leaflet opening 52a in the right host leaflet 10a, followed by formation of a second leaflet opening 52b in the left host leaflet 10b, wherein the first leaflet opening 52 can be in the form of a full tear through the right host leaflet 10a, while the second leaflet opening 52b can be in the form of an opening that does not tear the leaflet, in which a guest prosthetic valve can be positioned and expanded.

[0352] Figs. 29A-29K illustrate some steps in a method for utilizing a system, such as any of the exemplary systems 200 or 300 disclosed herein, for forming a first leaflet opening 52a in a first host leaflet 10a, which can be in the form of a full tear 52a in a right host leaflet 10a, and a second leaflet opening 52b in a second host leaflet 10b, which can be a bounded hole formed in a left host leaflet 10b, which can be performed prior to implanting a guest prosthetic valve inside the host valvular structure. Any of the first and second host leaflets 10a can be native leaflets 30 or prosthetic valve leaflets 114 of a previously implanted prosthetic valve. References to a “right host leaflet” and to a “left host leaflet”, as used herein, can refer to host leaflets positioned next to the right coronary ostium 44 and next to the left coronary ostium 42, respectively.

[0353] Fig. 29A shows an anchor device 229 and needle 270 advanced towards a first host leaflet 10a, which can be, in some examples, a right host leaflet. In some examples, an outer shaft 208 can be advanced towards, and positioned proximal to, the first host leaflet 10a. While a system 200 that can include an anchor device 229 and needle 270 extendable through an outer shaft 208 are illustrated in Fig. 29A, it is to be understood that any other exemplary system 200 or 300 disclosed herein can be employed, including an outer shaft 208 of a steerable delivery apparatus 302 through which a delivery catheter 370 with an anchor device 229 and needle 270 of a perforation apparatus 360 can be advanced.

[0354] As shown in Fig. 29B, the anchor head 250 can be then anchored to the first host leaflet 10a according to any examples described above, such as with respect to Fig. 6B, followed by advancement of the needle 270 through the first host leaflet 10a, in a manner similar to that described above with respect to Fig. 6C, so as to form a first pilot puncture 50a in the first host leaflet 10a, as shown in Fig. 29C. Figs 29D-29F show the guidewire 80 extended through the pilot puncture 50 (Fig. 29D), the needle 270 retracted from the first host leaflet 10a (Fig. 29E), and the anchor device 229 released and retracted from the first host leaflet 10a (Fig. 29F), according to any of the examples described herein, such as with respect to Figs. 6E-6F. The order of execution of the various stages shown in Figs. 29A-29F can follow any of the examples described above with respect to Figs. 6A-6F. When a system 300 is form the first pilot puncture 50a, the needle 270 and anchor device 229 can be optionally retrieved from the patient’s body while a delivery catheter 370 remains in situ.

[0355] Subsequent to retrieval of the needle 270 and the anchor device 229, an expansion member, such as a hole-dilating balloon 296, can be advanced, for example over guidewire 80, towards the first pilot puncture 50a, as shown in Fig. 29G. In some examples, the hole-dilating balloon 296 and balloon catheter 290 advanced towards the first pilot puncture 50a are part of a dilation apparatus 380. It is to be understood that the balloon catheter 290 is shown in Figs. 29G-29G to extend through the outer shaft 208 for illustrative purpose, and that the balloon catheter 290 can be advanced towards the first host leaflet 10a according to any example disclosed herein, including through a delivery catheter 370 that may remain in situ after retrieval of the anchor device 229 and needle 270.

[0356] In some examples, an exemplary hole-dilating balloon 296^p, which can be part of an exemplary dilation apparatus 380^p, is advanced towards the first host leaflet 10a. Hole-dilating balloon 296 can be similar to any example of a hole-dilating balloon 296 disclosed herein, except that hole-dilating balloon 296^p can be configured to expand to a diameter large enough so as to cause the first host leaflet 10a to rip and/or tear. In some examples, the maximum diameter to which the hole-dilating balloon 296^p can be inflated can be greater than 12 mm., such as a maximum expansion diameter of at least 20 mm., and/or a maximum expansion diameter of at least 25 mm.

[0357] Figs. 29H and 291 show advancement of a dilator 280 through the first pilot puncture 50a to dilate the first pilot puncture 50a (Fig. 29H), and positioning the hole-dilating balloon 296^p inside the first pilot puncture 50a (Fig. 291), in a manner that can be similar to any example described herein, such as with respect to Figs. 6H and 61, respectively. The hole-dilating balloon 296^p is then expanded to a diameter large enough to form a leaflet opening 52a which is a tear that extends from the first pilot puncture 50a fully to the free edge of the first host leaflet 10a (the coaptation edge of the leaflet 10a), as shown in Fig. 29J. Fig. 29K shows the balloon 296^p deflated, exposing the first leaflet opening 52a in the form of a tear extending to the free edge of the first host leaflet 10a, after which the balloon catheter 290 carrying the holedilating balloon 296^p can be retracted from the first host leaflet 10a, in a similar manner to that described above with respect to Fig. 6K for example.

[0358] The anchor device 229 and needle 270 can be then readvanced towards the second host leaflet 10b, which can be a left host leaflet, as shown in Fig. 29L. In some examples, such as when a system 300 is employed, the dilation apparatus 380^p can be retrieved from the steerable delivery apparatus 302, leaving the outer shaft 208 and the guidewire 80 in situ, wherein the guidewire 80 can be retracted to a proximal position out of the first host leaflet 10a, and the outer shaft 208 can be optionally steered towards the second host leaflet 10b. If the handle proximal portion 366 was separated from the handle distal portion 364 prior to insertion of dilation apparatus 380^p, the proximal handle portion 366 can be reconnected to the first handle portion 366 after removal of the dilation apparatus 380^p. Delivery catheter 370, along with the anchor device 229 and needle 270 disposed therein, can be reinserted in such examples into the handle 304 and advanced through the outer shaft 208, over guidewire 80, towards the second host leaflet 10b, as illustrated in Fig. 29L.

[0359] As shown in Fig. 29M, the anchor head 250 can be secured to the second host leaflet 10b, the needle 270 advanced to form a second pilot puncture 50b in the second host leaflet 10b, and the guidewire 80 extended through the second pilot puncture 50b, after which, as shown in Fig. 29N, the anchor head 250 can be released and retrieved, along with the needle 270, from the second host leaflet 10b.

[0360] After retraction of the anchor device 229 and needle 270, a hole-dilating balloon 296 can be advanced towards the second host leaflet 10b and positioned inside the second pilot puncture 50b (Fig. 290), inflated therein to form a second leaflet opening 52b in the second host leaflet 10b (Fig. 29P), and deflated (Fig. 29Q) followed by retrieval thereof from the second host leaflet 10b, in a manner similar to that described above, for example with respect to Figs. 6G-6K.

[0361] In some examples, an exemplary hole-dilating balloon 296^q, which can be part of an exemplary dilation apparatus 280^q, may be used for formation of the second leaflet opening 52b in the second host leaflet 10b, as illustrated in Figs. 29O-29Q. The hole-dilating balloon 296^q can be similar to any example of a hole-dilating balloon 296 disclosed herein, except that hole-dilating balloon 296^q can be configured to expand to a diameter that does not reach the free edge of the second host leaflet 10b, such that the second leaflet opening 52b formed thereby is a bounded hole that does not form a full tear reaching the leaflet’ s edge. In some examples, the maximum diameter to which the hole-dilating balloon 296^q can be inflated is not greater than 12 mm.

[0362] In some examples, the same anchor device 229 and needle 270 can be used to form both the first pilot puncture 50a and second pilot puncture 50b, while different hole-dilating balloons are expanded in each of the host leaflets, such as a hole-dilating balloon 296^p inflated inside the first host leaflet 10a, configured to expand to a maximum diameter greater than the maximum diameter of a hole-dilating balloon 296^q inflated inside the second host leaflet 10b. [0363] After retrieval of the hole-dilating balloon 296^q from the second host leaflet 10b, a guest prosthetic valve 100 can be placed inside the second leaflet opening 52b and expanded therein, in a manner similar to that described above with respect to Figs. 9L-9M, for example.

[0364] While two different hole-dilating balloon 296^p and 296^q are described above for use in a method illustrated in Figs. 29A-29Q for forming a tear 52a in a first host leaflet 10a and a bound hole 52b in a second host leaflet, in some examples, the same hole-dilating balloon 296 can be used to form both the tear 52a and the bounded hole 52b. For example, a hole-dilating balloon 296 can be configured to expand to a maximal diameter large enough to for a tear 52a in a first host leaflet 10a, and can also inserted into a second pilot puncture 50b of the second host leaflet 10b while expanded to a smaller diameter, so as to form the bounded opening 52b. This may require, though, adaptation of the balloon’s design parameters, since conventional inflatable balloons may not properly expand in a symmetric manner when partially inflated to expand to a diameter which is significantly smaller than the nominal or maximum expansion diameter.

[0365] While a sequence of steps in the method described above with respect to Figs. 29A- 29Q includes forming a tear 52a in the first leaflet 10a prior to forming a bounded hole 52b in the second leaflet 10b, it is to be understood that the order can be reversed, and that a bounded hole 52b can be formed in the second leaflet 10b prior to tearing the first leaflet 10a. For examples, steps similar to those described above with respect to Figs. 29L-29Q can be performed first, after which the second hole-dilating balloon 296^q can be removed while the guidewire over which it was advanced towards the second leaflet 10b can remain in situ, extending through the bounded hole 52b. The steps described above with respect to Figs. 29 A- 29K can be then performed by components of the apparatus 200 or system 300 guided over a different guidewire. After tearing the first leaflet 10a, a guest prosthetic valve 100 can be advanced, over the first guidewire, into the leaflet opening 52b of the second leaflet 10b, and expanded therein. This sequence can be advantageous since tearing one leaflet prior to forming a bounded hole in the other leaflet, will prevent the existing valvular structure to properly function as a valve the prevent backflow of blood during diastole, while the procedure for forming the bounded hole is performed.

[0366] In some examples, a single non-uniform hole-dilating balloon 296 that include portions configured to expand to different diameters can be used in a method for forming both a tear 52a in a first host leaflet 10a and a bounded hole 52b in a second host leaflet 10b, by positioning a different portion of the balloon in each of the corresponding pilot puncture 50a and 50b, respectively, prior to full or almost full inflation of the balloon 296. Figs. 30A-30I illustrate some steps in a method for utilizing an exemplary non-uniform hole-dilating balloon 296^r for forming a first leaflet opening 52a in a first host leaflet 10a, which can be in the form of a full tear 52a in a right host leaflet 10a, and a second leaflet opening 52b in a second host leaflet 10b, which can be a bounded hole formed in a left host leaflet 10b, which can be performed prior to implanting a guest prosthetic valve inside the host valvular structure. [0367] Fig. 30A shows an exemplary hole-dilating balloon 296^r, which can be part of an exemplary dilation apparatus 380^r, advanced towards the first host leaflet 10a, optionally after formation of a first pilot puncture 50a in a manner that can be similar to that described above with respect to Figs. 29A-29F. Non-uniform hole-dilating balloon 296^r can be similar to any example of a hole-dilating balloon 296 disclosed herein, except that the non-uniform holedilating balloon 296¹ comprises a first balloon portion 386 and a second balloon portion 388, each configured, upon balloon inflation, to expand to a different maximum diameter. In some examples, the first balloon portion 386 can be expandable to a maximum diameter that is greater than that of the second balloon portion 388. In some examples, the maximum diameter to which the first balloon portion 386 can be inflated can be greater than 12 mm., such as a maximum expansion diameter of at least 20 mm., and/or a maximum expansion diameter of at least 25 mm. In some examples, the maximum diameter to which the second balloon portion 388 can be inflated is not greater than 12 mm.

[0368] Figs. 30B and 30C show advancement of a dilator 280 through the first pilot puncture 50a to dilate the first pilot puncture 50a (Fig. 30B), and positioning the hole-dilating balloon 296¹ inside the first pilot puncture 50a (Fig. 30C), in a manner that can be similar to any example described herein, such as with respect to Figs. 29H and 29K, respectively, with the exception that axial positioning of the non-uniform hole-dilating balloon 296^r relative to first host leaflet 10a is such that the first balloon portion 386 is positioned inside the first pilo5 puncture 50a.

[0369] The hole-dilating balloon 296¹ is then inflated, causing it to assume a non-uniform expanded geometry, wherein the first balloon portion 386 expands to a diameter large enough to form a leaflet opening 52a which is a tear that extends from the first pilot puncture 50a fully to the free edge of the first host leaflet 10a (the coaptation edge of the leaflet 10a), as shown in Fig. 30D. Fig. 30E shows the balloon 296¹ deflated, exposing the first leaflet opening 52a in the form of a tear extending to the free edge of the first host leaflet 10a, after which the balloon catheter 290 carrying the non-uniform hole-dilating balloon 296^r can be retracted from the first host leaflet 10a, in a similar manner to that described above with respect to Fig. 29K for example.

[0370] The anchor device 229 and needle 270 can be then readvanced towards the second host leaflet 10b, which can be a left host leaflet, as shown in Fig. 30F. In some examples, such as when a system 300 is employed, the dilation apparatus 380^r can be retrieved from the steerable delivery apparatus 302, leaving the outer shaft 208 and the guidewire 80 in situ, wherein the guidewire 80 can be retracted to a proximal position out of the first host leaflet 10a, and the outer shaft 208 can be optionally steered towards the second host leaflet 10b. If the handle proximal portion 366 was separated from the handle distal portion 364 prior to insertion of dilation apparatus 380^r, the proximal handle portion 366 can be reconnected to the first handle portion 366 after removal of the dilation apparatus 380^r. Delivery catheter 370, along with the anchor device 229 and needle 270 disposed therein, can be reinserted in such examples into the handle 304 and advanced through the outer shaft 208, over guidewire 80, towards the second host leaflet 10b, as illustrated in Fig. 30F.

[0371] As further shown in Fig. 30F, the anchor head 250 can be secured to the second host leaflet 10b, the needle 270 advanced to form a second pilot puncture 50b in the second host leaflet 10b, and the guidewire 80 extended through the second pilot puncture 50b, after which the anchor head 250 can be released and retrieved, along with the needle 270, from the second host leaflet 10b, in a similar manner to that described above with respect to Fig. 29N for example.

[0372] After retraction of the anchor device 229 and needle 270, the same non-uniform holedilating balloon 296^r can be advanced towards the second host leaflet 10b, with the second balloon portion 388 positioned this time inside the second pilot puncture 50b, as shown in Fig. 30G. The hole-dilating balloon 296^r is then inflated, causing it to re-assume its non-uniform expanded geometry, wherein the second balloon portion 388 expands to a diameter that does not reach the free edge of the second host leaflet 10b, such that the second leaflet opening 52b formed thereby is a bounded hole that does not form a full tear reaching the leaflet’s edge, as shown in Fig. 30H.

[0373] Following deflation of the balloon 296^r as shown in Fig. 301, and retrieval thereof from the second host leaflet 10b, a guest prosthetic valve 100 can be placed inside the second leaflet opening 52b and expanded therein, in a manner similar to that described above with respect to Figs. 9L-9M, for example.

[0374] It is to be understood that the first balloon portion 386 is shown to be proximal to second balloon portion 388 by way of illustration and not limitation, and that in some examples, the first balloon portion 386 can be distal to the second balloon portion 388.

[0375] While a sequence of steps in the method described above with respect to Figs. 30A-30I includes forming a tear 52a in the first leaflet 10a prior to forming a bounded hole 52b in the second leaflet 10b, it is to be understood that the order can be reversed, and that a bounded hole 52b can be formed in the second leaflet 10b prior to tearing the first leaflet 10a. For example, steps similar to those described above with respect to Figs. 30F-30I can be performed first, after which the non-uniform hole-dilating balloon 296^r can be removed while the guidewire over which it was advanced towards the second leaflet 10b can remain in situ, extending through the bounded hole 52b. The steps described above with respect to Figs. 30A-30E can be then performed by components of the apparatus 200 or system 300 guided over a different guidewire. After tearing the first leaflet 10a by the first balloon portion 386 of the non-uniform hole-dilating balloon 296^r, a guest prosthetic valve 100 can be advanced, over the first guidewire, into the leaflet opening 52b of the second leaflet 10b, and expanded therein.

[0376] It is to be understood that any of the exemplary anchor devices 229 and/or helical anchor heads 250 described herein can be used with any exemplary stabilized tissue modification system, including exemplary system 200^a, exemplary system 200^b, exemplary system 200^c, or exemplary system 300. Furthermore, any of the methods described above with respect to Figs. 6A-6K, 9A-9M, 29A-29Q, or 30A-30I, can be modified for use with a helical anchor head 250 configured to form a pilot puncture or opening 50 without the use of a complementary perforating member, such as a needle 270. For example, a method described above with respect to Figs. 6A-6K can be adapted for use with a helical anchor head 250 utilized as a perforating member, wherein the pilot puncture or opening 50 is formed as the anchor head 250 is rotatably passed through the host leaflet 10 as shown in Fig. 6B. Steps of passing a separate needle to puncture through the leaflet, as well as retraction of such a needle, as described with respect to Figs. 6C-6E, can be skipped, wherein the guidewire 80 can be passed through the pilot puncture 50 subsequent to formation of the puncture 50, and prior to release of the anchor head 250 from the leaflet. Similar equivalent adaptation are contemplated for the methods described with respect to Figs. 29A-29Q or 30A-30I, mutatis mutandis.

[0377] The method described above with respect to Fig. 9A-9K can be similarly adapted for use with a helical anchor head 250 utilized as a perforating member, wherein the pilot puncture or opening 50 is formed as the anchor head 250 is rotatably passed through the host leaflet 10 as shown in Fig. 9C. Steps of passing a separate needle to puncture through the leaflet, as well as re-concealing such a needle, as described with respect to Figs. 9D-9F, can be skipped, wherein the guidewire 80 can be passed through the pilot puncture 50 prior to, simultaneously with, or after, extending a dilator 280 through the pilot puncture 50 to expand it. The size of dilator lumen 288 in such examples can be adapted to allow passage of the guidewire 80 therethrough.

[0378] In some examples, the guidewire 80 of any system 200 or 300 or method described herein, can be used as a perforating or lacerating member for forming a pilot puncture 50. A perforating guidewire 80 can be used instead of, or in addition to, a needle 270 and/or a perforating helical anchor head 250. In such examples, the guidewire 80 can be a relatively stiff wire having a distal tip 82 configured to pierce the host leaflet 10 when the guidewire 80 is pressed against the leaflet. In some examples, the guidewire 80 can include a radio-frequency (RF) energy delivery tip 82 to assist with penetration through the leaflet tissue. For this purpose, a suitable RF energy device may be coupled to the guidewire 80, and the RF energy device can apply the RF energy to the guidewire tip 82 to penetrate the host leaflet 10.

[0379] In any example disclosed herein wherein a guidewire is used to puncture a leaflet, the guidewire can be coupled to a source of RF energy that applies RF energy to the tip of the guidewire. When the guidewire 80 is used to pierce the leaflet 10, a needle 270 can be omitted, or it can be used in combination with the guidewire 80 that forms an initial puncture in the leaflet 10. For example, the guidewire 80 can be used to form an initial pilot puncture 50, after which a needle 270 can be advanced through the leaflet to form a slightly larger pilot puncture for subsequent advancement of the dilator 280 through the host leaflet 10.

[0380] In some examples, the guide wire 80 is used as a perforating member without any additional separate perforating member, such as a needle or a perforating helical anchor, disposed thereover, such that the guidewire 80 can be utilized as the sole component that forms the pilot puncture 50.

[0381] In some examples, the guidewire 80 is used as a perforating member that can be used in addition to another perforating member, such as a needle 270, such that the guide wire 80 can form an initial puncture via a sharp tip 82 or an RF energy delivery tip 82, followed by penetration of needle 270 into the leaflet 10 to form the pilot puncture 50, or a pilot puncture 50 which is greater in size than an initial puncture formed by the guidewire tip 82.

[0382] In some examples, the guidewire tip 82 is not necessarily sharp enough or otherwise configured to puncture through the host leaflet 10, in which case the guidewire 80 can be utilized for advancement of the system 200 or 300 and/or shafts thereof toward the valvular structure 12, but terminate in proximity of the host leaflet 10 without piercing through it, and helical anchor head 250 can be then rotated and advanced to engage with and pass through the host leaflet 10, and can be optionally configured to form the pilot puncture 50, or be used in combination with a needle 270 advanced into the stabilized tissue to form the pilot puncture 50.

[0383] Thus, formation of a pilot puncture 50 in a host leaflet 10, utilizing various examples of a stabilized tissue perforating system 200 or 300 disclosed above, can be accomplished by a perforating component of the system 200 or 300 that can be part of: the helical anchor head 250, the hollow needle 270, and/or the guidewire 80. Specifically, any of the methods described above with respect to Figs. 6A-6K, 9A-9M, 29A-29Q, or 3OA-3OI, while illustrated to include a step of forming a pilot puncture 50 utilizing a needle 270, can be modified such that the pilot puncture 50 is formed by any other perforating component disclosed above. In some examples, the perforating component of a system 200 or 300 is a sharp needle tip 278 at a needle head 274 of the needle 270. In some examples, the perforating component of a system 200 or 300 is a gradually increasing width WT of the one or more helical turn 256 of a helical anchor head 250. In some examples, the perforating component of a system 200 or 300 is a helical slot 260 of the helical anchor head 250 tapering towards the slot proximal end 262. In some examples, the perforating component of a system 200 or 300 is a thinned wall portion 259 of the helical anchor head 250, terminating at the slot proximal end 262. In some examples, the perforating component of a system 200 or 300 is a sharp tip 82 of the guidewire 80. In some examples, the perforating component of a system 200 or 300 is an RF energy conducting tip 82 of the guidewire 80. In some examples, a system 200 or 300 can include a combination of more than one perforating component of any of the examples described above.

[0384] While a valve-expanding balloon 296 is described above and illustrated for expanding a pilot puncture 50 to form a leaflet opening 52, it is to be understood that other types of expansion members can be used instead of a balloon 296 in any of the methods and/or systems described herein. For example, U.S. Provisional Application No. 63/335,739, which is incorporated herein by reference in its entirety, describes an expandable frame that can be used instead of a valve-expanding balloon.

[0385] Any of the tools, devices, apparatuses, etc. herein can be sterilized (for example, with heat, radiation, and/or chemicals, etc.) to ensure they are safe for use with patients, and any of the methods herein can include sterilization of the associated assembly, device, apparatus, etc. as one of the steps of the method. Examples of radiation for use in sterilization include, without limitation, gamma radiation and ultra-violet radiation. Examples of chemicals for use in sterilization include, without limitation, ethylene oxide and hydrogen peroxide.

Some Examples of the Disclosed Implementations

[0386] Some examples of above-described implementations are enumerated below. It should be noted that one feature of an example in isolation or more than one feature of the example taken in combination and, optionally, in combination with one or more features of one or more examples below are examples also falling within the disclosure of this application.

[0387] Example 1. A stabilized tissue modification system, comprising: an anchor device comprising: an anchor shaft defining an anchor shaft lumen; a helical anchor head coupled to the anchor shaft, the helical anchor defining an anchor channel in fluid communication with the anchor shaft lumen, the helical anchor head comprising: an anchor proximal end; and at least one helical slot extending distally from the anchor proximal end, the at least one helical slot defining one or more helical turns, wherein a distal- most helical turn of the one or more helical turns defines a tip portion terminating at an anchor tip; a balloon catheter defining a balloon catheter lumen; and a hole-dilating balloon mounted on the balloon catheter and in fluid communication with the balloon catheter lumen, the hole-dilating balloon configured to transition between deflated and inflated states thereof; wherein the anchor shaft is a flexible torque shaft configured to rotate around a central axis thereof, such that when the anchor shaft is rotated, the helical anchor head is configured to rotate therewith.

[0388] Example 2. The system of any example herein, particularly of example 1, wherein the anchor shaft is configured to be axially advanced over a guidewire, and wherein the balloon catheter is configured to be axially advanced over the same guidewire.

[0389] Example 3. The system of any example herein, particularly of any one of examples 1 to 8, wherein the anchor tip is a sharp tip, configured to penetrate through a target tissue during rotational movement of the helical anchor.

[0390] Example 4. The system of any example herein, particularly of example 3, wherein the one or more helical turns define a turn width in a direction parallel to the central axis, and wherein the turn width gradually increases from the anchor tip towards the anchor proximal end.

[0391] Example 5. The system of any example herein, particularly of example 3 or 4, wherein the helical anchor head defines a non-uniform pitch that gets narrower in a proximal direction.

[0392] Example 6. The system of any example herein, particularly of any one of examples 3 to 5, wherein the helical slot has a width that tapers towards a slot proximal end thereof.

[0393] Example 7. The system of any example herein, particularly of any one of examples 3 to 6, wherein the helical anchor head comprises a thinned wall portion terminating at a slot proximal end of the helical slot. [0394] Example 8. The system of any example herein, particularly of any one of examples 3 to 7, wherein the tip portion further comprises a cutting edge opposite to an inner side of the tip portion.

[0395] Example 9. The system of any example herein, particularly of example 8, wherein the inner side of the tip portion is curved.

[0396] Example 10. The system of any example herein, particularly of example 8 or 9, wherein a length of the cutting edge spans at least 90° from the anchor tip.

[0397] Example 1 1 . The system of any example herein, particularly of example 8 or 9, wherein a length of the cutting edge spans at least 180° from the anchor tip.

[0398] Example 12. The system of any example herein, particularly of any one of examples 8 to 11, wherein a thickening length of the tip portion spans at least 90° from the anchor tip.

[0399] Example 13. The system of any example herein, particularly of any one of examples 8 to 11, wherein a thickening length of the tip portion spans at least 180° from the anchor tip.

[0400] Example 14. The system of any example herein, particularly of any one of examples 10 to 13, wherein the helical anchor head is configured to form a pilot opening in the target tissue by gradually increasing a circumferential length of a cut formed in the target tissue during rotational movement of the helical anchor head through the target tissue.

[0401] Example 15. The system of any example herein, particularly of example 14, wherein inflation of the hole-dilating balloon, while positioned inside the pilot opening, is configured to expand the pilot opening to form a leaflet opening.

[0402] Example 16. The system of any example herein, particularly of any one of examples 1 to 15, wherein the at least one helical slot comprises a plurality of helical slots, and wherein the one or more helical turns comprise a plurality of sets of helical turns.

[0403] Example 17. The system of any example herein, particularly of example 16, wherein the plurality of sets of helical turns are arranged in an alternating configuration along a length of the helical anchor.

[0404] Example 18. The system of any example herein, particularly of any one of examples 1 to 17, wherein the helical anchor head is integrally formed with the anchor shaft.

[0405] Example 19. The system of any example herein, particularly of any one of examples 1 to 18, wherein the anchor shaft comprises a plurality of circumferential bands arranged between a plurality of circumferential slits of the anchor shaft.

[0406] Example 20. The system of any example herein, particularly of any one of examples 1 to 17, wherein the anchor shaft comprises a helical hollow strand tube. [0407] Example 21. The system of any example herein, particularly of example 20, wherein the helical hollow strand tube is a single layer helical hollow strand tube.

[0408] Example 22. The system of any example herein, particularly of any one of examples 1 to 21, further comprising a dilator attached to a dilator shaft extending proximally therefrom. [0409] Example 23. The system of any example herein, particularly of example 22, wherein the dilator comprises a dilator tapering portion.

[0410] Example 24. The system of any example herein, particularly of example 22 or 23, wherein the dilator shaft extends through the balloon catheter lumen.

[0411] Example 25. The system of any example herein, particularly of any one of examples 22 to 24, wherein the hole-dilating balloon is attached at a proximal end thereof to the balloon catheter, and at a distal end of the hole-dilating balloon to the dilator.

[0412] Example 26. The system of any example herein, particularly of any one of examples 1 to 25, wherein the one or more helical turns define a rectangular cross-sectional shape.

[0413] Example 27. The of any example herein, particularly of example 26, wherein the helical anchor head is cut from a tube.

[0414] Example 28. The system of any example herein, particularly of example 26 or 27, wherein a radius of curvature of an inner side of the tip portion is greater than the inner radius of the helical anchor head.

[0415] Example 29. The system of any example herein, particularly of example 28, wherein a radius of curvature of an outer side of the tip portion is smaller than an outer radius of the helical anchor head.

[0416] Example 30. The system of any example herein, particularly of example 28 or 29, wherein an intersection edge between the inner side and a distally-facing axial side of the tip portion is rounded.

[0417] Example 31. The system of any example herein, particularly of example 26 or 27, wherein the tip portion comprises three planar facets intersecting with each other.

[0418] Example 32. The system of any example herein, particularly of example 31, wherein the three planar facets comprise a primary facet and two secondary facets symmetrically angled relative to the primary facet on opposite sides thereof.

[0419] Example 33. The system of any example herein, particularly of any one of examples 1 to 25, wherein the one or more helical turns define a circular cross-sectional shape.

[0420] Example 34. The system of any example herein, particularly of example 33, wherein the tip portion is conical. [0421] Example 35. The system of any example herein, particularly of any one of examples 1 to 34, further comprising a needle defining a needle lumen, the needle extending through the anchor shaft lumen.

[0422] Example 36. The system of any example herein, particularly of example 35, wherein the needle is configured to pierce a target tissue to form a pilot puncture in the target tissue.

[0423] Example 37. The system of any example herein, particularly of any one of examples 35 to 36, wherein the needle comprises a needle head configured to extend through the anchor channel.

[0424] Example 38. The system of any example herein, particularly of example 37, wherein the needle head comprises a needle sharp tip.

[0425] Example 39. The system of any example herein, particularly of example 37 or 38, wherein the needle head comprises an angled surface.

[0426] Example 40. The system of any example herein, particularly of any one of examples 37 to 39, wherein the needle is axially movable relative to the anchor shaft.

[0427] Example 41. The system of any example herein, particularly of example 40, wherein the needle further comprises a needle shaft proximally extending from the needle head.

[0428] Example 42. The system of any example herein, particularly of example 41, wherein the needle shaft comprises a plurality of circumferential slits.

[0429] Example 43. The system of any example herein, particularly of example 42, wherein the needle shaft comprises a needle shaft distal portion comprising the plurality of circumferential slits.

[0430] Example 44. The system of any example herein, particularly of example 43, wherein the needle shaft further comprises a needle shaft proximal portion extending proximally from the needle shaft distal portion.

[0431] Example 45. The system of any example herein, particularly of example 44, wherein the needle shaft proximal portion is devoid of circumferential slits.

[0432] Example 46. The system of any example herein, particularly of example 43 or 44, wherein the proximal portion of the needle shaft comprises a polymeric material.

[0433] Example 47. The system of any example herein, particularly of any one of examples 40 to 46, wherein the anchor shaft further comprises a movement limiting segment defining a limiting segment channel which is continuous with the anchor shaft lumen, and wherein the needle comprises a stopper extending radially outward therefrom, the stopper configured to axially translate within the limiting segment channel. [0434] Example 48. The system of any example herein, particularly of example 47, wherein the needle is axially movable relative to the movement limiting segment.

[0435] Example 49. The system of any example herein, particularly of example 47 or 48, wherein the anchor device comprises a distal inner step.

[0436] Example 50. The system of any example herein, particularly of example 49, wherein the distal inner step is formed in the movement limiting segment and is proximal to the helical anchor head.

[0437] Example 51. The system of any example herein, particularly of example 49, wherein the distal inner step is formed by a proximal surface of the helical anchor head.

[0438] Example 52. The system of any example herein, particularly of any one of examples 49 to 51 , wherein the stopper is proximal to the distal inner step.

[0439] Example 53. The system of any example herein, particularly of any one of examples 49 or 52, wherein the needle is configured to move between a first position and a second position, wherein the stopper is in contact with the distal inner step in the second position, and wherein the needle, in the first position, is proximal to the needle in the second position.

[0440] Example 54. The system of any example herein, particularly of example 53, wherein distally-oriented movement of the needle is prevented when the needle is in the second position. [0441] Example 55. The system of any example herein, particularly of example 54, wherein, in the second position, the needle head is positioned in the anchor channel, but does not extend distally past the anchor tip.

[0442] Example 56. The system of any example herein, particularly of any one of examples 53 to 55, wherein the movement limiting segment further comprises a proximal inner step.

[0443] Example 57. The system of any example herein, particularly of example 56, wherein the stopper is in contact with the proximal inner step in the first position.

[0444] Example 58. The system of any example herein, particularly of example 57, wherein proximally-oriented movement of the needle is prevented when the needle is in the first position.

[0445] Example 59. The system of any example herein, particularly of any one of examples 47 to 58, wherein the helical anchor head is distal to the movement limiting segment.

[0446] Example 60. The system of any example herein, particularly of any one of examples 37 to 39, wherein the needle is axially immovable relative to the anchor shaft.

[0447] Example 61. The system of any example herein, particularly of example 60, wherein the needle and the anchor shaft are configured to simultaneously move in the axial direction. [0448] Example 62. The system of any example herein, particularly of example 60 or 61, wherein the needle head extends through the anchor channel without extending distally past the anchor tip.

[0449] Example 63. The system of any example herein, particularly of any one of examples 60 to 62, wherein the anchor shaft is rotatable around the needle, and wherein the needle is non-rotatable around the central axis.

[0450] Example 64. The system of any example herein, particularly of any one of examples 60 to 63, further comprising a bearing disposed between the needle and the anchor shaft.

[0451] Example 65. The system of any example herein, particularly of any one of examples 37 to 58, wherein the balloon catheter is axially movable relative to the anchor shaft.

[0452] Example 66. The system of any example herein, particularly of example 65, wherein the balloon catheter and the anchor shaft are coaxial.

[0453] Example 67. The system of any example herein, particularly of example 65 or 66, wherein the balloon catheter extends through the anchor shaft lumen.

[0454] Example 68. The system of any example herein, particularly of any one of examples 65 to 67, further comprising a delivery shaft disposed between the balloon catheter and the anchor shaft.

[0455] Example 69. The system of any example herein, particularly of example 68, wherein the delivery shaft is movable relative to the balloon catheter.

[0456] Example 70. The system of any example herein, particularly of example 68 or 69, wherein the delivery shaft is movable relative to the anchor shaft.

[0457] Example 71. The system of any example herein, particularly of any one of examples 68 to 70, wherein the delivery shaft comprises a plurality of circumferential bands arranged between a plurality of circumferential slits of the delivery shaft.

[0458] Example 72. The system of any example herein, particularly of any one of examples 68 to 71 , wherein the delivery shaft comprises an atraumatic distal end.

[0459] Example 73. The system of any example herein, particularly of any one of examples 68 to 72, wherein the delivery shaft is configured to extend around the hole-dilating balloon.

[0460] Example 74. The system of any example herein, particularly of any one of examples 65 to 73, wherein the needle is axially movable relative to the balloon catheter.

[0461] Example 75. The system of any example herein, particularly of any one of examples 35 to 59, further comprising an outer shaft defining an outer shaft lumen, wherein the anchor shaft is axially movable relative to the outer shaft lumen. [0462] Example 76. The system of any example herein, particularly of example 75, wherein the anchor shaft is extendable through the outer shaft lumen.

[0463] Example 77. The system of any example herein, particularly of example 75 or 76, wherein the balloon catheter is axially movable relative to the outer shaft.

[0464] Example 78. The system of any example herein, particularly of any one of examples 75 to 77, wherein the balloon catheter is extendable through the outer shaft lumen.

[0465] Example 79. The system of any example herein, particularly of any one of examples 75 to 78, wherein the outer shaft further comprises a capsule terminating at a capsule distal end portion.

[0466] Example 80. The system of any example herein, particularly of example 79, wherein the capsule defines a capsule proximal step.

[0467] Example 81. The system of any example herein, particularly of example 80, wherein an inner diameter of the capsule is greater than an outer diameter of the helical anchor.

[0468] Example 82. The system of any example herein, particularly of example 81, wherein a diameter of the outer shaft lumen along a length of the outer shaft extending proximally from the capsule proximal step, is greater than an outer diameter of the anchor shaft, and smaller than the outer diameter of the helical anchor.

[0469] Example 83. The system of any example herein, particularly of any one of examples 75 to 82, wherein the outer shaft is coupled to, and distally extends from, a handle of a steerable delivery apparatus.

[0470] Example 84. The system of any example herein, particularly of example 83, wherein the handle of the steerable delivery apparatus further comprises a valve assembly proximal to the outer shaft.

[0471] Example 85. The system of any example herein, particularly of example 84, wherein the valve assembly comprises a cross-slit valve, a disc valve distal to the cross-slit valve, and a hemostatic valve distal to the disc valve.

[0472] Example 86. The system of any example herein, particularly of example 85, wherein the cross-slit valve comprises a semi-spherical portion and define an aperture.

[0473] Example 87. The system of any example herein, particularly of example 86, wherein the disc valve comprises a circulatory body portion and an aperture aligned with the aperture of the cross-slit valve.

[0474] Example 88. The system of any example herein, particularly of example 87, wherein the hemostatic valve comprises a pair of flaps defining elongated slits therebetween. [0475] Example 89. The system of any example herein, particularly of any one of examples 83 to 88, wherein the anchor device and the needle extend through a delivery catheter, and wherein the delivery catheter is configured to be insertable, through a rear port of the handle of the steerable delivery apparatus, into the handle of the steerable delivery apparatus and the outer shaft lumen.

[0476] Example 90. The system of any example herein, particularly of example 89, wherein the delivery catheter, the anchor device, and the needle, are coupled to and extend distally from a handle of a perforation apparatus.

[0477] Example 91. The system of any example herein, particularly of example 90, wherein the handle of the perforation apparatus comprises an anchor control knob configured to control rotational movement of the anchor device, and a needle advancement knob configured to control axial movement of the needle.

[0478] Example 92. The system of any example herein, particularly of example 90, wherein the handle of the perforation apparatus comprises a first handle portion and a second handle portion releasably coupled to the first handle portion, wherein the delivery catheter is rigidly attached to the first handle portion, and wherein the anchor device and the needle are coupled to the second handle portion.

[0479] Example 93. The system of any example herein, particularly of any one of examples 83 to 88, wherein the balloon catheter is configured to be insertable, through a rear port of the handle of the steerable delivery apparatus, into the handle of the steerable delivery apparatus and the outer shaft lumen.

[0480] Example 94. The system of any example herein, particularly of example 92, wherein the balloon catheter is configured to be insertable into, and extendable through, the delivery catheter.

[0481] Example 95. The system of any example herein, particularly of any one of examples 1 to 94, wherein the hole-dilating balloon comprises a first balloon portion and a second balloon portion, each configured to expand to a different maximum diameter.

[0482] Example 96. The system of any example herein, particularly of example 95, wherein the maximum diameter of the first balloon portion is greater than the maximum diameter of the second balloon portion.

[0483] Example 97. The system of any example herein, particularly of example 96, wherein the maximum diameter of the first balloon portion is greater than 20 mm.

[0484] Example 98. The system of any example herein, particularly of example 96 or 97, wherein the maximum diameter of the second balloon portion is not greater than 12 mm. [0485] Example 99. The system of any example herein, particularly of any one of examples 1 to 98, further comprising a guidewire extendable through the anchor channel.

[0486] Example 100. The system of any example herein, particularly of example 99, wherein the guidewire comprises a sharp tip configured to penetrate through a target tissue.

[0487] Example 101. The system of any example herein, particularly of example 99, further comprising an RF energy source coupled to the guidewire and configured to provide RF energy to a tip of the guidewire.

[0488] Example 102. A method comprising: advancing an anchor device of a stabilized tissue modification system, over a guidewire, to a host valvular structure, wherein the anchor device comprises an anchor shaft and a helical anchor head distal to the anchor shaft; and securing the helical anchor head to a host leaflet of the host valvular structure.

[0489] Example 103. The method of any example herein, particularly of example 102, wherein the securing the helical anchor head comprises rotating the anchor shaft in a first rotational direction, thereby causing the helical anchor head to rotate therewith.

[0490] Example 104. The method of any example herein, particularly of any one of examples 102 to 103, wherein the securing the helical anchor head comprises penetrating the host leaflet by an anchor tip of the helical anchor head.

[0491] Example 105. The method of any example herein, particularly of any one of examples 102 to 104, wherein the helical anchor head comprises a plurality of sets of helical turns.

[0492] Example 106. The method of any example herein, particularly of example 105, wherein the plurality of sets of helical turns are arranged in an alternating configuration along a length of the helical anchor head.

[0493] Example 107. The method of any example herein, particularly of any one of examples 102 to 106, further comprising: forming, with a perforating component of the stabilized tissue modification system, a pilot puncture in the host leaflet; passing the guidewire through the pilot puncture; releasing the helical anchor head from the host leaflet; positioning a hole-dilating balloon, mounted on a balloon catheter of the stabilized tissue modification system, inside the pilot puncture, in a radially deflated state of the holedilating balloon; and inflating the hole-dilating balloon to expand the pilot puncture and form a leaflet opening within the host leaflet. [0494] Example 108. The method of any example herein, particularly of example 107, wherein the releasing the helical anchor head from the host leaflet comprises rotating the anchor shaft in a second rotational direction which is opposite to the first rotational direction.

[0495] Example 109. The method of any example herein, particularly of any one of examples 107 or 108, wherein the helical anchor head comprises a helical slot having a slot proximal end.

[0496] Example 110. The method of any example herein, particularly of example 109, wherein the securing the helical anchor head comprises retaining the host leaflet within the helical slot.

[0497] Example 111. The method of any example herein, particularly of example 109 or 110, wherein the perforating component comprises a portion of the helical slot that tapers towards the slot proximal end.

[0498] Example 112. The method of any example herein, particularly of any one of examples 109 to 111, wherein the perforating component comprises a thinned wall portion of the helical anchor head, the thinned wall portion terminating at the slot proximal end.

[0499] Example 113. The method of any example herein, particularly of any one of examples 107 to 109, wherein the perforating component comprises a gradually increasing width, in a proximal direction, of one or more helical turns of the helical anchor head.

[0500] Example 114. The method of any example herein, particularly of any one of examples 107 to 109, wherein the perforating component comprises a cutting edge extending along a tip portion of a distal-most helical turn of the helical anchor head.

[0501] Example 115. The method of any example herein, particularly of example 114, wherein a length of the cutting edge spans at least 90° of the distal-most helical turn.

[0502] Example 116. The method of any example herein, particularly of example 114, wherein a length of the cutting edge spans at least 180° of the distal-most helical turn.

[0503] Example 117. The method of any example herein, particularly of any one of examples 111 to 116, wherein the forming the pilot puncture comprises forming a cut, through the host leaflet, which gradually increases in length in the circumferential direction, during rotational movement of the helical anchor head.

[0504] Example 118. The method of any example herein, particularly of example 117, wherein the formed cut spans less than 360° around a central axis of the helical anchor head.

[0505] Example 119. The method of any example herein, particularly of example 118, wherein the formed cut spans more than 180° around the central axis of the helical anchor head. [0506] Example 120. The method of any example herein, particularly of any one of examples 107 to 108, wherein the perforating component comprises a distal tip of the guidewire.

[0507] Example 121. The method of any example herein, particularly of example 120, wherein the guidewire tip is a sharp guidewire tip, and wherein forming the pilot puncture comprises perforating the host leaflet by the sharp guidewire tip.

[0508] Example 122. The method of any example herein, particularly of example 120, wherein the forming the pilot puncture comprises applying RF energy to the guidewire tip.

[0509] Example 123. The method of any example herein, particularly of any one of examples 107 to 121, wherein the stabilized tissue modification system further comprises a needle having a needle head, and wherein the perforating component is a sharp needle tip of the needle head. [0510] Example 124. The method of any example herein, particularly of example 123, wherein the forming the pilot puncture comprises perforating the host leaflet by the needle head.

[0511] Example 125. The method of any example herein, particularly of example 123 or 124, wherein the securing the helical anchor head to the host leaflet further comprises keeping the needle head proximal to the host leaflet.

[0512] Example 126. The method of any example herein, particularly of any one of examples 123 to 125, wherein the forming the pilot puncture comprises extending the needle head through an anchor channel defined by the helical anchor head.

[0513] Example 127. The method of any example herein, particularly of example 126, wherein the forming the pilot puncture comprises positioning the needle head inside the anchor channel, such that the needle head does not extend distally beyond the helical anchor head.

[0514] Example 128. The method of any example herein, particularly of example 127, wherein the forming the pilot puncture comprises moving the needle from a first position, in which the needle head is proximal to the host leaflet, to a second position, in which the needle head is advanced through the host leaflet and the anchor channel.

[0515] Example 129. The method of any example herein, particularly of example 128, wherein the moving the needle to the second position comprises advancing a stopper extending radially outward from the needle, to contact with a distal inner step of a movement limiting segment of the anchor shaft.

[0516] Example 130. The method of any example herein, particularly of any one of examples 123 to 129, wherein the forming the pilot puncture comprises distally advancing the needle through an anchor shaft lumen defined by the anchor shaft. [0517] Example 131. The method of any example herein, particularly of any one of examples 123 to 130, wherein the passing the guidewire through the pilot puncture comprises distally advancing the guidewire through a needle lumen defined by the needle.

[0518] Example 132. The method of any example herein, particularly of any one of examples 123 to 131, further comprising, after the forming the pilot puncture, proximally pulling the needle head from the host leaflet, while maintaining the guidewire extending through the pilot puncture.

[0519] Example 133. The method of any example herein, particularly of example 1 2, further comprising, subsequent to the proximally pulling the needle head from the host leaflet and prior to positioning the hole-dilating balloon in the pilot puncture, retrieving the needle.

[0520] Example 134. The method of any example herein, particularly of any one of examples 107 to 133, further comprising, subsequent to releasing the helical anchor head from the host leaflet and prior to positioning the hole-dilating balloon in the pilot puncture, retrieving the helical anchor head while maintaining the guidewire extending through the pilot puncture.

[0521] Example 135. The method of any example herein, particularly of example 134, wherein the positioning the hole-dilating balloon inside the pilot puncture comprises, subsequent to the retrieving the helical anchor head, advancing the balloon catheter, over the guidewire, towards the host leaflet.

[0522] Example 136. The method of any example herein, particularly of example 135, wherein the advancing a helical anchor head towards the host valvular structure comprises advancing an outer shaft, defining an outer shaft lumen through which the anchor shaft extends, towards the host valvular structure, and wherein the retrieving the helical anchor comprises pulling the helical shaft through the outer shaft lumen, while maintaining the outer shaft in position.

[0523] Example 137. The method of any example herein, particularly of example 136, wherein the advancing the balloon catheter towards the host leaflet comprises advancing the balloon catheter through the outer shaft lumen.

[0524] Example 138. The method of any example herein, particularly of example 135 or 136, wherein the advancing the outer shaft towards the host valvular structure comprises contacting the host leaflet by a distal end portion of the outer shaft.

[0525] Example 139. The method of any example herein, particularly of any one of examples 107 to 132, wherein the positioning the hole-dilating balloon inside the pilot puncture comprises advancing the balloon catheter through the anchor shaft. [0526] Example 140. The method of any example herein, particularly of example 139, further comprising, prior to the releasing the helical anchor head from the host leaflet, advancing a delivery shaft disposed between the balloon catheter and the anchor shaft, towards the host leaflet.

[0527] Example 141. The method of any example herein, particularly of example 140, wherein the advancing the delivery shaft towards the host leaflet is performed prior to the securing the helical anchor head to a host leaflet.

[0528] Example 142. The method of any example herein, particularly of example 141 , wherein the advancing the delivery shaft towards the host leaflet comprises contacting the host leaflet by a distal end portion of the delivery shaft.

[0529] Example 143. The method of any example herein, particularly of any one of examples 140 to 142, further comprising, subsequent to the releasing the helical anchor head from the host leaflet and prior to the positioning the hole-dilating balloon inside the pilot puncture, proximally pulling the delivery shaft so as to expose the hole-dilating balloon.

[0530] Example 144. The method of any example herein, particularly of any one of examples 139 to 143, wherein the advancing a helical anchor head towards the host valvular structure comprises maintaining the helical anchor head concealed inside a capsule of an outer shaft through which the anchor shaft extends.

[0531] Example 145. The method of any example herein, particularly of example 144, further comprising, prior to the securing the helical anchor head to the host leaflet, exposing the helical anchor out of the capsule.

[0532] Example 146. The method of any example herein, particularly of any one of examples 107 to 145, further comprising, subsequent to the forming the pilot puncture and prior to the positioning the hole-dilating balloon inside the pilot puncture, passing a dilator through the pilot puncture, thereby expanding the pilot puncture.

[0533] Example 147. The method of any example herein, particularly of example 146, wherein the dilator is distal to the hole-dilating balloon.

[0534] Example 148. The method of any example herein, particularly of example 146 or 147, wherein the dilator is attached to a dilator shaft extending proximally therefrom, through a lumen of the balloon catheter.

[0535] Example 149. The method of any example herein, particularly of any one of examples 146 to 148, wherein the dilator comprises a dilator tapering portion. [0536] Example 150. The method of any example herein, particularly of any one of examples 146 to 149, wherein the hole-dilating balloon is attached at a proximal end thereof to the balloon catheter, and at a distal end of the hole-dilating balloon to the dilator.

[0537] Example 151. The method of any example herein, particularly of any one of examples 146 to 150, wherein the passing the dilator through the pilot puncture comprises maintaining the helical anchor head secured to the host leaflet.

[0538] Example 152. The method of any example herein, particularly of any one of examples 107 to 151 , further comprising, subsequent to the inflating the balloon, deflating the balloon.

[0539] Example 153. The method of any example herein, particularly of any one of examples 107 to 152, further comprising, subsequent to the forming the leaflet opening, positioning a guest prosthetic valve in a radially compressed state thereof within the host valvular structure, and radially expanding the guest prosthetic valve.

[0540] Example 154. The method of any example herein, particularly of example 153, wherein the positioning the guest prosthetic valve within the host valvular structure comprises positioning the guest prosthetic valve within the leaflet opening.

[0541] Example 155. The method of any example herein, particularly of example 153, wherein the positioning the guest prosthetic valve within the host valvular structure comprises positioning the guest prosthetic valve between host leaflets of the host valvular structures.

[0542] Example 156. The method of any example herein, particularly of any one of examples 153 to 155, wherein the radially expanding the guest prosthetic valve comprises inflating a valve-expanding balloon over which the guest prosthetic valve is disposed.

[0543] Example 157. The method of any example herein, particularly of any one of examples 153 to 155, wherein the radially expanding the guest prosthetic valve comprises actuating a mechanical actuator of the guest prosthetic valve.

[0544] Example 158. The method of any example herein, particularly of any one of examples 153 to 155, wherein the guest prosthetic valve is a self-expandable prosthetic valve, and wherein radially expanding the guest prosthetic valve comprises removing a restraint from around the guest prosthetic valve.

[0545] Example 159. The method of any example herein, particularly of any one of examples 123 to 133, further comprising, before the advancing the anchor device, advancing an outer shaft of a steerable delivery apparatus of the stabilized tissue modification system towards the host valvular structure, wherein the outer shaft defines an outer shaft lumen and distally extends from a handle of the steerable delivery apparatus, and wherein the handle of the steerable delivery apparatus comprises a rear port. [0546] Example 160. The method of any example herein, particularly of example 159, wherein the advancing the outer shaft comprises adjusting the curvature of a distal section of the outer shaft by a knob of the handle of the steerable delivery apparatus.

[0547] Example 161. The method of any example herein, particularly of example 159 or 160, wherein the handle of the steerable delivery apparatus further comprises a valve assembly proximal to the outer shaft, the valve assembly comprising a cross-slit valve, a disc valve distal to the cross-slit valve, and a hemostatic valve distal to the disc valve.

[0548] Example 162. The method of any example herein, particularly of any one of examples 159 to 161, further comprising, before the advancing the outer shaft, inserting an introducer that includes an introducer shaft and a tapered distal portion, through the rear port of the handle of the steerable delivery apparatus, into the handle of the steerable delivery apparatus and the outer shaft lumen.

[0549] Example 163. The method of any example herein, particularly of example 162, wherein the advancing the outer shaft comprises advancing the outer shaft over the introducer, while the tapered distal portion of the introducer distally extends out of the outer shaft.

[0550] Example 164. The method of any example herein, particularly of example 163, further comprising, after the advancing the outer shaft, retrieving the dilator out of the steerable delivery apparatus while maintaining the outer shaft in situ.

[0551] Example 165. The method of any example herein, particularly of example 164, further comprising, after the retrieving the dilator, inserting a delivery catheter of a perforation apparatus of the stabilized tissue modification system, through the rear port of the handle of the steerable delivery apparatus, into the handle of the steerable delivery apparatus and the outer shaft lumen, wherein the perforation apparatus comprises the anchor device and the needle extending through the delivery catheter.

[0552] Example 166. The method of any example herein, particularly of example 165, wherein the advancing the anchor device comprises advancing the delivery catheter through the outer shaft.

[0553] Example 167. The method of any example herein, particularly of example 165 or 166, wherein the delivery catheter, the anchor device, and the needle, are coupled to and extend distally from a handle of a perforation apparatus.

[0554] Example 168. The method of any example herein, particularly of any one of examples 165 to 167, further comprising, after the releasing the helical anchor head and before the positioning the hole-dilating balloon, retrieving the perforation apparatus out of the steerable delivery apparatus while maintaining the outer shaft in situ. [0555] Example 169. The method of any example herein, particularly of example 168, further comprising, after the retrieving the perforation apparatus and before the positioning the holedilating balloon, inserting the balloon catheter, comprised in a dilation apparatus of the stabilized tissue modification system, through the rear port of the handle of the steerable delivery apparatus, into the handle of the steerable delivery apparatus and the outer shaft lumen. [0556] Example 170. The method of any example herein, particularly of example 169, wherein the positioning the hole-dilating balloon comprises advancing the balloon catheter through the outer shaft.

[0557] Example 171. The method of any example herein, particularly of example 167, wherein handle of the perforation apparatus comprises a first handle portion and a second handle portion releasably coupled to the first handle portion, wherein the delivery catheter is rigidly attached to the first handle portion, and wherein the anchor device and the needle are coupled to the second handle portion.

[0558] Example 172. The method of any example herein, particularly of example 171, further comprising, after the releasing the helical anchor head and before the positioning the holedilating balloon, releasing the second handle portion from the first handle portion, and retrieving the anchor device and the needle out of the delivery catheter while maintaining the delivery catheter in situ.

[0559] Example 173. The method of any example herein, particularly of example 172, further comprising, after the retrieving the anchor device and the needle and before the positioning the hole-dilating balloon, inserting the balloon catheter, comprised in a dilation apparatus of the stabilized tissue modification system, through the second handle portion, into the delivery catheter.

[0560] Example 174. The method of any example herein, particularly of example 173, wherein the positioning the hole-dilating balloon comprises advancing the balloon catheter through the delivery catheter.

[0561] Example 175. The method of any example herein, particularly of any one of examples 107 to 158, wherein the host valvular structure is a native valvular structure of native heart valve.

[0562] Example 176. The method of any example herein, particularly of any one of examples 107 to 175, wherein the host valvular structure is a valvular structure of previously implanted prosthetic valve that is implanted within a native heart valve.

[0563] Example 177. The method of any example herein, particularly of any one of examples 107 to 176, wherein the inflating the hole-dilating to expand the pilot puncture and form the leaflet opening within the host leaflet comprises inflating a first hole-dilating balloon, mounted on a first balloon catheter, to expand a first pilot puncture and form a first leaflet opening in a first host leaflet, and wherein the method further comprises: deflating and retrieving the first hole-dilating balloon; advancing the anchor device to the host valvular structure; securing the helical anchor head to a second host leaflet of the host valvular structure; forming, with the perforating component, a second pilot puncture in the second host leaflet; releasing the helical anchor head from the second host leaflet; positioning a second hole-dilating balloon, mounted on a second balloon catheter of the stabilized tissue modification system, inside the second pilot puncture, in a radially deflated state of the second hole-dilating balloon; and inflating the second hole-dilating balloon to expand the second pilot puncture and form a second leaflet opening within the second host leaflet.

[0564] Example 178. The method of any example herein, particularly of example 177, wherein the first hole-dilating balloon is configured to expand to a maximum diameter which is greater than a maximum diameter to which the second hole-dilating balloon is configured to expand.

[0565] Example 179. The method of claim 178, wherein the maximum diameter of the first hole-dilating balloon is greater than 20 mm.

[0566] Example 180. The method of any example herein, particularly of example 178 or 179, wherein the maximum diameter of the second hole-dilating balloon is not greater than 12 mm. [0567] Example 181. The method of any example herein, particularly of any one of examples 107 to 176, wherein the positioning the hole-dilating balloon inside the pilot puncture comprises positioning a first balloon portion of the hole-dilating balloon inside a first pilot puncture of a first host leaflet, wherein inflating the hole-dilating to expand the pilot puncture and form the leaflet opening within the host leaflet comprises inflating a hole-dilating balloon to expand the first pilot puncture and form a first leaflet opening in a first host leaflet, and wherein the method further comprises: deflating and retrieving the hole-dilating balloon; advancing the anchor device to the host valvular structure; securing the helical anchor head to a second host leaflet of the host valvular structure; forming, with the perforating component, a second pilot puncture in the second host leaflet; releasing the helical anchor head from the second host leaflet; positioning a second balloon portion of the hole-dilating balloon inside the second pilot puncture, in a radially deflated state of the hole-dilating balloon; and inflating the hole-dilating balloon to expand the second pilot puncture and form a second leaflet opening within the second host leaflet.

[0568] Example 182. The method of any example herein, particularly of example 181, wherein the first balloon portion is configured to expand to a maximum diameter which is greater than a maximum diameter to which the second balloon portion is configured to expand.

[0569] Example 183. The method of any example herein, particularly of example 182, wherein the maximum diameter of the first balloon portion is greater than 20 mm.

[0570] Example 184. The method of any example herein, particularly of example 182 or 183, wherein the maximum diameter of the second balloon portion is not greater than 12 mm.

[0571] Example 185. The method of any example herein, particularly of any one of examples 175 to 184, wherein the first host leaflet is a right host leaflet, and wherein the second host leaflet is a left host leaflet.

[0572] Example 186. The method of any example herein, particularly of any one of examples 175 to 185, wherein the first leaflet opening is a tear extending to a free edge of the first leaflet, and wherein the second leaflet opening is a bounded hole.

[0573] It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate examples, may also be provided in combination in a single example. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single example, may also be provided separately or in any suitable sub-combination or as suitable in any other described example of the disclosure. No feature described in the context of an example is to be considered an essential feature of that example, unless explicitly specified as such.

[0574] In view of the many possible examples to which the principles of the disclosure may be applied, it should be recognized that the illustrated examples are only preferred examples and should not be taken as limiting the scope. Rather, the scope is defined by the following claims. We therefore claim all that comes within the scope and spirit of these claims.

Claims

1. A stabilized tissue modification system, comprising: an anchor device comprising: an anchor shaft defining an anchor shaft lumen; a helical anchor head coupled to the anchor shaft, the helical anchor head defining an anchor channel in fluid communication with the anchor shaft lumen, the helical anchor head comprising: an anchor proximal end; and at least one helical slot extending distally from the anchor proximal end, the at least one helical slot defining one or more helical turns, wherein a distal- most helical turn of the one or more helical turns defines a tip portion terminating at an anchor tip; a balloon catheter defining a balloon catheter lumen; and a hole-dilating balloon mounted on the balloon catheter and in fluid communication with the balloon catheter lumen, the hole-dilating balloon configured to transition between deflated and inflated states thereof; wherein the anchor shaft is a flexible torque shaft configured to rotate around a central axis thereof, such that when the anchor shaft is rotated, the helical anchor head is configured to rotate therewith.

2. The system of claim 1, wherein the anchor shaft is configured to be axially advanced over a guidewire, and wherein the balloon catheter is configured to be axially advanced over the same guide wire.

3. The system of any one of claims 1 or 2, wherein the helical slot has a width that tapers towards a slot proximal end thereof.

4. The system of any one of claims 1 to 3, wherein the helical anchor head comprises a thinned wall portion terminating at a slot proximal end of the helical slot.

5. The system of any one of claims 1 to 4, wherein the tip portion further comprises a cutting edge opposite to an inner side of the tip portion.

6. The system of claim 5, wherein a length of the cutting edge spans at least 90° from the anchor tip.

7. The system of any one of claims 1 to 6, wherein a thickening length of the tip portion spans at least 90° from the anchor tip.

8. The system of any one of claims 1 to 7, wherein the helical anchor head is configured to form a pilot opening in a target tissue by gradually increasing a circumferential length of a cut formed in the target tissue during rotational movement of the helical anchor head through the target tissue.

9. The system of claim 8, wherein inflation of the hole-dilating balloon, while positioned inside the pilot opening, is configured to expand the pilot opening to form a leaflet opening.

10. The system of any one of claims 1 to 9, further comprising a needle defining a needle lumen, the needle extending through the anchor shaft lumen.

11. The system of claim 10, wherein the needle is axially movable relative to the anchor shaft, wherein the anchor shaft further comprises a movement limiting segment defining a limiting segment channel which is continuous with the anchor shaft lumen, and wherein the needle comprises a stopper extending radially outward therefrom, the stopper configured to axially translate within the limiting segment channel.

12. A method comprising: advancing an anchor device of a stabilized tissue modification system, over a guidewire, to a host valvular structure, wherein the anchor device comprises an anchor shaft and a helical anchor head distal to the anchor shaft; and securing the helical anchor head to a host leaflet of the host valvular structure.

13. The method of claim 12, further comprising: forming, with a perforating component of the stabilized tissue modification system, a pilot opening in the host leaflet; passing the guidewire through the pilot opening; releasing the helical anchor head from the host leaflet; positioning a hole-dilating balloon, mounted on a balloon catheter of the stabilized tissue modification system, inside the pilot opening, in a radially deflated state of the holedilating balloon; and inflating the hole-dilating balloon to expand the pilot opening and form a leaflet opening within the host leaflet.

14. The method of claim 13, wherein the perforating component comprises a cutting edge extending along a tip portion of a distal-most helical turn of the helical anchor head.

15. The method of any one of claims 13 or 14, wherein the forming the pilot opening comprises forming a cut, through the host leaflet, which gradually increases in length in the circumferential direction, during rotational movement of the helical anchor head, and wherein the formed cut spans less than 360° around a central axis of the helical anchor head.

16. The method of any one of claims 13 to 15, wherein the stabilized tissue modification system further comprises a needle having a needle head, wherein the perforating component is a sharp needle tip of the needle head, and wherein the forming the pilot opening comprises perforating the host leaflet by the needle head.

17. The method of any one of claims 13 to 16, further comprising, subsequent to the forming the pilot opening and prior to the positioning the hole-dilating balloon inside the pilot opening, passing a dilator through the pilot opening, thereby expanding the pilot opening.

18. The method of any one of claims 13 to 17, further comprising, subsequent to the forming the leaflet opening, positioning a guest prosthetic valve in a radially compressed state thereof within the host valvular structure, and radially expanding the guest prosthetic valve.

19. The method of any one of claims 13 to 18, further comprising, before the advancing the anchor device, advancing an outer shaft of a steerable delivery apparatus of the stabilized tissue modification system towards the host valvular structure, wherein the outer shaft defines an outer shaft lumen and distally extends from a handle of the steerable delivery apparatus, and wherein the handle of the steerable delivery apparatus comprises a rear port.

20. The method of any one of claims 13 to 19, wherein the inflating the hole-dilating to expand the pilot opening and form the leaflet opening within the host leaflet comprises inflating a first hole-dilating balloon, mounted on a first balloon catheter, to expand a first pilot opening and form a first leaflet opening in a first host leaflet, and wherein the method further comprises: deflating and retrieving the first hole-dilating balloon; advancing the anchor device to the host valvular structure; securing the helical anchor head to a second host leaflet of the host valvular structure; forming, with the perforating component, a second pilot opening in the second host leaflet; releasing the helical anchor head from the second host leaflet; positioning a second hole-dilating balloon, mounted on a second balloon catheter of the stabilized tissue modification system, inside the second pilot opening, in a radially deflated state of the second hole-dilating balloon; and inflating the second hole-dilating balloon to expand the second pilot opening and form a second leaflet opening within the second host leaflet.

91

21. The method of claim 20, wherein the first hole-dilating balloon is configured to expand to a maximum diameter which is greater than a maximum diameter to which the second hole-dilating balloon is configured to expand.

22. A stabilized tissue modification system, comprising: an anchor shaft comprising a helical anchor head, the helical anchor head comprising at least one helical slot defining one or more helical turns: a balloon catheter; a needle; and a hole-dilating balloon mounted on the balloon catheter, the hole-dilating balloon configured to transition between deflated and inflated states thereof.

23. The tissue modification system of claim 22, wherein the anchor shaft is a flexible torque shaft configured to rotate around a central axis thereof, such that when the anchor shaft is rotated, the helical anchor head is configured to rotate therewith.

24. The tissue modification system of claim 22 or claim 23, wherein a distal-most helical turn of the one or more helical turns defines a tip portion terminating at an anchor tip.

25. The tissue modification system of any one of claims 22 to 24, wherein the helical anchor head is configured to form a pilot opening in a target tissue during rotational movement of the helical anchor head through the target tissue.

26. The tissue modification system of claim 25, wherein inflation of the holedilating balloon, while the hold-dilating balloon is positioned inside the pilot opening, is configured to expand the pilot opening to form a leaflet opening.

27. The tissue modification system of any one of claims 22 to 26, wherein the needle extends through the anchor shaft, wherein the needle is axially movable relative to the anchor shaft towards a target tissue to form a pilot opening.