US20040127982A1 - Devices, systems, and methods for reshaping a heart valve annulus - Google Patents

Abstract

Devices, systems, and methods employ an implant that is sized and configured to attach to the annulus of a dysfunctional heart valve annulus. In use, the implant extends across the major axis of the annulus above and/or along the valve annulus. The implant reshapes the major axis dimension and/or other surrounding anatomic structures. The implant restores to the heart valve annulus and leaflets a more functional anatomic shape and tension. The more functional anatomic shape and tension are conducive to coaptation of the leaflets, which, in turn, reduces retrograde flow or regurgitation. The implant improves function to the valve, without surgically cinching, resecting, and/or fixing in position large portions of a dilated annulus, or without the surgical fixation of ring-like structures.

Description

RELATED APPLICATIONS
• This application claims the benefit of co-pending U.S. patent application Ser. No. 09/666,617, filed Sep. 20, 2000 and entitled “Heart Valve Annulus Device and Methods of Using Same,” which is incorporated herein by reference. This application also claims the benefit of Patent Cooperation Treaty application Ser. No. PCT/US 02/31376, filed Oct. 1, 2002 and entitled “Systems and Devices for Heart Valve Treatments,” which claimed the benefit of U.S. Provisional Patent Application Serial No. 60/326,590, filed Oct. 1, 2001, which are incorporated herein by reference. This application also claims the benefit of U.S. Provisional Application Serial No. 60/429,444, filed Nov. 26, 2002, and entitled “Heart Valve Remodeling Devices;” U.S. Provisional Patent Application Serial No. 60/429,709, filed Nov. 26, 2002, and entitled “Neo-Leaflet Medical Devices;” and U.S. Provisional Patent Application Serial No. 60/429,462, filed Nov. 26, 2002, and entitled “Heart Valve Leaflet Retaining Devices,” which are each incorporated herein by reference.[0001]
FIELD OF THE INVENTION
• The invention is directed to devices, systems, and methods for improving the function of a heart valve, e.g., in the treatment of mitral valve regurgitation.[0002]
BACKGROUND OF THE INVENTION
• I. The Anatomy of a Healthy Heart[0003]
• The heart (see FIG. 1) is slightly larger than a clenched fist. It is a double (left and right side), self-adjusting muscular pump, the parts of which work in unison to propel blood to all parts of the body. The right side of the heart receives poorly oxygenated (“venous”) blood from the body from the superior vena cava and inferior vena cava and pumps it through the pulmonary artery to the lungs for oxygenation. The left side receives well-oxygenation (“arterial”) blood from the lungs through the pulmonary veins and pumps it into the aorta for distribution to the body.[0004]
• The heart has four chambers, two on each side —the right and left atria, and the right and left ventricles. The atria are the blood-receiving chambers, which pump blood into the ventricles. A wall composed of membranous and muscular parts, called the interatrial septum, separates the right and left atria. The ventricles are the blood-discharging chambers. A wall composed of membranous and muscular parts, called the interventricular septum, separates the right and left ventricles.[0005]
• The synchronous pumping actions of the left and right sides of the heart constitute the cardiac cycle. The cycle begins with a period of ventricular relaxation, called ventricular diastole. The cycle ends with a period of ventricular contraction, called ventricular systole.[0006]
• The heart has four valves (see FIGS. 2 and 3) that ensure that blood does not flow in the wrong direction during the cardiac cycle; that is, to ensure that the blood does not back flow from the ventricles into the corresponding atria, or back flow from the arteries into the corresponding ventricles. The valve between the left atrium and the left ventricle is the mitral valve. The valve between the right atrium and the right ventricle is the tricuspid valve. The pulmonary valve is at the opening of the pulmonary artery. The aortic valve is at the opening of the aorta.[0007]
• At the beginning of ventricular diastole (i.e., ventricular filling)(see FIG. 2), the aortic and pulmonary valves are closed to prevent back flow from the arteries into the ventricles. Shortly thereafter, the tricuspid and mitral valves open (as FIG. 2 shows), to allow flow from the atria into the corresponding ventricles. Shortly after ventricular systole (i.e., ventricular emptying) begins, the tricuspid and mitral valves close (see FIG. 3)—to prevent back flow from the ventricles into the corresponding atria—and the aortic and pulmonary valves open—to permit discharge of blood into the arteries from the corresponding ventricles.[0008]
• The opening and closing of heart valves occur primarily as a result of pressure differences. For example, the opening and closing of the mitral valve occurs as a result of the pressure differences between the left atrium and the left ventricle. During ventricular diastole, when ventricles are relaxed, the venous return of blood from the pulmonary veins into the left atrium causes the pressure in the atrium to exceed that in the ventricle. As a result, the mitral valve opens, allowing blood to enter the ventricle. As the ventricle contracts during ventricular systole, the intraventricular pressure rises above the pressure in the atrium and pushes the mitral valve shut.[0009]
• The mitral and tricuspid valves are defined by fibrous rings of collagen, each called an annulus, which forms a part of the fibrous skeleton of the heart. The annulus provides attachments for the two cusps or leaflets of the mitral valve (called the anterior and posterior cusps) and the three cusps or leaflets of the tricuspid valve. The leaflets receive chordae tendineae from more than one papillary muscle. In a healthy heart, these muscles and their tendinous cords support the mitral and tricuspid valves, allowing the leaflets to resist the high pressure developed during contractions (pumping) of the left and right ventricles.[0010]
• In a healthy heart, the chordae tendineae become taut, preventing the leaflets from being forced into the left or right atria and everted. Prolapse is a term used to describe this condition. This is normally prevented by contraction of the papillary muscles within the ventricle, which are connected to the mitral valve leaflets by the chordae tendineae. Contraction of the papillary muscles is simultaneous with the contraction of the ventricle and serves to keep healthy valve leaflets tightly shut at peak contraction pressures exerted by the ventricle.[0011]
• II. Characteristics and Causes of Mitral Valve Dysfunction[0012]
• In a healthy heart (see FIG. 4), the dimensions of the mitral valve annulus—when measured septal (S)- to -lateral (L), as well as from posterior commissure CP to anterior commissure CA—create an anatomic shape and tension such that the leaflets coapt, forming a tight junction, at peak contraction pressures. Where the leaflets coapt at the opposing medial and lateral sides of the annulus are called the leaflet commissures, and are designated in FIG. 4 and in other Figures as CP(denoting the posterior commissure) and CA (denoting the anterior commissure).[0013]
• Valve malfunction can result from the chordae tendineae (the chords) becoming stretched, and in some cases tearing. When a chord tears, the result is a leaflet that flails. Also, a normally structured valve may not function properly because of an enlargement of or shape change in the valve annulus. This condition is referred to as a dilation of the annulus and generally results from heart muscle failure. In addition, the valve may be defective at birth or because of an acquired disease.[0014]
• Regardless of the cause (see FIG. 5), mitral valve dysfunction can occur when the leaflets do not coapt at peak contraction pressures. As FIG. 5 shows, the coaptation line of the two leaflets is not tight at ventricular systole. As a result, an undesired back flow of blood from the left ventricle into the left atrium can occur. This condition is called regurgitation.[0015]
• In some cases (see FIG. 6), the leaflets do not form a tight coaptation junction because the dimensions of the mitral valve annulus, measured from commissure to commissure—CP to CA—and/or septal to lateral—S to L—change. The changed dimensions no longer create the anatomic shape and tension in which the leaflets coapt at peak contraction pressures.[0016]
• Comparing a healthy annulus in FIG. 4 to an unhealthy annulus in FIG. 6, the unhealthy annulus is dilated and, in particular, the septal-to-lateral distance is increased. As a result, the shape and tension defined by the annulus becomes less oval (see FIG. 4) and more round (see FIG. 6). This condition is called dilation. When the annulus is dilated, the shape and tension conducive for coaptation at peak contraction pressures progressively deteriorate. Instead, at peak contraction pressures, the leaflets do not coapt completely, and a gap forms between the leaflets. During ventricular systole, regurgitation can occur through this gap. It is believed that the ratio between the commissure distance and septal-to-lateral distance bears a relationship to the effectiveness of leaflet coaptation. If the septal-to-lateral distance increases, the ratio changes, and when the ratio reaches a certain value, regurgitation or the likelihood of regurgitation is indicated.[0017]
• As a result of regurgitation, “extra” blood back flows into the left atrium. During subsequent ventricular diastole (when the heart relaxes), this “extra” blood returns to the left ventricle, creating a volume overload, i.e., too much blood in the left ventricle. During subsequent ventricular systole (when the heart contracts), there is more blood in the ventricle than expected. This means that: (1) the heart must pump harder to move the extra blood; (2) too little blood may move from the heart to the rest of the body; and (3) over time, the left ventricle may begin to stretch and enlarge to accommodate the larger volume of blood, and the left ventricle may become weaker.[0018]
• Although mild cases of mitral valve regurgitation result in few problems, more severe and chronic cases eventually weaken the heart and can result in heart failure. Mitral valve regurgitation can be an acute or chronic condition. It is sometimes called mitral insufficiency.[0019]
• III. Prior Treatment Modalities[0020]
• In the treatment of mitral valve regurgitation, diuretics and/or vasodilators can be used to help reduce the amount of blood flowing back into the left atrium. An intra-aortic balloon counterpulsation device is used if the condition is not stabilized with medications. For chronic or acute mitral valve regurgitation, surgery to repair or replace the mitral valve is often necessary.[0021]
• To date, invasive, open heart surgical approaches have been used to repair mitral valve dysfunction. During these surgical repair procedures, efforts are made to cinch or resect portions and/or fix in position large portions of the dilated annulus. During these surgical repair procedures, the annulus can be reshaped with annular or peri-annular rings or similar ring-like devices. The repair devices are typically secured to the annulus and surrounding tissue with suture-based fixation. The repair devices extend over the top and over much or all of the circumference of the annulus and leaflet surfaces.[0022]
• A physician may decide to replace an unhealthy mitral valve rather than repair it. Invasive, open heart surgical approaches are used to replace the natural valve with either a mechanical valve or biological tissue (bioprosthetic) taken from pigs, cows, or horses.[0023]
• The need remains for simple, cost-effective, and less invasive devices, systems, and methods for treating dysfunction of a heart valve, e.g., in the treatment of mitral valve regurgitation.[0024]
SUMMARY OF THE INVENTION
• The invention provides devices, systems and methods that reshape a valve annulus. The devices, systems, and methods include an implant that is sized and configured to rest near or within the leaflet commissures of a heart valve annulus. In use, the implant contacts and outwardly displaces tissue to reshape the heart valve annulus. The implant, in use, may restore to the heart valve annulus and leaflets a more effective anatomic shape and tension. The more normal anatomic shape and tension are conducive to coaptation of the leaflets, which, in turn, reduces retrograde flow or regurgitation. The implant restores function to the valve, without surgically cinching, resecting, and/or fixing in position large portions of a dilated annulus, or without the surgical fixation of ring-like structures.[0025]
• Other features and advantages of the invention shall be apparent based upon the accompanying description, drawings, and claims.[0026]
DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective, anterior anatomic view of the interior of a healthy heart.[0027]
• FIG. 2 is a superior anatomic view of the interior of a healthy heart, with the atria removed, showing the condition of the heart valves during ventricular diastole.[0028]
• FIG. 3 is a superior anatomic view of the interior of a healthy heart, with the atria removed, showing the condition of the heart valves during ventricular systole.[0029]
• FIG. 4 is a superior anatomic view of a healthy mitral valve during ventricular systole, showing the leaflets properly coapting.[0030]
• FIG. 5 is a superior anatomic view of the interior of a heart, with the atria removed, showing the condition of the heart valves during ventricular systole, and further showing a dysfunctional mitral valve in which the leaflets are not properly coapting, causing regurgitation.[0031]
• FIG. 6 is a superior anatomic view of a disfunctional mitral valve during ventricular systole, showing that the leaflets are not properly coapting, causing regurgitation.[0032]
• FIG. 7A is a side perspective view of an elastic implant sized and configured to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and improve leaflet coaptation.[0033]
• FIGS. 7B to[0034]7E are side perspective views of illustrative alternative configurations of the elastic implant shown in FIG. 7A.
• FIG. 8 is a side anterior anatomic view of a mitral valve annulus in which the elastic implant shown in FIG. 7A has been implanted.[0035]
• FIG. 9 is a superior anatomic view of a mitral valve in which the elastic implant shown in FIG. 7A has been implanted, showing the implant stretching the commissures to restore leaflet coaptation.[0036]
• FIG. 10 is a side perspective view of another embodiment of an elastic implant sized and configured to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and restore leaflet coaptation, the implant defining a closed annular structure.[0037]
• FIG. 11 is a perspective anatomic view, taken from an anterior and slightly superior viewpoint, of a mitral valve in which the elastic implant of the type shown in FIG. 10 has been implanted, showing the implant stretching the commissures to restore leaflet coaptation, and also showing the implant as hugging the annulus.[0038]
• FIG. 12 is a perspective anatomic view, taken from an anterior and slightly superior viewpoint, of a mitral valve in which the elastic implant of the type shown in FIG. 10 has been implanted, showing the implant stretching the commissures to restore leaflet coaptation, and also showing the implant as rising above the annulus.[0039]
• FIGS. 13A to[0040]13C are side perspective views of illustrative embodiments of an elastic implant sized and configured to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and restore leaflet coaptation, the implant defining an open annular structure.
• FIGS. 13D and 13E are side perspective views of illustrative embodiments of an elastic implant sized and configured to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and restore leaflet coaptation, the implant defining an open annular structure that can be optionally closed.[0041]
• FIG. 14 is a side perspective view of an elastic implant of the open annular type shown in FIGS. 13D and 13E, showing how the mechanical characteristics of the implant can be varied along its structure, surface area, and interface with the tissue.[0042]
• FIG. 15A is a side perspective view of another embodiment of an elastic implant sized and configured to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and restore leaflet coaptation, the implant defining a closed annular structure that can be symmetrically folded upon itself.[0043]
• FIG. 15B is a side view of the implant shown in FIG. 15A when folded upon itself.[0044]
• FIG. 15C is a perspective anatomic view, taken from an anterior and slightly superior viewpoint, of a mitral valve in which the elastic implant of the type shown in FIG. 15A has been implanted, showing the implant stretching the commissures to restore leaflet coaptation, and also showing the implant as hugging the annulus.[0045]
• FIG. 15D is a side perspective view of another embodiment of an elastic implant sized and configured to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and restore leaflet coaptation, the implant defining a closed annular structure that can be asymmetrically folded upon itself.[0046]
• FIG. 15E is a perspective anatomic view, taken from an anterior and slightly superior viewpoint, of a mitral valve in which the elastic implant of the type shown in FIG. 15D has been implanted, showing the implant stretching the commissures to restore leaflet coaptation, and also showing the implant as hugging the annulus.[0047]
• FIG. 16A is a side perspective view of an elastic implant of the type shown in FIG. 10, showing an illustrative embodiment of tab structures that serve to anchor and stabilize the implant in an annulus.[0048]
• FIG. 16B is a side anterior anatomic view of a mitral valve annulus in which the elastic implant shown in FIG. 16A has been implanted.[0049]
• FIG. 17A is a side perspective view of an elastic implant of the type shown in FIG. 10, showing an illustrative embodiment of multiple contact structures that serve to anchor and stabilize the implant in an annulus.[0050]
• FIG. 17B is a side anterior anatomic view of a mitral valve annulus in which the elastic implant shown in FIG. 17A has been implanted.[0051]
• FIGS. 18A and 18B are side perspective views of an elastic implant of the type shown in FIG. 10, showing illustrative embodiments of frictional struts that serve to anchor and stabilize the implant in an annulus.[0052]
• FIG. 19 is a side perspective view of an elastic implant of the type shown in FIG. 10, showing an illustrative embodiment of tissue in-growth surfaces that serve to anchor and stabilize the implant in an annulus.[0053]
• FIGS. 20A and 20B are, respectively, a side perspective view and an anatomic view (when implanted) of an elastic implant sized and configured to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and restore leaflet coaptation and also showing the implant as rising significantly above the annulus.[0054]
• FIGS. 20B and 20C are, respectively, a side perspective view and an anatomic view (when implanted) of an elastic implant sized and configured to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and restore leaflet coaptation, and showing the presence of one rail that hugs the annulus and another rail that rises above the implant to serve as a mechanism that anchors and stabilizes the implant in the annulus.[0055]
• FIG. 21 is a side elevation view of a tool for implanting an elastic implant in a valve annulus in a open heart surgical procedure to reshape the annulus and restore leaflet coaptation.[0056]
• FIGS. 22A to[0057]22F diagrammatically show a method of using the tool shown in FIG. 21 to install an elastic implant in a valve annulus to reshape the annulus and restore leaflet coaptation.
• FIGS. 23A to[0058]23C diagrammatically show a method of gaining intravascular access to the left atrium for the purpose of deploying a delivery catheter to place an implant in a valve annulus to reshape the annulus and restore leaflet coaptation.
• FIG. 24 is a side elevation view of the distal end of the implant delivery catheter shown in FIG. 23C, showing an elastic implant of the type shown in FIG. 10 collapsed in a sleeve for deployment into the left atrium in the manner shown in FIGS. 23A to[0059]23C.
• FIGS. 25A to[0060]25E are diagrammatic perspective views of a method for manipulating the distal end of the implant delivery catheter shown in FIG. 24 to deploy an elastic implant of the type shown in FIG. 10 into a valve annulus to reshape the annulus and restore leaflet coaptation.
• FIG. 26 is a side view of the distal end of the implant delivery catheter of the type shown in FIG. 23C, showing an elastic implant of the type shown in FIG. 10 collapsed in a sleeve for deployment into the left atrium in the manner shown in FIGS. 23A to[0061]23C, also and showing the presence of a guide wire loop to aid in the deployment.
• FIGS. 27A to[0062]27I are diagrammatic views of a method for deploying an elastic implant of the type shown in FIG. 10 into a valve annulus with the aid of a guide wire loop to reshape the annulus and restore leaflet coaptation.
• FIGS. 28A and 28B are perspective view of elastic implants of the type shown in FIGS. 13B to[0063]13E, showing the tethering of such implants to one or more wire loops to aid in their deployment into a valve annulus to reshape the annulus and restore leaflet coaptation.
• FIG. 29 is a side view of the distal end of the implant delivery catheter of the type shown in FIG. 23C, showing a symmetrical foldable elastic implant of the type shown in FIG. 15A folded and collapsed in a sleeve for deployment into the left atrium in the manner shown in FIGS. 23A to[0064]23C.
• FIGS. 30A to[0065]30D are diagrammatic views of a method for manipulating the distal end of the implant delivery catheter shown in FIG. 29 to deploy a symmetrically folded and collapsed elastic implant of the type shown in FIG. 15A into a valve annulus to reshape the annulus and restore leaflet coaptation.
• FIGS. 31A to[0066]31E are diagrammatic views of a method for manipulating the distal end of the implant delivery catheter shown in FIG. 29 to deploy an asymmetrically folded and collapsed elastic implant of the type shown in FIG. 15D into a valve annulus to reshape the annulus and restore leaflet coaptation.
• FIG. 32 is a side view of the distal end of the implant delivery catheter of the type shown in FIG. 23C, showing a symmetrical foldable elastic implant of the type shown in FIG. 15A tethered to a guide wire loop to aid in its implantation into a valve annulus to reshape the annulus and restore leaflet coaptation.[0067]
• FIGS. 33A to[0068]33D are diagrammatic views of a method for manipulating the distal end of the implant delivery catheter shown in FIG. 32 to deploy a symmetrically folded and collapsed elastic implant of the type shown in FIG. 15A into a valve annulus with the aid of a guide wire loop to reshape the annulus and restore leaflet coaptation.
• FIG. 34 is a side elevation view of the distal end of the implant delivery catheter of the type shown in FIG. 23C, showing a symmetrical foldable elastic implant of the type shown in FIG. 15A tethered to two guide wire loops to aid in its implantation into a valve annulus to reshape the annulus and restore leaflet coaptation.[0069]
• FIGS. 35 and 36A to[0070]36D are diagrammatic views of a method for manipulating the distal end of the implant delivery catheter to deploy a symmetrically folded and collapsed elastic implant of the type shown in FIG. 15A into a valve annulus with the aid of a separate guide wires to reshape the annulus and restore leaflet coaptation.
• FIGS. 37A to[0071]37C are diagrammatic views of the deployment a symmetrically folded and collapsed elastic implant of the type shown in FIG. 15A into a valve annulus with the aid of a wrapper or bag to reshape the annulus and restore leaflet coaptation.
• FIG. 38 is a side perspective view of a plastically deformable implant sized and configured to be expanded in situ to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and restore leaflet coaptation.[0072]
• FIGS. 39A to[0073]39C are diagrammatic views of the deployment of a plastically deformable implant of the type shown in FIG. 38 into a valve annulus with the aid of a mechanical expansion device.
• FIGS. 40A to[0074]40C are diagrammatic anatomic views of the deployment of a plastically deformable implant of the type shown in FIG. 38 into a valve annulus with the aid of a balloon expansion device.
• FIG. 41 is a diagrammatic view of a non-compliant balloon deployed into a valve annulus for the purpose of assessing the size and mechanical properties of an implant for the annulus.[0075]
• FIG. 42 is a side perspective view of a multi-functional elastic implant sized and configured to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and restore leaflet coaptation as well serve as a neo-leaflet to either replace or supplement a damaged heart valve leaflet.[0076]
• FIGS. 43 and 44 are side perspective views of a multi-functional elastic implants sized and configured to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and restore leaflet coaptation as well serve as a leaflet retainer to prevent a native valve leaflet from being pushed into the atrium upon ventricular contraction.[0077]
• FIGS.[0078]45 to47 are side perspective views of a multi-functional elastic implants sized and configured to rest within or near the leaflet commissures of a dysfunctional heart valve annulus to reshape the annulus and restore leaflet coaptation as well serve as a leaflet retainer to prevent a native valve leaflet from being pushed into the atrium upon ventricular contraction, the implants also including a framework that serves to help position and secure the implant in situ.
DETAILED DESCRIPTION
• Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.[0079]
• I. Implants for Reshaping a Heart Valve Annulus[0080]
• A. Overview[0081]
• FIGS. 7A and 8 show an[0082]implant10 sized and configured to rest within or near a heart valve annulus. The implant is shown in a mitral valve, and, in this arrangement, extends along the major (i.e., longest) axis above and/or along the valve annulus. Theimplant10 is sized and shaped so that, in use, it applies a mechanical force along the major axis. The mechanical force serves to outwardly displace tissue (i.e., to displace tissue away from the center of the annulus) to reshape the annulus. In the illustrated embodiment (on the mitral valve), the mechanical-force serves to lengthen the long axis of the annulus and, in doing so, can reactively shorten in the minor (i.e. shortest) axis, as well as correspondingly reshape other surrounding anatomic structures. It should be appreciated that, when situated in other valve structures, the axes affected may not be the “major” and “minor” axes, due to the surrounding anatomy. It should also be appreciated that, in order to be therapeutic, the implant may only need to reshape the annulus during a portion of the heart cycle, such as during ventricular systolic contraction. For example, the implant may be sized to produce small or negligible outward displacement of tissue during ventricular diastole when the tissue is relaxed, but restrict the inward movement of tissue during ventricular systolic contraction.
• The mechanical force applied by the[0083]implant10 restores to the heart valve annulus and leaflets a more normal anatomic shape and tension (see FIG. 9). The more normal anatomic shape and tension are conducive to coaptation of the leaflets during ventricular systole, which, in turn, reduces regurgitation. Theimplant10 restores normal function to the valve, without surgically cinching, resecting, and/or fixing in position large portions of a dilated annulus or leaflets, or without the surgical fixation of ring-like structures.
• As will be described in greater detail later, the[0084]implant10 lends itself to delivery to a targeted heart valve site by catheter-based, intravascular techniques, under image guidance. Image guidance includes but is not limited to fluoroscopy, ultrasound, magnetic resonance, computed tomography, or combinations thereof. Alternatively, theimplant10 can be delivered using conventional open heart surgical techniques or by thoracoscopic surgery techniques.
• In its most basic form, the[0085]implant10 is made—e.g., by bending, shaping, joining, machining, molding, or extrusion—from a biocompatible metallic or polymer material, or a metallic or polymer material that is suitably coated, impregnated, or otherwise treated with a material to impart biocompatibility, or a combination of such materials. The material is also desirably radio-opaque to facilitate fluoroscopic visualization.
• As FIG. 7A shows, the[0086]implant10 includes a pair ofstruts12 joined by anintermediate rail14. As FIG. 8 shows, thestruts14 are sized and configured to rest at or near the leaflet commissures. It should be appreciated that the leaflet commissures may not, and typically are not, situated at geometrically opposite sides of the annulus (although for the purpose of illustration, they are shown that way in the Figures). The position of thestruts12 can be selected to conform to an asymmetric morphology of the annulus, as is later described in connection with FIGS. 13A and 13B.
• The[0087]rail14 spans thestruts12. The rail14 (like the struts12) can take various shapes and have various cross-sectional geometries. The rail14 (and/or the struts12) can have, e.g., a generally curvilinear (i.e., round or oval) cross-section, or a generally rectilinear cross section (i.e., square or rectangular), or combinations thereof.
• In FIGS. 7A and 8, the implant is “elastic.” The[0088]rail14 is sized and configured to possess a normal, unloaded, shape or condition (shown in FIG. 7A), in which therail14 is not in compression and thestruts12 are spaced apart farther than the anterior commissure to posterior commissure dimension of the targeted heart valve annulus. The material of the implant is selected to possess a desired spring constant. The spring constant imparts to therail14 the ability to be elastically compressed out of its normal, unloaded condition, in response to external compression forces applied at the struts. Therail14 is sized and configured to assume an elastically loaded, in compression condition, during which thestruts12 are spaced apart a sufficiently shorter distance to rest in engagement with tissue at or near the leaflet commissures (see FIG. 8).
• When in its elastically loaded, compressed condition (see FIG. 9), the[0089]rail14 exerts opposing forces to the tissues at or near the commissures through thestruts12, tending to outwardly displace tissue and stretch the annulus along its major axis, which also typically stretches the leaflet commissures, shortens the minor axis, and/or reshapes surrounding anatomic structures. The implant thereby reshapes the valve annulus toward a shape more conducive to leaflet coaptation.
• An elastic implant can be made, e.g., from superelastic alloy, such that the implant can be elastically straightened and/or folded to fit within a catheter or sheath during deployment, and will regain its shape upon deployment (this characteristic will be described in greater detail later).[0090]
• Desirably, the elasticity of the[0091]implant10 itself, along with the elasticity of the valve tissue, ensure that theimplant10 can be positioned in the valve under a state of net compression and thus remain anchored without the use of sutures, adhesives, or other fixation materials, i.e. which is called compressive anchoring. Theimplant10 may itself deform elastically, although not necessarily so, but the characteristic of theimplant10 being elastically deformable may help to maintain compressive anchoring. If theimplant10 does not deform elastically or does so only slightly, theimplant10 relies on tissue elasticity to keep the implant anchored.
• As FIGS. 7A to[0092]7E and8 show, and as will be described in greater detail later, thestruts12 may carry other structures ormechanisms16 to further enhance the anchorage and stabilization of the implant in the heart valve annulus. Themechanisms16 may be located below the plane of the annulus, to engage infra-annular heart tissue adjoining the annulus in the ventricle, and/or be located at or above the plane of the annulus, to engage tissue on the annulus or in the atrium.
• The spring constant of the implant may be selected to be greater than the spring constant of adjoining tissue. Alternatively, the spring constant of the implant may be selected to approximate the spring constant of adjoining tissue, thereby providing compliance to allow the[0093]implant10 to adapt to tissue morphology during use. The spring constant of theimplant10 may vary along the length of therail14, so that some portions of therail14 are stiffer or more compliant than other portions of therail14.
• In an alternative arrangement, the[0094]implant10 may be formed from a plastically deformable material. In this embodiment, theimplant10 is manufactured in a normally collapsed condition. Theimplant10 is expanded in situ into an in use condition within the annulus, e.g., by an inflatable body (e.g., balloon) or by a suitable mechanical device (e.g., a scissorjack). The use and deployment of a plastically deformable implant will be described in greater detail later, after the structure, deployment, and use of elastic implants are described.
• B. Illustrative Elastic Implant Configurations[0095]
• An[0096]elastic implant10 having the characteristic just described can take various forms and configurations. The following describes various illustrative arrangements.
• 1. Collapsible Annular Implants[0097]
• The[0098]implants10 in FIGS. 7A to7C comprise asingle rail14 spanning the distance between thestruts12. As shown in FIGS. 7D and 10, animplant10 can include more than asingle rail14, imparting a normally closed, annular shape to the implant. As will be described in greater detail later, animplant10 of this type can be conveyed to an implantation site, e.g., within a catheter or sheath, in a collapsed, straightened condition (with therails14 collapsed side-by-side) When deployed from the catheter or sheath, theimplant10 springs open to assume the normally closed, annular shape shown in FIGS. 7D and 10.
• In the arrangement illustrated in FIG. 10, the[0099]implant10 includes tworails14 spanning thestruts12. The shape and configuration of therails14 can be varied, depending upon the desired orientation of therails14 with respect to the annulus itself. For example, in FIG. 11, the tworails14 are shaped and configured so that, when implanted, therails14 follow the circumferential path of the annulus and rest in generally the same plane as the annulus. This implant can be characterized as “hugging” the annulus. In the example shown in FIG. 12, the tworails14 are shaped and configured so that, when implanted, therails14 follow the circumferential path of the annulus, and also rise above the plane of the annulus. Thisimplant10 can be characterized as “riding above” the annulus. Animplant10 that “rides above” the annulus can extend close to the annulus (as FIG. 12 shows) or rise significantly above the annulus toward the dome of the atrium as FIGS. 20A and 20B show. As FIGS. 20C and 20D show, animplant10 can include arail14A that hugs the annulus and arail14B that rides above the annulus and contacts a heart wall, serving as amechanism16 that orients and stabilizes the implant.
• When the rail or rails[0100]14 of a given implant follow the circumferential contour of the annulus, either at or above the plane of the annulus, therails14 rest out of the way of blood flow though the valve and may reduce hemolysis or thrombosis.
• As FIGS. 13A to[0101]13E show, therails14 of a givenannular implant10 can be interrupted to impart a normally open annular (“hemi”) shape to theimplant10. As will be described in greater detail later, animplant10 of this type also can be conveyed to an implantation site, e.g., within a catheter or sheath, in a collapsed, straightened condition, and then deployed to assume the open, annular shape shown in FIGS. 13A to13E.
• In FIG. 13A, the open annular shape is configured so that, when implanted, the[0102]implant10 hugs the annulus. In FIG. 13B, the open annular shape is configured so that, when implanted, the implant rides above the annulus. FIGS. 13C and 13D show another style of open annular implant, one that hugs the annulus (FIG. 13C) and the other that rides above the annulus (FIG. 13D). In this arrangement, the interruptedrail14 includes interlocking hooks18 that can be coupled, if desired, to close the annulus of the implant10 (see FIG. 13E). In FIG. 13E, the interlockedimplant10 is configured to ride above the annulus.
• As FIGS. 13A and 13B show, the[0103]struts12 need not be placed at diametrically opposite sides of the rail or rails14. The commissures of a given valve annulus may not be at geometrically opposite sides of the annulus. Accordingly, the position of thestruts12 may be selected to conform to an asymmetric morphology of the annulus. Thestruts12 may be used to simply locate theimplant10 in the valve, imparting little or no force on their own. In this arrangement, the annulus reshaping forces emanate from the rail or rails14 above the commissures.
• The implant possesses a spring constant that approximates the spring constant of tissue, making the implant more accommodating to the movement of the tissue. As FIG. 14 shows, a given rail or rails[0104]14 can include undulations or the like to impart regions having different spring constants and/or mechanical properties along the length of therail14. Alternatively, or in combination, the cross-sectional width and/or thickness and/or geometry of a givenrail14 need not be uniform, but can vary along the length of therail14 to impart regions of different spring constants and/or mechanical properties. For example, in FIG. 13A, the region of thecontinuous rail14 between the asymmetrically placedstruts12 may be thickened or thinned to impart different mechanical properties to achieve the desired shape changing objectives.
• 2. Foldable Elastic Annular Implants[0105]
• The[0106]implants10 shown in FIGS. 15A to15E comprise more than asingle rail14, imparting a normally closed, annular shape to the implant. Unlike the normally closed,annular implant10 shown in FIG. 10, therails14 of theimplants10 shown in FIGS. 15A to15E includecusps20. Thecusps20 permit the implants to be resiliently folded along their minor (transverse axis) axis—with thecusps20 occupying the fold—without permanently deforming the implant (see FIG. 15B). As will be described in greater detail later, animplant10 of this type can be conveyed to an implantation site, e.g., within a catheter or sheath, in a folded as well as collapsed condition, and then deployed to assume the normally closed, annular shape shown in FIG. 15A, as FIG. 15C shows. As before explained, the shape and configuration of therails14 can be varied so that, when deployed, the implant hugs the annulus or rides above the annulus.
• In FIG. 15A, the[0107]cusps20 are symmetric, being formed on eachrail14 equidistant to thestruts12. In FIG. 15A, thestruts12 are also shown symmetric as to height above therail14. FIG. 15D shows that thecusps20 need not be symmetric in either respect. As will be described in greater detail later, this asymmetry permits a stepwise, staggered deployment of the implant, in which the parts of the implant are deployed one at a time in succession—e.g., one strut, then one cusp, then another strut, and then the other cusp—until the implant assumes the closed, annular shape shown in FIG. 15D, as FIG. 15E shows.
• 3. Fixation of Implants[0108]
• As before stated, the[0109]struts12 can include other structures ormechanisms16 to further enhance the anchorage and stabilization of the implant in the heart valve annulus. These structures orother mechanisms16 can comprise, e.g., loops, pads, barbs, vertical legs, or circumferential legs, or other anchoring structures below, at, and/or above the valve plane. The structures andmechanisms16 desirably increase the surface area of contact between thestruts12 and tissue adjoining the annulus. The structures andmechanism16 desirably rely solely or partly on the valve and neighboring anatomic structures to anchor and fix the position of the implant in the annulus and resist its migration out of the annulus. Implant fixation can also assist in the achieving the desired coaptation of the leaflets and to resist upward movement or eversion of the leaflets during the cardiac cycle.
• For example, in the embodiment shown in FIGS. 7A and 8, the[0110]rails14 carry four struts12, two supra-annular (contacting tissue on the atrial side of the valve) and two infra-annular (contacting tissue on the ventricular size of the valve). Thestruts12 are separated by a thin spine that curves away from thestruts12 to avoid contact with the commissures themselves, so as not to interfere with the opening and closing of the valve.
• As shown in FIG. 7A, the[0111]struts12 may be cushioned to increase traction, decrease erosion, and improve their interaction with the valve annulus. In addition, thestruts12 may be coated, covered, or impregnated with a tissue growth promoting material. Therails14 spanning thestruts12 functions to exert compressive forces on the annulus. Thestruts12 are secured by the compression forces created by the rail's interaction with the valve annulus. Thestruts12 assure that the implant is positioned correctly in situ, because they will only seat when positioned at or near the commissures of the valve.
• The[0112]struts12 may be sized and shaped in various ways. FIGS. 7B, 7C, and7D show various embodiments with alternative designs for thestruts12. As another example, in FIG. 7E, the supra-annular struts12 are somewhat larger than the infra-annular struts12 to improve the anatomical fit of the device in situ.
• In the embodiment shown in FIGS. 16A and 16B, the[0113]struts12 can carry flat infra-annulartissue contacting pads26, located below the plane of the valve annulus. Thepads26 rest on outwardly bowed extensions below the commissures, applying holding forces upon the heart walls. Thepads26 can take the form of flat surfaces, as FIGS. 16A and 16B show. Tissue penetrating barbs28 (shown in phantom lines in FIG. 16B) may enhance the effect of the compression forces to fix the location of the implant.
• As FIGS. 17A and 17B show, the[0114]struts12 can extend in an undulating fashion below the plane of the valve annulus, to create a series of infra-annular contact surfaces30 between the implant and the heart walls below and adjoining the annulus. The series of contact surfaces30 increase the points of contact between the implant and tissue below the annulus. These multiple points ofcontact30 are additive to the contact between the implant and tissue at or near the commissures themselves. In FIGS. 17A and 17B, additional struts and/or barbs or similar anchoring surfaces (such as shown in FIGS. 16A and 16B) are not shown associated with the contact surfaces, but they could be included, if desired.
• As FIGS. 18A and 18B show, the implant can include infra-annular frictional struts[0115]32 located below the level of the annulus. The infra-annular frictional struts32 engage tissue of the heart walls below and adjoining the annulus. Thestruts32 resist migration of the implant out of the annulus. As FIG. 18A shows, the frictional struts32 can be placed in a single level immediately below the commissures, or (as FIG. 18B shows) thestruts32 can be arranged in multiple levels below the commissures.
• As FIG. 19 shows, the[0116]struts12 and/or therails14 can include tissue in-growth surfaces34. Thesurfaces14 provide an environment that encourages the in-growth of neighboring tissue on the implant. Once in-growth occurs, theimplant10 becomes resistant to migration or dislodgment from the annulus. Conventional in-growth materials such as polyester fabric can be used.
• Any fixation mechanism or structure may, if desired, be combined with an adhesive or like material to further secure the implant.[0117]
• II. Deployment of Elastic Implants for Reshaping a Heart Valve Annulus[0118]
• The various implants as just described lend themselves to implantation in a heart valve annulus in various ways. They can be implanted, e.g., in an open heart surgical procedure. Alternatively, they can be implanted using catheter-based technology via a peripheral venous access site, such as in the femoral or jugular vein or femoral artery, or alternatively by thoracoscopically through the chest or by means of other surgical access through the right atrium.[0119]
• A. Open Heart Surgical Procedures[0120]
• FIG. 21 shows a[0121]tool40 for deploying anelastic implant10 of the type generally described in an annulus of a heart valve in an open surgical procedure. FIGS. 22A to22F diagrammatically show the steps of an open surgical procedure for deploying theimplant10 in a mitral valve annulus using thetool40 shown in FIG. 21.
• The[0122]tool40 includes a scissors-action mechanism42 comprising an operatingend46 and ahandle end48. The operatingend46 includesprongs44 that can be moved apart and together by manipulation of the handle end48 (see FIGS. 22A and 22B). Theprongs44 are sized and configured to mate withdeployment apertures50 formed on thestruts12 of the implant10 (shown in FIG. 21). The deployment apertures50 are also shown in the implants in preceding FIGS.10 to19, which can be likewise be deployed using thetool40.
• In using the[0123]tool40, the scissors-action mechanism42 is manipulated to spread theprongs44 apart (see FIGS. 22A and 22B), so that they can be mated in theapertures50 of theimplant10. The scissors-action mechanism44 is manipulated to bring theprongs44 together, thereby applying force to thestruts12 to place theimplant10 in a compressed condition (see FIG. 22C).
• With the[0124]tool40 holding theimplant10 in this condition, thetool40 andimplant10 are introduced through an open surgical approach into the left atrium. Thetool40 places theimplant10 within the mitral valve annulus (see FIG. 22D). As shown in FIG. 22D, the annulus is shown to have a dimension of D1. This dimension D1 is not conducive to leaflet coaptation, and regurgitation is occurring. It is the purpose of the surgical procedure to repair this dysfunction by reshaping the annulus with theimplant10.
• The scissors-[0125]action mechanism42 is manipulated to spread theprongs44 apart until thestruts12 of theimplant10 rest within or near the commissures of the mitral valve (see FIG. 22E). At this point in the procedure, the dimension D1 of the annulus remains unchanged. Thetool40 is withdrawn, freeing theprongs12 from the apertures50 (see FIG. 22F). The elastic unloading of theimplant10 displaces and spreads the valve tissue apart, achieving a new dimension D2 for the annulus, which is larger than D1. The new dimension D2 is conducive to leaflet coaptation. Theimplant10 has reshaped the annulus to restore valve function.
• B. Illustrative Catheter-Based Intra-Vascular Procedures[0126]
• 1. Linear Deployment of Elastic Implants[0127]
• FIGS.[0128]23 to25 show a representative embodiment of a percutaneous catheter-based linear deployment of an unfoldedelastic implant10 of the type shown in FIGS.7 to14.
• Percutaneous vascular access is achieved by conventional methods into the femoral or jugular vein. As FIG. 23A shows, under image guidance, a[0129]catheter52 is steered through the vasculature into the right atrium. Aneedle cannula54 carried on the distal end of the catheter is deployed to pierce the septum between the right and left atrium. As FIG. 23B shows, aguide wire56 is advanced trans-septally through theneedle catheter52 into the left atrium. Thefirst catheter52 is withdrawn, and (as FIG. 23C shows) under image guidance, animplant delivery catheter58 is advanced over theguide wire56 into the left atrium into proximity with the mitral valve. Alternatively, theimplant delivery catheter58 can be deployed trans-septally by means of surgical access through the right atrium.
• The[0130]implant delivery catheter58 carries asheath60 at its distal end (see FIG. 24). Thesheath60 encloses anelastic implant10 of a type shown in FIGS.7 to14. Theimplant10 is constrained in a collapsed, straightened condition within the sheath, as FIG. 24 shows. Thesheath60 can be sized and configured to be withdrawn (e.g., by sliding it proximally), to free theimplant10. Free of thesheath60, theelastic implant10 will expand. Alternatively, aflexible push rod62 in thecatheter58 can be used to expel theimplant10 from thesheath60, with the same result. Desirably, thestrut12 on the trailing end of theimplant10 is folded within thesheath60 to reduce the collapsed profile and facilitate the expansion of theimplant10 once free from thesheath60.
• As FIG. 25A shows, under image guidance, the[0131]strut12 on the leading end of theimplant10 is freed from thesheath60 and seated retrograde in the posterior commissure of the valve annulus. Anchoring structures or mechanisms associated with the strut are also placed into desired contact with adjoining tissue below and/or above the plane of the annulus. As FIG. 25B shows, thedelivery catheter58 maintains force on the leadingstrut12 within the posterior commissure, as thesheath60 is withdrawn in line with the coaptation line in a posterior-to-anterior direction along the coaptation line. As shown in FIG. 25B, thedelivery catheter58 may need to dip down retrograde below the plane of the leaflets to maintain sufficient force on the leading end of the implant while the trailing end is freed from thesheath60. However, as shown in FIG. 25C, thedelivery catheter58 may be sized and configured to have the column strength sufficient to maintain force on the leading strut without passage below the leaflet plane.
• Progressively freed from the[0132]sheath60, theelastic implant10 shapes and seats (as FIGS.25B/C and25D shows), until the trailingstrut12 unfolds and seats within the anterior commissure (see FIG. 25E). The implant can also be positioned or repositioned under image guidance within the left atrium using a catheter-deployed grasping instrument.
• 2. Guide Loop Deployment of Unfolded Elastic Implants[0133]
• FIGS. 26 and 27A to[0134]27I show another embodiment of animplant delivery catheter58 that can be used to deploy a foldedelastic implant10 of the type shown in FIGS.7 to14 within the left atrium.
• In this embodiment, as in the previous embodiment, the[0135]implant delivery catheter58 includes asheath60 that constrains theimplant10 in a collapsed, straightened condition for passage into the left atrium (see FIG. 26). Thesheath60 is sized and configured to be withdrawn (e.g., by sliding it proximally), to free the implant for expansion within the left atrium, or apush rod62 can be used to eject the implant from thesheath60. To create a desired profile, one or both struts can be folded against the body of the implant within thesheath60.
• Unlike the previous embodiment, a metallic, fiber, or[0136]polymer guide wire64 is looped through thedeployment apertures50 on thestruts12 of theimplant10 prior to the insertion of theimplant12 into thesheath60. The legs of the resultingguide wire loop66 are passed out the proximal end of thesheath60 for manipulation, as will now be described.
• In use, the[0137]implant delivery catheter58 is introduced trans-septally into the left atrium in the manner previously described. With the distal end of thecatheter58 positioned above the valve annulus (see FIG. 27A), and prior to withdrawal of thesheath60, both legs of theguide wire loop66 are advanced distally in tandem through thesheath60 to advance theloop60 beyond thedeployment apertures50 and out the distal end of thesheath60. Theguide wire loop66 desirably carries radio-opaque markers68 to aid in fluoroscopic visualization. Themarkers68 identify a desired distance between them and the distal end of thesheath60, marking a space in which theimplant10 can freely expand without contacting tissue or anatomic structures within the atrium. Guided by themarkers68, theloop66 can be dropped into the annulus a desired distance beyond the distal end of thesheath60, as FIG. 27A shows.
• With the[0138]loop66 positioned in the desired way within the annulus, thesheath60 can be withdrawn to free theimplant10 for expansion (see FIG. 27B). While tethered to theguide wire loop66, theimplant10 opens within the left atrium—first one strut, then the other—as thesheath60 is withdrawn, as FIGS. 27C and 27D show.
• Once the[0139]implant10 is fully free of thesheath60 and expanded, both legs of theguide wire loop66 can be advanced proximally in tandem through the sheath60 (see FIG. 27E). Thewire loop66 applies force to thestruts12 and brings them together (see FIG. 27F). This places theimplant10 in a compressed, elastically loaded condition. Proximal advancement of the legs of thewire loop66 also draws theimplant10 in this condition snuggly against the distal end of thecatheter58 for greater control, as FIG. 27F shows.
• With the[0140]implant10 tethered to thecatheter58 in this condition (see FIG. 27G), thecatheter58 can be advanced under image guidance to place theimplant10 within the annulus. Manipulation of thecatheter58 will bring the struts of the implant into desired alignment. Subsequent distal advancement of the legs of the wire loop66 (see FIG. 27H) allows the struts of theimplant10 to be elastically unloaded and brought into contact with the surrounding tissue. Anchoring structures or mechanisms associated with thestruts12 can also be placed into desired contact with adjoining tissue below and/or above the plane of the annulus. The legs of thewire loop66 can be manipulated to pull thestruts12 together and/or allow them to separate, until the desired orientation and tissue contact in and about the annulus are achieved.
• Once desired orientation and tissue contact are achieved for the[0141]implant10, one leg of thewire loop66 can be pulled to release the implant from the guide wire64 (see FIG. 27I). Theimplant10 is allowed to fully unfold and seat within the annulus.
• A[0142]guide loop66 can be used to deploy open annular implants as well as closed annular implants. As shown in FIG. 28A, asingle guide loop66 can be threaded through an openannular implant10 of the type shown in FIG. 13B. Or, as shown in FIG. 28B, twoguide wire loops66A and66B can be threaded through an inter-locking implant of the type shown in FIGS. 13D and 13E. In this arrangement, the firstguide wire loop66A can be manipulated to position thestruts12 of the implant within the annulus, as just described. The secondguide wire loop66B can be separately manipulated to pull therails14 together for interlocking, once the struts rest in a desired manner in the commissures.
• 3. Deployment of Folded Elastic Implants[0143]
• FIGS. 15A to[0144]15E showelastic implants10 that can be folded aboutcusps20. As FIG. 29 shows, the folding allows theimplant10 to be conveyed into the left atrium within asheath60 of animplant delivery catheter58 with a delivery profile that not only constitutes a side-to-side collapsed condition—which minimizes the delivery profile diameter—but also constitutes a lengthwise folded condition—which minimizes the delivery profile length.
• FIGS. 30A to[0145]30D illustrate the deployment of a symmetrically foldedelastic implant10 of the type shown in FIGS. 15A and 15B. Theimplant10 is constrained in a symmetrically folded and collapsed condition within thesheath60, as FIG. 30A shows. In this condition, thestruts12 form the leading end of the implant. Apush rod62 in thecatheter58 includes agripping mechanism70 that holds the foldedimplant10 by thecusps20. Thepush rod62 is advanced to expel theimplant12 from thesheath60, bothstruts12 first.
• As FIG. 30B shows, under image guidance, the folded[0146]implant10 is aligned with coaptation line generally equidistant from the commissures, with thestruts12 oriented to face the commissures (thedelivery catheter58 has been previously introduced trans-septally into the left atrium, as already described). Manipulating thepush rod62 advances theimplant10, both struts first, from thesheath60. Connecting thepush rod62 to theimplant10 allows theimplant10 to be translated and rotated and retracted during deployment. Freed from the sheath60 (see FIG. 30B), theimplant10 begins to unfold along thecusps20, and thestruts12 draw apart toward the commissures. Further advancement of thepush rod62 frees more of the unfoldingimplant10 from thesheath60, until thestruts12 draw apart sufficiently to contact the commissures (as FIG. 30C shows). Prior to release of thecusps20 from the grippingmechanism70, theimplant10 can be manipulated to assure that anchoring structures or mechanisms associated with the strut are placed into desired contact with adjoining tissue below and/or above the plane of the annulus. The grippingmechanism70 can then be activated (see FIG. 30D), releasing theimplant10.
• FIGS. 31A to[0147]31E illustrate the deployment of an asymmetrically foldedelastic implant10 of the type shown in FIGS. 15D and 15E. Theimplant10 is constrained in an asymmetrically folded and collapsed condition within thesheath60, as FIG. 31A shows. The grippingmechanism70 holds one, but not both of thecusps20. This is because the height of thecusps20 above therails14 is also asymmetric. The grippingmechanism70 will couple to thetaller cusp20. Thepush rod62 can be advanced to expel theimplant10 from thesheath60. Due to the asymmetry of thecusps20, one of thestruts12 is positioned for deployment before theother strut12. Also due to the asymmetry of thecusps20, theshorter cusp20 is positioned for advancement out of thesheath60 before thetaller cusp20 is released by the grippingmechanism70.
• As FIG. 31B shows, under image guidance, the folded and collapsed[0148]implant10 is aligned with coaptation line near one of the commissures (thedelivery catheter58 has been previously introduced trans-septally into the left atrium, as already described). Manipulating thepush rod62 advances theimplant10 from thesheath60. The leadingstrut12 is freed first (see FIG. 31B) and placed against the adjacent commissure. Theimplant10 can be manipulated to assure that anchoring structures or mechanisms associated with the leading strut are placed into desired contact with adjoining tissue below and/or above the plane of the annulus. Further advancement ofpush rod62 causes theimplant10 to unfold toward the opposite commissure. Continued advancement of thepush rod62 frees more of the unfoldingimplant10 from thesheath60, until the trailingstrut12 contacts the opposite commissure (as FIG. 31C shows). Theimplant10 can be manipulated to assure that anchoring structures or mechanisms associated with the trailingstrut12 are placed into desired contact with adjoining tissue below and/or above the plane of the annulus. Further advancement of thepush rod62 frees theshorter cusp12 from thesheath60, and theimplant10 springs open along this side (see FIG. 31D). The grippingmechanism70 can then be activated (see FIG. 31), releasing thetaller cusp12. Theimplant10 springs open in this direction. It can be seen that the. asymmetry of theimplant10 make possible a step-wise deployment of theimplant10, one component at a time, in the annulus.
• 4. Guide Wire Assisted Deployment of Folded Elastic Implants[0149]
• The use of one or[0150]more guide loops66 or tethers to assist in the deployment of unfolded elastic implants has been previously discussed. One ormore guide loops66 or tethers can likewise be employed to assist in the deployment of folded elastic implants of either symmetric or asymmetric types.
• For example, as shown in FIG. 32, a metallic, fiber, or[0151]polymer guide wire64 can be looped through the deployment apertures on the struts of a folded symmetric orasymmetric implant10 prior to the folding and insertion of theimplant10 into thesheath60. The legs of the resultingguide wire loop66 are passed out the proximal end of thesheath60 for manipulation.
• In use (see FIG. 33A)—after the[0152]implant delivery catheter58 is introduced trans-septally into the left atrium in the manner previously described, and prior to activation of thepush rod62—both legs of theguide wire loop66 are advanced distally in tandem through thesheath60 to advance theloop66 beyond the deployment apertures and out the distal end of thesheath60. Theloop66 is placed within the annulus.
• The[0153]push rod62 is manipulated to free the foldedimplant10 for expansion (see FIG. 33B). Theimplant10 opens while tethered to theguide wire loop66. Theloop66 increases in diameter as thestruts12 expand apart. The perimeter of theloop66 will orient itself along the greatest dimension of the annulus—which is the distance between the commissures. Theloop66 thereby orients theimplant10 with the coaptation line duringimplant10 expansion. The legs of theloop66 guide thestruts12 to the commissures (as FIG. 33C shows).
• Tethered to the[0154]catheter58, theimplant10 is deployed in the annulus. Theguide wire loop66 maintains control of the strut spacing within the commissures during implant expansion.
• Once desired orientation and tissue contact are achieved for the[0155]implant10, the grippingmechanism70 can release theimplant10. One leg of thewire loop66 can be pulled to release theimplant10 from the guide wire (see FIG. 33D). Theimplant10 is allowed to fully unfold and seat within the annulus.
• As FIG. 34 shows, a second guide wire loop[0156]72 can also be passed through apertures on thecusps20. This guide wire loop72 can be manipulated independently of the firstguide wire loop66, to control deployment of the expandingimplant10 in the septal-to-lateral dimension. Simultaneous, although independent, control of the expandingimplant10 can be achieved by manipulation of thefirst guide wire66.
• As FIGS. 35 and 36A to[0157]36D show, separate metallic, fiber, orpolymer guide wires92 can be individually threaded (without looping) through small holes on the struts of a folded symmetric orasymmetric implant10 prior to the folding and insertion of theimplant10 into the sheath60 (see FIG. 35). Theseparate guide wires92 are passed out the proximal end of thesheath60 for manipulation.
• In use (see FIG. 36A)—after the[0158]implant delivery catheter58 is introduced trans-septally into the left atrium in the manner previously described, and prior to activation of thepush rod62—theseparate guide wires92 are advanced distally in tandem through thesheath60 and out the distal end of thesheath60. The ends of thewires92 are placed within the annulus.
• The[0159]push rod62 is manipulated to free the foldedimplant10 for expansion (see FIG. 36B). Theimplant10 opens while tethered to theseparate guide wires92. Theguide wires92 will orient themselves along the major axis of the annulus—which is the distance between the commissures, to orient theimplant10 with the coaptation line duringimplant10 expansion. Theguide wires92 separately guide therespective struts12 to the commissures (as FIG. 36C shows).
• Tethered to the[0160]catheter58, theimplant10 is deployed in the annulus. Theguide wires92 maintain control of the strut spacing within the commissures during implant expansion.
• Once desired orientation and tissue contact are achieved for the[0161]implant10, the grippingmechanism70 can release theimplant10. Theguide wires92 can be pulled to release theimplant10 from the guide wires (see FIG. 36D). Theimplant10 is allowed to fully unfold and seat within the annulus.
• 5. Other Forms of Assisted Deployment of Folded Elastic Implants[0162]
• The foregoing embodiments demonstrate that the unfolding of an[0163]elastic implant10 can be controlled during deployment in either the major axis dimension, or the minor axis (septal-to-lateral) dimension, or in both dimensions by means of guide wires. Other forms of restraining mechanisms can be used to control the unfolding of theimplant10.
• For example, as shown in FIG. 37A, the folded[0164]implant10 can be restrained within a bag orwrapper76 as theimplant10 is advanced from thedelivery sheath60. The bag orwrapper76 restricts expansion of theimplant10 beyond a selected point (e.g., 80% of full deployment), allowing the physician to attend to the important task of seating the struts in the commissures before theimplant10 fully opens across the annulus. Once theimplant10 has been seated in the commissures and released from the delivery sheath60 (see FIG. 37B), a ripcord78 coupled to the bag orwrapper76 can be pulled, to release the bag orwrapper76 from the implant10 (see FIG. 37C). Freed from the bag orwrapper76, theimplant10 completes its expansion, to achieve final shaping and seating within the annulus. One or more guide wires can be used in combination with the bag orwrapper76. The bag orwrapper76 can alternatively be sized and configured to tear away as a result of theimplant10 expanding beyond a given point, without the use of a ripcord78 or similar induced tearing mechanism. In another arrangement, theimplant10 can be enclosed within a shrink-wrap structure having a score line. In these arrangements, the structure is sized and configured to restrain expansion of theimplant10 until theimplant10 is advanced outside of the delivery sheath beyond a given point, at which time the score line parts or the material strength of the structure is exceeded, to open and fully release theimplant10.
• III. Plastically Deformable Implants for Reshaping a Heart Valve Annulus and Their Deployment[0165]
• As previously described, the[0166]implant10 may be formed from plastically deformable material (see FIG.38). Theimplant10 includes struts and one or more rails, as previously described. Theimplant10 is deployed by animplant delivery catheter58 into the left atrium in a normally collapsed condition. In this arrangement, animplant delivery catheter58 can carry amechanical expansion device80, such as a scissorjack or the like (see FIGS. 39A to39C), to expand the plastically deformable material of theimplant10 in situ within the annulus. Alternatively, animplant delivery catheter58 can carry an inflatable body82 (e.g., balloon) (see FIGS. 40A to40C), to expand theimplant10 within the annulus. During expansion, the plasticallydeformable implant10 stretches the annulus to achieve a desired major axis size. Once expanded, the plasticallydeformable implant10 maintains the desired distance, thereby resisting contraction of the annulus. The plasticallydeformable implant10 may include other structures or mechanisms to further anchor and stabilize theimplant10 in the heart valve annulus.
• IV. Ascertaining Implant Size and Resistance[0167]
• The shape and structure of a heart valve such as a mitral valve and the neighboring anatomic structures are generally understood by medical professionals using textbooks of human anatomy along with their knowledge of the site and its disease or injury. Ranges of shapes and dimensions for a given implant are defined by the site to be treated. Precise dimensions for a given patient can be determined by X-ray, MRI, or CT scanning of the site to be treated prior to implantation of an implant.[0168]
• A physician may also ascertain the size and resistance for a given implant by the deployment of a[0169]non-compliant balloon gauge84 in the targeted annulus, as shown in FIG. 41. Theballoon gauge84 can carry radio-opaque markers86 so that dimensions of the annulus can be determined using imaging means and/or other forms of in situ visualization. The compliance and tension forces of the annulus can also be physically measured, by sensing and quantifying the resistance theballoon gauge84 encounters during expansion in the annulus. Based upon this data, and taking into account the physician's knowledge of the site and its disease or injury, a physician can select a desired size and mechanical properties for the implant.
• V. Multi-Functional Implants[0170]
• Various embodiments of[0171]implants10 have described the context of reshaping a heart valve annulus. A givenimplant10 having technical features suited for this function can also incorporate other technical features well suited for other functions.
• By way of illustration, FIG. 42 shows an[0172]annulus remodeling implant10 in which therails14 are sized and configured to define a pseudo-annulus. Aneoleaflet element88 comprising a fabric-covered bridge structure is coupled to the rails. The neoleaflet element is sized and configured to occupy the space of at least a portion of a native heart valve leaflet to provide a one-way valve function. In response to ventricular diastolic pressure, the one-way valve function assumes a valve opened condition within the pseudo-annulus. In response to ventricular systolic pressure, the one-way valve function assumes a valve closed condition within the pseudo-annulus. Theneoleaflet element88 serves to repair, replace, or supplement a damaged heart valve.
• FIGS. 43 and 44 show an[0173]annulus remodeling implant10 in which therails14 are sized and configured serve as a pseudo-annulus. Theimplant10 includes a retainingstructure90 near or within the pseudo-annulus that is sized and shaped to overlay at least a portion of one or more native valve leaflets. The retainingstructure90 retains a native valve leaflet, keeping the valve leaflet from a retrograde flow condition, e.g., by being pushed into the atrium, i.e., eversion and/or prolapse.
• As further examples of multi-functional implants, FIGS.[0174]45 to47 shows anannulus remodeling implant10 in which the rails further include a framework38 (as previously described) to help position and secure the device in situ. In FIGS.45 to47, theframework38 also includes aleaflet retaining structure90, as just described.
• While the new devices and methods have been more specifically described in the context of the treatment of a mitral heart valve, it should be understood that other heart valve types can be treated in the same or equivalent fashion. By way of example, and not by limitation, the present systems and methods could be used to prevent or reduce retrograde flow in any heart valve annulus, including the tricuspid valve, the pulmonary valve, or the aortic valve. In addition, other embodiments and uses of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. The specification and examples should be considered exemplary and merely descriptive of key technical; features and principles, and are not meant to be limiting. The true scope and spirit of the invention are defined by the following claims. As will be easily understood by those of ordinary skill in the art, variations and modifications of each of the disclosed embodiments can be easily made within the scope of this invention as defined by the following claims.[0175]

Claims (44)

What is claimed is:

1. An implant to reshape a heart valve annulus comprising a body sized and configured to rest near or within a heart valve annulus, including a portion of the body contacting and outwardly displacing tissue to reshape the heart valve annulus.

2. An implant to reshape a heart valve annulus comprising a body sized and configured to rest in net compression near or within a heart valve annulus, including a portion of the body contacting tissue to displace tissue to reshape the heart valve annulus.

3. An implant to reshape a heart valve annulus comprising

a body sized and configured to rest in net compression near or within a heart valve annulus, and

spaced-apart struts appended to the body to contact tissue near or within the heart valve annulus, the struts being sized and configured to displace tissue as a result of the net compression to reshape the heart valve annulus.

4. An implant to reshape a heart valve having an annulus and leaflet commissures comprising

a body sized and configured to rest in net compression near or within a heart valve annulus, and

spaced-apart struts appended to the body to contact tissue at or near the leaflet commissures, the struts being sized and configured to displace tissue as a result of the net compression to reshape the heart valve annulus.

5. An implant to reshape a heart valve annulus comprising

a body sized and configured to rest in net compression near or within a heart valve annulus, and

spaced-apart struts appended to the body to contact tissue near or within the heart valve annulus, the struts being sized and configured to apply tension to tissue as a result of the compression of the body to reshape the heart valve annulus.

6. An implant to reshape a heart valve having an annulus and leaflet commissures comprising

a body sized and configured to rest in net compression near or within the heart valve annulus, and

spaced-apart struts appended to the body to contact tissue at or near the leaflet commissures, the structures being sized and configured to apply tension to tissue at or near the leaflet commissures as a result of the compression of the body to shape and tension the heart valve annulus for leaflet coaptation.

7. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body comprises an annular shape.

8. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body comprises a closed annular shape.

9. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body comprises an open annular shape.

10. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body comprises at least one rail.

11. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body comprises a wire-form structure.

12. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body is collapsible for placement within a catheter.

13. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body includes at least one cusp sized and configured to permit folding of the body without permanent deformation.

14. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body carries a tissue in-growth material.

15. An implant according toclaim 1 or2 or3 or4 or5 or6

further including at least one structure appended to the body and being sized and configured to contact tissue at, above, or below the heart valve annulus to stabilize the body.

16. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body is sized and configured to extend close to the annulus.

17. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body is sized and configured to extend above the annulus.

18. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body is sized and configured to contact tissue above the annulus.

19. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body is sized and configured to include one portion that extends close to the annulus and another portion that extends above the annulus.

20. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body is sized and configured to include one portion that extends close to the annulus and another portion that contacts tissue above the annulus.

21. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body comprises an elastic material.

22. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body comprises a plastically deformable material.

23. An implant according toclaim 1 or2 or3 or4 or5 or6

wherein the body comprises a superelastic material.

24. An implant according toclaim 1 or2 or3 or4 or5 or6

and further including a retaining element appended to the body and extending over at least a portion of a native heart valve leaflet, the restraining element being shaped to restrain retrograde movement of the heart valve leaflet.

25. An implant according toclaim 1 or2 or3 or4 or5 or6

and further including a neoleaflet element appended to the body and occupying the space of at least one native heart valve leaflet, the neoleaflet element being shaped to provide a one-way valve function.

26. An implant according toclaim 1 or2 or3 or4 or5 or6

and further including a second heart valve treatment element appended to the body to affect a heart valve function.

27. An implant according toclaim 26

wherein the second heart valve treatment element includes means for supplementing, repairing, or replacing a native heart valve leaflet.

28. An implant according toclaim 26

wherein the second heart valve treatment element includes means for retaining a native heart valve leaflet.

29. An implant according toclaim 3 or4 or5 or6

wherein at least one of the struts comprises a wire-form structure.

30. An implant according toclaim 3 or4 or5 or6

wherein the body and the struts each comprises a wire-form structure.

31. An implant according toclaim 3 or4 or5 or6

wherein at least one of the struts is collapsible onto the body.

32. An implant according toclaim 3 or4 or5 or6

wherein at least one of the struts carries a tissue in-growth material.

33. An implant according toclaim 3 or4 or5 or6

wherein at least one of the struts carries a structure sized and configured to increase a surface area of contact with tissue at, above, or below the annulus.

34. A method for reshaping a heart valve annulus comprising the steps of

introducing an implant as defined inclaim 1 or2 or3 or4 into a heart, and

displacing tissue to reshape the heart valve annulus by locating the body of the implant as defined inclaim 1 or2 or3 or4 near or within a heart valve annulus.

35. A method according toclaim 34

wherein the introducing step comprises using an open heart surgical procedure.

36. A method according toclaim 34

wherein the introducing step comprises using a surgical procedure in which the implant is carried within a catheter.

37. A method according toclaim 34

wherein the introducing step comprises using an intravascular surgical procedure.

38. A method according toclaim 34

wherein the displacing tissue step comprises tethering the body of the implant as defined inclaim 1 or2 or3 or4 to at least one wire while locating the body near or within a heart valve annulus.

39. A method for reshaping a heart valve annulus comprising the steps of

introducing an implant as defined inclaim 5 into a heart, and

applying tension to reshape the heart valve annulus by locating the body of the implant as defined inclaim 5 in net compression at or near a heart valve annulus with the struts in contact with and applying tension to tissue near or within the heart valve annulus.

40. A method for reshaping a heart valve having an annulus and leaflet commissures comprising the steps of

introducing an implant as defined inclaim 6 into a heart, and

applying tension to shape and tension the heart valve annulus for leaflet coaptation by locating the body of the implant as defined inclaim 6 in net compression at or near the leaflet commissures with the struts in contact with and applying tension to tissue at or near the leaflet commissures.

41. A method according toclaim 39 or40

wherein the introducing step comprises using an open heart surgical procedure.

42. A method according toclaim 39 or40

wherein the introducing step comprises using a surgical procedure in which the implant is carried within a catheter.

43. A method according toclaim 39 or40

wherein the introducing step comprises using an intravascular surgical procedure.

44. A method according toclaim 39 or40

wherein the applying tension step comprises tethering the body of the implant as defined inclaim 5 or6, respectively, to at least one wire while locating the body in compression at or near a heart valve annulus.

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