WO2025064478A1 - Steerable delivery systems - Google Patents

Abstract

The present disclosure relates to systems that include a low-profile steerable catheter assembly. In an example, the steerable catheter assembly comprises an inner tube having a slotted portion and a distal end portion, an outer tube having a slotted portion and a distal end portion, and a pull-member having a pull-ring portion and at least one elongated pull-arm proximally extending from the pull-ring portion. The pull-ring portion is affixed to the distal portions of the inner tube and the outer tube. The elongated pull-arm slidingly extends between the slotted portions of the inner tube and the outer tube. The elongated pull-arm has a circumferential width that is greater than its radial thickness, and is configured to bend the steerable catheter assembly when proximally pulled.

Description

STEERABLE DELIVERY SYSTEMS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63/583,915, filed September 20, 2023, which is incorporated by reference herein.

FIELD

[0002] The present disclosure relates to systems and catheter assemblies for delivering prosthetic tools and devices, and to methods and devices for orienting a distal portion of a steerable delivery assembly at a desired direction.

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] One potential technique for mitigating the risk of coronary ostial obstruction involves formation of a hole in one or more leaflets of the host valve (which can be an aortic bioprosthetic valve or a native aortic valve). A guest prosthetic valve can be optionally placed within the leaflet hole and expanded in a manner that tears the host leaflet and prevents it from obstructing the coronary ostium. A flexible delivery catheter can be used to orient an appropriate cutting or lacerating apparatus towards a desired region of treatment, such as toward a left leaflet in vicinity of the left coronary ostium. However, the ability to steer the delivery catheter to a desired orientation, such as orienting a perforating member extendable therethrough towards a desired leaflet of the host valve, can be challenging.

[0007] According to some aspects of the disclosure, there is provided a steerable delivery system comprising a handle and a steerable catheter assembly extending distally from the handle.

[0008] In some examples, the steerable catheter assembly comprises a steerable assembly lumen defining a steerable assembly central longitudinal axis, and an inner tube.

[0009] In some examples, the inner tube of the steerable catheter assembly comprises an inner tube slotted portion, defining an inner tube outer surface oriented away from the steerable assembly central longitudinal axis, and an inner tube distal end portion distal to the inner tube slotted portion.

[0010] In some examples, the steerable catheter assembly comprises an outer tube disposed around the inner tube, and a pull-member.

[0011] In some examples, the outer tube of the steerable catheter assembly comprises an outer tube slotted portion, defining an outer tube inner surface oriented towards the steerable assembly central longitudinal axis, and an outer tube distal end portion distal to the inner tube slotted portion.

[0012] In some examples, the pull-member comprises a pull-ring portion affixed to the inner tube distal end portion and to the outer tube distal end portion.

[0013] In some examples, the pull-member comprises at least one elongated pull-arm extending proximally from the pull-ring portion.

[0014] In some examples, the at least one elongated pull-arm is disposed between the inner tube outer surface and the outer tube inner surface and is axially slidable relative to the inner tube slotted portion and the outer tube slotted portion. [0015] In some examples, the at least one elongated pull-arm defines a circumferential width between arm circumferential ends that is greater than a radial thickness of the at least one elongated pull-arm.

[0016] In some examples, the at least one elongated pull-arm is configured to bend the steerable catheter assembly when the at least one elongated pull-arm is proximally pulled.

[0017] According to some aspects of the disclosure, there is provided a method comprising advancing a steerable delivery system comprising a steerable catheter assembly, over a guidewire, to a target tissue.

[0018] In some examples, the steerable catheter assembly comprises an inner tube, an outer tube disposed around the inner tube, and a pull-member.

[0019] In some examples, the pull member comprises a pull -ring portion affixed to an inner tube distal end portion of the inner tube and to an outer tube distal end portion of the outer tube, and at least one elongated pull-arm extending proximally from the pull-ring portion.

[0020] In some examples, the at least one elongated pull-arm is slidingly movable between and relative to the inner tube and the outer tube.

[0021] In some examples, the method comprises bending a distal portion of the steerable catheter assembly by proximally pulling the at least one elongated pull-arm.

[0022] In some examples, the method \comprises forming, with a perforating member tip of a perforating member extending through a steerable assembly lumen defined by the steerable catheter assembly, a pilot puncture within a target tissue.

[0023] In some examples, the at least one elongated pull-arm defines a circumferential width between arm circumferential ends that is greater than a radial thickness of the at least one elongated pull.

[0024] According to some aspects of the disclosure, there is provided a steerable catheter comprising an inner tube.

[0025] In some examples, the inner tube comprises an inner tube slotted portion, and an inner tube distal end portion distal to the inner tube slotted portion.

[0026] In some examples, the steerable catheter further comprises an outer tube disposed around the inner tube.

[0027] In some examples, the outer tube comprises an outer tube slotted portion, and an outer tube distal end portion distal to the inner tube slotted portion.

[0028] In some examples, the steerable catheter further comprises a pull-member.

[0029] In some examples, the pull-member comprises a pull-ring portion affixed to the inner tube and the outer tube. [0030] In some examples, the pull-member comprises an elongated pull-arm disposed between the inner tube and the outer tube and extending proximally from the pull-ring portion.

[0031] In some examples, the proximal pulling of the elongated pull-arm causes bending of the inner tube slotted portion and the outer tube slotted portion.

[0032] According to some aspects of the disclosure, there is provided a method comprising advancing a steerable delivery system comprising a perforating member and a steerable catheter assembly to a target tissue.

[0033] In some examples, the steerable catheter assembly comprises an inner tube, an outer tube disposed around the inner tube, and a pull-member.

[0034] In some examples, the pull-member comprises a pull-ring portion affixed to distal ends of the inner tube and the outer tube, and an elongated pull-arm extending proximally from the pull-ring portion and disposed between the inner tube and the outer tube.

[0035] In some examples, the method comprises pulling the elongated pull-arm, and advancing the perforating member through a lumen of the steerable delivery system and towards the target tissue to form a puncture within the target tissue.

[0036] 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

[0037] 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:

[0038] Fig. 1 is a sectional view of an aortic root.

[0039] Fig. 2A shows a cross-sectional view of a prosthetic heart valve implanted in the native aortic valve of within the aortic root of Fig. 1, according to an example. [0040] Fig. 2B shows the implanted prosthetic heart valve of Fig. 1A as viewed from the ascending aorta, according to an example.

[0041] Fig. 3 shows a valve-in- valve implantation within the native aortic valve of Fig. 1, according to an example.

[0042] Fig. 4 shows an exemplary steerable delivery system comprising a steerable catheter assembly.

[0043] Fig. 5 shows a sectional view of a delivery assembly being delivered in situ to a treatment site.

[0044] Fig. 6 shows a distal portion of an exemplary steerable delivery catheter, with some components and/or layers thereof removed from view.

[0045] Fig. 7 A shows a perspective view of a distal segment of an exemplary steerable delivery catheter.

[0046] Fig. 7B shows a longitudinal cross-sectional view of the distal segment of the steerable delivery catheter of Fig. 7B.

[0047] Fig. 7C shows a transverse cross-sectional view along line 7C-7C of Fig. 7A.

[0048] Fig. 8 shows a distal portion of an exemplary slotted tube of the steerable delivery catheter of Figs. 7A-7C.

[0049] Fig. 9A shows an exemplary steerable delivery catheter advanced, along the aortic arch, towards the native aortic valve.

[0050] Fig. 9B shows the distal portion of the steerable delivery catheter of Fig. 9A deflected partially sideways.

[0051] Fig. 10A is a perspective view of a distal portion of an exemplary steerable catheter assembly.

[0052] Fig. 10B is a perspective view of a distal portion of the steerable catheter assembly of Fig. 10A, with an outer tube thereof removed from view.

[0053] Fig. 10C is a perspective view of a distal portion of the steerable catheter assembly of Fig. 10B, with a pull-member thereof removed from view.

[0054] Fig. 11 A is a longitudinal cross-sectional view of a distal portion of the steerable catheter assembly of Fig. 10A.

[0055] Fig. 1 IB is a longitudinal cross-sectional view of a distal portion of the steerable catheter assembly of Fig. 11A ,with an inner tube thereof removed from view.

[0056] Fig. 12 is a perspective view of a proximal portion of an exemplary steerable catheter assembly, wherein some components thereof are shown with partial transparency. [0057] Fig. 13A is a perspective view of a distal portion of an exemplary pull-member of the steerable catheter assembly.

[0058] Fig. 13B is a transverse cross-sectional view taken along line 13B-13B of Fig. 13A.

[0059] Fig. 14A is a perspective view of a distal portion of an exemplary pull-member that includes two elongated pull-arms.

[0060] Fig. 14B is a perspective view of a distal portion of an exemplary pull-member that includes a single elongated pull-arm.

[0061] Fig. 15 is a sectional perspective view of a distal portion of an exemplary steerable delivery system.

[0062] Fig. 16A is a cross-sectional side view of the steerable delivery system of Fig. 15 in an unbent state of the steerable catheter assembly.

[0063] Fig. 16B is a cross-sectional side view of the steerable delivery system of Fig. 16A in a bent state of the steerable catheter assembly.

[0064] Figs. 17A-17J illustrate steps in an exemplary method for utilizing an exemplary steerable delivery system for forming an opening within a host leaflet.

[0065] Fig. 18A is a sectional perspective view of a distal portion of an exemplary steerable delivery system comprising a balloon catheter extending through a steerable catheter assembly. [0066] Fig. 18B is a cross-sectional side view of the steerable delivery system of Fig. 18A.

[0067] Figs. 19A-19G illustrate steps in an exemplary method for utilizing the steerable delivery system of Figs. 18A- 18B for forming an opening within a host leaflet.

[0068] Fig. 20A is a perspective view of a host prosthetic valve subsequent to forming a leaflet opening thereof.

[0069] Fig. 20B is a perspective view of a guest prosthetic valve expanded within a leaflet opening of a host prosthetic valve.

[0070] Fig. 21A is a perspective view of a distal portion of an exemplary steerable catheter assembly that includes spacers between the elongated pull-arms, with an outer tube thereof removed from view.

[0071] Fig. 21B is a longitudinal cross-sectional view of a distal portion of the steerable catheter assembly of Fig. 21 A, with an inner tube thereof removed from view.

[0072] Fig. 21C is a transverse cross-sectional view of a pull-member of the steerable catheter assembly, with spacers disposed between the elongated pull-arms.

[0073] Fig. 22A is a perspective view of a proximal portion of an exemplary pull-member having pull-arms attached to a steering plate, with the steering plate shown in a non-tilted state thereof. [0074] Fig. 22B is a perspective view of the pull-member’s proximal portion of Fig. 22A, with the steering plate shown in a tilted state.

DETAILED DESCRIPTION

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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".

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] Described herein are steerable delivery catheters and related methods, which can be used to deliver tools and prosthetic devices to a location within a body of a subject. In some examples, steerable delivery catheters described herein can be used to deliver tools for modifying leaflets of an existing valvular structure in a patient’s heart, and/or for implanting prosthetic valves. 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.

[0090] 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, such as cutting tools and/or implantable 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.).

[0091] 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, but aortic valves with fewer than three leaflets are possible. The three native leaflet 30 of the aortic valve 20 include the left leaflet 60, right leaflet 62, an non-coronary leaflet 64. The leaflets 30 are supported at native commissures 40 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 left coronary artery 34 and the right coronary artery 36. The coronary ostia 42, 44 are the openings that connect the aortic root 22 to the coronary arteries 34, 36. The left coronary ostium 42 is positioned proximate to the left leaflet 60, and the right coronary ostium 44 is positioned proximate to the right leaflet 62. [0092] 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 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 maximum 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 maximum 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.

[0093] 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/US 2021/052745 and U.S. Provisional Application Nos. 63/85,947 and 63/150904, 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. [0094] 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.

[0095] 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.

[0096] The term "inflow", as used herein, refers to a region of the prosthetic valve through which the blood flows into the prosthetic valve 100.

[0097] 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.

[0098] 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.

[0099] The terms "longitudinal" and "axial", as used herein, refer to an axis extending in the proximal and distal directions, unless otherwise expressly defined.

[0100] 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 equivalent expansion mechanism. 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. [0101] 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. [0102] 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.

[0103] 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.

[0104] 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. [0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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. [0110] 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.

[0111] 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 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.

[0112] 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.

[0113] 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 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.

[0114] 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.

[0115] When a guest prosthetic valve 100 is deployed inside a host valvular structure 12, it displaces the host leaflets 10 of the host valve radially outwards, towards and against a host interior surface 14, which can be the interior surface of the aortic wall 38 if the host valve is the native valve, or an interior surface of the frame 102a of a previously implanted prosthetic valve 100a serving as the host valve.

[0116] 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. In some examples, a delivery apparatus according to any example described throughout the current disclosure, can be configured to deliver a device configured to modify the host valvular structure 12 (i.e., modify at least one of the host leaflets 10). In some examples, a delivery apparatus according to any example described throughout the current disclosure, can be configured to deliver and implant a guest prosthetic valve 100 within a modified valvular structure 12.

[0117] A delivery assembly comprising any delivery apparatus described throughout the current disclosure can be utilized, for example, to deliver a cutting tool for modifying a valvular structure at the region of the aortic valve, at the region of the mitral valve, or at the region of any other valve. A delivery assembly comprising any delivery apparatus described throughout the current disclosure can be 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.

[0118] Fig. 4 illustrates an exemplary steerable delivery system 200 that includes a steerable catheter assembly 210. In some examples, the steerable catheter assembly 210 can extend through a delivery catheter 150, which can be optionally implemented as a steerable catheter. The steerable catheter assembly 210 can be part of a cutting or lacerating device for modifying a host leaflet, optionally configured to allow passage of a perforating member 264 therethrough, and/or part of an apparatus that can carry an implantable prosthetic device, such as prosthetic valve 100 described above with respect to Figs. 2A-2B. In some examples, the steerable delivery system 200 includes a handle 204 from which the steerable catheter assembly 210, and optionally the delivery catheter 150 and/or perforating member 264, can distally extend. A steerable catheter assembly 210 can extend through a primary lumen 152 (indicated, for example, in Figs.7A-7C) of the delivery catheter 150.

[0119] The delivery catheter 150 and the steerable catheter assembly 210 can be configured to be axially movable relative to each other. For example, a distally oriented movement of the steerable catheter assembly 210 relative to the delivery catheter 150, can expose a distal portion of the steerable catheter assembly 210.

[0120] The proximal ends of the steerable catheter assembly 210 and the delivery catheter 150, as well as an optional perforating member 264, can be coupled to the handle 204. During advancement through a 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 system 200, such as the delivery catheter 150 and/or the steerable catheter assembly 210, as well as any other components passing therethrough, such as a perforating member 264.

[0121] The handle 204 can include a steering mechanism configured to adjust the curvature of the distal end portion of the steerable catheter assembly 210. 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(s) of a pull-member of the steerable catheter assembly 210. The pull-member can extend distally from the handle 204 through the steerable catheter assembly 210 and has a distal pull-ring portion affixed to tubes of the steerable catheter assembly 210. Rotating the knob 206a can pull or release one or more elongated pull-arms of the pull-member, thereby adjusting the curvature of the distal end portion of the steerable catheter assembly 210.

[0122] In some examples, such as when the delivery catheter 150 is a steerable catheter, the handle can further include a steering mechanism configured to adjust the curvature of the distal end portion of the delivery catheter 150. For example, the handle 204 can include an adjustment member, such as the illustrated rotatable knob 206b, which in turn is operatively coupled to the proximal end of a pull-wire. The pull- wire can extend distally from the handle 204 through the steerable delivery catheter 150 and has a distal end portion affixed to the steerable delivery catheter 150 at or near the distal end of the delivery catheter 150. Rotating the knob 206b can increase or decrease the tension in the pull-wire, thereby adjusting the curvature of the distal end portion of the delivery catheter 150. Further details on steering or flex mechanisms implemented in a handle 204 for controlling the tension of a pull-wire can be found in U.S. Patent No. 9,339,384, which is incorporated by reference herein.

[0123] The handle 204 can further include an adjustment mechanism including an adjustment member, that can be in the form of an additional knob or actuator, or can be controlled by an existing knot maneuvered in a different direction. The adjustment mechanism can be configured to adjust the axial position of the steerable catheter assembly 210 relative to the delivery catheter 150. The handle can include additional adjustment mechanisms controllable by additional knobs to maneuver additional components of the system 200, such as axial movement of other components and/or shafts, including an axial position of an optional perforating member 264. The terms "steerable delivery system 200" and "system 200", as used herein, are interchangeable. [0124] Fig. 5 shows a sectional view of a system 200 being delivered in situ to a treatment site. When positioned in situ, steering of the system 200 may be of importance in order to properly position a tool or prosthetic device at a desired location next to a site of treatment. The delivery catheter 150 is flexible and may be either passively bent, such as by being forced to articulate by the walls of the anatomical passageways, or actively steered if provided as a steerable catheter, for example by manipulating a pull-wire as described above, to permit a user to navigate the system 200 through a curved anatomy such as the aortic arch 46 as shown in Fig. 5.

[0125] The steering mechanism of a delivery catheter 150 can be implemented in a similar manner to that of conventional steering mechanisms utilized in delivery assemblies that include a prosthetic valve 100 delivered towards a site of implantation inside a patient's body. Conventional steering mechanisms can assist the user in properly aligning a prosthetic valve within the target site, such as the native annulus. For example, the a prosthetic valve 100 needs to be properly aligned, axially and annularly/circumferentially, so that the prosthetic valve 100 properly engages the native annulus of the target site, e.g., the aortic annulus 24, or a previously implanted prosthetic valve in case of ViV procedures, without causing conduction blockages by implanting too deep (e.g., the prosthetic valve positioned too far towards the left ventricle) or causing an embolization of the prosthetic valve 100 because it was implanted too high (e.g., the prosthetic valve positioned not far enough towards the left ventricle). Some types of steering mechanisms allow the distal end portion of the delivery apparatus to bend in a predefined direction in a two-dimensional plane. If it is desired to bend or deflect the distal portion of the delivery apparatus in a different direction, the steerable delivery catheter may be torqued or rotated and then the pull-wire may be actuated to bend the distal portion of the delivery catheter 150. Torquing the delivery catheter 150 can be accomplished via rotation of the handle 204, thus permitting the user to circumferentially align the prosthetic valve 100 within the target site, e.g., the native annulus, in situ.

[0126] Fig. 6 shows a distal portion an exemplary steerable delivery catheter 150, with some components and/or layers thereof removed from view for illustrative purpose. The exposed portion illustrated in Fig. 6 can include components and/or layers of a steerable delivery catheter 150. Figs. 7A and 7B show a perspective view and a longitudinal cross-sectional view, respectively, of a distal segment of an exemplary steerable delivery catheter 150. Fig. 7C is a transverse cross-sectional view along line 7C-7C of Fig. 7A. Fig. 8 shows a distal portion of an exemplary slotted tube 168 of the delivery catheter 150 of Figs. 6-7C. Figs. 6-8 are described herein together. The terms "steerable delivery catheter 150", "delivery catheter 150" and "catheter 150", as used herein with respect to a catheter that includes a pull-wire 188 as shown and described with respect to Figs. 6-8, for example, are interchangeable.

[0127] A delivery catheter 150 has a primary lumen 152 that extends the length of the catheter 150, defining a delivery catheter central longitudinal axis CD, for example, as shown in Fig. 7B. The delivery catheter 150 further includes a pull-wire lumen 160 through which a pullwire 188 extends. The pull-wire lumen 160 is defined or preformed in a sidewall of the steerable delivery catheter 150, such as in a polymeric layer 156 of catheter 150. As shown, the pull-wire lumen 160 is radially offset from the central longitudinal axis CD, and has a diameter that is less than diameter DL of the primary lumen 152. In some examples, the pullwire 188 can be formed from aramid fiber, carbon, or another relatively hard polymeric material. In some examples, the pull-wire 188 can be formed from Nitinol or stainless steel.

[0128] Delivery catheter 150 can include a plurality of layers comprising a variety of different materials configured to impart various properties to the catheter 150. In some examples, a low- friction and/or flexible primary lumen liner 154 can cover the inner surface around primary lumen 152, which can be made of (or coated by) a lubricious material such as polytetrafluoroethylene (PTFE), and can extend the full length of the primary lumen 152 of the delivery catheter 150. The primary lumen liner 154 fully surrounds the interior surface of the primary lumen 152, to provide a smooth surface so that an steerable catheter assembly 210 and/or any other device, such as a prosthetic valve 100, can be easily passed therethrough.

[0129] Delivery catheter 150 can include a polymeric layer 156 radially outward to the primary lumen liner 154. In some examples, a polymeric layer 156 can be comprised of at least two layers that can be fused to each other: an encapsulating polymeric layer 158 that can be disposed around the primary lumen liner 154, and an outer polymeric layer 166 which is radially outward to the encapsulating polymeric layer 158. The polymeric layer 156, and optionally an encapsulating polymeric layer 158 thereof, can encapsulate the pull- wire lumen 160 along at least some, and optionally along most, of the length of the delivery catheter 150. The pull-wire lumen 160 can be defined or preformed in a sidewall of the steerable delivery catheter 150, such as in a polymeric layer 156 of catheter 150. The polymeric layer 156, or a sub-layer thereof, such as the encapsulating polymeric layer 158, can have a non-uniform cross- sectional thickness to provide a thicker wall section for the pull- wire lumen 160, which is sized and dimensioned to receive the pull-wire 188.

[0130] The pull-wire lumen 160 can be formed within the polymeric layer 156, such as within encapsulating polymeric layer 158, as an elongated radial protrusion that axially extends along the primary lumen liner 154 and radially extends or protrudes into the primary lumen 152, as illustrated in Fig. 7C. The pull-wire lumen 160 can be offset or off-centered within the polymeric layer 156 such that the pull- wire lumen 160 is disposed closer to the primary lumen 152 than an outer surface of the steerable delivery catheter 150, 150.

[0131] The pull-wire lumen 160 is sized and dimensioned to receive the pull-wire 188. As mentioned above, the pull- wire 188 is operable to bend the delivery catheter 150. The pull- wire 188 is disposed within the pull-wire lumen 160 such that it can be selectively tensioned by the operator to bend the distal portion of delivery catheter 150. The term "slidably", as used herein, refers to back and forth movement in a longitudinal direction, which can be generally parallel to, and/or somewhat angled relative to, the delivery catheter central longitudinal axis CD. The term "tensioned", as used herein, refers to a pull-wire 188 being proximally pulled such that an initial positive tension force is imposed thereon, as contrasted to an untensioned pull- wire 188 having no axial force applied thereto.

[0132] A conduit defining the pull- wire lumen 160 can include low-friction and/or flexible pull- wire lumen liner 162 covering the inner surface of the pull- wire lumen 160, and can comprise ePTFE, PTFE or another suitable material to reduce friction between the conduit and the pull-wire 188.

[0133] As mentioned above, the delivery catheter 150 can include, in some examples, an outer polymeric layer 166 disposed radially outwards of the encapsulating polymeric layer 158 and the pull-wire lumen 160, such that the encapsulating polymeric layer 158 and the outer polymeric layer 166 can together form a combined polymeric layer 156. In some examples, the encapsulating polymeric layer 158 and the outer polymeric layer 166 are made of the same material. In some examples, the material properties of the outer polymeric layer 166 can be different from those of the encapsulating polymeric layer 158. In some examples, the outer polymeric layer 166 can have a uniform thickness around the circumference of the delivery catheter central longitudinal axis CD. Any of the polymeric layer 156, encapsulating polymeric layer 158, and/or outer polymeric layer 166 can comprise, for example, any of a variety of polymeric materials such as polyamides (e.g., VESTAMID®), polyether block amides (e.g., Pebax®), nylon, or any other suitable biocompatible polymer or combinations thereof along its length.

[0134] In some examples, delivery catheter 150 can include a braid 164, shown for example in Fig. 6, but removed from view in Fig. 7A for illustrative purpose. In some examples, the braid 164 can be embedded in the polymeric layer 156. In some examples, the braid 164 can be disposed radially outward the encapsulating polymeric layer 158 and the pull-wire lumen 160. In some examples, the braid 164 can be disposed between the encapsulating polymeric layer 158 and the outer polymeric layer 166. The braid 164 can be composed of, in some examples, metal wires (for example, stainless steel or titanium flat wires) braided together in a pattern, such as a one-over, one-under woven pattern as illustrated in Fig. 6, or any other pattern.

[0135] The braid 164 may be formed of a material such as stainless steel, Nitinol, tungsten, carbon, aramid, glass fiber, a stainless steel that has been reinforced with polyimide, or molybdenum. In some examples, the material utilized for the braid 164 has an ultimate tensile strength (UTS) in the range of 200,000 to 350,000 lbs/in². In some examples, the material utilized for the braid 164 is high temper stainless steel type 2913B ribbon wire.

[0136] The braid 164 can be configured to resist undesirable torsional deformation of the steerable delivery catheter 150 to allow the catheter to transmit torque, which can aid in positioning a steerable catheter assembly 210 extending therethrough at the treatment site. The braid 164 can also provide crush or kink-resistance properties to delivery catheter 150.

[0137] A steerable delivery catheter may further comprise a slotted tube 168 which is configured for elastic deformation. In some examples, the slotted tube 168 is embedded in the polymeric layer 156, along at least part of a distal portion of the delivery catheter 150. In some examples, the slotted tube 168 can be disposed radially outward the encapsulating polymeric layer 158 and the pull-wire lumen 160. In some examples, the slotted tube 168 can be disposed between the encapsulating polymeric layer 158 and the outer polymeric layer 166. In the illustrated example, the slotted tube 168 overlays the braid 164. However, it is to be understood that in some examples, the braid 164 can overlay the slotted tube 168. In some examples, a delivery catheter can be devoid of a braid. For example, the polymeric layer can be formed of a material which is compliant and flexible while still maintaining a sufficient degree of column strength to resist buckling of the delivery catheter, and sufficient tear resistance to reduce the likelihood that a component extending through the steerable delivery catheter will cause the catheter to tear.

[0138] The pull-wire 188 can exit the pull-wire lumen 160 at a distal end thereof, and be coupled at its distal end to a pull ring 184. In some examples, the pull ring 184 can be embedded in the polymeric layer 156, optionally between the encapsulating polymeric layer 158 and the outer polymeric layer 166. Pull ring 184 can be disposed inside a portion of catheter 150 distal to the slotted tube 168. The pull- wire 188 is fixedly attached to the pull ring 184, which is embedded inside the distal part of the delivery catheter 150. Pull-wire 188 can be, for example, welded to the pull ring 184.

[0139] During manufacturing of a steerable delivery catheter, the primary lumen liner 154 can be formed, for example around a mandrel (not shown), over which an encapsulating polymeric layer 158 can be formed. The pull-wire lumen 160 can be placed over or formed inside of the encapsulating polymeric layer 158, and a braid 164 can be formed in a desired pattern around the encapsulating polymeric layer 158 and the pull- wire lumen 160. The pull ring 184 can be placed around the encapsulating polymeric layer 158, distal to the braid 164, as illustrated in Fig. 6. The pull ring 184 can include a groove through which the pull-wire 188 and/or pullwire lumen 160 can extend radially outward and over a portion of the pull ring 184, and the distal end of the pull-wire 188, extending out of the pull- wire lumen 160, can be affixed to the pull ring, such as by welding, gluing, or any other suitable manner.

[0140] The slotted tube can be placed around the encapsulating polymeric layer 158 and the pull-wire lumen 160, optionally over the braid 164. The outer polymeric layer 166 can then be formed over the other layers and components, encapsulating the slotted tube 168, the braid 164, and/or the pull- wire lumen 160, inside the resulting polymeric layer 156, between the encapsulating polymeric layer 158 and the outer polymeric layer 166. The slotted tube can be reflowed with the polymeric material to facilitate flexibility, as the polymeric material fills the voids formed by the laser cut pattern of the slotted tube, including slots 170, such that both polymeric layers 166 and 158 can be sintered together during manufacturing, fully covering the slotted tube. The polymeric material may be similarly reflowed during manufacturing, through the spaces of the braid 164.

[0141] Pull ring 184 can be provided either as a stand-alone component attachable to the polymeric layer 156 and/or slotted tube 168, or can be integrally formed with the slotted tube 168. While pull ring 184 is described and illustrated in some examples herein as a separate component coupled, directly or indirectly, to the slotted tube, it is to be understood that this is not meant to be limiting, and that any reference to a pull-ring 184 throughout the specification and the claims, similarly refers to a distal portion 184 of the slotted tube itself, to which the pull- wire 188 can be coupled, such as by welding, gluing, and the like

[0142] Pull-wire 188 is coupled to the slotted tube 168 either directly or indirectly. Any reference to a pull-wire 188 coupled to the slotted tube 168 throughout the specification and the claims, refers to a distal end of the pull- wire 188 being attached either directly to a distal end of the slotted tube, or to another component (such as a separate pull-ring 184 or part of the polymeric layer 156) which is attached, in turn, to a distal end of the slotted tube. While the pull- wire 188 is described and illustrated in some examples herein to be indirectly attached to a distal end of the slotted tube by being affixed to a pull -ring 184 which, in turn, is coupled to the distal end of the slotted tube, it is to be understood that the pull- wire 188 can be, in some examples, directly attached to the slotted tube 168, such as when the pull-ring 184 is provided as an integral distal end portion of the slotted tube itself. Similarly, the pull- wire 188 can be indirectly attached to a distal end of the slotted tube 168 by having its distal end coupled to (for example, embedded in) a distal region of the polymeric layer 156, which is in turn coupled to the slotted tube (for example, by having the slotted tube embedded inside the polymeric layer 156)

[0143] While the pull-wire 188 is primarily housed or disposed with the pull-wire lumen 160, a proximal portion of the delivery catheter 150 can include an exit point (not shown) from which the proximal end of the pull-wire can radially extend out of the polymeric layer 156, and continue further therefrom into the handle 204 to be pulled, which results in controlled bending movement of the distal portion of the delivery catheter 150.

[0144] In some examples, the distal portion of the delivery catheter 150 may include a tip 186 distal to the slotted tube 168 that is configured to be relatively rigid and not sufficiently flexible to bend, to provide structural support to a component extendable through and out of the steerable delivery catheter, such as a steerable catheter assembly 210. The tip 186 can include a polymeric layer 156 distal to the pull ring 184 that is devoid of the slotted tube 168, the braid 164, and/or the pull-wire lumen 160.

[0145] In some examples, the slotted tube 168 is comprised in the distal portion of the delivery catheter 150. The slotted tube 168 can be formed by seamless drawn tubing where slots are laser cut into the tube. A slotted tube 168 can be made of a metal, such as stainless steel, Nitinol, or any other suitable material.

[0146] A slotted tube 168 comprises a plurality of successive discrete slots 170 which are cut (such as by laser-cutting or any other suitable manufacturing procedure) through the wall thickness of the slotted tube. Each of the slots 170 extends in a transverse direction of the tube 168 between slot ends 172 thereof, spanning more than 180° of the circumference of the tube 168 around the delivery catheter central longitudinal axis CD- In some examples, slot 170 spans more than 270° around the delivery catheter central longitudinal axis CD. In some examples, slots 170 extend around the circumference of the slotted tube, for example over at least 200°, at least 220°, at least 280°, at least 300°, at least 320°, or at least 340° circumferentially, leaving an uncut gap between the slot ends 172 that defines the backbone 176. Slots 170 define ribs 174 extending axially therebetween. The portion of the tube 168 not cut by the slots 170 may be also referred to as a backbone 176 of the slotted tube.

[0147] In some examples, a slotted tube 168 can further comprise a plurality of opposite cuts 178 that extend through the backbone 176 of the tube 168, and may partially extend along parts of the ribs 174, but do not extend through the portions of the ribs 174 that are directly opposite to the backbone 176. Each opposite cut 178 can include an opening 182 aligned with the center of the backbone 176, and two side slits 180 that extend circumferentially from both ends of the opening 182, passing over parts of the ribs 174 that do not reach the portions which are opposite to the opening 182. Stated another way, the uncut portions of the ribs 174 are generally opposite to the openings 182. As shown, the opening 182 of an opposite cut 178 can be wider (in the longitudinal direction) than the side slits 180 extending therefrom.

[0148] In some examples, the slots 170 along the length of the slotted tube 168 are equally spaced from each other, such that the ribs 174 formed therebetween have similar widths (defined as the dimension of rib 174 between two adjacent slots 170 in a longitudinal direction) along the entire length of the slotted tube 168. In some examples, the slots 170 of at least one portion of the slotted tube 168 can be differently spaced from each other relative to the slots 170 of at least one other portion of the tube 168, such that the ribs 174 along different portions can be wider or narrower to change the radius of the greatest possible bend by the corresponding bending portions. For example, the ribs 174 of a distal portion of the slotted tube 168 can be narrower than the ribs 174 of a proximal portion of the slotted tube 168, which will result in variable flexibility of the slotted tube 168 such that its distal portion is more flexible. [0149] In some examples, the slots 170 of at least one portion of the slotted tube 168 can be differently shaped and/or dimensioned with respect to slots 170 of at least one other portion of the tube 168, such that the different shapes and/or dimensions of the slots can change the radius of the greatest possible bend by the corresponding bending portions.

[0150] In some examples, the width of the slot 170, defined as a dimension thereof in the longitudinal direction, can increase in size from the slot ends 172 towards a circumferential center of the slot, thus forming an extended ovaloid shape.

[0151] As mentioned above, the curvature of one or more portions of the steerable delivery catheter can be changed based on the operator manipulating the pull- wire 188 via an actuator of the handle. In the examples illustrated in Fig. 4, the actuator is a knob 206b that is rotatable relative to the housing of the handle 204. When the knob 206b is rotated in a first direction (i.e., one of clockwise or counterclockwise), the pull-wire 188 is retracted and placed under tension to bend or deflect the distal portion of the steerable delivery catheter. Stated another way, when the pull-wire 188 is retracted via actuation of the actuator 206b, the pull-wire 188 is placed under tension and bends the distal portion of the catheter 150. When the knob 206b is rotated in a second direction opposite from the first direction (i.e., the other of clockwise or counterclockwise), tension on the pull- wire 188 is released and the distal portion of the delivery catheter resumes its straightened (or passively bent) configuration. [0152] Bending of the delivery catheter, such as by pulling on the pull-wire 188, results in the ribs 174 being moved closer together at the portions opposite to the backbone 176. The slots 170 can be narrowed or closed at their circumferential centers, bending the delivery catheter in the direction of the closure. When present, the opposite cuts 178, including openings 182 thereof, can open as the delivery catheter is bent, such as along the backbone 176. The backbone 176 flexes during bending of the delivery catheter. The backbone 176 can be configured to resist axial compression of the slotted tube, for example when pushing the steerable delivery catheter along the vasculature of a patient or when bending the steerable delivery catheter along a direction that is not in line with the predetermined bending direction of the respective bending portion. The side slits 180 are configured to operate similar to relief cuts in that the side slits 180 are closed or substantially closed when the slotted tube 168 is in a straight configuration, and can open or expand when the ribs 174 move toward one another as the slotted tube 168 is transitioned into a bent configuration.

[0153] Resilience of the slotted tube material can be configured to assist the steerable delivery catheter in returning to a straight or unbent condition (or less bent) condition, when the pullwire 188 is released (i.e., no longer tensioned, or tensioned at a smaller pulling force). The shape of the slots and/or cuts and the material from which the slotted tube is made, such as Nitinol in some examples, can facilitate "spring-back" of the slotted tube to its pre-bent configuration. This can be advantageous because, in some examples, the pull-wire 188 will not be compressed, thus avoiding kinks.

[0154] It is to be understood that the steerable delivery catheter 150 in not only actively bendable due to pulling of a pull-wire 188, but can be also passively bendable, configured to bend in a similar manner, when the catheter is forced to conform to the shape of the vascular path when it impacts the anatomical walls during advancement thereof.

[0155] Fig. 9A shows a steerable delivery catheter 150 advanced, along the aortic arch 46, towards the native aortic valve 22. In some cases, as the delivery catheter 150 is pressed against the aortic wall 38 during advancement through the curved aortic arch 46, the anatomical structure of the aortic arch 46 orients the distal end of the delivery catheter 150 towards a portion of the aortic root 22 adjacent to the right coronary ostium 44, such as the right- none commissure 66 or other regions of the right leaflet 62 or non-coronary leaflet 64. This position may be different from a desired site of treatment in a leaflet modification procedure (e.g., modifying a left leaflet 60 to prevent obstruction of the left coronary ostium 42). Thus, it may be desired, in some occasions, to be able to direct or steer the distal end of the delivery catheter, and any component extendable therethrough, such as an catheter assembly 210 through which a perforating member 264 can be advanced, to a region that is different from the region at which the distal end of the delivery catheter 150 lands due to the native anatomy of the patient.

[0156] When positioned in situ, steering and torqueing of delivery catheter 150 may be of utmost importance in order to properly position the distal portion of the delivery catheter 150 within a host valvular structure 12 prior to treatment. Steering of the delivery catheter 150 can be accomplished via manipulation of the pull-wire 188 as described herein, and permits the user to navigate the delivery catheter 150 through curved anatomy such as the aortic arch as shown in Fig. 5 and 9A. Further, steering of the delivery catheter 150 assists the user in properly aligning the distal end of the delivery catheter 150 and/or any component extendable therethrough, within the target site, e.g., the host valvular structure 12.

[0157] As mentioned above, when the pull-wire 188 of a steerable delivery catheter 150 is tensioned (e.g., pulled in the proximal direction), the distal portion of the delivery catheter 150 will bend in a planar manner. In some examples, the delivery catheter 150 may be torqued via rotation of the handle 204. If it is desired to bend or deflect the distal portion of the delivery catheter 150 in a different direction that that along which it bends when the pull-wire 188 is tensioned, the steerable delivery catheter 150 may be torqued or rotated (for example, rotated approximately 180° if the desired bending is in an opposite direction), and then the pull-wire 188 may be actuated (e.g., pulled) to bend the distal portion of the steerable delivery catheter 150.

[0158] Nevertheless, torquing (or rotating) of the handle, may only partially deflect the distal end (or distal portion) of the delivery catheter 150 relative to its state prior to wire-pulling, due to the radius of bending and the distance along which the distal end of the delivery catheter 150 may be deflected. For example, torquing the handle may cause the distal end of the steerable delivery catheter 150 to move towards the vicinity of the central of aortic annulus 24 (such as the center of coaptation of the leaflets 30), as illustrated in Fig. 9B. While this centralized position may be sufficiently adequate for some interventional procedures, such as deployment of a prosthetic valve in conventional transcatheter aortic valve intervention (TAVI) procedures, a greater extent of deflection of the distal portion of the delivery catheter 150 may be required in some desired procedures, such as when treatment of a left leaflet 60, in the vicinity of the left coronary ostium 44, is desired.

[0159] In order to treat a desired target host leaflet 10, such as a left leaflet 60 in the vicinity of a left coronary artery 34, a perforating member 264 can be advanced out of the primary lumen 152, optionally extending through a tube or catheter disposed thereover, such as a catheter assembly 210. As further illustrated in Fig. 9B, if the catheter assembly 210, as well as any tool extending therethrough such as a perforating member 264, is distally advanced in a relatively linear orientation relative to the distal end of the delivery catheter 150, linearly extending over the direction of the delivery catheter central longitudinal axis CD at an orientation thereof at the delivery catheter tip 186, for example, the catheter assembly 210 or any tool extending therefrom can encounter the host interior surface 14 instead of being directed towards the desired host leaflet 10. Thus, it may be required to provide additional steering capabilities to a catheter assembly 210 extendable through the delivery catheter 150, through which a perforating member 264 can be advanced, to oriented the perforating member 264 towards a desired target host leaflet 10, such as the left leaflet 60.

[0160] As shown in Fig. 7C, a pull-wire 188 utilized in a conventional steering mechanism, has a diameter Dp which is set to withstand the pull-forces (such as tension) applied thereto in order to bend the catheter. It may be often desired for any catheter passable through a patient's vasculature, including delivery catheter 150, to have a relatively small outer diameter in order to facilitate advancement thereof through narrow passageways along the vasculature. On the other hand, the lumen of a steerable catheter, such as primary lumen 152 of delivery catheter 150, needs to be wide enough to allow passage of tools or other shafts therethrough, including passage of a crimped prosthetic valve 100 when the delivery catheter 150 is used in TAVI procedures, for example. The difference between the outer diameter and inner diameter of a steerable catheter, such as delivery catheter 150, at least partly depends on the radial thickness of the pull-wire 188, which may either protrude to some extend into the primary lumen 152 as illustrated in Fig. 7C, or otherwise cause local or global thickening of the wall thickness of catheter 150 to accommodate the pull-wire lumen 160 therein.

[0161] When the steerable catheter is an outer catheter of a delivery system, such as a delivery catheter 150, the diameter Dp of a conventional pull-wire 188 having a substantially circular cross-section, can be significantly less than the diameter of the primary lumen 152. However, when a significantly smaller component, such as a perforating member 264 that can be optionally implemented as a hollow needle, need to be steered, a catheter or catheter assembly disposed therearound can define an inner lumen in the order of the diameter of the needle 264, in which case the diameter of a circularly-shaped pull-wire, such as a pull-wire 188, may result in a significantly greater influence on the profile of the steering catheter or catheter assembly. Disclosed herein are exemplary steerable catheter assemblies 210 that include one or more elongated pull-arms having non-circular cross-sectional profiles, in order to reduce the overall thickness of the steerable catheter assemblies 210, thus allowing for a reduced outer diameter of the steerable catheter assembly 210 relative to a steerable assembly lumen 208 defined thereby. Such steerable catheter assemblies can be also referred to, in some examples, as “low- profile" steerable catheter assemblies.

[0162] Figs. 10A-13B show an exemplary steerable catheter assembly 210 that includes a pull- member 250 having at least one elongated pull-arm 252 disposed inside an inter-tubular space 249 formed between an outer tube 218 and an inner tube 234. Fig. 10A is a perspective view of a distal portion of an exemplary steerable catheter assembly 210. Fig. 10B is a perspective view of a distal portion of the steerable catheter assembly 210 of Fig. 10A, with the outer tube 218 removed from view for illustrative purpose. Fig. 10C is a perspective view of a distal portion of the steerable catheter assembly 210 of Fig. 10B, with the pull-member 250 removed from view for illustrative purpose. Fig. 11A is a longitudinal cross-sectional view of a distal portion of the steerable catheter assembly 210 of Fig. 10A. Fig. 1 IB is a longitudinal cross- sectional view of a distal portion of the steerable catheter assembly 210 of Fig. 11 A, with the inner tube 234 removed from view for illustrative purpose. Fig. 12 is a perspective view of a proximal portion of an exemplary steerable catheter assembly 210, with the outer tube 218 and the inner tube 234 shown with partial transparency for illustrative purpose. Fig. 13A is a perspective view of a distal portion of an exemplary pull-member 250 of the steerable catheter assembly 210. Fig. 13B is a transverse cross-sectional view taken along line 13B-13B of Fig. 13 A. Figs. 10A-13B are described herein together.

[0163] The steerable catheter assembly 210 defines a steerable assembly lumen 208 around a steerable assembly central longitudinal axis Cx. The steerable catheter assembly 210 can be axially movable through, and relative to, the delivery catheter 150, such that the steerable assembly central longitudinal axis Cx may coincide with the delivery catheter central longitudinal axis CD along the congruent portions of the catheter 150 and catheter assembly 210. While a steerable delivery catheter 150 is described above with respect to Figs. 6-8, it is to be understood that a steerable catheter assembly 210 of any system 200 disclosed herein can be similarly used in combination with a non-steerable delivery catheter 150, or can be utilized in an exemplary system 200 that is devoid of a separate delivery catheter 150.

[0164] The outer tube 218 of the steerable catheter assembly 210 extends from an outer tube distal end portion 220 to an outer tube proximal end portion 222, and includes an outer tube slotted portion 224 along at least part of its length, such as along at least a distal section of the tube 218 adjacent outer tube distal end portion 222. The outer tube 218 further defines an outer tube inner surface 232 directed towards the steerable assembly central longitudinal axis Cx, having a radius Ros (indicated, for example, in Fig. 11A). [0165] In some examples, the outer tube slotted portion 224 is formed as a hypotube, configured to increase flexibility of the outer tube 218 along the outer tube slotted portion 224. The outer tube slotted portion 224 can optionally include a plurality of circumferential bands 228 arranged between circumferential slits 226, with axially extending connecting portions 230 connecting adjacent bands 228. Two adjacent circumferential bands 228 can be connected by a plurality of angularly spaced connecting portions 230. In such arrangements, the slotted portion 224 of the outer tube 218 exhibits sufficient flexibility to allow it to flex, either as it is pushed through a tortuous pathway or when the catheter assembly 210 is actively articulated by actuating the pull-member 250, without kinking or buckling.

[0166] While a specific pattern is illustrated in Fig. 10A, 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 slotted portion 224 of the outer tube 218 in order to vary stiffness of the outer tube 218 along its length. For example, the width of the bands 228 can decrease from the outer tube proximal end portion 222 to the outer tube distal end portion 220 to provide greater stiffness near the outer tube proximal end portion 222 and greater flexibility near the outer tube distal end portion 220.

[0167] The inner tube 234 of the steerable catheter assembly 210 extends from an inner tube distal end portion 236 to an inner tube proximal end portion 238, and includes an inner tube slotted portion 240 along at least part of its length, such as along at least a distal section of the tube 234 adjacent inner tube distal end portion 236. The inner tube 234 further defines an inner tube outer surface 248 directed away from the steerable assembly central longitudinal axis Cx, having a radius Ris (indicated, for example, in Fig. 11 A).

[0168] In some examples, the inner tube slotted portion 240 is formed as a hypotube, configured to increase flexibility of the inner tube 234 along the inner tube slotted portion 240. The inner tube slotted portion 240 can optionally include a plurality of circumferential bands 244 arranged between circumferential slits 242, with axially extending connecting portions 246 connecting adjacent bands 244. Two adjacent circumferential bands 244 can be connected by a plurality of angularly spaced connecting portions 246. In such arrangements, the slotted portion 240 of the inner tube 234 exhibits sufficient flexibility to allow it to flex, either as it is pushed through a tortuous pathway or when the catheter assembly 210 is actively articulated by actuating the pull-member 250, without kinking or buckling.

[0169] While a specific pattern is illustrated in Fig. 10C, which can be a laser cut pattern, it is to be understood that the pattern of bands 244 and slits 242 and/or the width of the bands 244 and/or slits 242 can vary along the length of the slotted portion 240 of the inner tube 234 in order to vary stiffness of the inner tube 234 along its length. For example, the width of the bands 244 can decrease from the inner tube proximal end portion 238 to the inner tube distal end portion 236 to provide greater stiffness near the section and greater flexibility near the inner tube distal end portion 236.

[0170] While the outer tube slotted portion 224 and the inner tube slotted portion 240 are shown in the example illustrated in Figs. 10A-11B to have similar cut patterns, it is to be understood that this is shown by way of illustration and not limitation, and that in some examples, each of the outer tube slotted portion 224 and the inner tube slotted portion 240 can have different cut patterns.

[0171] The pull-member 250 comprises a pull-ring portion 251 and at least one elongated pullarm 252 extending proximally from the pull-ring portion 251 to an arm proximal portion 258. In some examples, the at least one elongated pull-arm 252 is attached to the pull-ring portion 251. In some examples, the at least one elongated pull-arm 252 is integrally formed with the pull-ring portion 251, together forming a unitary pull-member 250. In some examples, the pullmember 250 is a tube-cut pull-member, which can be formed by cutting (for example, laser cutting) a tubular member to form one or more elongated pull-arms 252. A tube-cut pullmember 250 can be cut from a tube having an inner diameter RAI and an outer diameter RAO, such that each elongated pull-arm 252 cut therefrom is curved between arms circumferential ends 262 thereof, defining a curved arm inner surface 254 having a radius of curvature RAI and a curved arm outer surface 256 having a radius of curvature RAO, as shown in Fig. 13B.

[0172] The outer tube distal end portion 220 can be a portion of the outer tube 218 which is devoid of circumferential slits 226, and the inner tube distal end portion 236 can be a portion of the inner tube 234 which is devoid of circumferential slits 242. The pull-ring portion 251 is affixed, directly or indirectly, both to the outer tube distal end portion 220 and the inner tube distal end portion 236, such as by welding, soldering, gluing, and the like. In contrast, any elongated pull-arm 252 of the pull-member 250 is disposed inside the inter-tubular space 249 between the outer tube inner surface 232 and the inner tube outer surface 248 without being attached thereto, such that the elongated pull-arm 252 can axially slide within the space defined between the surfaces 232 and 248 relative to the outer tube 218 and/or the inner tube 234.

[0173] In some examples, the distal portion of the steerable catheter assembly 210 may include a distal tip portion 212 distal to the pull-ring portion 251 of the pull-member 250. The distal tip portion 212 can be configured to be relatively rigid and not sufficiently flexible to bend, to provide structural support to a component extendable through and out of the steerable catheter assembly 210, such as a perforating member 264. The distal tip portion 212 can include a polymeric layer distal to the pull-ring portion 251 that is devoid of the outer tube slotted portion 224 and/or the inner tube slotted portion 240. The distal tip portion 212 can terminate at a distal atraumatic end 214, which can be optionally rounded and/or curved radially inwards, or can be otherwise formed to include an outer surface tapering in the distal direction.

[0174] In some examples, the distal tip portion 212 can include an inner recess 216 configured to accommodate at least part of the inner tube distal end portion 236, so as to provide a flush inner surface smoothly transitioning between the inner tube 234 and the distal tip portion 212. In some examples, the distal tip portion 212 can be formed by overmolding a polymeric layer around the inner tube distal end portion 236.

[0175] The curvature of the steerable catheter assembly 210, at least along a distal portion thereof, can be changed based on the operator manipulating the elongated pull-arm 252 via an actuator of the handle 204. The arm proximal portion 258 can extend into the handle 204 and be coupled to a mechanism controlled by a handle actuator, such as a knob or any other type of actuator, that can be utilized to axially pull the elongated pull-arm 252 in a proximal direction. As further illustrated in Fig. 12, each arm proximal portion 258 can include a coupling aperture 260 through which a fastener (not shown) can extend to couple the elongated pull-arm 252 to a control mechanism in the handle 204.

[0176] When a proximally-oriented force is applied to the elongated pull-arm 252, the force is transmitted, via the pull-ring portion 251, to the outer tube distal end portion 220 and the inner tube distal end portion 236, resulting in adjacent circular bands 228 and 244 being moved closer together at the circumferential regions aligned with the circumferential position of the elongated pull-arm 252. The circumferential slits 226 and 242 can be narrowed or closed at the regions circumferentially aligned with the position of the axially pulled elongated pull-arm 252, bending the distal portion of the steerable catheter assembly 210 in the direction of closure. When the proximally-oriented pull force is released, the distal portion of the steerable catheter assembly 210 resumes its straightened (or passively bent) configuration.

[0177] Resilience of the material of any of the outer tube 218 and the inner tube 234 can be configured to assist the steerable catheter assembly 210 in returning to a straight or unbent (or less bent) condition, when the elongated pull-arm 252 is released (i.e., no longer proximally pulled, or proximally pulled at a smaller pulling force). The shape of the slits and the material from which each of the tubes is made, such as Nitinol in some examples, can facilitate "spring- back" of the outer tube 218 and/or inner tube 234 to the pre-bent configuration. This can be advantageous because the elongated pull-arm 252 is made of a relatively rigid material, such as metal (though other suitable materials are contemplated) that will not be compressed, thus avoiding kinks.

[0178] An elongated pull-arm 252 must withstand the proximally-directed pull force applied thereto in order to bend the steerable catheter assembly 210. If the pull-arm would have been implemented as a conventional pull-wire, similar to pull-wire 188 described herein with respect to a steerable delivery catheter 150, this would have been achieved by providing the pull-wire with sufficient thickness, which is the diameter Dp of the pull-wire. In some cases, a pull components, such as a pull-arm 252 or pull-wire 188, needs to withstand as much as 100N (Newtons) of force applied thereto. In the case of a conventional pull-wire having a circular cross-section, this can result in a pull-wire diameter Dp that can be at least two times greater than a radial thickness of the pull-ring it is attached to, making the pull-wire a dominant component influencing the overall radial thickness of the steerable catheter or catheter assembly as a whole.

[0179] In contrast to a pull-wire having a circular cross-section, such as pull-wire 188 illustrated in Fig. 7C having a diameter Dp, an elongated pull-arm 252 has an arcuate flattened configuration, defining a pull-arm thickness TA in the radial direction, and a pull-arm circumferential width WA defined between the corresponding arm circumferential end 262, as indicated in Fig. 13B, wherein the pull-arm circumferential width WA is greater than the pullarm thickness TA. The cross-sectional area of the elongated pull-arms 252 can be designed to withstand a desired pull-force, such as at least 100N, in a manner that is equivalent to a circular cross-sectional area of an alternative conventional pull-wire having a pull-wire diameter Dp designed to withstand the same axial pull force. Thus, the pull-arm thickness TA is less than an alternative pull-wire diameter Dp, while the pull-arm circumferential width WA is greater than the same pull-wire diameter Dp. In some examples, the pull-arm circumferential width WA is at least two times as great as the pull-arm thickness TA. In some examples, the pull-arm circumferential width WA is at least three times as great as the pull-arm thickness TA.

[0180] While an elongated pull-arm 252 can have a pull-arm circumferential width WA along most of the length of the steerable catheter assembly 210, sized to withstand a minimal pullforce threshold as described above, it can transition to a greater circumferential width at its arm proximal portion 258, as illustrated for example in Fig. 12. The greater width at the proximal portion 258 can provide greater surface area for coupling of the arm to a steering mechanism within the handle 204.

[0181] While a conventional pull-wire can extend through a sleeve defining a lumen through which it may slide, such as the pull-wire lumen liner 162 defining a pull- wire lumen 160 through which the pull-wire 188 extends, an elongated pull-arm 252 of a steerable catheter assembly 210 disclosed herein is disposed between the inner tube 234 and the outer tube 218, without necessarily including a separate sleeve around the elongated pull-arm 252, thus potentially further reducing the cross-sectional profile by not including a sleeve that could have added to the overall thickness of the steerable catheter assembly 210.

[0182] As mentioned, the outer tube 218, inner tube 234, and pull-member 250 are affixed to each other at their distal ends, by attaching the outer tube distal end portion 220 and inner tube distal end portion 236 to the pull-ring portion 251 disposed therebetween, while the one or more elongated pull-arm 252 is disposed between the outer tube inner surface 232 and the inner tube outer surface 248, without being attached thereto, such that the elongated pull-arm 252 is "free-floating" relative to the outer tube 218 and the inner tube 234. The radial space or gap formed between the outer tube inner surface 232 and the inner tube outer surface 248 serves as a lumen or space within which the one or more elongated pull-arm 252 can slide relative to the outer tube 218 and the inner tube 234. When the elongated pull-arm 252 is proximally pulled to bend the steerable catheter assembly 210, it assumes a bent configuration as it is sandwiched between the outer tube 218 and the inner tube 234, articulating therewith while the outer tube 218 and the inner tube 234 disposed on both the outer and inner sides of the elongated pullarm 252 prevent it from assuming a linearly-angled orientation between the pull-ring portion 251 and the arm proximal portion 258. Thus, the inner tube 234 and the outer tube 218 can be referred to, in some examples, as an inner bendable tube and an outer bendable tube, respectively.

[0183] The curvature of an elongated pull-arm 252 can generally match the curvatures of the corresponding tubes between which it is disposed. In some examples, the radius of curvature RAI of the curved arm inner surface 254 is equal to or greater than the radius Ris of the inner tube outer surface 248, and the radius of curvature RAO of the curved arm outer surface 256 is equal to or less than the radius Ros of the outer tube inner surface 232.

[0184] Various exemplary implementations for steerable delivery systems 200 and/or steerable catheter assemblies 210 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 system, assembly 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 system, assembly or component, referred to with a superscript, may be optionally shared by some but not necessarily all other exemplary implementations. For example, steerable catheter assemblies 210^a is an exemplary implementation of steerable catheter assembly 210, and thus can include any of the features described for steerable catheter assembly 210 throughout the current disclosure, except that while a pull-member 250 of a steerable catheter assembly 210 can include any number of elongated pull-arm(s) 252, the pull-member 250^a of steerable catheter assembly 210^a illustrated in Figs. 10A-13B is shown to include four elongated pullarms 252 that can be circumferentially disposed at 90° from each other. In such an arrangement, the steerable catheter assembly 210 can be controllably steered in two planes orthogonal to each other.

[0185] When a pull-member 250 includes a plurality of elongated pull-arms 252, such as the four elongated pull-arms 252 of pull-member 250^a, adjacent pull-arms 252 can define circumferential inter-arm spacings or slots 298 therebetween. As mentioned above, the pullmember 250 can be implemented, in some examples, as a tube-cut pull-member, in which case a tubular member can be cut (such as by laser cutting or any other suitable tube-cutting procedure) to remove the material along the circumferential inter-arm slots 298, leaving only the pull-ring portion 251 and the elongated pull-arm(s) 252 extending proximally therefrom. [0186] As shown in Fig. 12, the circumferential inter-arm slots 298 can extend all the way to the proximal end of the pull-member 250, such that the elongated pull-arms 252 remain unattached to each other along their lengths, including having their arms proximal portions 258 separated from each other, in order to enable each of the elongated pull-arms 252 to be independently pulled. When a plurality of elongated pull-arms 252 are provided, as shown for pull-member 250^a, each circumferential inter-arm slot 298 defined between circumferentially neighboring elongated pull-arms 252 can have a uniform circumferential width along most of the length of the steerable catheter assemblies 210, yet transition to a circumferentially narrower slot 298 between the arm circumferential ends 262, if the arm circumferential ends 262 are provided as wider portions of the elongated pull-arms 252, as illustrated for example in Fig. 12.

[0187] Fig. 14A is a perspective view of a distal portion of an exemplary pull-member 250^b. Pull-member 250^b is an exemplary implementation of pull-member 250, and thus can include any of the features described for pull-member 250 throughout the current disclosure, except that the pull-member 250^b comprises two elongated pull-arms 252 that can be circumferentially disposed at 180° from each other. In such an arrangement, in which the two elongated pullarms 252 are disposed directly across from each other, the steerable catheter assembly 210 can be controllably steered in two directions across a plane defined by the two elongated pull-arms 252.

[0188] Fig. 14B is a perspective view of a distal portion of an exemplary pull-member 250^c. Pull-member 250^c is an exemplary implementation of pull-member 250, and thus can include any of the features described for pull-member 250 throughout the current disclosure, except that the pull-member 250^c comprises a single elongated pull-arm 252 extending proximally from the pull-ring portion 251. In such an arrangement, the steerable catheter assembly 210 can be bent in a single direction defined by the circumferential position of the elongated pullarm 252. Any exemplary steerable catheter assembly 210 disclosed herein can be optionally torqued in a desired rotational direction. Thus, even when a single pull-arm 252 is provided as shown for pull-member 250^c, or two pull-arms 252 are provided across each other to enable bending in a single plane as shown for pull-member 250^b, the steering mechanism inside the handle 204 to which the proximal portion of the steerable catheter assembly 210 is coupled, can be configured to rotate the steerable catheter assembly 210 in a clockwise or counterclockwise direction, about the steerable assembly central longitudinal axis Cx, after which an appropriate elongated pull-arm 252 can be proximally pulled, thereby bending the steerable catheter assembly 210 in a desired orientation.

[0189] While a single, two and four elongated pull-arms 252 are illustrated, it is to be understood that any other number of elongated pull-arms 252 is contemplated, limited primarily by the circumferential width WA with respect to the total number of discrete pullarms 252 that can be circumferentially disposed around the steerable assembly central longitudinal axis Cx between the inner tube 234 and the outer tube 218. While a plurality of elongated pull-arms 252 are illustrated in the examples shown for pull-member 250^a and pullmember 250^b, to be similarly sized and shaped and to be equally spaced from each other in the circumferential direction, it is to be understood that in some examples, the shape and/or dimensions of the elongated pull-arms 252 may vary, and the elongated pull-arms 252 can be unequally spaced from each other in the circumferential dimension, meaning that at least some of the circumferential inter-arm slots 298 can have different widths in the circumferential dimension.

[0190] While in some examples, one or more elongated pull-arm(s) 252 can be separately formed and then attached to a pull-ring portion 251, such as by welding, soldering, adhering, suturing, and the like, forming the pull-member 250 as a unitary tube-cut pull-member 250 may be advantageous as it may simplify production by obviating the need to attached separately formed components of the pull-member, as well as optionally reduce the thickness of a steerable catheter assembly 210. For example, a separately formed elongated pull-arm 252 needs to be attached to the separate pull-ring portion 251 in a manner that retains attachment therebetween when a pull-force, such as a pull force of at least 100N, is applied to the pull-arm 252. In some cases, the elongated pull-arm 252 can be overlaid, at a distal end thereof, over the pull-ring portion 251, which will cause both the ring and the pull-arm to contribute to the overall thickness of the steerable catheter assembly 210. In some cases, the weld line or other region of attachment can be thicker than the pull-arm 252 and/or the pull-ring portion 251, thereby locally increasing the thickness of the steerable catheter assembly 210. In contrast, when provided as a unitary tube-cut pull-member 250, no separate attachment is required, and the elongated pull-arm(s) continuously extend from the pull-ring portion 251 such that the radial thickness of the pull-ring portion 251 is equal to the radial thickness TA of elongated pull-arm 252.

[0191] Fig. 15 is a sectional perspective view of a distal portion of an exemplary steerable delivery system 200^d. Steerable delivery system 200^d is an exemplary implementation of steerable delivery system 200, and thus can include any of the features described for steerable delivery system 200 throughout the current disclosure, except that the steerable delivery system 200^d further comprises a perforating member 264 extending through the steerable assembly lumen 208. The perforating member 264 can define a perforating member lumen 266 through which a guidewire 80 (shown, for example, in Figs. 17A-17J) can extend. The perforating member 264 can comprise a perforating member distal end portion 268 terminating at a perforating member tip 272, 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, when a perforating member distal end portion 268 is positioned distal to the steerable catheter assembly 210.

[0192] In some examples, the steerable catheter assembly 210 and the perforating member 264 are configured to be movable axially relative to each other in the proximal and distal directions. The perforating member 264 can be coupled to a handle 204. The handle 204 can have one or more actuators (for example, in the form of knobs) that are operatively coupled to the perforating member 264 to facilitate axial movement thereof. In such examples, the perforating member distal end portion 268 can be configured to pierce a host leaflet 10 when axially translated to a position which is distal to the distal tip portion 212 of the steerable catheter assembly 210. In some examples, the perforating member distal end portion 268 is not necessarily configured to be axially translatable relative to the steerable catheter assembly 210, in which case it is positioned distal to the distal tip portion 212 at all times. [0193] In some examples, the perforating member 264 may include and/or be a needle, such as a spring-loaded needle and/or a Veress needle. In the example illustrated in Fig. 15, the perforating member is a hollow needle 264 that defines a needle lumen 266, and the perforating member distal end portion is a needle distal end portion 268 that can define an angled surface 270 terminating at a needle tip 272.

[0194] In some examples, at least a portion of the needle 264 is formed as a hypotube, configured to increase flexibility thereof. The needle 264 can optionally include a plurality of circumferential bands 276 arranged between circumferential slits 274, with axially extending connecting portions 278 connecting adjacent bands 276. Two adjacent circumferential bands 276 can be connected by a plurality of angularly spaced connecting portions 278. In such arrangements, the needle 264 exhibits sufficient flexibility to allow it to flex when another component of the system 200 disposed therearound, such as a steerable catheter assembly 210, is bent.

[0195] While a specific pattern is illustrated in Fig. 15, which can be a laser cut pattern, it is to be understood that the pattern of bands 276 and slits 274 and/or the width of the bands 276 and/or slits 274 can vary along the length of the needle 264 in order to vary stiffness of the needle 264 along its length. For example, the width of the bands 276 can decrease from the proximal end to the distal end of the needle 264 to provide greater stiffness near the proximal end and greater flexibility near the distal end of the needle 264.

[0196] Fig. 16A and 16B are cross-sectional side views of the steerable delivery system 200^d of Fig. 15, in unbent and bent states, respectively, of the steerable catheter assembly 210. Optional slotted pattern of the needle 264 is removed from view in Fig. 16B for illustrative purpose. As shown, a steerable catheter assembly 210 according to any of the examples described herein, can extend through the primary lumen 152 of a delivery catheter 150. In some examples, the steerable catheter assembly 210 is axially movable through, and relative to, the delivery catheter 150. The delivery catheter 150 can be either a steerable delivery catheter, as described above with respect to Figs. 6-8 for example, or can be a flexible shaft which is not necessarily actively steerable.

[0197] In some examples, the outer tube 218 and/or inner tube 234 can be encapsulated in one or more polymeric layers. For example, the outer tube slotted portion 224 and/or inner tube slotted portion 240 can be reflowed with the polymeric material that fills the voids formed by the laser cut patterns of the slotted tubes, including circumferential slits 226 and/or 242, respectively. In some examples, the steerable catheter assembly 210 comprises an inner liner or layer (noy shown), that can be formed of Teflon® or other suitable material, to minimize sliding friction with a perforating member, such as the needle 264.

[0198] The steerable assembly lumen 208 can be sized to allow passage of a perforating member 264, such as a needle 264, therethrough. Since a needle 264 is a component that is conventionally provided with a relatively small diameter, utilization of a steerable catheter assembly 210 in combination with a needle 264 (or any other type of small-diameter perforating member 264) may be of advantage. As shown in Fig. 16B, when the steerable catheter assembly 210 is bent, for example by proximally pulling a corresponding elongated pull-arm 252 thereof, the portion of the perforating member, such as needle 264, extending through the articulating portion of the steerable catheter assembly 210, is bent therewith. Thus, a steerable catheter assembly 210 can be utilized to actively orient the perforating member 264 in a desired direction.

[0199] Figs. 17A-17J illustrate some steps in a method for utilizing a steerable delivery system 200, such as exemplary steerable delivery system 200^d, in a method for forming an opening within a target tissue. An exemplary implementation of the method is illustrated in Figs. 17A- 17J 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 114 of a previously implanted prosthetic valve. The below method is an example of the manner by which a system 200 that includes a steerable catheter assembly 210 can be used. It will be understood that systems 200 described herein can be used as part of other methods as well.

[0200] The distal end portion of the system 200 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 system 200 relative to the host leaflet 10 may comprise advancing the system 200 toward the leaflet over a guidewire 80. As mentioned, the needle lumen 266 can be configured to accommodate a guidewire 80 that can passed therethrough. In such examples, the guidewire 80 can be inserted into the patient’s vasculature, and then the needle 264, along with steerable catheter assembly 210 and/or other shafts or tubes of the system 200, may be advanced toward the host leaflet 10 over the guidewire 80.

[0201] During delivery, the needle distal end portion 268 can be retained inside the steerable assembly lumen 208 and/or within the primary lumen 152, such that the sharp needle tip 272 is concealed inside the corresponding lumen, as illustrated in Fig. 17A. This position conceals the needle tip 272 from the surrounding anatomy, to protect the anatomical structures from being engaged or punctured by the needle tip 272 during advancement towards the site of treatment.

[0202] When the distal end portion of system 200 lands at the target site, it may be initially positioned at a position that is different than the position of the desired host leaflet 10, as described above with respect to Fig. 9 A. If the delivery catheter 150 is a steerable delivery catheter, it can be bent to navigate the distal portion of the system 200 toward the desired host leaflet 10, such as a leaflet that can be closer to the left coronary ostium. In some cases, orienting the system 200 sideways, towards a host leaflet 10, optionally in some proximity to the nadir of the leaflet, can orient the delivery catheter central longitudinal axis CD towards a host interior surface 14, which can be the interior surface of the aortic wall if the host valve is the native valve, or an interior surface of a frame of a previously implanted prosthetic valve serving as the host valve. In such cases, merely advancing a perforating member such as needle 264 in the distal direction to expose it prior to penetrating through the host leaflet 10, can direct the needle towards the host interior surface 14 instead of the host leaflet 10 itself.

[0203] In order to properly orient the needle 264, a distal portion of the steerable catheter assembly 210 can be exposed out of the delivery catheter 150 and bent, by pulling an appropriate elongated pull-arm 252 thereof as described above, advantageously orienting the distal tip portion 212 toward the host leaflet 10, as illustrated in Fig. 17B, such that during advancement of the needle 264, its distal end portion 268 can contact and pierce through the host leaflet 10, without posing a risk of contacting and damaging adjacent anatomical structures, such as the host interior surface 14. Exposing the steerable catheter assembly 210 out of delivery catheter 150 can be accomplished by distally pushing the steerable catheter assembly 210 relative to the delivery catheter 150, by proximally pulling the delivery catheter 150 relative to the steerable catheter assembly 210, or both.

[0204] As shown in Fig. 17C, the needle 264 is configured to puncture the host leaflet 10 to form a pilot puncture 50 within host leaflet 10, for example when its distal end portion 268 is axially translated relative to the distal tip portion 212 of steerable catheter assembly 210. The guidewire 80 can be then advanced through the needle lumen 266 to terminate with guidewire tip 82 distal to the pilot puncture 50 of host leaflet 10 as shown in Fig. 17D.

[0205] Subsequent to forming the pilot puncture 50 and optionally advancing the guidewire 80 to extend therethrough, the needle 264 can be optionally retracted, along with the steerable catheter assembly 210, as shown in Fig. 17E, leaving the guidewire 80 extending through the pilot puncture 50. [0206] 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 264, as illustrated in Fig. 17D. In some examples, the guidewire 80 can be advanced simultaneously with advancement of the needle 264 towards the host leaflet 10 and/or during formation of the pilot puncture 50. In some examples, the needle 264 can be pulled back into the steerable assembly lumen 208 while the steerable catheter assembly 210 may remain in position. In some examples, the steerable catheter assembly 210 can be retracted simultaneously with, or subsequent to, retraction of needle 264.

[0207] In some examples, the method can further include steps of positioning an expansion member 296 inside the pilot puncture 50, for expanding the puncture and forming a wider opening 52 in the host leaflet 10. An expansion member can be either part of the system 200, or provided as a separate component advanced into a pilot puncture formed by a perforating member 264 of the system 200. The expansion member 296 can be optionally advanced through the primary lumen 152 of delivery catheter 150, or a different shaft or catheter can be used for delivery the expansion member. The expansion member 296 may include and/or be any suitable structure for expanding the pilot puncture 50 to form a leaflet opening 52. In some examples, the expansion member 296 may have a circular profile when in the radially expanded configuration. This is not required of all examples, however, and it additionally is within the scope of the present disclosure that the expansion member 296 may have a non-circular profile when in the radially expanded configuration.

[0208] In some examples, the expansion member is an inflatable balloon 296 that can be mounted on a distal portion of a balloon catheter 290. In some examples, a balloon catheter 290 carrying balloon 296 can be advanced over the guidewire 80 towards the pilot puncture 50 formed in host leaflet 10, after retraction of the perforating member 264 and/or steerable catheter assembly 210, as shown in Fig. 17F. The 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 294 (indicated, for example, in Fig. 18B), through which a guidewire 80, and one or more additional shafts of the system 200, can optionally extend. The balloon catheter 290 can extend through a handle 204 of the system 200 and be fluidly connectable to a fluid source (not shown) for inflating the 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 balloon 296. The inflation fluid source is in fluid communication with the balloon catheter lumen 294, such that fluid from the fluid source can flow through the balloon catheter lumen 294 into balloon 296 to inflate it.

[0209] An inflatable balloon 296 of system 200, utilized as a hole-dilating balloon, is 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 balloon 296). In some examples, 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.

[0210] In some examples, a dilator 280 (see Figs. 17F and 18A-18B) can be positioned distal to the balloon 296 (or other suitable expansion member). The dilator 280 can be either part of the system 200, or provided as a separate component advanced towards a pilot puncture formed by a perforating member 264 of the system 200. The 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 288 that extends proximally therefrom. A dilator lumen 281 continuously extends through the dilator shaft 288 and the dilator 280, open ended at the dilator distal end 282. Attachment of the dilator shaft 288 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 288 can extend through the entire length of the dilator 280, such that a distal end of the dilator shaft 288 is aligned with the dilator distal end 282. In some examples (not illustrated), the dilator shaft 288 is coupled to one or more components, such as collars or other connectors, which are in turn attached to the dilator 280.

[0211] In some examples, the 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 another component of the system 200, such as the dilator 280 or dilator shaft 288. In the examples illustrated in Figs. 17F and 18A-18B, the 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.

[0212] The delivery catheter 150, balloon catheter 290, and/or dilator shaft 288, can be configured to be axially movable relative to each other. For example, a proximally oriented movement of the delivery catheter 150 relative to the balloon catheter 290, or a distally oriented movement of the balloon catheter 290 relative to the delivery catheter 150, can expose the balloon 296 from the delivery catheter 150. Similarly, a proximally oriented movement of the dilator 280 relative to the delivery catheter 150, or a distally oriented movement of the delivery catheter 150 relative to the dilator 280, can expose the dilator 280 and axially translate it in a desired direction.

[0213] In some examples, such as when the balloon 296is attached at both ends thereof to the dilator 280 and balloon catheter 290, both the dilator 280 with dilator shaft 288 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, the system 200 can be designed such that axial movement of the balloon catheter 290 causes the dilator shaft 288 to move therewith, or such that axial movement of one of the dilator shaft 288 or dilator 280 causes the balloon catheter 290 to move therewith.

[0214] The proximal ends of various components of system 200, such as delivery catheter 150, steerable catheter assembly 210, needle 264, balloon catheter 290, and/or dilator shaft 288, 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 delivery catheter 150, steerable catheter assembly 210, needle 264, balloon catheter 290, and/or dilator shaft 288, through the patient’s vasculature and/or along the target site of treatment, to manipulate s pullOwire 188 and/or one an elongated pull-arm 252 to articulate a steerable delivery catheter 150 and/or steerable catheter assembly 210, respectively, and to expand an expansion member, such as to inflate a 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.

[0215] Subsequent to forming the pilot puncture 50 and extending the guidewire 80 therethrough, and optionally after retraction of the needle 264 and/or steerable catheter assembly 210 as shown in Fig. 17E, a balloon 296 carried over a balloon catheter 290 can be advanced towards the host leaflet 10, as shown in Fig. 17F. In some examples, when a dilator 280 is present distal to the expansion member (such as balloon 296) as also shown in the example illustrated in Fig. 17F, the dilator 280 can be advanced, optionally along with the balloon catheter 290 and balloon 296, towards the host leaflet 10. In such examples, the dilator 280 can be inserted into the pilot puncture 50 to expand the pilot puncture 50, as shown in Fig. 17G. 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.

[0216] In some examples, the balloon catheter 290 with 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 needle 264 and/or steerable catheter assembly 210 towards the host leaflet 10 for formation of the pilot puncture 50. In some examples, the balloon catheter 290 with balloon 296 and/or dilator 280 are advanced towards the pilot puncture 50 of host leaflet 10 through the primary lumen 152 of the same delivery catheter 150 used for advancement of the needle 264 and/or steerable catheter assembly 210 therethrough towards the host leaflet 10 for formation of the pilot puncture 50.

[0217] For example, as illustrated in Figs. 17E-17F, the needle 264 and/or steerable catheter assembly 210 can be retracted through the primary lumen 152 while the delivery catheter 150 remains in position, in the vicinity of the host leaflet 10, with the guidewire 80 extending through the primary lumen 152 into the pilot puncture 50. This allows the balloon catheter 290, and optionally dilator shaft 288, to be advanced towards the pilot puncture 50 of the host leaflet 10 over the guidewire 80, through the primary lumen 152 of the same delivery catheter 150. In some examples, the delivery catheter 150 can be retracted along with the needle 264 and/or steerable catheter assembly 210, and then readvanced towards the host leaflet 10 with the balloon catheter 290 and/or dilator shaft 288 extending therethrough.

[0218] In a subsequent step of the method, illustrated in Fig. 17H, the balloon 296 may be inserted within the pilot puncture 50, such as by further advancement of the dilator 280 with dilator shaft 288 and/or balloon catheter 290. With the balloon 296 received within the pilot puncture 50, inflating the balloon 296 to transition it from a radially deflated state (Fig. 17H) to a radially inflated state (Fig. 171) 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. 171, the balloon 296 is deflated, as shown in Fig. 17J, optionally allowing for insertion of a guest prosthetic valve inside the leaflet opening 52. [0219] In some examples, inflating the 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 other 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.

[0220] In some examples, inflating the 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).

[0221] Figs. 10A and 10B show a perspective cross-section view and a cross-sectional side view, respectively, an exemplary steerable delivery system 200^e. System 200^e is an exemplary implementation of system 200, and thus can include any of the features described for system 200 throughout the current disclosure, except that the system 200^e further includes an expansion member 296, such as inflatable balloon 296 mounted on balloon catheter 290, extending through the steerable assembly lumen 208. The system 200^d can optionally comprise the dilator 280 attached to dilator shaft 288, and the balloon 296can 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 288, and/or balloon 296. The steerable assembly lumen 208 of the system 200^e is sized to allow passage of the balloon catheter 290 and the balloon 296, in the deflated state, therethrough.

[0222] The perforating member, such as needle 264, extends through the dilator lumen 281 as illustrated in Figs. 18A-18B, and is configured to be axially movable in the distal and proximal direction relative to any of the steerable catheter assembly 210, dilator shaft 288 and/or the balloon catheter 290. The dilator shaft 288 can extend through the balloon catheter lumen 294, and may be sized such that an annular space is formed within balloon catheter lumen 294 between an inner surface of the balloon catheter 290 and an outer surface of the dilator shaft 288 along the length of balloon catheter 290. This annular space is in fluid communication with one or more balloon catheter inflation openings 292 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 balloon 296, for example during formation of leaflet opening 52. The pressure of the inflation fluid within balloon 296 may provide the force that allows it to dilate a leaflet opening 52. Further, the balloon catheter lumen 294 may be configured to withdraw fluid from the balloon 296 through the balloon catheter inflation opening(s) 292, to deflate the balloon 296.

[0223] In the illustrated example, the 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 balloon 296, such that the outer surface of the balloon 296can be flush or otherwise relatively continuous with the outer surface of the dilator 280.

[0224] Figs. 19A-19G illustrate some steps in a method for utilizing a system 200^e for forming an opening within a target tissue. An exemplary implementation of the method is illustrated in Figs. 19A-19G 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^e 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.

[0225] The distal end portion of the system 200^e 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 delivery catheter 150 and/or steerable catheter assembly 210 and/or the dilator 280 and/or the needle 264, relative to the host leaflet 10, may comprise advancing the delivery catheter 150 and/or steerable catheter assembly 210 and/or the dilator 280 and/or the needle 264 toward the leaflet over the guidewire 80 as described above with respect to Fig. 17A for example. As mentioned above, the needle lumen 266 can be configured to accommodate a guidewire 80 that can extend through the needle lumen 266. In such examples, the guidewire 80 can be inserted into the patient’ s vasculature, and then the hollow needle 264 along with the dilator 280, dilator shaft 288, balloon catheter 290, steerable catheter assembly 210, and/or delivery catheter 150, may be advanced toward the host leaflet 10 over the guidewire 80.

[0226] During delivery, the needle distal end portion 268 can be retained inside the dilator lumen 281, retaining the sharp needle tip 272 therein as illustrated in Fig. 19A. This position conceals the needle tip 272 from the surrounding anatomy, to protect the anatomical structures from being engaged or punctured by the needle tip 272 during advancement towards the site of treatment.

[0227] When the distal end portion of system 200^e lands at the target site, it may be initially positioned at a position that is different than the position of the desired host leaflet 10, as described above with respect to Fig. 9 A. If the delivery catheter 150 is a steerable delivery catheter, it can be bent to navigate the distal portion of the system 200^e toward the desired host leaflet 10, such as a leaflet that can be closer to the left coronary ostium. In some cases, as described above with respect to Fig. 17A, deflecting the system 200 sideways can orient the delivery catheter central longitudinal axis CD towards a host interior surface 14, which can be the interior surface of the aortic wall if the host valve is the native valve, or an interior surface of a frame of a previously implanted prosthetic valve serving as the host valve. In such cases, merely advancing a perforating member such as needle 264 in the distal direction to expose it prior to penetrating through the host leaflet 10, can direct the needle towards the host interior surface 14 instead of the host leaflet 10 itself.

[0228] In order to properly orient the needle 264, and optionally the dilator 280 and expansion member 296 as well, a distal portion of the steerable catheter assembly 210 can be exposed out of the delivery catheter 150 and bent, by pulling an appropriate elongated pull-arm 252 thereof as described above, advantageously orienting the distal tip portion 212 toward the host leaflet 10, as illustrated in Fig. 19B, such that during advancement of the needle 264, its distal end portion 268 can contact and pierce through the host leaflet 10, without posing a risk of contacting and damaging adjacent anatomical structures, such as the host interior surface 14. Exposing the steerable catheter assembly 210 out of delivery catheter 150 can be accomplished by distally pushing the steerable catheter assembly 210 relative to the delivery catheter 150, by proximally pulling the delivery catheter 150 relative to the steerable catheter assembly 210, or both.

[0229] In some examples, the dilator 280 can be flexible enough to bend along with the steerable catheter assembly 210 as it is passed therethrough in a bent state of the steerable catheter assembly 210, as illustrated in Fig. 19B. In some examples, when the dilator 280 is disposed inside a sufficient length of the inner tube slotted section 240 in a bent state of the steerable catheter assembly 210, at least a portion of the dilator 280, such as the dilator tapering portion 284, may be passively bent therewith.

[0230] As shown in Fig. 19C, the needle 264 is configured to puncture the host leaflet 10 to form a pilot puncture 50 within host leaflet 10, for example when its distal end portion 268 is axially translated relative to the distal tip portion 212 of the steerable catheter assembly 210 and/or relative to dilator 280.

[0231] Fig. 19D shows a subsequent step of distally extending the dilator 280 distally from the distal tip portion 212 of the steerable catheter assembly 210 and through the pilot puncture 50, optionally covering the needle distal end portion 268 to reconceal the needle tip 272 inside dilator lumen 281. As the dilator 280 is passed through the pilot puncture 50, it can also further expand the pilot puncture 50 to a greater diameter. Advancement of the dilator 280 with dilator shaft 288 and/or balloon catheter 290 can continue until the balloon 296 is inserted within the pilot puncture 50, as shown in Fig. 19E.

[0232] With the balloon 296 received within the pilot puncture 50, inflating the balloon 296 to transition it from a radially deflated state (Fig. 19E) to a radially inflated state (Fig. 19F) 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. 19F, the balloon 296 is deflated, as shown in Fig. 19G, optionally allowing for insertion of a guest prosthetic valve inside the leaflet opening 52.

[0233] 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. 17A-17J or 19A-19G, 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 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).

[0234] Similarly, the host valvular structure 12 in the examples of Figs. 17A-17J or 19A-19G 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.

[0235] 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. 17A-17J or 19A-19G to form a tissue opening, equivalent to leaflet opening 52 described with respect to Figs. 17A-17J or 19A-19G in a target tissue, equivalent to a host leaflet 10 described with respect to Figs. 17A-17J or 19A-19G.

[0236] 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 steerable delivery 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.

[0237] A steerable delivery 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.

[0238] In some examples, after forming the leaflet opening 52, and optionally after deflating the 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. In some examples, the guest prosthetic valve 100 can be positioned inside a leaflet opening 52 in a radially compressed state thereof, and expanded therein in a manner that modifies the host leaflet 10. Radially expanding the guest prosthetic valve 100 can be performed in any suitable manner, such as using any suitable valve expansion technique and/or mechanism that is known to the art. In some examples, radial expansion of the guest prosthetic valve 100 can be achieved by inflating an inflatable valve-expanding balloon on which the guest prosthetic valve is mounted. As mentioned above, in contrast to the hole-dilating balloon 296, the valve-expanding balloon (not shown) is configured to expand to a diameter which is significantly greater than a maximum diameter of the hole-dilating balloon 296.

[0239] In some examples, a steerable delivery 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 holedilating 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.

[0240] In some examples, a steerable delivery 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.

[0241] In some examples, more than one guidewire can be utilized in a method that includes forming the leaflet opening 52 by a steerable delivery 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 steerable delivery system 200 following the steps described with respect to Figs. 17A-17J or 19A-19G herein, 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.

[0242] 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.

[0243] 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.

[0244] 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. 17A-17J or 19A-19G 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.

[0245] 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.

[0246] 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.

[0247] 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. [0248] In other 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).

[0249] In some examples, forming the first leaflet opening can be performed prior to forming the second leaflet opening. In other 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.

[0250] 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.

[0251] 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. 20A 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. 17A-17J or 19A-19G. Fig. 20B 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. 20B, 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.

[0252] In the example of Fig. 20A, 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.

[0253] As shown in Fig. 20B, 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 114a 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.

[0254] In some examples, the guidewire 80 of any system 200 or method described herein, can be used as a perforating member for forming a pilot puncture 50 prior to and/or simultaneously with the needle 264. 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 guide wire 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.

[0255] In any examples 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. In some examples, the guidewire 80 is used as a perforating member that can be used in addition needle 264, such that the guidewire 80 can form an initial puncture via a sharp tip 82 or an RF energy delivery tip 82, followed by penetration of needle 264 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.

[0256] 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 and/or steerable catheter assembly 210 thereof, along with needle 264 and/or other shafts or components of the system 200, toward the valvular structure 12, but terminate in proximity of the host leaflet 10 without piercing through it, and the needle 264 can be then advanced into the leaflet 10 to form the pilot puncture 50.

[0257] While a hole-dilating balloon 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 member 296 can be used instead of a balloon in any of the methods and/or systems described herein. For example, U.S. Provisional Application Nos. 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] Figs. 21A-21C show an exemplary steerable catheter assembly 210^f. Steerable catheter assembly 210^f is an exemplary implementation of steerable catheter assembly 210, and thus can include any of the features described for steerable catheter assembly 210 throughout the current disclosure, except that the steerable catheter assembly 210^f further comprises one or more spacers 297 disposed between arm circumferential ends 262 of the one or more elongated pull-arms 252. Fig. 21A is a perspective view of a distal portion of the steerable catheter assembly 210^f with the outer tube 218 removed from view for illustrative purpose. Fig. 2 IB is a longitudinal cross-sectional view of a distal portion of the steerable catheter assembly 210^f with the inner tube 234 removed from view for illustrative purpose. Fig. 21C is a transverse cross-sectional view of a pull-member 250^f of the steerable catheter assembly 210^f, with spacers 297 disposed between the elongated pull-arms 252.

[0259] The number of spacer(s) 297 can generally match, in some examples, the number of elongated pull-arm(s) 252. When a plurality of elongated pull-arms 252 are provided, as illustrated in Figs. 21A-21C, the spacers 297 are positioned between the arm circumferential ends 262 of adjacent elongated pull-arms 252. The spacers 297 are configured to prevent accidental lateral movement of the elongated pull-arms 252 in the circumferential direction.

[0260] Each spacer 297 is disposed between the inner tube 234 and the outer tube 218, and can be generally curved in the same manner described above with respect to the at least one elongated pull-arm 252. A spacer 297 can have a spacer radial thickness Ts between inner and outer surfaces thereof (surfaces not annotated separately), wherein an inner surface of the spacer can have a radius of curvature that is generally similar to the radius of curvature RAI of the arm inner surface 254, and an outer surface of the spacer can have a radius of curvature that is generally similar to the radius of curvature RAO of the arm outer surface 256.

[0261] While a plurality of spacers 297 are illustrated in Figs. 21A-21C, it is to be understood that in the case of a single elongated pull-arm 252, as illustrated for pull-member 250^c for example, a single spacer 297 can be provided to span more than 180° around the steerable assembly central longitudinal axis Cx, such that the spacer 297 can circumferentially extend from one circumferential end 262 of the single elongated pull-arm 252 towards the opposite arm circumferential end 262.

[0262] In some examples, one or more spacers 297 can be provided as separate component(s) positioned between the tube(s) 218 and 234 during assembly of the steerable catheter assembly 210^f. In some examples, the spacers 297 can be formed by reflowing polymeric material between the slits 226 and/or 242 during manufacturing and assembly of the steerable catheter assembly 210^f.

[0263] Figs. 22A and 22B perspective view of an exemplary pull-member 250^g in non-tilted and tilted states, respectively, of a steering plate 259. Pull-member 250^s is an exemplary implementation of pull-member 250, and thus can include any of the features described for pull-member 250 throughout the current disclosure, except that the arm proximal portions 258 of pull-member 250⁸ are attached to a steering plate 259 that can be part of a steering control mechanism inside the handle 204.

[0264] The elongated pull-arms 252 of pull-member 250^s can have a uniform circumferential width WA along their entire lengths, without being widened at the arm proximal portions 258. The arm proximal portions 258 are attached to a steering plate 259, which can be in the form of a plate, a ring, and the like, configured to tilt relative to the steerable assembly central longitudinal axis Cx or relative to a longitudinal axis of the handle 204. Fig. 22A shows the steering plate in a non-tilted state thereof, wherein the plate 259 is substantially orthogonal to the steerable assembly central longitudinal axis Cx- This corresponds to an unbent state of the steerable catheter assembly 210. In some examples, the steering plate 259 is configured to tilt multidirec tionally .

[0265] An actuator of the handle 204 (such as a knob 206) can be maneuvered to tilt the steering plate 259 in a desired direction that can proximally pull at least one elongated pullarm 252, as illustrated in Fig. 22B, which in turn will bend a distal portion of the steerable catheter assembly 210 as described above. It is to be understood that while an exemplary pullmember 250^f is illustrated in Figs. 22A-22B to include four elongated pull-arms 252, the proximal portion(s) 258 of one or more elongated pull-arm(s) 252 of any other pull-member 250 disclosed herein can be attached to a steering plate 259, such that the pull-member 250^g can include two elongated pull-arms 252 as described with respect to pull-member 250^b, a single elongated pull-arm 252 as described with respect to pull-member 250^c, or any other number of elongated pull-arms 252. Similarly, one or more spacers 297 can be optionally placed between circumferential end 262 of the one or more elongated pull-arms 252 of pullmember 250⁸.

[0266] It is to be understood that any of the exemplary steerable catheter assembly 210 and/or any of the exemplary pull-members 250 described above can be used with any exemplary system 200, including any of the exemplary system 200^d and 200^e.

[0267] Any of the systems, devices, assemblies, 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 Technology

[0268] Some examples of above-described technology 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.

[0269] Example 1. A steerable delivery system comprising: a handle; and a steerable catheter assembly extending distally from the handle and comprising: a steerable assembly lumen defining a steerable assembly central longitudinal axis; an inner tube comprising: an inner tube slotted portion defining an inner tube outer surface oriented away from the steerable assembly central longitudinal axis; and an inner tube distal end portion distal to the inner tube slotted portion; an outer tube disposed around the inner tube, the outer tube comprising: an outer tube slotted portion defining an outer tube inner surface oriented towards the steerable assembly central longitudinal axis; and an outer tube distal end portion distal to the inner tube slotted portion; and a pull-member comprising: a pull-ring portion affixed to the inner tube distal end portion and to the outer tube distal end portion; and at least one elongated pull-arm extending proximally from the pull-ring portion, wherein the at least one elongated pull-arm is disposed between the inner tube outer surface and the outer tube inner surface, and is axially slidable relative to the inner tube slotted portion and the outer tube slotted portion; wherein the at least one elongated pull-arm defines a circumferential width between arm circumferential ends that is greater than a radial thickness of the at least one elongated pull-arm; and wherein the at least one elongated pull-arm is configured to bend the steerable catheter assembly when the at least one elongated pull-arm is proximally pulled.

[0270] Example 2. The system of any example herein, particularly of example 1, wherein a radial thickness defined by the pull-ring portion is equal to the radial thickness of the at least one elongated pull-arm.

[0271] Example 3. The system of any example herein, particularly of example 1 or 2, wherein the at least one elongated pull-arm is integrally formed with the pull-ring portion.

[0272] Example 4. The system of any example herein, particularly of example 3, wherein the pull-member is cut from a tube.

[0273] Example 5. The system of any example herein, particularly of any one of examples 1 to 4, wherein the at least one elongated pull-arm comprises a plurality of elongated pull-arms. [0274] Example 6. The system of any example herein, particularly of example 5, wherein the plurality of elongated pull-arms comprises two elongated pull-arms disposed at 180° from each other.

[0275] Example 7. The system of any example herein, particularly of example 5, wherein the plurality of elongated pull-arms comprises four elongated pull-arms disposed at 90° from each other.

[0276] Example 8. The system of any example herein, particularly of any one of examples 1 to 7, wherein the circumferential width of the at least one elongated pull-arm is at least two times as great as its radial thickness.

[0277] Example 9. The system of any example herein, particularly of any one of examples 1 to 7, wherein the circumferential width of the at least one elongated pull-arm is at least three times as great as its radial thickness.

[0278] Example 10. The system of any example herein, particularly of any one of examples 1 to 9, wherein the at least one elongated pull-arm comprises a curved arm inner surface oriented towards the steerable assembly central longitudinal axis, and a curved arm outer surface oriented away from the steerable assembly central longitudinal axis. [0279] Example 11. The system of any example herein, particularly of example 10, wherein the arm inner surface defines a radius of curvature that is equal to or greater than a radius defined by the inner tube outer surface.

[0280] Example 12. The system of any example herein, particularly of example 10 or 11, wherein the arm outer surface defines a radius of curvature that is equal to or less than a radius defined by the outer tube inner surface.

[0281] Example 13. The system of any example herein, particularly of any one of examples 1 to 12, wherein the at least one elongated pull-arm comprises an arm proximal portion extending into the handle.

[0282] Example 14. The system of any example herein, particularly of example 13, wherein the circumferential width of the elongated pull- arm at the arm proximal portion is greater than the circumferential width of the elongated pull-arm at a portion of the at least one elongated pull-arm disposed between the inner tube slotted portion and the outer tube slotted portion.

[0283] Example 15. The system of any example herein, particularly of example 13 or 14, wherein the arm proximal portion comprises a coupling aperture.

[0284] Example 16. The system of any example herein, particularly of example 13, further comprising a steering plate disposed inside the handle, wherein the arm proximal portion is attached to the steering plate.

[0285] Example 17. The system of any example herein, particularly of example 16, wherein the steering plate is configured to tilt relative to the steerable assembly central longitudinal axis.

[0286] Example 18. The system of any example herein, particularly of any one of examples 1 to 17, wherein the steerable catheter assembly further comprises at least one spacer radially disposed between the inner tube and the outer tube, and circumferentially extending between the arm circumferential ends of the at least one elongated pull- arm.

[0287] Example 19. The system of any example herein, particularly of any one of examples 1 to 18, wherein the inner tube slotted portion comprises a plurality of circumferential bands arranged between a plurality of circumferential slits of the inner tube slotted portion.

[0288] Example 20. The system of any example herein, particularly of any one of examples 1 to 19, wherein the outer tube slotted portion comprises a plurality of circumferential bands arranged between a plurality of circumferential slits of the outer tube slotted portion.

[0289] Example 21. The system of any example herein, particularly of any one of examples 1 to 20, wherein the steerable catheter assembly further comprises a distal tip portion, attached to at least one of the pull-ring portion, the inner tube distal end portion, or the outer tube distal end portion.

[0290] Example 22. The system of any example herein, particularly of example 21, wherein the distal tip portion comprises a distal atraumatic end.

[0291] Example 23. The system of any example herein, particularly of any one of examples 1 to 22, further comprising a delivery catheter extending distally from the handle, the delivery catheter comprising a primary lumen through which the steerable catheter assembly extends.

[0292] Example 24. The system of any example herein, particularly of example 23, wherein the steerable catheter assembly is axially movable relative to the delivery catheter.

[0293] Example 25. The system of any example herein, particularly of example 23 or 24, wherein the delivery catheter is a steerable delivery catheter comprising a slotted tube disposed around the primary lumen.

[0294] Example 26. The system of any example herein, particularly of example 25, wherein the steerable delivery catheter further comprises a pull-wire lumen extending along at least a portion of the steerable delivery catheter.

[0295] Example 27. The system of any example herein, particularly of example 26, further comprising a pull-wire slidingly extending through the pull-wire lumen and attached to the slotted tube.

[0296] Example 28. The system of any example herein, particularly of example 27, wherein the pull- wire defines a pull- wire diameter that is greater than the radial thickness of the at least one elongated pull-arm.

[0297] Example 29. The system of any example herein, particularly of example 28, wherein the circumferential width of the at least one elongated pull-arm is greater than the pull-wire diameter.

[0298] Example 30. The system of any example herein, particularly of any one of examples 25 to 29, wherein the slotted tube comprises a plurality of slots axially spaced from each other, and a plurality of ribs defined between the slots.

[0299] Example 31. The system of any example herein, particularly of example 30, wherein each slot spans more than 180° of a circumference of the slotted tube.

[0300] Example 32. The system of any example herein, particularly of example 30, wherein each slot spans more than 220° of a circumference of the slotted tube.

[0301] Example 33. The system of any example herein, particularly of example 30, wherein each slot spans more than 270° of a circumference of the slotted tube. [0302] Example 34. The system of any example herein, particularly of any one of examples 30 to 33, wherein the slotted tube further comprises a backbone opposite circumferential centers of the slots, the backbone defined by uncut portions of the slotted tube between circumferential ends of the slots.

[0303] Example 35. The system of any example herein, particularly of example 34, wherein the slotted tube further comprises a plurality of opposite cuts axially spaced from each other and extending through the backbone.

[0304] Example 36. The system of any example herein, particularly of example 35, wherein the opposite cuts are axially disposed between the slots.

[0305] Example 37. The system of any example herein, particularly of example 35 or 36, wherein each opposite cut comprises an opening and two side slits circumferentially extending therefrom.

[0306] Example 38. The system of any example herein, particularly of any one of examples 35 to 37, wherein the steerable delivery catheter further comprises a polymeric layer disposed around the primary lumen.

[0307] Example 39. The system of any example herein, particularly of example 38, wherein the slotted tube is embedded within the polymeric layer.

[0308] Example 40. The system of any example herein, particularly of example 38 or 39, wherein the steerable delivery catheter further comprises a braid.

[0309] Example 41. The system of any example herein, particularly of example 40, wherein the braid is embedded within the polymeric layer.

[0310] Example 42. The system of any example herein, particularly of any one of examples 1 to 41, further comprising a perforating member defining a perforating member lumen, the perforating member extending through the steerable assembly lumen.

[0311] Example 43. The system of any example herein, particularly of example 42, wherein the perforating member is configured to pierce a target tissue to form a pilot puncture in the target tissue.

[0312] Example 44. The system of any example herein, particularly of example 43, wherein the perforating member is axially movable relative to the steerable catheter assembly.

[0313] Example 45. The system of any example herein, particularly of example 43 or 44, wherein the perforating member comprises a plurality of circumferential bands arranged between a plurality of circumferential slits of the perforating member. [0314] Example 46. The system of any example herein, particularly of any one of examples 43 to 45, wherein the perforating member comprises a needle, and wherein the perforating member lumen comprises a needle lumen.

[0315] Example 47. The system of any example herein, particularly of example 46, wherein the needle comprises a needle distal end portion defining an angled surface.

[0316] Example 48. The system of any example herein, particularly of example 47, wherein the needle distal end portion terminates at a needle tip.

[0317] Example 49. The system of any example herein, particularly of any one of examples 46 to 48, wherein the needle is one or both of a spring-loaded needle and a Veress needle.

[0318] Example 50. The system of any example herein, particularly of any one of examples 46 to 49, further comprising a guidewire extending through the needle lumen.

[0319] Example 51. The system of any example herein, particularly of example 43 or 44, wherein the perforating member comprises a guidewire.

[0320] Example 52. The system of any example herein, particularly of example 50 or 51, wherein the guidewire comprises a sharp tip configured to pierce through the target tissue.

[0321] Example 53. The system of any example herein, particularly of example 50 or 51, further comprising an RF energy source coupled to the guidewire and configured to provide RF energy to a tip of the guidewire.

[0322] Example 54. The system of any example herein, particularly of any one of examples 43 to 53, wherein the target tissue is a host leaflet of a host valvular structure.

[0323] Example 55. The system of any example herein, particularly of example 54, wherein the host valvular structure is a native valvular structure of native heart valve.

[0324] Example 56. The system of any example herein, particularly of example 54, wherein the host valvular structure is a valvular structure of previously implanted prosthetic valve that is implanted within a native heart valve.

[0325] Example 57. The system of any example herein, particularly of example 55 or 56, wherein the native heart valve is an aortic valve.

[0326] Example 58. The system of any example herein, particularly of any one of examples 43 to 57, further comprising an expansion member configured to expand a pilot puncture formed in a target tissue by the perforating member.

[0327] Example 59. The system of any example herein, particularly of example 58, wherein the expansion member is axially movable through, and relative to, the steerable catheter assembly. [0328] Example 60. The system of any example herein, particularly of example 58 or 59, further comprising a balloon catheter defining a balloon catheter lumen, wherein the expansion member comprises a balloon mounted on the balloon catheter and in fluid communication with the balloon catheter lumen, the balloon configured to transition between deflated and inflated states thereof.

[0329] Example 61. The system of any example herein, particularly of example 60, wherein the balloon catheter is extendable through the steerable assembly lumen.

[0330] Example 62. The system of any example herein, particularly of example 60 or 61 , wherein the perforating member is axially movable relative to the balloon catheter.

[0331] Example 63. The system of any example herein, particularly of any one of examples 60 to 62, further comprising a dilator attached to a dilator shaft extending proximally therefrom through the balloon catheter lumen, wherein the perforating member extends through a dilator lumen defined by the dilator and the dilator shaft.

[0332] Example 64. The system of any example herein, particularly of example 63, wherein the perforating member is axially movable relative to the dilator.

[0333] Example 65. The system of any example herein, particularly of example 63 or 64, wherein the perforating member is axially movable relative to the dilator shaft.

[0334] Example 66. The system of any example herein, particularly of any one of examples 63 to 65, wherein the dilator comprises a dilator tapering portion.

[0335] Example 67. The system of any example herein, particularly of example 66, wherein the dilator further comprises a dilator proximal portion which is proximal to the dilator tapering portion.

[0336] Example 68. The system of any example herein, particularly of any one of examples 63 to 67, wherein the balloon is attached on one end to the balloon catheter, and on an opposite end to the dilator.

[0337] Example 69. The system of any example herein, particularly of any one of examples 63 to 67, wherein the balloon is attached on one end to the balloon catheter, and on an opposite end to the dilator shaft.

[0338] Example 70. A method comprising: advancing a steerable delivery system comprising a steerable catheter assembly, over a guidewire, to a target tissue, the steerable catheter assembly comprising an inner tube, an outer tube disposed around the inner tube, and a pull-member that comprises a pull-ring portion affixed to an inner tube distal end portion of the inner tube and to an outer tube distal end portion of the outer tube, and at least one elongated pull-arm extending proximally from the pull-ring portion and which is slidingly movable between and relative to the inner tube and the outer tube; bending a distal portion of the steerable catheter assembly by proximally pulling the at least one elongated pull-arm; and forming, with a perforating member tip of a perforating member extending through a steerable assembly lumen defined by the steerable catheter assembly, a pilot puncture within a target tissue; wherein the at least one elongated pull-arm defines a circumferential width between arm circumferential ends that is greater than a radial thickness of the at least one elongated pull.

[0339] Example 71. The method of any example herein, particularly of example 70, wherein a radial thickness defined by the pull-ring portion is equal to the radial thickness of the at least one elongated pull-arm.

[0340] Example 72. The method of any example herein, particularly of example 70 or 71, wherein the at least one elongated pull-arm is integrally formed with the pull-ring portion.

[0341] Example 73. The method of any example herein, particularly of example 72, wherein the pull-member is cut from a tube.

[0342] Example 74. The method of any example herein, particularly of any one of examples 70 to 73, wherein the at least one elongated pull-arm comprises a plurality of elongated pullarms, and wherein the bending by proximally pulling the at least one elongated pull-arm proximally pulling at least one of the plurality of elongated pull-arms relative to another one of the plurality of elongated pull-arms.

[0343] Example 75. The method of any example herein, particularly of example 74, wherein the plurality of elongated pull-arms comprises two elongated pull-arms disposed at 180° from each other.

[0344] Example 76. The method of any example herein, particularly of example 74, wherein the plurality of elongated pull-arms comprises four elongated pull-arms disposed at 90° from each other.

[0345] Example 77. The method of any example herein, particularly of any one of examples 70 to 76, wherein the circumferential width of the at least one elongated pull-arm is at least two times as great as its radial thickness.

[0346] Example 78. The method of any example herein, particularly of any one of examples 70 to 76, wherein the circumferential width of the at least one elongated pull-arm is at least three times as great as its radial thickness. [0347] Example 79. The method of any example herein, particularly of any one of examples 70 to 78, wherein the at least one elongated pull-arm comprises a curved arm inner surface oriented towards a steerable assembly central longitudinal axis defined by the steerable catheter assembly, and a curved arm outer surface oriented away from the steerable assembly central longitudinal axis.

[0348] Example 80. The method of any example herein, particularly of example 79, wherein the arm inner surface defines a radius of curvature that is equal to or greater than a radius defined by the inner tube outer surface.

[0349] Example 81. The method of any example herein, particularly of example 79 or 80, wherein the arm outer surface defines a radius of curvature that is equal to or less than a radius defined by the outer tube inner surface.

[0350] Example 82. The method of any example herein, particularly of any one of examples 70 to 81, wherein the pulling the at least one elongated pull-arm comprises tilting a steering plate to which an arm proximal portion of the at least one elongated pull-arm is attached.

[0351] Example 83. The method of any example herein, particularly of any one of examples 70 to 82, wherein the perforating member is axially movable relative to the steerable catheter assembly.

[0352] Example 84. The method of any example herein, particularly of any one of examples 70 to 83, wherein the advancing the steerable delivery system to the target tissue comprises retaining the perforating member tip inside the steerable assembly lumen.

[0353] Example 85. The method of any example herein, particularly of example 84, wherein the forming the pilot puncture comprises advancing the perforating member so as to expose the perforating member tip out of the steerable assembly lumen.

[0354] Example 86. The method of any example herein, particularly of any one of examples 70 to 85, wherein the perforating member defines a perforating member lumen through which the guidewire extends.

[0355] Example 87. The method of any example herein, particularly of example 86, wherein the perforating member comprises a needle, wherein the perforating member lumen comprises a needle lumen, and wherein the perforating member tip comprises a needle tip.

[0356] Example 88. The method of any example herein, particularly of example 87, wherein the needle comprises a needle distal end portion defining an angled surface.

[0357] Example 89. The method of any example herein, particularly of example 87 or 88, wherein the needle is one or both of a spring-loaded needle and a Veress needle. [0358] Example 90. The method of any example herein, particularly of any one of examples 87 to 89, wherein the forming the pilot puncture comprises perforating the target tissue by the guidewire, followed by piercing the target tissue by the perforating member, advanced over the guidewire to form the pilot puncture.

[0359] Example 91. The method of any example herein, particularly of example 90, wherein the perforating the target tissue by the guidewire comprises applying RF energy to a tip of the guidewire.

[0360] Example 92. The method of any example herein, particularly of any one of examples 70 to 85, wherein the perforating member comprises the guidewire, and wherein the perforating member tip comprises a guide wire tip.

[0361] Example 93. The method of any example herein, particularly of example 92, wherein the forming the pilot puncture comprises applying RF energy to the guidewire tip.

[0362] Example 94. The method of any example herein, particularly of any one of examples 70 to 89, wherein the steerable delivery system further comprises a delivery catheter defining a primary lumen through which the steerable catheter assembly extends.

[0363] Example 95. The method of any example herein, particularly of example 94, wherein the steerable catheter assembly is axially movable relative to the delivery catheter.

[0364] Example 96. The method of any example herein, particularly of example 94 or 95, further comprising, prior to the bending the distal portion of the steerable catheter assembly, distally advancing the steerable catheter assembly relative to the delivery catheter.

[0365] Example 97. The method of any example herein, particularly of any one of examples 94 to 96, wherein the delivery catheter is a steerable delivery catheter comprising a slotted tube disposed around the primary lumen.

[0366] Example 98. The method of any example herein, particularly of example 97, further comprising, prior to the bending the distal portion of the steerable catheter assembly, bending the steerable delivery catheter.

[0367] Example 99. The method of any example herein, particularly of example 98, wherein the bending the distal portion of the steerable catheter assembly comprises bending the distal portion of the steerable catheter assembly at a different bending direction than a bending direction of the steerable delivery catheter.

[0368] Example 100. The method of any example herein, particularly of example 98 or 99, wherein the bending the steerable delivery catheter comprises proximally pulling a pull-wire attached to the slotted tube. [0369] Example 101. The method of any example herein, particularly of example 100, wherein the pull- wire defines a pull- wire diameter that is greater than the radial thickness of the at least one elongated pull-arm.

[0370] Example 102. The method of any example herein, particularly of example 101, wherein the circumferential width of the at least one elongated pull-arm is greater than the pull-wire diameter.

[0371] Example 103. The method of any example herein, particularly of any one of examples 97 to 102, wherein the slotted tube comprises a plurality of slots axially spaced from each other, and a plurality of ribs defined between the slots.

[0372] Example 104. The method of any example herein, particularly of any one of examples 97 to 103, wherein the steerable delivery catheter further comprises a polymeric layer disposed around the primary lumen.

[0373] Example 105. The method of any example herein, particularly of example 104, wherein the slotted tube is embedded within the polymeric layer.

[0374] Example 106. The method of any example herein, particularly of example 104 or 105, wherein the steerable delivery catheter further comprises a braid.

[0375] Example 107. The method of any example herein, particularly of example 106, wherein the braid is embedded within the polymeric layer.

[0376] Example 108. The method of any example herein, particularly of any one of examples 70 to 102, further comprising passing the guidewire through the pilot puncture to terminate distally to the pilot puncture of the target tissue.

[0377] Example 109. The method of any example herein, particularly of example 108, further comprising, after the passing the guidewire through the pilot puncture, retrieving the perforating member while maintaining the guidewire extending through the pilot puncture.

[0378] Example 110. The method of any example herein, particularly of example 109, wherein the retrieving the perforating member further comprises retrieving the steerable catheter assembly.

[0379] Example 111. The method of any example herein, particularly of example 109 or 110, further comprising, subsequent to the retrieving the perforating member, advancing an expansion member, over the guidewire, towards the target tissue.

[0380] Example 112. The method of any example herein, particularly of example 111, further comprising, subsequent to the advancing the expansion member, positioning the expansion member inside the pilot puncture, in a compacted state of the expansion member. [0381] Example 113. The method of any example herein, particularly of example 112, further comprising, subsequent to the positioning the expansion member inside the pilot puncture, expanding the expansion member to expand the pilot puncture and form a tissue opening within the target tissue.

[0382] Example 114. The method of any example herein, particularly of example 113, wherein the expansion member comprises a balloon mounted on a balloon catheter, wherein the compacted state of the expansion member is a deflated state of the balloon, and wherein the expanding the expansion member comprises inflating the balloon.

[0383] Example 115. The method of any example herein, particularly of example 114, further comprising, subsequent to the forming the pilot puncture and prior to the positioning the balloon inside the pilot puncture, passing a dilator through the pilot puncture, thereby further expanding the pilot puncture.

[0384] Example 116. The method of any example herein, particularly of any one of examples 70 to 102, wherein the steerable delivery system further comprises an expansion member axially movable relative to the steerable catheter assembly.

[0385] Example 117. The method of any example herein, particularly of example 116, wherein the perforating member is axially movable relative to the expansion member.

[0386] Example 118. The method of any example herein, particularly of example 116 or 117, further comprising, after the forming the pilot puncture, positioning the expansion member inside the pilot puncture, in a compacted state of the expansion member.

[0387] Example 119. The method of any example herein, particularly of example 118, further comprising, subsequent to the positioning the expansion member inside the pilot puncture, expanding the expansion member to expand the pilot puncture and form a tissue opening within the target tissue.

[0388] Example 120. The method of any example herein, particularly of example 119, wherein the expansion member comprises a balloon mounted on a balloon catheter, wherein the compacted state of the expansion member is a deflated state of the balloon, and wherein the expanding the expansion member comprises inflating the balloon.

[0389] Example 121. The method of any example herein, particularly of example 120, wherein the steerable delivery system further comprises a dilator defining a dilator lumen, and wherein the perforating member extends through the dilator lumen.

[0390] Example 122. The method of any example herein, particularly of example 121, further comprising, subsequent to the forming the pilot puncture and prior to the positioning the balloon inside the pilot puncture, passing the dilator through the pilot puncture, thereby further expanding the pilot puncture.

[0391] Example 123. The method of any example herein, particularly of any one of examples 115 or 122, wherein the dilator is attached to a dilator shaft extending proximally therefrom, through a lumen of the balloon catheter.

[0392] Example 124. The method of any example herein, particularly of any one of examples 115 or 122-123, wherein the dilator comprises a dilator tapering portion terminating at a dilator distal end.

[0393] Example 125. The method of any example herein, particularly of any one of examples 115 or 122-124, wherein the balloon is attached at a proximal end thereof to the balloon catheter, and at a distal end of the balloon to the dilator.

[0394] Example 126. The method of any example herein, particularly of any one of examples 113-115 or 119-122, further comprising, subsequent to the expanding the expansion member, transitioning the expansion member back to its compacted state.

[0395] Example 127. The method of any example herein, particularly of any one of examples 113-115 or 119-122 or 126, wherein the target tissue is a host leaflet of a host valvular structure, and wherein the tissue opening is a leaflet opening.

[0396] Example 128. The method of any example herein, particularly of example 127, 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.

[0397] Example 129. The method of any example herein, particularly of example 128, wherein the positioning the guest prosthetic valve within the host valvular structure comprises positioning the guest prosthetic valve within the leaflet opening.

[0398] Example 130. The method of any example herein, particularly of example 128, 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 structure.

[0399] Example 131. The method of any example herein, particularly of any one of examples 128 to 130, wherein the radially expanding the guest prosthetic valve comprises inflating a valve-expanding balloon over which the guest prosthetic valve is disposed.

[0400] Example 132. The method of any example herein, particularly of any one of examples 128 to 130, wherein the radially expanding the guest prosthetic valve comprises actuating a mechanical actuator of the guest prosthetic valve. [0401] Example 133. The method of any example herein, particularly of any one of examples 128 to 130, 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.

[0402] Example 134. The method of any example herein, particularly of any one of examples 127 to 133, wherein the host valvular structure is a native valvular structure of native heart valve.

[0403] Example 135. The method of any example herein, particularly of any one of examples 127 to 133, wherein the host valvular structure is a valvular structure of previously implanted prosthetic valve that is implanted within a native heart valve.

[0404] Example 136. The method of any example herein, particularly of example 134 or 135, wherein the native heart valve is an aortic valve.

[0405] Example 137. A steerable catheter comprising: an inner tube comprising: an inner tube slotted portion; and an inner tube distal end portion distal to the inner tube slotted portion; an outer tube disposed around the inner tube, the outer tube comprising: an outer tube slotted portion; and an outer tube distal end portion distal to the inner tube slotted portion; and a pull-member comprising: a pull-ring portion affixed to the inner tube and the outer tube; and an elongated pull-arm disposed between the inner tube and the outer tube and extending proximally from the pull-ring portion, wherein proximal pulling of the elongated pull-arm causes bending of the inner tube slotted portion and the outer tube slotted portion.

[0406] Example 138. The system of any example herein, particularly of example 137, wherein the elongated pull- arm has a circumferential width greater than its radial thickness.

[0407] Example 139. The system of any example herein, particularly of example 137 or 138, wherein the pull-ring portion is affixed to the inner tube distal end portion and the outer tube distal end portion.

[0408] Example 140. The system of any example herein, particularly of any one of examples 137 to 139, wherein the elongated pull-arm is axially slidable relative to the inner tube and the outer tube. [0409] Example 141. The system of any example herein, particularly of any one of examples 137 to 140, wherein the bending of the inner tube slotted portion and the outer tube slotted portion causes the steerable catheter to bend.

[0410] Example 142. A method comprising: advancing a steerable delivery system comprising a perforating member and a steerable catheter assembly to a target tissue, the steerable catheter assembly comprising an inner tube, an outer tube disposed around the inner tube, and a pull-member, wherein the pull-member comprises a pull-ring portion affixed to distal ends of the inner tube and the outer tube, and an elongated pull-arm extending proximally from the pull-ring portion and disposed between the inner tube and the outer tube; pulling the elongated pull-arm; and advancing the perforating member through a lumen of the steerable delivery system and towards the target tissue to form a puncture within the target tissue.

[0411] 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.

[0412] 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

WE CLAIM:

1. A steerable delivery system comprising: a handle; and a steerable catheter assembly extending distally from the handle and comprising: a steerable assembly lumen defining a steerable assembly central longitudinal axis; an inner tube comprising: an inner tube slotted portion defining an inner tube outer surface oriented away from the steerable assembly central longitudinal axis; and an inner tube distal end portion distal to the inner tube slotted portion; an outer tube disposed around the inner tube, the outer tube comprising: an outer tube slotted portion defining an outer tube inner surface oriented towards the steerable assembly central longitudinal axis; and an outer tube distal end portion distal to the inner tube slotted portion; and a pull-member comprising: a pull-ring portion affixed to the inner tube distal end portion and to the outer tube distal end portion; and at least one elongated pull-arm extending proximally from the pull-ring portion, wherein the at least one elongated pull-arm is disposed between the inner tube outer surface and the outer tube inner surface, and is axially slidable relative to the inner tube slotted portion and the outer tube slotted portion; wherein the at least one elongated pull-arm defines a circumferential width between arm circumferential ends that is greater than a radial thickness of the at least one elongated pull-arm; and wherein the at least one elongated pull-arm is configured to bend the steerable catheter assembly when the at least one elongated pull-arm is proximally pulled.

2. The system of claim 1, wherein the at least one elongated pull-arm is integrally formed with the pull-ring portion.

3. The system of any one of claims 1 to 2, wherein the at least one elongated pullarm comprises a plurality of elongated pull-arms.

4. The system of claim 3, wherein the plurality of elongated pull-arms comprises four elongated pull-arms disposed at 90° from each other.

5. The system of any one of claims 1 to 4, wherein the circumferential width of the at least one elongated pull-arm is at least two times as great as its radial thickness.

6. The system of any one of claims 1 to 5, wherein the at least one elongated pullarm comprises a curved arm inner surface oriented towards the steerable assembly central longitudinal axis, and a curved arm outer surface oriented away from the steerable assembly central longitudinal axis.

7. The system of any one of claims 1 to 6, wherein the at least one elongated pullarm comprises an arm proximal portion extending into the handle, and wherein the circumferential width of the elongated pull-arm at the arm proximal portion is greater than the circumferential width of the elongated pull-arm at a portion of the at least one elongated pullarm disposed between the inner tube slotted portion and the outer tube slotted portion.

8. The system of claim 7, further comprising a steering plate disposed inside the handle, wherein the arm proximal portion is attached to the steering plate, and wherein the steering plate is configured to tilt relative to the steerable assembly central longitudinal axis.

9. The system of any one of claims 1 to 8, further comprising a delivery catheter extending distally from the handle, the delivery catheter comprising a primary lumen through which the steerable catheter assembly extends.

10. The system of claim 9, wherein the delivery catheter is a steerable delivery catheter comprising a slotted tube disposed around the primary lumen, and a pull-wire lumen extending along at least a portion of the steerable delivery catheter, and wherein the system further comprises a pull-wire slidingly extending through the pull-wire lumen and attached to the slotted tube.

11. The system of claim 10, wherein the pull- wire defines a pull-wire diameter that is greater than the radial thickness of the at least one elongated pull-arm.

12. The system of any one of claims 1 to 11, further comprising a perforating member defining a perforating member lumen, the perforating member extending through the steerable assembly lumen.

13. The system of claim 12, wherein the perforating member is configured to pierce a target tissue to form a pilot puncture in the target tissue.

14. The system of claim 13, further comprising an expansion member configured to expand a pilot puncture formed in a target tissue by the perforating member.

15. A method comprising : advancing a steerable delivery system comprising a steerable catheter assembly, over a guidewire, to a target tissue, the steerable catheter assembly comprising an inner tube, an outer tube disposed around the inner tube, and a pull-member that comprises a pull-ring portion affixed to an inner tube distal end portion of the inner tube and to an outer tube distal end portion of the outer tube, and at least one elongated pull-arm extending proximally from the pull-ring portion and which is slidingly movable between and relative to the inner tube and the outer tube; bending a distal portion of the steerable catheter assembly by proximally pulling the at least one elongated pull-arm; and forming, with a perforating member tip of a perforating member extending through a steerable assembly lumen defined by the steerable catheter assembly, a pilot puncture within a target tissue; and wherein the at least one elongated pull-arm defines a circumferential width between arm circumferential ends that is greater than a radial thickness of the at least one elongated pull.

16. The method of claim 15, wherein the pulling the at least one elongated pull- arm comprises tilting a steering plate to which an arm proximal portion of the at least one elongated pull- arm is attached.

17. The method of any one of claims 1 to 16, wherein the steerable delivery system further comprises a delivery catheter defining a primary lumen through which the steerable catheter assembly extends, and a slotted tube disposed around the primary lumen, and wherein the method further comprises, prior to the bending the distal portion of the steerable catheter assembly, bending the steerable delivery catheter.

18. The method of claim 17, wherein the bending the distal portion of the steerable catheter assembly comprises bending the distal portion of the steerable catheter assembly at a different bending direction than a bending direction of the steerable delivery catheter.

19. The method of claim 17 or 18, wherein the bending the steerable delivery catheter comprises proximally pulling a pull-wire attached to the slotted tube.

20. The method of any one of claims 15 to 19, wherein the steerable delivery system further comprises an expansion member axially movable relative to the steerable catheter assembly.

21. The method of claim 20, further comprising, after the forming the pilot puncture, positioning the expansion member inside the pilot puncture, in a compacted state of the expansion member.

22. The method of claim 21, further comprising, subsequent to the positioning the expansion member inside the pilot puncture, expanding the expansion member to expand the pilot puncture and form a tissue opening within the target tissue.

23. A steerable delivery assembly comprising: an inner tube comprising an inner tube slotted portion and an inner tube distal portion distal to the inner tube slotted portion; an outer tube comprising an outer tube slotted portion and an outer tube distal portion distal to the outer tube slotted portion; a pull-member comprising: a distal portion affixed to the inner tube distal end portion or the outer tube distal end portion; and at least one elongated pull-arm extending proximally from the distal portion.

24. The steerable delivery assembly of claim 23, wherein the at least one elongated pull-arm defines a circumferential width between arm circumferential ends that is greater than a radial thickness of the at least one elongated pull-arm.

25. The steerable delivery assembly of any one of claims 23 to 24, wherein the at least one elongated pull-arm is configured to bend the steerable catheter assembly when the at least one elongated pull-arm is proximally pulled.

26. The steerable delivery assembly of any one of claims 23 to 25 , wherein the distal portion of the pull-member is a ring positioned between the inner tube distal end portion or the outer tube distal end portion.

27. The steerable delivery assembly of any one of claims 23 to 26, wherein the at least one elongated pull-arm is disposed between the inner tube outer surface and the outer tube inner surface, and is axially slidable relative to the inner tube slotted portion and the outer tube slotted portion.