Heart valve prothesis having improved commissure durability

Abstract

A transcatheter heart valve prosthesis is disclosed that includes a tubular frame, which defines a central lumen of the prosthesis, and a tubular valve-skirt subassembly disposed within the central lumen. The valve-skirt subassembly includes a skirt element and a valve component having a plurality of leaflets. Each leaflet of the plurality of leaflets is formed to have a first commissure tab and a second commissure tab disposed at opposing lateral ends of the leaflet. The first commissure tab of a respective leaflet, in a folded state, forms a first commissure of the respective leaflet that is directly coupled only to the skirt element of the valve-skirt subassembly, and the second commissure tab of the respective leaflet, in a folded state, forms a second commissure of the respective leaflet that is directly coupled only to the skirt element of the valve-skirt subassembly.

Description

HEART VALVE PROTHESIS HAVING IMPROVED COMMISSURE DURABILITYCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 579,695, filed August 30, 2023, the entire content of which is incorporated herein by reference.FIELD

[0002] The present invention generally relates to medical devices. More particularly, the present technology is related to a transcatheter heart valve prosthesis and a method of assembling the transcatheter heart valve prosthesis.BACKGROUND

[0003] Patients suffering from various medical conditions or diseases may require surgery to install an implantable medical device. For example, valve regurgitation or stenotic calcification of leaflets of a heart valve may be treated with a heart valve replacement procedure. A traditional surgical valve replacement procedure requires a sternotomy and a cardiopulmonary bypass, which creates significant patient trauma and discomfort. Traditional surgical valve procedures may also require extensive recuperation times and may result in life-threatening complications.

[0004] One alternative to a traditional surgical valve replacement procedure is delivering implantable medical devices using minimally invasive techniques. For example, a prosthetic valve can be percutaneously and transluminally delivered to be deployed at the site of the diseased heart valve through catheter-based delivery systems. Such heart valve prostheses can be delivered while in a low-profile or compressed / contracted configuration so that the valve prosthesis can be advanced through the patient’s vasculature. Once positioned at the treatment site, the valve prosthesis can be expanded to engage tissue at the diseased heart valve region to, for instance, hold the valve prosthesis in position. While these valve prostheses offer minimally invasive methods for heart valve repair and / or replacement, challenges remain to providing effective and durable mitral valve and / or tricuspid valve replacements. Recent analysis of stresses on the leaflets of prosthetic heart valves positioned within variousellipticities mirroring native mitral valves has found that significant stresses occur in the commissure regions of the leaflets when in the closed (hydrodynamically loaded) state. The present disclosure relates to producing a prosthetic heart valve with improved commissure durability that aims to reduce stresses, caused by hydrodynamic loading of the leaflets, in the commissure regions of the leaflets.BRIEF SUMMARY

[0005] In accordance with a first example hereof, a transcatheter heart valve prosthesis includes: a frame having a tubular structure that defines a central lumen of the prosthesis; and a valve-skirt subassembly having a substantially tubular structure and being disposed within the central lumen of the frame, the valve-skirt subassembly including: an inner skirt having an exterior surface positioned against an interior of the frame; and a valve component included of a plurality of leaflets, wherein a respective leaflet of the plurality of leaflets is formed of a graft material with, a first commissure tab being located at a first lateral end of the respective leaflet, a second commissure tab being located at a second lateral end of the respective leaflet, and a free edge of the respective leaflet that extends between the first and second commissure tabs, wherein the first commissure tab of the respective leaflet, in a folded state, forms a first commissure of the respective leaflet having two layers of the graft material, the first commissure being directly coupled only to the inner skirt of the valve-skirt subassembly, and wherein the second commissure tab of the respective leaflet, in a folded state, forms a second commissure of the respective leaflet having two layers of the graft material, the second commissure being directly coupled only to the inner skirt of the valve-skirt subassembly.

[0006] In a second example, in a transcatheter heart valve prosthesis of the first example or any of the subsequent examples herein, a first commissure of a first leaflet of the plurality of leaflets is not attached to an adjacent first or second commissure of an adjoining second leaflet of the plurality of leaflets.

[0007] In a third example, in a transcatheter heart valve prosthesis according to any of the previous or subsequent examples herein, a second commissure of the first leaflet is not attached to an adjacent first or second commissure of an adjoining third leaflet of the plurality of leaflets.

[0008] In a fourth example, in a transcatheter heart valve prosthesis according to any of the previous or subsequent examples herein, the frame includes a plurality of commissure posts, and the inner skirt of the valve-skirt subassembly is disposed between pairs of adjacent firstand second commissures of adjoining leaflets and each of the plurality of commissure posts of the frame.

[0009] In a fifth example, in a transcatheter heart valve prosthesis according to any of the previous or subsequent examples herein, a suture is passed through the two layers of the graft material of a first commissure of a pair of adjacent first and second commissures and a graft material of the inner skirt to attach the first commissure and the inner skirt to a first commissure post of the plurality of commissure posts of the frame.

[0010] In a sixth example, in a transcatheter heart valve prosthesis according to any of the previous or subsequent examples herein, a suture is passed through the two layers of the graft material of a second commissure of the pair of adjacent first and second commissures and the graft material of the inner skirt to separately attach the second commissure and the inner skirt to the first commissure post.

[0011] In a seventh example, in a transcatheter heart valve prosthesis according to any of the previous or subsequent examples herein, each first or second commissure of a pair of adjacent first and second commissures from adjoining leaflets is independently attached to a respective commissure post of the plurality of commissure posts of the frame with the inner skirt being positioned between the pair of adjacent first and second commissures and the respective commissure post.

[0012] In an eight example, in a transcatheter heart valve prosthesis according to any of the previous or subsequent examples herein, first and second commissures of a pair of adjacent first and second commissures are not sewn or attached to each other.

[0013] In a ninth example, in a transcatheter heart valve prosthesis according to any of the previous or subsequent examples herein, a frame is an inner frame of the prosthesis that is surrounded by and attached to an outer frame of the prosthesis.

[0014] In a tenth example, a method of assembling a transcatheter heart valve prosthesis includes: arranging a first leaflet of a graft material in a flat state on a skirt element in a flat state; folding first and second commissure tabs of the first leaflet and attaching each of the first and second commissure tabs of the first leaflet, in a folded state, only to the skirt element to thereby create first and second commissures of the first leaflet each having two layers of the graft material; arranging a second leaflet of a graft material in a flat state on the skirt element in the flat state at a position adjacent to the first leaflet; and folding first and second commissuretabs of the second leaflet and attaching each of the first and second commissure tabs of the second leaflet, in a folded state, only to the skirt element to thereby create first and second commissures of the second leaflet each having two layers of the graft material, wherein the second commissure of the first leaflet is adjacent and is not attached to the first commissure of the second leaflet.

[0015] In an eleventh example, in a method of the tenth example or any of the subsequent examples herein, a method further includes: arranging a third leaflet of a graft material in a flat state on the skirt element in the flat state at a position adjacent to the second leaflet; and folding first and second commissure tabs of the third leaflet and attaching each of the first and second commissure tabs of the third leaflet, in a folded state, only to the skirt element to thereby create first and second commissures of the third leaflet each having two layers of the graft material, wherein the second commissure of the second leaflet is adjacent and is not attached to the first commissure of the third leaflet.

[0016] In a twelfth example, in a method according to any of the previous or subsequent examples herein, outflow edges of first, second and third leaflets are spaced inward from an outflow edge of a skirt element.

[0017] In a thirteenth example, in a method according to any of the previous or subsequent examples herein, a method further includes: attaching margin of attachment regions of first, second and third leaflets to a skirt element; attaching first and second side edges of the skirt element to form a side seam and a tubular structure having the first, second and third leaflets contained therein, and thereby forming a valve-skirt subassembly; and attaching the valve-skirt subassembly to a frame of the transcatheter heart valve prosthesis, the frame having a substantially tubular structure that defines a central lumen, and the valve-skirt subassembly being disposed within the central lumen of the frame.

[0018] In a fourteenth example, in a method according to any of the previous or subsequent examples herein, prior to attaching the valve-skirt subassembly to the frame, the valve-skirt subassembly is placed within the central lumen of the frame with an exterior surface of the skirt element disposed against an interior of the frame, and with each of a first pair, a second pair and a third pair of adjacent first and second commissures of adjoining first, second and / or third leaflets being aligned with a respective first, second or third commissure post of the frame.

[0019] In a fifteenth example, in a method according to any of the previous or subsequent examples herein, attaching the valve-skirt subassembly to the frame includes passing a suture through the two layers of the graft material of a first commissure of the first pair of adjacent first and second commissures and a graft material of the skirt element to attach the first commissure of the first pair of adjacent first and second commissures and the skirt element to the first commissure post of the frame.

[0020] In a sixteenth example, in a method according to any of the previous or subsequent examples herein, attaching a valve-skirt subassembly to a frame includes passing a suture through the two layers of the graft material of a second commissure of the first pair of adjacent first and second commissures and the graft material of the skirt element to separately attach the second commissure of the first pair of adjacent first and second commissures and the skirt element to the first commissure post of the frame.

[0021] In a seventeenth example, in a method according to any of the previous or subsequent examples herein, attaching a valve-skirt subassembly to a frame includes passing a suture through the two layers of the graft material of a first commissure of the second pair of adjacent first and second commissures and the graft material of the skirt element to attach the first commissure of the second pair of adjacent first and second commissures and the skirt element to the second commissure post of the frame.

[0022] In an eighteenth example, in a method according to any of the previous or subsequent examples herein, attaching a valve-skirt subassembly to a frame includes passing a suture through the two layers of the graft material of a second commissure of the second pair of adjacent first and second commissures and the graft material of the skirt element to separately attach the second commissure of the second pair of adjacent first and second commissures and the skirt element to the second commissure post of the frame.

[0023] In a nineteenth example, in a method according to any of the previous or subsequent examples herein, attaching a valve-skirt subassembly to a frame includes passing a suture through the two layers of the graft material of a first commissure of the third pair of adjacent first and second commissures and the graft material of the skirt element to attach the first commissure of the third pair of adjacent first and second commissures and the skirt element to the third commissure post of the frame.

[0024] In a twentieth example, in a method according to any of the previous or subsequent examples herein, attaching a valve-skirt subassembly to a frame includes passing a suture through the two layers of the graft material of a second commissure of the third pair of adjacent first and second commissures and the graft material of the skirt element to separately attach the second commissure of the third pair of adjacent first and second commissures and the skirt element to the third commissure post of the frame.

[0025] The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF DRAWINGS

[0026] The foregoing and other features and advantages of the present disclosure will be apparent from the following description of embodiments hereof as illustrated in the accompanying drawings. The accompanying drawings, which are incorporated herein and form a part of the specification, further explain the principles of the present disclosure and are meant to enable a person skilled in the pertinent art to make and use the embodiments of the present disclosure. The drawings are not to scale.

[0027] FIG. 1 depicts a perspective view of a prosthetic heart valve in accordance with embodiments hereof.

[0028] FIG. 2 depicts a perspective view of an inner frame of the prosthetic heart valve of FIG. 1 with a valve component secured therein in accordance with embodiments hereof.

[0029] FIG. 3 depicts an atrial or upstream end view of the prosthetic heart valve shown in FIG. 1 in accordance with embodiments hereof.

[0030] FIG. 4 depicts a ventricular or downstream end view of the prosthetic heart valve shown in FIG. 1 in accordance with embodiments hereof.

[0031] FIG. 5 depicts a valve leaflet, in an as-cut flat state, in accordance with embodiments hereof.

[0032] FIG. 6 depicts an inner skirt, in an as-cut flat state, in accordance with embodiments hereof.

[0033] FIG. 7 depicts a valve-skirt subassembly in accordance with embodiments hereof.

[0034] FIG. 8 depicts a valve leaflet in an as-cut flat state laid upon, and in alignment with, a first leaflet attachment segment of an inner skirt in an as-cut flat state in preparation for attachment thereto in accordance with embodiments hereof.

[0035] FIG. 8A is an enlarged depiction of Area A of FIG. 8 showing alignment between corresponding features of a commissure tab of the valve leaflet and an outflow edge of the inner skirt in accordance with embodiments hereof.

[0036] FIG. 8B is an enlarged depiction of Area A of FIG. 8 showing a commissure tab of the valve leaflet in a folded state and attached to the inner skirt in accordance with embodiments hereof.

[0037] FIG. 8C is an enlarged depiction of Area A of FIG. 8 showing a folded and attached commissure tab of the valve leaflet as shown in FIG. 8B trimmed to form a commissure in accordance with embodiments hereof.

[0038] FIG. 9A depicts a frame for use in a prosthetic heart valve in accordance with embodiments hereof.

[0039] FIG. 9B depicts the frame of FIG. 9A with the valve-skirt subassembly of FIG. 7 attached within a central lumen of the frame in accordance with embodiments hereof.DETAILED DESCRIPTION

[0040] Specific embodiments of the present disclosure are now described with reference to the figures, wherein like reference numbers indicate identical or functionally similar elements. As used in this specification, the singular forms “a”, “an” and “the” specifically also encompass the plural forms of the terms to which they refer, unless the content clearly dictates otherwise. The term “adjacent” or “adjoining” is used herein to mean a structure that is directly next to, bordering, or neighboring another structure. Further, numerical terms such as “first”, “second”, “third”, etc. used herein are not meant to be limiting such that use of the term “second” when referring to a part in the specification does not mean that there necessarily is a “first” of a part in order to fall within the scope of the invention. Instead, such numbers are merely describing that the embodiment being described has a “first” part and a “second” part. The invention is instead defined by the claims, in which one or more of such parts may be claimed.

[0041] The following detailed description is merely exemplary in nature and is not intended to limit the invention of the application and uses of the invention. Furthermore, there is nointention to be bound by any expressed or implied theory presented in the preceding field of the invention, background, summary, or the following detailed description.

[0042] FIGS. 1-4 illustrate an exemplary prosthetic heart valve 100 in accordance with embodiments hereof. The prosthetic heart valve 100 is presented by way of example only, and other shapes and designs of prosthetic heart valves are also consistent with embodiments hereof. The prosthetic heart valve 100 may also be referred to as a transcatheter heart valve prosthesis that is configured for placement within a tricuspid heart valve or a mitral heart valve via a catheter-based delivery systems utilizing minimally invasive techniques. As well, embodiments described herein may be adapted for use as a transcatheter heart valve prosthesis configured for placement within a pulmonary heart valve and / or an aortic heart valve via catheter-based delivery systems utilizing minimally invasive techniques.

[0043] The prosthetic heart valve 100 is configured to be radially compressed into a reduced- diameter configuration (not shown) for transcatheter delivery within a vasculature, for instance, and to return to an expanded, deployed configuration, which is shown in FIGS. 1-4. Stated another way, the prosthetic heart valve 100 has a crimped configuration for delivery within a vasculature, or other minimally invasive path, and an expanded configuration for deployment within a native heart valve. In accordance with embodiments hereof, when in the radially compressed or reduced-diameter configuration, the prosthetic heart valve 100 has a low profile suitable for delivery to and deployment within a native heart valve via a suitable delivery system that may be tracked to the deployment site of the native heart valve of a heart via any one of a transatrial, antegrade, or transapical approach. The prosthetic heart valve 100 includes a stent or frame 102 and a valve component 101 including leaflets 107A, 107B, 107C disposed within and secured to the frame 102. The valve component 101 of the prosthetic heart valve 100 is capable of regulating blood flow therethrough via the valve leaflets 107A, 107B, 107C that form a replacement valve.

[0044] Any portion of the frame 102 described herein as an element of a heart valve prothesis 100 may be made from any number of suitable biocompatible materials, e.g., stainless steel, nickel titanium alloys such as Nitinol™, cobalt chromium alloys such as MP35N, other alloys such as ELGILOY® (Elgin, Ill.), various polymers, pyrolytic carbon, silicone, polytetrafluoroethylene (PTFE), or any number of other materials or combination of materials. A suitable biocompatible material would be selected to permit the transcatheter heart valveprothesis 100 to be configured to be compressed into a reduced-diameter crimped configuration for transcatheter delivery to a native valve, whereby release from a delivery catheter returns the prosthesis to an expanded, deployed configuration. Alternatively, the prosthetic heart valve 100 may be balloon expandable as would be understood by one of ordinary skill in the art.

[0045] In an embodiment, the frame 102 of the prosthetic heart valve 100 includes a valve support or inner frame 102A at least partially surrounded by and attached to an anchoring member or outer frame 102B. The inner frame 102A is configured to support the valve component 101 therein. The inner frame 102A is a tubular stent-like or support structure that defines a central lumen from a first end 108 of the inner frame 102A to a second end 109 of the inner frame 102A. When positioned in situ within a native mitral or tricuspid valve, the first end 108 is an inflow or upstream end 108 and the second end 109 is an outflow or downstream end 109. At the outflow end 109, the inner frame 102A is attached to the outer frame 102B via, for instance, a plurality of connector components 104. In an embodiment, the plurality of connector components are rivets.

[0046] Referring to FIG. 2, the structure of the inner frame 102A will now be described in more detail. The inner frame 102A includes a plurality of crowns 111 A and a plurality of struts 11 IB with each crown 111A being formed between a pair of opposing struts 11 IB. Each crown 111A is a curved segment or bend extending between opposing struts 11 IB. The inner frame 102A is tubular, with a plurality of side openings 110 being defined by edges of the plurality of crowns 111A and the plurality of struts 11 IB. In an embodiment, the plurality of side openings 110 may be substantially diamond-shaped. The inner frame 102A includes a plurality of nodes 111C. A node 111C is defined as a region where two interior crowns of the plurality of crowns 111A meet or connect within the inner frame 102A. At the outflow end 109 thereof, the inner frame 102A includes a plurality of attachment bars 112 extending therefrom that function to releasably couple the prosthetic heart valve 100 to a delivery system. In an embodiment, the inner frame 102A includes three attachment bars 112 that are circumferentially spaced apart from each other at equal intervals.

[0047] The anchoring member or outer frame 102B is a stent-like or support structure that functions as an anchor for the prosthetic heart valve 100 to secure its deployed position within a native annulus. The outer frame 102B is a substantially cylindrically shaped structure that is configured to engage heart tissue at or below an annulus of a native heart valve, such as anannulus of a native mitral or tricuspid valve. At the first or inflow end 108 of the inner frame 102A, the outer frame 102B is radially spaced a distance S from the inner frame 102A to mechanically isolate the inflow end 108 of the inner frame 102A from the outer frame 102B. The outer frame 102B includes one or more fixation elements 105 that extend outward from an exterior side thereof to engage heart tissue. The fixation elements 105 project radially outward and are inclined toward an upstream direction. The fixation elements 105, for example, can be prongs, cleats, barbs, hooks, or other elements.

[0048] The outer frame 102B includes a plurality of crowns 113A and a plurality of struts 113B with each crown 113 A being formed between a pair of opposing struts 113B. Each crown 113 A is a curved segment or bend extending between opposing struts 113B. The outer frame 102B is tubular, with the plurality of side openings 114 being defined by edges of the plurality of crowns 113A and the plurality of struts 113B. In an embodiment, the plurality of side openings 114 may be substantially diamond-shaped. The outer frame 102B includes a plurality of nodes 113C. A node 113C is defined as a region where two interior crowns of the plurality of crowns 113A meet or connect within the outer frame 102B. When attached to the inner frame 102A via the plurality of connecting components 104, for instance, the outer frame 102B forms an outer frame portion of the frame 102 and the inner frame 102A forms an inner frame portion of the frame 102 with the outer frame 102B circumferentially surrounding the inner frame 102A disposed therein.

[0049] In accordance with embodiments hereof, the inner frame 102A has an inner skirt 103 A of a biocompatible graft material secured thereto, which will be described in more detail below with respect to FIG. 6, and the outer frame 102B has an outer skirt 103B of a biocompatible graft material secured thereto. The outer skirt 103B is coupled to an inner surface of the outer frame 102B to line a portion thereof. The outer engagement surface of the outer frame 102B is not covered by any sealing or graft material so that the outer engagement surface directly contacts the tissue of the native annulus. The graft material for the inner and outer skirts 103 A, 103B may be a natural or biological material such as pericardium or another membranous tissue such as intestinal submucosa. Alternatively, the graft material for the inner and outer skirts 103 A, 103B may be a low-porosity woven fabric, such as polyester, Dacron fabric, or PTFE, which creates a one-way fluid passage when attached to the respective frame portions.

[0050] In an embodiment, the prosthetic heart valve 100 further includes an extension member or brim 115 that extends outwardly from an inflow end of the outer frame 102B. The brim 115 is formed by a brim support 116 and a flexible web, which in this embodiment is a portion of the graft material that forms the outer skirt 103B and extends past or beyond the inflow end of the outer frame 102B. In the depicted embodiment, the brim support 116 includes overlapping, 180 degrees out of phase sinusoidal wire forms. However, the brim support 116 may have other configurations. The brim 115 may act as an atrial retainer, if present, and to serve such a function the brim 115 may be configured to engage tissue above a native annulus, such as a supra-annular surface or some other tissue in the right or left atrium, to thereby inhibit downstream migration of a prosthetic heart valve 100.

[0051] The valve component 101 of the prosthetic heart valve 100 is capable of regulating flow therethrough via valve leaflets 107A, 107B, 107C to thereby function as a replacement valve. FIGS. 1-4 illustrate a valve component having three leaflets, although a bicuspid leaflet configuration may be used in embodiments hereof. When deployed in situ, the valve component 101 is configured, in a closed state, to block blood flow in one direction to regulate blood flow through the central lumen of the valve support or inner frame 102A.

[0052] FIG. 2 depicts a perspective view of the valve support or inner frame 102A with a valve component 101 secured therein, for ease of illustration the inner frame 102A is shown in FIG. 2 removed from the remainder of the prosthetic heart valve 100 shown in FIG. 1. FIG. 3 depicts an atrial, inflow or upstream end view of the prosthetic heart valve 100 shown in FIG. 1, and FIG. 4 depicts a ventricular, outflow or downstream end view of the prosthetic heart valve 100 shown in FIG. 1.

[0053] In embodiments hereof and as previously noted above, the valve component 101 includes a first valve leaflet 107A, a second valve leaflet 107B and a third valve leaflet 107C that are disposed such that their free edges coapt within an upstream portion of the inner frame 102A, as shown in FIG. 3, with leaflet commissures 118A, 118AA, 118B, 118BB, 118C, 118CC of the respective valve leaflets 107A, 107B, 107C being located within a downstream portion of the inner frame 102A, as shown in FIG. 4. When configured as described, the first, second and third valve leaflets 107A, 107B, 107C open during diastole to function properly as a replacement heart valve. The first, second and third leaflets 107A, 107B, 107C are attached using sutures to the inner skirt 103 A, as described below.

[0054] The first, second and third valve leaflets 107A, 107B, 107C may be formed of various flexible materials including, but not limited to natural pericardial material such as tissue from bovine, equine or porcine origins, or synthetic materials such as polytetrafluoroethylene (PTFE), DACRON® polyester, pyrolytic carbon, or other biocompatible materials. With certain prosthetic leaflet materials, it may be desirable to coat one or both sides of the replacement valve leaflet with a material that will prevent or minimize overgrowth. It is further desirable that the prosthetic leaflet material is durable and not subject to stretching, deforming, or fatigue.

[0055] Each of the first, second and third leaflets 107A, 107B, 107C is substantially identical to another, and the structures shown and described with reference to the first leaflet 107A, shown in FIG. 5, should be understood to apply to the remaining second and third leaflets 107B, 107C. The first leaflet 107A is shown in FIG. 5 in an as-cut flat state such that a pattern of the leaflet may be depicted in accordance with embodiments hereof. The first leaflet 107A has an outer edge 520, opposing first and second commissure tabs 522A, 522B, and a free edge 524. The outer edge 520 of the first leaflet 107A is of a substantially semi-circular shape with a respective commissure tab 522A, 522B extending from each end thereof. The free edge 524 extends between the opposing first and second commissure tabs 522A, 522B. The first leaflet 107A further includes a margin of attachment 526 that runs substantially parallel to the outer edge 520 of the leaflet and is spaced inward thereof.

[0056] Each of the first and second commissure tabs 522A, 522B includes an outer fold-over portion 523A, 523B configured to fold over a respective fold line FL of each commissure tab 522A, 522B in an inward direction as represented by respective arrows ARI and AR2. Each of the outer fold-over portions 523A, 523B includes a first alignment cutout 525A, 525B that is configured to align with a second alignment cutout 527A, 527B of the first and second commissure tabs 522A, 522B, respectively, when the outer fold-over portions 523A, 523B are folded over their respective fold lines FL. Stated another way, the first and second alignment cutouts 525A, 527A of the first commissure tab 522A align with each other when the outer fold-over portion 523A is folded over the fold line FL of the first commissure tab 522A, and the first and second alignment cutouts 525B, 527B of the second commissure tab 522B align with each other when the outer fold-over portion 523B is folded over the fold line FL of the second commissure tab 522B. With reference to FIGS. 4, 7 and 9B, and as will be understoodfrom the further description below, the first and second commissure tabs 522A, 522B of the first leaflet 107A in a folded state form the commissures 118A, 118AA, respectively, similar first and second commissure tabs of the second leaflet 107B in a folded state form the commissures 118B, 118BB, respectively, and similar first and second commissure tabs of the third leaflet 107C in a folded state form the commissures 118C, 118CC, respectively.

[0057] The first, second and third valve leaflets 107A, 107B, 107C are attached to the graft material of the inner skirt 103 A in order to form the valve component 101. FIG. 6 depicts the inner skirt 103 A, in an as-cut flat state, in accordance with an embodiment hereof. The inner skirt 103 A includes a straight inflow end or inflow edge 630 having side seam alignment tabs 631A, 63 IB proximate each end thereof, an outflow end or edge 632 with a series of tabs as will be explained below, a first side edge 634A, a second side edge 634B, an interior surface 635, and an exterior surface 733 (see FIG. 7). The first side edge 634A and the second side edge 634B extend between the inflow edge 630 and the outflow edge 632, as shown in FIG. 6, and are sewn to each other to form the tubular structure of the valve component 101 as described with reference to FIG. 7.

[0058] For purposes of this description, the inner skirt 103 A is described as including a first leaflet attachment segment 638A, a second leaflet attachment segment 638B, and a third leaflet attachment segment 638C that are defined, and equally spaced, across a width W of the inner skirt 103A. Each of the first, second and third leaflet attachment segments 638A, 638B, 638C receives therein a respective first, second and third leaflet 107A, 107B, 107C for attachment to the inner skirt 103 A. Along the outflow edge 632 of the inner skirt 103 A, as also shown in FIG. 6, each of the first, second and third leaflet attachment segments 638A, 638B, 638C includes a first pair of alignment tabs 637A, 637B, 637C at a first lateral end thereof and a second pair of alignment tabs 637AA, 637BB, 637CC at a second lateral end thereof. During assembly, the first and second pairs of alignment tabs of the inner skirt 103 A are used to assure proper placement and alignment of the first, second and third leaflets 107A, 107B, 107C.

[0059] The inner skirt 103 A when assembled with the valve component 101 , i. e. , with the three leaflets 107A, 107B, 107C, is referred to herein as a valve-skirt subassembly 740, which is shown in FIG. 7. To form the valve-skirt subassembly 740, each of the first, second and third leaflets 107A, 107B, 107C are individually attached to the inner skirt 103A and this attachment begins with the formation and attachment of the respective commissures of each leaflet.

[0060] With reference to FIGS. 8 and 8A-8C, the following describes how the first commissure 118A of the first leaflet 107A is formed and attached to the inner skirt 103 A. As shown in FIG. 8, the first leaflet 107A is positioned to overlap the interior surface 635 of the inner skirt 103A at the first leaflet attachment segment 638 A such that the free edge 524 of the first leaflet 107A is spaced a distance D 1 from, but is substantially parallel with, the outflow edge 632 of the inner skirt 103A. In order to assure proper positioning of the first commissure 118A being formed, the first alignment cutout 525A of the first commissure tab 522A is longitudinally aligned with the space between the first pair of alignment tabs 637B of the second leaflet attachment segment 638B and the second alignment cutout 527A of the first commissure tab 522A is longitudinally aligned with the space between the second pair of alignment tabs 637AA of the first leaflet attachment segment 638A, as best shown in FIG. 8A. Once the commissure tab 522A is suitably positioned and aligned with respect to the outflow edge 632 of the inner skirt 103A, the outer fold-over portion 523 A of the first commissure tab 522A is folded over its fold line FL onto the remainder of the first commissure tab 522A, such that the first and second alignment cutouts 525A, 527A of the first commissure tab 522A overlay each other and are together longitudinally aligned with the space between the second pair of alignment tabs 637AA of the first leaflet attachment segment 638A, as best shown by a comparison of FIGS. 8A and 8B. The first commissure tab 522A in a folded state, which now includes two layers of graft material, is then sewn directly to only the inner skirt 103 A, and trimmed to remove excess material, to form the first commissure 118A. Accordingly, the first commissure 118A is thereby directly coupled only, or solely, to the inner skirt 103A. The first commissure 118A has a substantially straight outflow edge portion 524A, as shown in FIG. 8C. Stated another way, once trimmed, the outflow edge portion 524A of the first commissure 118A is substantially in line with the remainder of the free edge 524 of the valve leaflet 107A. The second commissure 118AA of the first leaflet 107A is next independently formed and directly coupled only, or solely, to the inner skirt 103 A in a similar manner to that described above for the first commissure 118A.

[0061] The commissure formation and attachment process is then repeated for creating the respective first and second commissures 118B, 118BB of the second leaflet 107B at the second leaflet attachment segment 638B of the inner skirt 103 A, and independently attaching each of the first and second commissures 118B, 118BB to the inner skirt 103A. The commissureformation and attachment process is then finally repeated for creating the respective first and second commissures 118C, 118CC of the third leaflet 107C at the third leaflet attachment segment 638C of the inner skirt 103A, and independently attaching each of the first and second commissures 118C, 118CC to the inner skirt 103A.

[0062] In accordance with embodiments hereof, the valve leaflet commissure tabs, such as commissure tabs 522A, 522B, are designed in a pattern to permit or allow an overlay of multiple layers as is evident from the description above. The commissures formed having this overlay of multiple layers of tissue that are than individually or separately attached to the inner skirt results in stronger valve commissures being formed and improves the distribution of load at the respective commissure locations thereby increasing the long-term durability of the prosthetic heart valve.

[0063] After formation and attachment of the respective commissures, each of the first, second and third leaflets 107A, 107B, 107C is then sewn to the inner skirt 103A by at least one line of sutures that runs parallel to the outer edge 520 of the respective leaflet thereby forming a respective margin of attachment 526 for each leaflet. Once the leaflets 107A, 107B, 107C are sewn to the inner skirt 103 A at their margin of attachments, the first and second side seam alignment tabs 631A, 63 IB of the inner skirt 103A are aligned with each other and the first and second side edges 634A, 634B of the inner skirt 103 A are joined to each other to create a side seam 742 and a tubular structure having the leaflets 107A, 107B, 107C contained therein and thereby secure the valve-skirt subassembly 740 in a tubular configuration, as shown in FIG. 7. The commissures 118A, 118AA, 118B, 118BB, 118C, 118CC of the respective valve leaflets 107A, 107B, 107C are spaced a distance DI from the outflow edge 632 of the inner skirt 103A as shown in FIG. 7, which depicts a downstream or outflow end of the valve-skirt subassembly 740. The valve-skirt subassembly 740 so formed is then ready for attachment to a frame, such as the inner frame 102A of the transcatheter heart valve prosthesis 100 or a frame or valve support 902 as described below.

[0064] A prosthetic valve leaflet design in accordance with embodiments described above includes commissure tabs of an elongated and / or widened shape, such as the shape shown in FIG. 5, that permits folding of the commissure tab to thereby form a commissure having two layers of graft material. Once the two-layered commissure is sewn or attached to a skirt element, such as the inner skirt 103A, it provides a durable commissure attachment and astronger valve commissure that improves load distribution at the commissure location thereby increasing the long-term durability of a prosthetic heart valve. Notably adjacent two-layered commissures so formed are independent of each other and are not directly attached or sewn to each other. Stated another way, each leaflet commissure is only directly attached or sewn to a skirt element, such as the inner skirt 103 A, and is not attached or sewn to an adjoining or adjacent leaflet commissure or other leaflet structure. For instance, with reference to FIG. 4, the first commissure 118A of the first leaflet 107A is not attached or sewn to the adjacent second commissure 118CC of the adjoining third leaflet 107C, and the second commissure 118AA of the first leaflet 107A is not attached or sewn to the adjacent first commissure 118B of the adjoining second leaflet 107B.

[0065] With reference to FIGS. 9A and 9B, after the valve-skirt subassembly 740 is completed, the valve-skirt subassembly 740 is attached or sewn to a frame or valve support 902, which as would be understood by one of ordinary skill in the art may in an embodiment be used as the inner frame 102A of the prosthetic heart valve 100. The frame 902 is a tubular stent-like or support structure that defines a central lumen 906 between a first end 908 of the frame 902 and a second end 909 of the frame 902. When positioned in situ within a native mitral or tricuspid valve, the first end 908 is an inflow or upstream end 908 and the second end 909 is an outflow or downstream end 909. For attachment, the valve-skirt subassembly 740 is placed within the central lumen 906 of the frame 902 with the exterior surface 733 of the inner skirt 103A disposed against an interior of the frame 902, and with each pair of leaflet commissures of the valve component 101 being aligned with a respective first, second or third commissure post 911A, 91 IB, 911C of the frame 902. With reference to FIG. 9B, a first pair of adjacent first and second commissures 118A, 118CC are aligned with the first commissure post 911 A, a second pair of adjacent first and second commissures 118B, 118AA are aligned with the second commissure post 91 IB, and a third pair of adjacent first and second commissures 118C, 118BB are aligned with the third commissure post 911C.

[0066] When the pairs of leaflet commissures of the valve component 101 are aligned with a respective first, second or third commissure post 911A, 91 IB, 911C of the frame 102, the inflow edge 630 of the inner skirt 103A of the valve-skirt subassembly 740 is positioned within the frame 902 to be disposed below the last row of nodes at the inflow edge 630 of the frame 902 and the outflow edge 632 of the inner skirt 103A of the valve-skirt subassembly 740 ispositioned within the frame 902 to be disposed above the last row of nodes at the outflow end 909 of the frame 902. With the valve-skirt subassembly 740 so positioned, the valve-skirt subassembly 740 is then attached or sewn to the frame 902 using sutures. During attachment, each commissure of the first pair of adjacent first and second commissures 118A, 118CC is independently sewn to the first commissure post 911 A, each commissure of the second pair of adjacent first and second commissures 118B, 118AA is independently sewn to the second commissure post 91 IB, and each commissure of the third pair of adjacent first and second commissures 118C, 118BB are independently sewn to the third commissure post 911C. Stated another way, and by example using the first pair of adjacent first and second commissures 118A, 118CC, a suture is passed through the two layers of graft material of the first commissure 118A and the graft material of the inner skirt 103 A thereunder to attach or sew the first commissure 118A of the first leaflet 107A and the underlying fabric of the inner skirt to the first commissure post 911A, and separately or independently of this attachment a suture is passed through the two layers of graft material of the second commissure 118CC of the third leaflet 107C and the graft material of the inner skirt 103 A thereunder to attach or sew the second commissure 118CC and the underlying fabric of the inner skirt to the first commissure post 911A. This process is then repeated for the second pair of adjacent first and second commissures 118B, 118AAB and the third pair of adjacent first and second commissures 118C, 118BB. This defined pattern of commissure attachment results in a prosthetic heart valve having stronger valve commissures thereby increasing the long-term durability of the prosthetic heart valve.

[0067] As referred to herein prostheses, prosthetic heart valves or prosthetic valves of the present disclosure may assume a wide variety of configurations. Prosthetic heart valves can include, for example, a bioprosthetic heart valve having tissue leaflets or a synthetic heart valve having polymeric, metallic or tissue-engineered leaflets, and can be specifically configured for replacing valves of the human heart. The prosthetic valves of the present disclosure may be self-expandable, balloon expandable and / or mechanically expandable or combinations thereof. In general terms, the prosthetic valves of the present disclosure include a stent or stent frame having an internal lumen maintaining a valve structure (tissue or synthetic), with the stent frame having a normal, expanded condition or arrangement and collapsible to a compressed condition or arrangement for loading within the delivery system. For example, stents or stent frames aresupport structures that comprise a number of struts or wire segments arranged relative to each other to provide a desired compressibility and strength to the prosthetic valve. The struts or wire segments are arranged such that they are capable of self-transitioning from, or being forced from, a compressed or collapsed arrangement to a normal, radially expanded arrangement. The struts or wire segments can be formed from a shape memory material, such as a nickel titanium alloy (e.g., Nitinol). The stent frame can be laser-cut from a single piece of material or can be assembled from a number of discrete components.

[0068] Various embodiments disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single device or component for purposes of clarity, the techniques of this disclosure may be performed by a combination of devices or components.

Claims

CLAIMSWhat is claimed is:

1. A transcatheter heart valve prosthesis comprising: a frame having a tubular structure that defines a central lumen of the prosthesis; and a valve-skirt subassembly having a substantially tubular structure and being disposed within the central lumen of the frame, the valve-skirt subassembly including: an inner skirt having an exterior surface positioned against an interior of the frame; and a valve component comprised of a plurality of leaflets, wherein a respective leaflet of the plurality of leaflets is formed of a graft material with, a first commissure tab being located at a first lateral end of the respective leaflet, a second commissure tab being located at a second lateral end of the respective leaflet, and a free edge of the respective leaflet that extends between the first and second commissure tabs, wherein the first commissure tab of the respective leaflet, in a folded state, forms a first commissure of the respective leaflet having two layers of the graft material, the first commissure being directly coupled only to the inner skirt of the valve-skirt subassembly, and wherein the second commissure tab of the respective leaflet, in a folded state, forms a second commissure of the respective leaflet having two layers of the graft material, the second commissure being directly coupled only to the inner skirt of the valve-skirt subassembly.

2. The transcatheter heart valve prosthesis according to claim 1, wherein a first commissure of a first leaflet of the plurality of leaflets is not attached to an adjacent first or second commissure of an adjoining second leaflet of the plurality of leaflets.

3. The transcatheter heart valve prosthesis according to claim 2, wherein a second commissure of the first leaflet is not attached to an adjacent first or second commissure of an adjoining third leaflet of the plurality of leaflets.

4. The transcatheter heart valve prosthesis according to claim 1, wherein the frame includes a plurality of commissure posts, and the inner skirt of the valve-skirt subassembly is disposed between pairs of adjacent first and second commissures of adjoining leaflets and each of the plurality of commissure posts of the frame.

5. The transcatheter heart valve prosthesis according to claim 4, wherein a suture is passed through the two layers of the graft material of a first commissure of a pair of adjacent first and second commissures and a graft material of the inner skirt to attach the first commissure and the inner skirt to a first commissure post of the plurality of commissure posts of the frame.

6. The transcatheter heart valve prosthesis according to claim 5, wherein a suture is passed through the two layers of the graft material of a second commissure of the pair of adjacent first and second commissures and the graft material of the inner skirt to separately attach the second commissure and the inner skirt to the first commissure post.

7. The transcatheter heart valve prosthesis according to claim 4, wherein each first or second commissure of a pair of adjacent first and second commissures from adjoining leaflets is independently attached to a respective commissure post of the plurality of commissure posts of the frame with the inner skirt being positioned between the pair of adjacent first and second commissures and the respective commissure post.

8. The transcatheter heart valve prosthesis according to claim 7, wherein the first and second commissures of the pair of adjacent first and second commissures are not sewn or attached to each other.

9. The transcatheter heart valve prosthesis according to claim 1, wherein the frame is an inner frame of the prosthesis that is surrounded by and attached to an outer frame of the prosthesis.

10. A method of assembling a transcatheter heart valve prosthesis comprising: arranging a first leaflet of a graft material in a flat state on a skirt element in a flat state; folding first and second commissure tabs of the first leaflet and attaching each of the first and second commissure tabs of the first leaflet, in a folded state, only to the skirt element to thereby create first and second commissures of the first leaflet each having two layers of the graft material; arranging a second leaflet of a graft material in a flat state on the skirt element in the flat state at a position adjacent to the first leaflet; and folding first and second commissure tabs of the second leaflet and attaching each of the first and second commissure tabs of the second leaflet, in a folded state, only to the skirt element to thereby create first and second commissures of the second leaflet each having two layers of the graft material, wherein the second commissure of the first leaflet is adjacent and is not attached to the first commissure of the second leaflet.

11. The method according to claim 10, further comprising: arranging a third leaflet of a graft material in a flat state on the skirt element in the flat state at a position adjacent to the second leaflet; and folding first and second commissure tabs of the third leaflet and attaching each of the first and second commissure tabs of the third leaflet, in a folded state, only to the skirt element to thereby create first and second commissures of the third leaflet each having two layers of the graft material, wherein the second commissure of the second leaflet is adjacent and is not attached to the first commissure of the third leaflet.

12. The method according to claim 11, wherein outflow edges of the first, second and third leaflets are spaced inward from an outflow edge of the skirt element.

13. The method according to claim 11, further comprising: attaching margin of attachment regions of the first, second and third leaflets to the skirt element; attaching first and second side edges of the skirt element to form a side seam and a tubular structure having the first, second and third leaflets contained therein, and thereby forming a valve-skirt subassembly; and attaching the valve-skirt subassembly to a frame of the transcatheter heart valve prosthesis, the frame having a substantially tubular structure that defines a central lumen, and the valve-skirt subassembly being disposed within the central lumen of the frame.

14. The method according to claim 13, wherein, prior to attaching the valve-skirt subassembly to the frame, the valve-skirt subassembly is placed within the central lumen of the frame with an exterior surface of the skirt element disposed against an interior of the frame, and with each of a first pair, a second pair and a third pair of adjacent first and second commissures of adjoining first, second and / or third leaflets being aligned with a respective first, second or third commissure post of the frame.

15. The method according to claim 14, wherein attaching the valve-skirt subassembly to the frame includes passing a suture through the two layers of the graft material of a first commissure of the first pair of adjacent first and second commissures and a graft material of the skirt element to attach the first commissure of the first pair of adjacent first and second commissures and the skirt element to the first commissure post of the frame.

16. The method according to claim 15, wherein attaching the valve-skirt subassembly to the frame includes passing a suture through the two layers of the graft material of a second commissure of the first pair of adjacent first and second commissures and the graft material of the skirt element to separately attach the second commissure of the first pair of adjacent first and second commissures and the skirt element to the first commissure post of the frame.

17. The method according to claim 16, wherein attaching the valve-skirt subassembly to the frame includes passing a suture through the two layers of the graft material of a firstcommissure of the second pair of adjacent first and second commissures and the graft material of the skirt element to attach the first commissure of the second pair of adjacent first and second commissures and the skirt element to the second commissure post of the frame.

18. The method according to claim 17, wherein attaching the valve-skirt subassembly to the frame includes passing a suture through the two layers of the graft material of a second commissure of the second pair of adjacent first and second commissures and the graft material of the skirt element to separately attach the second commissure of the second pair of adjacent first and second commissures and the skirt element to the second commissure post of the frame.

19. The method according to claim 18, wherein attaching the valve-skirt subassembly to the frame includes passing a suture through the two layers of the graft material of a first commissure of the third pair of adjacent first and second commissures and the graft material of the skirt element to attach the first commissure of the third pair of adjacent first and second commissures and the skirt element to the third commissure post of the frame.

20. The method according to claim 19, wherein attaching the valve-skirt subassembly to the frame includes passing a suture through the two layers of the graft material of a second commissure of the third pair of adjacent first and second commissures and the graft material of the skirt element to separately attach the second commissure of the third pair of adjacent first and second commissures and the skirt element to the third commissure post of the frame.

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