Expandable stent with outflow commissure post for transcatheter implantation of heart valve prosthesis

Abstract

A transcatheter valve prosthesis includes a stent and a prosthetic valve. The stent is mechanically or balloon expandable. The bracket has an inflow portion and an outflow portion. The inflow portion includes a plurality of side openings defined by a plurality of crowns and a plurality of struts. The outflow portion has three circumferentially spaced apart commissure posts. The prosthetic valve is disposed within and secured to the outflow portion of the stent at least. The prosthetic valve is configured to block blood flow in one direction to regulate blood flow through the central lumen of the stent. The commissure posts are configured to flex radially inward or flex to reduce stress observed during valve loading and thereby improve or increase tissue durability of the prosthetic valve.

Description

[0001] This application is a divisional application of the invention patent application with Chinese application number 202080070275.6 and invention name “Expandable stent with outflow commissures for transcatheter implantation of heart valve prostheses” (the invention patent application with application number 202080070275.6 is an application for international patent application PCT / EP2020 / 079407 entering the Chinese national phase).

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent Application Serial No. 62 / 923,657, filed on October 21, 2019, which is hereby incorporated by reference in its entirety for all purposes. Technical Field

[0004] The present invention relates to a transcatheter valve prosthesis that is radially expandable, either mechanically or by means of a balloon. Background Art

[0005] The human heart contains four heart valves that determine the path of blood flow through the heart: the mitral valve, tricuspid valve, aortic valve and pulmonary valve. The mitral valve and tricuspid valve are atrioventricular valves, located between the atria and ventricles, while the aortic valve and pulmonary valve are semilunar valves, located in the arteries leaving the heart. Ideally, when the heart valve is in the open position, the natural leaflets of the valve move to separate from each other, and when the valve is in the closed position, the natural leaflets meet or "engage". Possible problems with the valve include stenosis where the valve does not open properly and / or insufficiency or regurgitation where the valve does not close properly. Stenosis and insufficiency may occur together in the same valve. The effects of valve dysfunction vary, with regurgitation or backflow usually causing relatively severe physiological consequences to the patient.

[0006] Recently, a flexible prosthetic valve that can be delivered percutaneously using a delivery system based on a catheter, supported by a stent structure, has been developed for use in heart and venous valve replacement. These prosthetic valves can include a self-expanding or balloon-expandable stent structure in which valve leaflets are attached to the inside of the stent structure. The diameter of the prosthetic valve can be reduced by curling onto a balloon catheter or by being contained in a sheath assembly of a delivery catheter, and can be advanced through a vein or arterial vascular system. When the prosthetic valve is positioned at the treatment site, such as in a functionally incompetent natural valve, the stent frame structure can be expanded to securely hold the prosthetic valve in place.

[0007] When designing a prosthetic valve, valve frame integration and frame mechanical properties often have competing needs or requirements. For example, when attaching the valve to the frame during valve-frame integration, it is desirable to reinforce the valve itself to the frame at certain locations without affecting the mechanical properties of the frame. Embodiments herein relate to an improved balloon-expandable transcatheter valve prosthesis that is configured to minimize the tradeoffs between the above-mentioned competing needs. Summary of the invention

[0008] According to the first embodiment of the present invention, the present disclosure provides a transcatheter valve prosthesis, which includes a stent and a prosthetic valve. The stent has a curled configuration for delivery in the vascular system and an expanded configuration for deployment in a natural heart valve. The stent is mechanically or balloon expandable. The stent has an inflow portion and an outflow portion. The inflow portion is formed near the inflow end of the tubular stent and includes a plurality of crowns and a plurality of pillars, wherein each crown is formed between a pair of opposing pillars. The plurality of crowns and the plurality of pillars define a plurality of side openings. The outflow portion is formed near the outflow end of the tubular stent and is connected to the inflow portion. The outflow portion has exactly three commissures, each commissure extending longitudinally from the crown of the inflow portion, and the three commissures are circumferentially spaced apart. The thickness of each commissure varies along its length, so that the first end is relatively thicker than the second end, and the first end is connected to the crown of the inflow portion. The prosthetic valve is placed in the outflow portion of the tubular stent and is fixed at least to the outflow portion. The prosthetic valve is configured to block blood flow in one direction to regulate blood flow through the central lumen of the stent.

[0009] In one aspect of the first embodiment, and in combination with any other aspects of the present invention, the present disclosure provides that the prosthetic valve includes three leaflets and three commissures, each commissure being formed by attached adjacent side ends of adjacent pairs of the three leaflets, and the three commissure posts are aligned with and attached to corresponding commissures of the three leaflets of the prosthetic valve.

[0010] In an aspect of the first embodiment, and in combination with any other aspects herein, the present disclosure provides that each commissure post is a planar rod.

[0011] In an aspect of the first embodiment, and in combination with any other aspects herein, the present disclosure provides that the thickness of each commissure post is configured to allow each commissure post to flex radially inwardly during loading of the transcatheter valve prosthesis.

[0012] In one aspect of the first embodiment, and in combination with any other aspects herein, the present disclosure provides that each strut of the inflow portion has a thickness along its length, and the thickness of each commissure at its first end is no greater than the thickness of the strut of the inflow portion.

[0013] In one aspect of the first embodiment, and in combination with any other aspect of the present invention, the present disclosure provides that each commissure post has a preset curve so that the second end is disposed radially inwardly relative to the first end. In one embodiment, the second end of each commissure post is disposed radially inwardly relative to the first end by 1 mm to 2 mm.

[0014] In an aspect of the first embodiment, and in combination with any other aspects herein, the present disclosure provides that each strut of the inflow portion has a first width along its length and each commissure post has a second width along its length, the first width being less than the second width.

[0015] In an aspect of the first embodiment, and in combination with any other aspects herein, the present disclosure provides that the inflow portion is formed of a first material and each commissure post of the outflow portion is formed of a second material, the first material being different from the second material. In an embodiment, the first material is plastically deformable and the second material is superelastic. In an embodiment, the second material is nitinol.

[0016] In an aspect of the first embodiment, and in combination with any other aspects herein, the present disclosure provides that the inflow end of the stent has a total of twelve distal-most inflow crowns.

[0017] In an aspect of the first embodiment, and in combination with any other aspects herein, the present disclosure provides that the outflow portion further comprises a plurality of axial struts extending longitudinally from a crown of the inflow portion, and at least one axial strut is disposed between circumferentially adjacent commissure posts.

[0018] In one aspect of the first embodiment, and in combination with any other aspects of the present invention, the present disclosure provides that the outflow portion includes exactly six axial frame components, and three of the six axial frame components are the commissure posts, and three of the six axial frame components are axial struts, each of which is disposed between circumferentially adjacent commissure posts.

[0019] In an aspect of the first embodiment, and in combination with any other aspect of the present invention, the present disclosure provides that the inflow portion includes at least three rows of a plurality of struts and crowns, and the at least three rows of the inflow portion are formed between the inflow end of the commissure post and the inflow end of the stent. In an embodiment, the inflow portion includes exactly three rows of a plurality of struts and crowns.

[0020] According to a second embodiment of the present invention, the present disclosure provides a transcatheter valve prosthesis, which includes a stent and a prosthetic valve. The stent has a curled configuration for delivery in the vascular system and an expanded configuration for deployment in a natural heart valve. The stent is mechanically or balloon expandable. The stent has an inflow portion and an outflow portion. The inflow portion is formed near the inflow end of the stent and includes a plurality of crowns and a plurality of pillars, wherein each crown is formed between a pair of opposing pillars. The plurality of crowns and the plurality of pillars define a plurality of side openings. The outflow portion is formed near the outflow end of the stent and is connected to the inflow portion. The outflow portion has exactly three commissures, each commissure extending longitudinally from the crown of the inflow portion, and the three commissures are circumferentially spaced apart. Each commissure has a length greater than the length of each pillar of the inflow portion, each commissure has a thickness along the length thereof, the thickness is less than the thickness of each pillar of the inflow portion along the length thereof, and each commissure has a width greater than the width of each pillar of the inflow portion. The prosthetic valve is disposed within the outflow portion of the stent and is secured to at least the outflow portion. The prosthetic valve is configured to block blood flow in one direction to regulate blood flow through a central lumen of the stent.

[0021] In one aspect of the second embodiment, and in combination with any other aspects of the present invention, the present disclosure provides that the prosthetic valve comprises three leaflets and three commissures, each commissure being formed by attached adjacent side ends of adjacent pairs of the three leaflets, and the three commissure posts being aligned with and attached to corresponding commissures of the three leaflets of the prosthetic valve.

[0022] In an aspect of the second embodiment, and in combination with any other aspects herein, the present disclosure provides that each commissure post is a planar rod.

[0023] In an aspect of the second embodiment, and in combination with any other aspects herein, the present disclosure provides that each commissure post has a strength greater than a strength of each strut of the inflow portion.

[0024] In an aspect of a second embodiment, and in combination with any other aspect herein, the present disclosure provides that the inflow portion is formed of a first material and each commissure post of the outflow portion is formed of a second material, the first material being different from the second material. In an embodiment, the first material is plastically deformable and the second material is superelastic. In an embodiment, the second material is nitinol.

[0025] In an aspect of the second embodiment, and in combination with any other aspects herein, the present disclosure provides that the inflow end of the stent has a total of twelve distal-most inflow crowns.

[0026] In an aspect of the second embodiment, and in combination with any other aspects herein, the present disclosure provides that the outflow portion further comprises a plurality of axial struts extending longitudinally from a crown of the inflow portion, and at least one axial strut is disposed between circumferentially adjacent commissure posts.

[0027] In one aspect of the second embodiment, and in combination with any other aspects of the present invention, the present disclosure provides that the outflow portion includes exactly six axial frame components, and three of the six axial frame components are the commissure posts, and three of the six axial frame components are axial struts, each of the axial struts being disposed between circumferentially adjacent commissure posts.

[0028] In an aspect of a second embodiment, and in combination with any other aspect of the present disclosure, the present disclosure provides that the inflow portion comprises at least three rows of a plurality of struts and crowns, the at least three rows of the inflow portion being formed between an inflow end of the commissure post and an inflow end of the stent. In an embodiment, the inflow portion comprises exactly three rows of a plurality of struts and crowns.

[0029] According to a third embodiment of the present invention, the present disclosure provides a transcatheter valve prosthesis comprising a stent and a prosthetic valve. The stent has a curled configuration for delivery in a vascular system and an expanded configuration for deployment in a natural heart valve. The stent is mechanically or balloon expandable. The stent has an inflow portion and an outflow portion. The inflow portion is formed near the inflow end of the tubular stent and comprises a plurality of crowns and a plurality of struts, wherein each crown is formed between a pair of opposing struts. The plurality of crowns and the plurality of struts define a plurality of side openings. The inflow portion is formed by a first material. The outflow portion is formed near the outflow end of the stent and is connected to the inflow portion. The outflow portion has exactly three commissures, each commissure extending longitudinally from the crown of the inflow portion, and the three commissures are circumferentially spaced apart. Each commissure is formed by a second material different from the first material. A prosthetic valve is disposed within and secured to at least the outflow portion of the stent, the prosthetic valve being configured to block blood flow in one direction to regulate blood flow through a central lumen of the stent.

[0030] In one aspect of the third embodiment, and in combination with any other aspects of the present invention, the present disclosure provides that the prosthetic valve comprises three leaflets and three commissures, each commissure being formed by attached adjacent side ends of adjacent pairs of the three leaflets, and the three commissure posts being aligned with and attached to corresponding commissures of the three leaflets of the prosthetic valve.

[0031] In an aspect of the third embodiment, and in combination with any other aspects herein, the present disclosure provides that each commissure post is a planar rod.

[0032] In one aspect of the third embodiment, and in combination with any other aspects of the present invention, the present disclosure provides that each fusion post has a length greater than the length of each strut of the inflow portion, each fusion post has a thickness along its length, the thickness is less than the thickness of each strut of the inflow portion along its length, and each fusion post has a width greater than the width of each strut of the inflow portion.

[0033] In an aspect of the third embodiment, and in combination with any other aspects herein, the present disclosure provides that the first material is plastically deformable and the second material is superelastic. In an embodiment, the second material is nitinol.

[0034] In an aspect of the third embodiment, and in combination with any other aspects herein, the present disclosure provides that the inflow end of the stent has a total of twelve distal-most inflow crowns.

[0035] In an aspect of the third embodiment, and in combination with any other aspects herein, the present disclosure provides that the outflow portion further comprises a plurality of axial struts extending longitudinally from a crown of the inflow portion, and at least one axial strut is disposed between circumferentially adjacent commissure posts.

[0036] In one aspect of the third embodiment, and in combination with any other aspects of the present invention, the present disclosure provides that the outflow portion includes exactly six axial frame components, and three of the six axial frame components are the commissure posts, and three of the six axial frame components are axial struts, each of the axial struts being disposed between circumferentially adjacent commissure posts.

[0037] In an aspect of a third embodiment, and in combination with any other aspect of the present disclosure, the present disclosure provides that the inflow portion comprises at least three rows of a plurality of struts and crowns, and the at least three rows of the inflow portion are formed between an inflow end of the commissure post and an inflow end of the stent. In an embodiment, the inflow portion comprises exactly three rows of a plurality of struts and crowns. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The foregoing and other features and advantages of the present invention will become apparent from the following description of the embodiments of the present invention as shown in the accompanying drawings. The accompanying drawings, which are incorporated herein and form a part of this specification, are further used to explain the principles of the present invention and enable those skilled in the relevant art to make and use the present invention. The accompanying drawings are not drawn to scale.

[0039] Figure 1 is a perspective side view of a transcatheter valve prosthesis according to embodiments herein, wherein the transcatheter valve prosthesis is in an expanded configuration.

[0040] Figure 1A yes Figure 1 Illustration of an end view of a transcatheter valve prosthesis.

[0041] Figure 2 is a side view of a transcatheter valve prosthesis according to another embodiment of the present invention, wherein the transcatheter valve prosthesis is Figure 1 The transcatheter valve prosthesis of is relatively long and is shown in an expanded configuration.

[0042] Figure 3 yes Figure 1 Side view of a transcatheter valve prosthesis implanted within the native aortic annulus.

[0043] Figure 4 yes Figure 1 A perspective view of a stent for a transcatheter valve prosthesis of FIG. 1 , wherein the stent is in an expanded configuration.

[0044] Figure 5 yes Figure 1 A side view of a stent for a transcatheter valve prosthesis, wherein the stent is in a non-expanded or crimped configuration.

[0045] Figure 6 yes Figure 1 A side view of a stent for a transcatheter valve prosthesis, wherein the stent is in an expanded configuration.

[0046] Fig. 6A yes Figure 1 An enlarged side view of a single cell or side opening of an inflow portion of a stent of a transcatheter valve prosthesis, wherein the stent is in an expanded configuration.

[0047] Figure 7 yes Figure 1 End view of the inflow end of a stent of a transcatheter valve prosthesis.

[0048] Figure 8 yes Figure 1 End view of the outflow end of a stent of a transcatheter valve prosthesis.

[0049] Fig. 9is a perspective view of a stent for a transcatheter valve prosthesis according to another embodiment herein, wherein the stent is in an expanded configuration.

[0050] Fig.10 yes Fig. 9 A side view of a stent for a transcatheter valve prosthesis, wherein the stent is in a non-expanded or crimped configuration.

[0051] Fig.11 yes Figure 1 A front view of commissure posts of a stent for a transcatheter valve prosthesis, wherein the commissure posts have variable wall thickness.

[0052] Fig.12 yes Fig.11 Side view of the commissure column.

[0053] Fig.13 According to the embodiments of this article Fig.11 Side view of the commissure posts of a stent of a transcatheter valve prosthesis.

[0054] Fig.14 According to the embodiments of this article Fig.11 Side view of the commissure posts of a stent of a transcatheter valve prosthesis.

[0055] Fig.15 yes Fig.14 A side view of the commissure post showing the flexion action of the commissure post.

[0056] Fig.16 is a front view of a commissure post of a stent according to another embodiment of the present invention, wherein the commissure post is preset to be in a bent configuration.

[0057] Fig.17 yes Fig.16 Side view of the commissure column.

[0058] Fig.18 is a side view of a commissure post of a stent according to another embodiment of the present disclosure, wherein the commissure post is preset to be in a bent configuration.

[0059] Fig.19 is a perspective view of a stent for a transcatheter valve prosthesis according to another embodiment herein, wherein the stent is in an expanded configuration and the commissure posts thereof are relatively longer, wider, and thinner than struts of an inflow portion of the stent.

[0060] Fig. 20 yes Fig.19 A side view of a stent for a transcatheter valve prosthesis, wherein the stent is in a non-expanded or crimped configuration.

[0061] Fig.21 According to the embodiments of this article Fig.19Anterior view of the commissure posts of a stent of a transcatheter valve prosthesis.

[0062] Fig. 22 yes Fig.21 Side view of.

[0063] Fig.23 yes Fig.21 lateral view showing the flexion of the commissural columns.

[0064] Fig.24 is a perspective view of a stent of a transcatheter valve prosthesis according to another embodiment herein, wherein the stent is in an expanded configuration and its commissure posts are formed of a superelastic material.

[0065] Fig.25 yes Fig.24 A side view of a stent for a transcatheter valve prosthesis, wherein the stent is in a non-expanded or crimped configuration. DETAILED DESCRIPTION

[0066] Specific embodiments of the present invention are now described with reference to the accompanying drawings, in which like reference numerals indicate like or functionally similar elements. The terms "distal" and "proximal" when used in the following specification to refer to a natural blood vessel, a natural valve, or a device to be implanted in a natural blood vessel or a natural valve, such as a heart valve prosthesis, are relative to the direction of blood flow. Thus, "distal" and "distalwardly" refer to positions in the downstream direction relative to the direction of blood flow, and the terms "proximal" and "proximally" refer to positions in the upstream direction relative to the direction of blood flow.

[0067] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and use of the invention. Although the description of the invention is carried out in the context of treating an aortic heart valve, the invention may also be used when it is considered to be useful in other locations within a valved lumen that are not in the heart. For example, the invention may also be applied to other heart valves or venous valves. In addition, it is not intended to be bound by any expressed or implied theory present in the above technical field, background technology, summary of the invention or the following specific embodiments.

[0068] Embodiments herein relate to a transcatheter valve prosthesis 100 having a radially expandable stent 102 and a prosthetic valve 132. The stent 102 is generally tubular and mechanically or balloon expandable, having a crimped configuration for delivery within the vasculature and an expanded configuration for deployment within a native heart valve. Figure 1 is a perspective side view of transcatheter valve prosthesis 100 in an expanded configuration, and Figure 1A1 is an end view illustration of a transcatheter valve prosthesis 100. When the transcatheter valve prosthesis 100 is deployed within the annulus of a native heart valve, the stent 102 of the transcatheter valve prosthesis 100 is configured to radially expand within the native valve leaflets of the patient's defective valve to thereby maintain the native valve leaflets in a permanently open state. In the embodiments herein, the transcatheter valve prosthesis 100 is configured to replace an aortic valve, such that the inflow end 106 of the transcatheter valve prosthesis 100 extends into and is anchored in the aortic annulus of the patient's left ventricle, and the outflow end 116 of the transcatheter valve prosthesis 100 is positioned in the aortic sinus.

[0069] The stent 102 of the transcatheter valve prosthesis 100 can be an integral frame or scaffold that supports a prosthetic valve 132, which includes one or more valve leaflets 134 located inside the stent 102. The prosthetic valve 132 is configured to block flow in one direction to regulate flow therethrough through the valve leaflets 134, which can form a mitral valve or a tricuspid valve replacement valve. Figure 1A yes Figure 1 ' is an end view taken from the outflow end 116 of the prosthesis and shows an exemplary tricuspid valve having three valve leaflets 134, but a mitral valve leaflet configuration may alternatively be used in the embodiments herein. More specifically, since the transcatheter valve prosthesis 100 is configured to be placed within a native aortic valve having three leaflets, the prosthetic valve 132 may include three valve leaflets 134. However, the transcatheter valve prosthesis 100 need not have the same number of leaflets as the native valve. If the transcatheter valve prosthesis 100 is alternatively configured to be placed within a native valve having two leaflets, such as a mitral valve, the prosthetic valve 132 may include two or three valve leaflets. The valve leaflets 134 may be attached to a graft material 144 that surrounds a portion of the stent 102 or is in line with the portion, as known to those of ordinary skill in the art of prosthetic tissue valve configurations. The valve leaflets 134 are sutured or otherwise securely and sealingly attached along their bases to the inner surface of the graft material 144, or otherwise attached to the stent 102. Adjacent pairs of leaflets are attached to each other at their lateral ends to form commissures 136, wherein the free edges 138 of the valve leaflets 134 meet in the region of the commissures 140 to form commissure edges. The commissures 136 of the leaflets are aligned with and attached to the commissure posts 126A of the stent 102, as will be described in greater detail herein.

[0070] The valve leaflets 134 can be made of pericardial material; however, the valve leaflets 134 can alternatively be made of another material. In one embodiment, the valve leaflets 134 are made of bovine pericardial tissue. The natural tissue of the valve leaflets 134 can be obtained from, for example, a heart valve from a human or animal, an aortic root, an aortic wall, an aortic leaflet, pericardial tissue such as a pericardial patch, a bypass graft, a blood vessel, intestinal submucosal tissue, umbilical tissue, etc. Synthetic materials suitable for use as the valve leaflets 134 include those commercially available from Invista North America SARL of Wilmington, DE. Polyesters, other cloths, nylon blends, polymer materials, and materials made of vacuum deposited nitinol. One polymer material from which the leaflets can be made is an ultra high molecular weight polyethylene material commercially available from Royal DSM of the Netherlands under the trade name DYNEEMA. For certain leaflet materials, it may be desirable to coat one or both sides of the leaflet with a material that will prevent or minimize overgrowth. It is further desirable that the leaflet material be durable and not subject to stretching, deformation, or fatigue.

[0071] The graft material 144 can surround the stent 102 or be in line with the stent, as known to those of ordinary skill in the field of prosthetic tissue valve construction. The graft material 144 can be a natural material or a biomaterial, such as pericardial tissue or another membranous tissue such as the intestinal submucosa. Alternatively, the graft material 144 can be a low-porosity woven fabric such as polyester, Dacron fabric or PTFE. In one embodiment, the graft material 144 can be a knitted or woven polyester that can be used when it is desired to provide a medium for tissue ingrowth and the fabric stretches to conform to the ability of the curved surface, such as polyester or PTFE knitting. Alternatively, polyester velvet fabric can be used, such as when it is desired to provide a medium for tissue ingrowth on one side and a smooth surface on the other side. For example, these and other suitable cardiovascular fabrics can be commercially available from Bard Peripheral Vascular, Inc. of Tempe, Ariz., Tempe, Arizona, USA.

[0072] As previously described, support 102 is mechanically or balloon expandable, as will be understood by those of ordinary skill in the art.Therefore, support 102 is made of plastically deformable material so that when expanded by an expansion balloon or other mechanical expansion device, support 102 maintains its radially expanded configuration.Support 102 can be formed by stainless steel or other suitable metals, such as platinum iridium, cobalt chromium alloys, such as MP35N, or various types of polymers or other materials known to those skilled in the art, including the material coated with various surface deposits for improving clinical function.Support 102 is configured to be hard so that it will not deflect or move when subjected to a subject's internal force, or so that deflection or movement is minimized when subjected to a subject's internal force.In one embodiment, the radial stiffness of tubular support 102 (that is, the measurement result of how much tubular support 102 deflected when subjected to a subject's internal force) is between 80N / m and 120N / m, and the radial stiffness of support 102 is scaled about 5N / mm across its deployment height. 2 In one embodiment, the radial stiffness of the tubular stent 102 is greater than 100 N / m. Further, in one embodiment, the device recoil force (i.e., a measurement of how much the stent 102 relaxes after balloon deployment) is less than 15%, and the recoil force after deployment is generally between 1 mm and 2 mm. Further, in one embodiment, the device crush force or yield force (i.e., the radial force to which the tubular stent 102 yields) is approximately 200 N.

[0073] The delivery of transcatheter valve prosthesis 100 can be accomplished by thoracotomy via percutaneous transfemoral approach or transapical approach directly through the apex of the heart, or can be positioned in the desired area of ​​the heart by different delivery methods known in the art for accessing the heart valve. Transcatheter valve prosthesis 100 has a cross profile between 15-30Fr, which is defined as the outer diameter (OD) of the transcatheter valve prosthesis 100 after it is curled onto the delivery catheter and allowed to recoil from the curling action. During delivery, the transcatheter valve prosthesis 100 remains compressed until it reaches the target diseased natural heart valve, at which time the balloon expansion of the balloon catheter or other mechanical expansion devices expands so that the transcatheter valve prosthesis 100 original position radial expansion. The delivery catheter is then removed and the transcatheter valve prosthesis 100 remains on the natural target heart valve and is deployed. Figure 3 A transcatheter valve prosthesis 100 is shown implanted in situ within a native aortic valve annulus, the transcatheter valve prosthesis being shown in cross section with native leaflets L N and the corresponding natural sinus S N . Figure 3Placement of the coronary artery CA is also shown. The transcatheter valve prosthesis 100 is configured to be placed intra-annularly within a native aortic valve. More specifically, the inflow end 106 of the transcatheter valve prosthesis 100 extends into and is anchored within the aortic valve annulus of the patient's left ventricle, while the outflow end 116 of the transcatheter valve prosthesis 100 is positioned within the aortic sinus, wherein no portion of the transcatheter valve prosthesis 100 extends into the patient's ascending aorta. When the transcatheter valve prosthesis 100 is deployed within the annulus of a native heart valve, the stent 102 is configured to be positioned within the native valve leaflets L of the patient's defective valve. N Inward expansion, so as to keep the native valve leaflets in a permanently open state. The height or length of the stent 102 in the expanded configuration is between 12mm and 24mm, and the height is measured from its most proximal portion (the most distal inflow crown 110A, which will be described in more detail herein) to its most distal portion (the second end 130A of the commissure post 126A, which will be described in more detail herein). In one embodiment of the present invention, the height or length of the stent 102 in the expanded configuration is between 18mm and 24mm. For example, in one embodiment, the diameter of the stent 102 is between 21mm-24mm, and its height is 19mm. In another embodiment, the diameter of the stent 102 is between 24mm-27mm, and its height is 21mm. In yet another embodiment, the diameter of the stent 102 is between 27mm-30mm, and its height is 23mm.

[0074] refer to Figure 4-8 , the stent 102 will now be described in more detail. The stent 102 has an expanded configuration and a non-expanded or crimped configuration, wherein the expanded configuration is respectively Figure 4 and 6 The non-expanded or curled configuration is shown in the perspective and side views of Figure 5 As used herein, the non-expanded or crimped configuration refers to the configuration in which the stent 102 is intended for delivery after being crimped onto a catheter, for example, after being crimped onto the balloon of a balloon catheter. Figure 7 is an end view of the inflow end 106 of the stent 102, and Figure 8 1 is an end view of the outflow end 116 of the stent 102. The stent 102 has an inflow portion 108 and an outflow portion 118. The stent 102 is a tubular component that defines a central lumen or passageway 142 and further defines an inflow or proximal end 106 and an outflow or distal end 116 of the transcatheter valve prosthesis 100. The inflow portion 108 forms the generally tubular shape of the stent 102, and the outflow portion 118 includes three commissures 126A extending longitudinally from the inflow portion 108, as will be described in more detail herein. When expanded, the diameter D of the inflow end 106 of the stent 102 is approximately 1.1 mm in diameter. I The diameter D of the outflow end 116 of the stent 102O In one embodiment, the diameter D I and D O The size of the stent 102 can be within a range between 18 mm and 30 mm to accommodate the size of the native valve anatomy. In other words, it may be desirable to obtain transcatheter valve prosthesis 100 in different size increments to accommodate different diameters or sizes of the patient's native valve annulus. The stent 102 can be formed by a laser cutting manufacturing method and / or another conventional stent forming method, as understood by those of ordinary skill in the art. The cross-section of the stent 102 can be circular, elliptical, rectangular, hexagonal, square or other polygonal shape, but it is currently believed that a circular or elliptical shape may be preferred when providing a transcatheter valve prosthesis 100 for aortic valve replacement.

[0075] The inflow portion 108 is formed near the inflow end 106 of the stent 102. The inflow portion 108 includes a plurality of crowns 110 and a plurality of struts 112, wherein each crown 110 is formed between a pair of opposing struts 112. Each crown 110 is a curved section or bend extending between the opposing struts 112. The inflow portion 108 is tubular and has a plurality of cells or side openings 114 defined by the plurality of crowns 110 and the plurality of struts 112. In one embodiment, the plurality of side openings 114 can be diamond-shaped. More specifically, as shown in FIG. Fig. 6A As best shown, each side opening 114 is formed by two pairs of opposing crowns 110 and four struts 112 therebetween, the figure being a side view of a single side opening 114 of the inflow portion 108 of the stent 102. Each side opening 114 is symmetrical to facilitate integration with the prosthetic valve 132. A series of terminal inflow side openings 114A and a series of terminal inflow crowns 110A are formed at the inflow end 106 of the stent 102. The inflow end 106 of the stent 102 has a total of twelve terminal inflow crowns 110A, as shown in FIG. Figure 7 best shown in an end view of the.

[0076] In one embodiment, the inflow portion 108 includes exactly three rows of struts 112 and crowns 110 extending longitudinally between the commissures 126A and the inflow end 106 of the stent 102. However, the length or height of the inflow portion 108 may vary from that depicted herein to accommodate the size of the native valve anatomy. Figure 2In another embodiment of the present invention shown, the transcatheter valve prosthesis 200 is shown as being relatively longer than the transcatheter valve prosthesis 100. More specifically, the transcatheter valve prosthesis 200 includes a stent 202 having a graft material 244 surrounding a portion of the stent 202 or in line with the portion, as is known to those of ordinary skill in the art of prosthetic tissue valve configurations. The stent 202 is a tubular component that defines an inflow end 206 and an outflow end 216 of the transcatheter valve prosthesis 200. The inflow portion 208 of the stent 202 is relatively longer than the inflow portion 108 of the stent 102, such that the overall length or height of the transcatheter valve prosthesis 200 can be relatively increased to accommodate the size of the native valve anatomy. For example, the height or length of the stent 202 in an expanded configuration is between 18 mm and 24 mm. Figure 2 In the embodiment of FIG. 2 , the inflow portion 208 includes exactly four rows of struts and crowns extending longitudinally between the commissure bars 226A and the inflow end 206 of the stent 202 .

[0077] The outflow portion 118 is formed near the outflow end 116 of the stent 102. As previously described, the outflow portion 118 includes three commissures 126A extending longitudinally or axially from the inflow portion 108 and substantially parallel to the central longitudinal axis of the stent 102. Each commissure 126A is a relatively rigid axial segment or planar rod having a first end 128A connected to the crown 110 of the inflow portion 108 and an unattached or free second end 130A. The three commissures 126A are circumferentially spaced apart and aligned with and attached to the corresponding commissures of the three leaflets of the prosthetic valve. The prosthetic valve 132 is placed in the outflow portion 118 of the stent 102 at the commissures 126A and is at least fixed to the outflow portion. In addition, the prosthetic valve 132 can also be placed in the inflow portion 108 of the stent 102 and fixed to the inflow portion. The three commissures 126A contribute to valve alignment and engagement. More specifically, three commissure posts 126A reinforce or strengthen the commissure regions of prosthetic valve 132 by shaping leaflets 134 and supporting the leaflets 134 during opening and closing, thereby providing more secure leaflet coaptation.

[0078] exist Figure 1-8In the depicted embodiment, three commissure posts 126A are the only structures formed at the outflow end 118 of the stent 102. In other words, the three commissure posts 126A are the only structures at the most distal crown 110 away from the inflow portion 108. The configuration of the stent 102 maximizes access to the coronary arteries because the commissure posts 126A are the only structures close to the coronary arteries at the outflow portion 118 of the stent 102. It is very unlikely that the right coronary artery and / or the left main coronary artery will be blocked or blocked by the commissure posts 126A, and therefore, the coronary arteries will be unimpeded by the coronary guide catheter when the transcatheter valve prosthesis 100 is deployed in situ. In addition, with the elimination of any outflow crown at the outflow portion 118 of the stent 102, the overall height of the stent 102 is reduced relative to a stent having an outflow crown formed away from the commissure posts 126A. The shorter overall height minimizes interaction with the aortic anatomy, thereby producing less vascular trauma or valve deformation.

[0079] exist Fig. 9 and 10 In another embodiment of the present invention depicted in FIG. 1 , in addition to three commissure posts 126A, the outflow portion 918 of the stent 902 may also include axial struts 126B arranged circumferentially between adjacent commissure posts 126A. The stent 902 has an expanded configuration and a non-expanded or crimped configuration, wherein the expanded configuration is Fig. 9 The non-expanded or curled configuration is shown in the side view of Fig.10. Each axial strut 126B is also a relatively rigid axial segment or planar rod having a first end 128B connected to the crown 110 of the inflow portion 108 and a second end 130B that is unattached or free. Similar to the commissure posts 126A, each axial strut 126B extends longitudinally from the crown 110 of the inflow portion 108 and is substantially parallel to the central longitudinal axis of the stent 902. However, unlike the commissure posts 126A, the axial struts 126B are not configured to align with and attach to the corresponding commissures of the three leaflets of the prosthetic valve. The axial struts 126B and the commissure posts 126A are collectively referred to herein as axial frame members 126. In one embodiment, the outflow portion 918 includes up to six axial frame members 126, wherein three of the axial frame members 126 are commissures 126A, and three of the axial frame members 126 are axial struts 126B circumferentially disposed between adjacent commissures 126A. The axial frame members 126 (i.e., commissures 126A and axial struts 126B collectively) minimize the cross profile of the transcatheter valve prosthesis while maximizing symmetrical unit expansion. Symmetrical unit expansion ensures that the stent 102 is well curled onto the balloon of the balloon catheter for delivery. Poor curling quality may cause portions of the stent to overlap during curling, which in turn may cause tissue damage to the valve leaflets of the prosthetic valve during the curling process.

[0080] The configuration of stent 902 provides excellent access to the coronary arteries since the axial frame member 126 is the only structure proximal to the coronary arteries at the outflow portion 918 of the stent 902. Even with the addition of axial struts 126B, it is highly unlikely that the right and / or left main coronary arteries will be blocked or impeded by the axial frame member 126, and thus unimpeded access to the coronary arteries will be provided by a coronary guide catheter when the transcatheter valve prosthesis is deployed in situ. Additionally, with the elimination of any outflow crown at the outflow portion 918 of the stent 902, the overall height of the stent 902 is reduced relative to a stent having an outflow crown formed away from the axial frame member 126. The shorter overall height minimizes interaction with the aortic anatomy, thereby resulting in less vascular trauma or valve deformation.

[0081] Each commissure post 126A of stent 102 is configured to flex radially inwardly during loading of transcatheter valve prosthesis 100. More specifically, referring to Figure 11-15, the thickness of each commissure post 126A varies along its length, such that the first end 128A (which is coupled to or extends from the crown 110 of the inflow portion 108) is relatively thicker than the second end 130A. The thickness of the commissure posts 126A decreases or tapers at the outflow portion 118 of the tubular stent 102. The commissure posts 126A are configured to flex slightly radially inward to reduce stresses observed during valve loading. By flexing or flexing radially inward, the commissure posts 126A improve or increase the tissue durability of the valve leaflets 134 due to the strains experienced during valve loading being transferred to the commissure posts 126A.

[0082] More specifically, compared to a self-expanding valve stent, a balloon-expandable valve stent is more rigid and stronger, but as a result, more stress may be applied to the valve leaflets 134 attached to the stent 102. The valve leaflets 134, which are typically formed of tissue, are more durable when the portion of the stent to which they are attached is more flexible, but such stent flexibility may be detrimental to stent fatigue. Therefore, the variable thickness of the commissure posts 126A achieves a balance between stent durability and tissue durability. Therefore, by changing the wall thickness of the commissure posts 126A in the radial direction to tune the flexure of the commissure posts 126A, the stent 102 maintains its strength and durability while allowing the commissure posts 126A to flex inwardly to increase tissue durability. In other words, the variable thickness of the commissure posts 126A extends the usable life of the balloon-expandable transcatheter valve prosthesis 100.

[0083] More specifically, Fig.11 FIG. 1 is a front view of the commissure column 126A of the stent 102. Fig.12 As shown, the wall thickness of the commissure post 126A varies in the radial direction to tune the flexure of the commissure post 126A, which is a side view of the commissure post 126A according to one embodiment. The first thickness T1 at the first end 128A of the commissure post 126A is thicker than the second thickness T2 at the second end 130A of the commissure post 126A. The thickness gradually decreases from the first thickness T1 to the second thickness T2, so that the tip or second end 130A is configured to flex radially inward, while the base or first end 128A is thicker at the junction of the crown 110 of the inflow portion 108 to maintain the load. Each strut 112 of the inflow portion 108 adjacent to the commissure post 126A has a uniform thickness along its entire or entire length, and the thickness T1 of the commissure post 126A at the first end 128A is not greater than the thickness of the strut 112 of the inflow portion 108. Commissure posts 126A are permitted to deflect or flex radially inwardly in a controlled and predictable manner, such as Fig.15 As shown, and as described above, this controlled deflection or flexing increases tissue durability without sacrificing the durability of the stent 102.

[0084] Fig.12 , 13Each of the embodiments of 14 and 15 demonstrates how the wall thickness of commissure posts 126A in the radial direction may be varied to tune the flexure of commissure posts 126A such that commissure posts 126A are configured to flex radially inward during loading of transcatheter valve prosthesis 100. The variable wall thickness of commissure posts 126A may be shaped or formed by micro-sandblasting and electro-polishing the target surface.

[0085] exist Fig.11 and 12 In the embodiment of the present invention, the innermost radial surface 1146 of the commissure post 126A (i.e., the surface in the direction of the central longitudinal axis of the stent 102) is tapered, while the outermost radial surface 1148 of the commissure post 126A is flush with the outer surface 1150 of the inflow portion 108. More specifically, the innermost radial surface 1146 of the commissure post 126A narrows radially outward in the direction from the first end 128A to the second end 130A of the commissure post 126A. In other words, in this embodiment, the wall thickness of the commissure post 126A is reduced by the innermost radial surface 1146 of the commissure post 126A. However, in Fig.13 In the embodiment of the present invention, the outermost radial surface 1348 of the commissure post 126A is tapered, while the innermost radial surface 1346 of the commissure post 126A is flush with the inner surface 1152 of the inflow portion 108. More specifically, the outermost radial surface 1348 of the commissure post 126A narrows radially inward in a direction from the first end 128A to the second end 130A of the commissure post 126A. In other words, in this embodiment, the wall thickness of the commissure post 126A is reduced by the outermost radial surface 1348 of the commissure post 126A. Finally, in Fig.14 In the embodiment of the present invention, the innermost radial surface 1446 of the commissure post 126A narrows radially outward, and the outermost radial surface 1448 of the commissure post 126A narrows radially inward. More specifically, the innermost radial surface 1446 of the commissure post 126A narrows radially outward in a direction from the first end 128A to the second end 130A of the commissure post 126A, while the outermost radial surface 1448 of the commissure post 126A narrows radially inward in a direction from the first end 128A to the second end 130A of the commissure post 126A. In other words, in this embodiment, the wall thickness of the commissure post 126A is narrowed by the innermost radial surface 1446 and the outermost radial surface 1448 of the commissure post 126A.

[0086] In addition to having a variable thickness, the commissure posts 126A also have a width in the circumferential direction that is relatively wider than the width of the struts 112 of the inflow portion 108 adjacent to the commissure posts 126A. More specifically, each strut 112 of the inflow portion 108 adjacent to the commissure posts 126A has a width W1 along all or the entire length thereof, and each commissure post 126A has a width W2 along all or the entire length thereof. The width W1 of the struts 112 is less than the width W2 of the commissure posts 126A. In one embodiment, the width W2 is at least two times greater than the width W1 of the struts 112. In another embodiment, the width W2 is at least three times greater than the width W1 of the struts 112. In yet another embodiment, the width W2 is at least four times greater than the width W1 of the struts 112. The relatively wide commissure posts 126A help to spread the loads experienced by the commissure posts over a wider area, and also allow the cross-section of the commissure posts 126A to be modified to flex radially inward.

[0087] In another embodiment of the present invention, now refer to Figure 16-18 , the commissure posts may be preformed or preset to have a bent or flexed configuration, rather than being configured to flex radially inwardly when forces are applied during valve loading. More specifically, Fig.16 is a front view of a commissure post 1626A having a first end 1628A connected to the crown 110 of the inflow portion 108 and a second end 1630A that is unattached or free. Fig.17 As described, the commissure posts 1626A are preformed or preset to be in a curved or flexed configuration in which the commissure posts 1626A are bent or flexed radially inwardly, and the figure is a side view of the commissure posts 1626A. In other words, the commissure posts 1626A have a preset curve so that the second end 1630A is disposed radially inwardly relative to the first end 1628A. In one embodiment, the second end 1630A of each commissure post 1626A is disposed radially inwardly relative to the first end 1630A by 1 mm to 2 mm. In one embodiment, the preset curve of the commissure posts 1626A can radially displace the second end 1630A 10 degrees to 20 degrees relative to the outer surface of the inflow portion of the tubular stent. The preset curve of the commissure posts 1626A is used to reduce interaction with the aortic root anatomy and further improve coronary access by pulling slightly away from the aortic anatomy. When a transcatheter valve prosthesis having preset curved commissure posts 1626A is crimped onto a balloon for delivery, commissure posts 1626A can be suspended from the balloon so that when the balloon is inflated, the outflow portion having commissure posts 1626A opens last and thus commissure posts 1626A maintain their preset curved configuration.

[0088] Commissure post 1626A may have a uniform thickness in the radial direction along its length, such as Fig.17 as shown, or alternatively with Figure 11-15The embodiments of can be similarly formed to have a variable thickness. More specifically, referring to Fig.18 In another embodiment depicted in FIG. 1 , the thickness of commissure post 1826A varies along its length such that a first end 1828A (which couples to crown 110 of inflow portion 108) is relatively thicker than a second end 1830A thereof. Similar to commissure post 1626A, commissure post 1826A is preformed or pre-set to have a curved or flexed configuration in which commissure post 1826A bends or flexes radially inward. However, in Fig.18 In an embodiment, the first thickness T1 at the first end 1828A of the commissure post 1826A is thicker than the second thickness T2 at the second end 1830A of the commissure post 1826A. The thickness tapers from the first thickness T1 to the second thickness T2 such that the tip or second end 1830A is configured to further flex radially inward during valve loading, while the base or first end 1828A is thicker at the junction of the crown 110 of the inflow portion 108 to maintain the load.

[0089] In another embodiment of the present invention, now refer to Figure 19-23 , the commissure posts can be relatively longer, wider, and thinner than the struts of the inflow portion, such that each commissure post 1926A of stent 1902 is configured to flex radially inwardly during transcatheter valve prosthesis loading. Similar to stent 102, stent 1902 has an expanded configuration and a non-expanded or crimped configuration, wherein the expanded configuration is Fig.19 The non-expanded or curled configuration is shown in the side view of Fig. 20 1902 is shown in a side view. Although only stent 1902 is shown, stent 1902 is configured to be used with a prosthetic valve assembly to form a transcatheter valve prosthesis similar to transcatheter valve prosthesis 100 described above. Stent 1902 has an inflow portion 1908 and an outflow portion 1918. Stent 1902 is a device that defines a central lumen or channel (not shown). Figure 19-201902 and further define an inflow or proximal end 1906 and an outflow or distal end 1916 of a transcatheter valve prosthesis. The inflow portion 1908 forms the general tubular shape of the stent 1902, and the outflow portion 1918 includes three connecting rods 1926A extending longitudinally from the inflow portion 1908, as will be described in more detail herein. The inflow portion 1908 of the stent 1902 has the same structure or configuration as the inflow portion 108 of the stent 102 described above, and therefore the details thereof are not repeated. When expanded, the diameter of the inflow end 1906 of the stent 1902 is the same as the diameter of the outflow end 1916 of the stent 1902. In one embodiment, the diameter of the inflow end and the outflow end can be in a range between 18 mm and 30 mm to accommodate the size of the natural valve anatomy. The stent 1902 can be formed by a laser cutting manufacturing method and / or another conventional stent forming method, as understood by a person of ordinary skill in the art. The cross-section of stent 1902 may be circular, oval, rectangular, hexagonal, square, or other polygonal shapes, but it is presently believed that a circular or oval shape may be preferred in the context of providing a transcatheter valve prosthesis for aortic valve replacement.

[0090] The outflow portion 1918 includes three commissure posts 1926A extending longitudinally or axially from the inflow portion 1908 and substantially parallel to the central longitudinal axis of the tubular stent 1902. Similar to the commissure posts 126A, each commissure post 1926A is a relatively rigid axial segment or planar rod having a first end 1928 connected to the crown 1910 of the inflow portion 1908 and a second end 1930 that is unattached or free. The three commissure posts 1926A are circumferentially spaced apart and aligned with and attached to the corresponding commissures of the three leaflets of the prosthetic valve. A prosthetic valve similar to the prosthetic valve 132 described above (in Figure 19-20 The commissure posts 1926A are disposed within and fixed to at least the outflow portion 1918 of the stent 1902 at the commissure posts 1926A. The three commissure posts 1926A facilitate valve alignment and coaptation. More specifically, the three commissure posts 1926A strengthen or reinforce the commissure region of the prosthetic valve by shaping the leaflets and supporting the leaflets during opening and closing of the leaflets, thereby providing more secure leaflet coaptation.

[0091] exist Figure 19-20In the depicted embodiment, three commissure posts 1926A are the only structures formed at the outflow end 1918 of the stent 1902. The configuration of the stent 1902 maximizes access to the coronary arteries because the commissure posts 1926A are the only structures proximal to the coronary arteries at the outflow portion 1918 of the stent 1902. It is highly unlikely that the right coronary artery and / or the left main coronary artery will be blocked or impeded by the commissure posts 1926A, and thus unimpeded access to the coronary arteries will be provided by the coronary guide catheter when the transcatheter valve prosthesis is deployed in situ. In addition, with the elimination of any outflow crown at the outflow portion 1918 of the tent 1902, the overall height of the stent 1902 is reduced relative to a stent having an outflow crown formed away from the commissure posts 1926A. The shorter overall height minimizes interaction with the aortic anatomy, thereby producing less vascular trauma or valve deformation. In another embodiment herein (not shown), in addition to the three commissure posts 1926A, the outflow portion 1918 of the stent 1902 may also include axial struts disposed between circumferentially adjacent commissure posts 1926A, the axial struts being aligned with the commissure posts 1926A. Figure 9-10 The axial strut 126B described in the embodiment is similar.

[0092] As previously described, the commissure posts 1926A can be relatively longer, wider, and thinner than the struts 1912 of the inflow portion 1910, so that each commissure post 1926A of the stent 1902 is configured to be flexed radially inward during transcatheter valve prosthesis loading. The longer, wider, and thinner commissure posts 1926A are configured to be slightly flexed radially inward to reduce the stress observed during valve loading, and thereby improve or increase the tissue durability of the valve leaflets attached to the stent due to the strain experienced during valve loading being transferred to the commissure posts 1926A. More specifically, compared to a self-expanding valve stent, a balloon-expandable valve stent is more rigid and stronger, but can therefore apply more stress to the valve leaflets attached to the stent 1902. Valve leaflets that are generally formed by tissue are more durable when the portion of the stent to which they are attached is more flexible, but such stent flexibility may be detrimental to stent fatigue. Thus, longer, wider, and thinner commissure posts 1926A achieve a balance between stent durability and tissue durability because stent 1902 maintains its strength and durability while allowing commissure posts 1926A to flex inwardly to increase tissue durability. In other words, longer, wider, and thinner commissure posts 1926A extend the useful life of a balloon-expandable transcatheter valve prosthesis. The size of longer, wider, and thinner commissure posts 1926A can be achieved by micro-blasting, bead blasting, electropolishing, or swaging commissure posts 1926A after stent 1902 is formed by a laser cutting manufacturing method and / or another conventional stent forming method.

[0093] Fig.21is a front view of commissure post 1926A of stent 1902, and Fig. 22 yes Fig.21 1908. Each commissure post 1926A has a length that is greater than the length of each strut 1912 of the inflow portion 1908, each commissure post 1926A has a thickness along its length that is less than the thickness of each strut 1912 of the inflow portion 1908 along its length, and each commissure post 1926A has a width that is greater than the width of each strut 1912 of the inflow portion 1908. Commissure posts 1926A are permitted to deflect or flex radially inwardly in a controlled and predictable manner, such as Fig.23 As shown, and this controlled deflection or flexing increases tissue durability as described above without sacrificing the durability of the stent 1902.

[0094] More specifically, each strut 1912 of the inflow portion 1908 adjacent to the commissure post 1926A has a uniform thickness T1 along all or the entire length thereof, and each commissure post 1926A has a uniform thickness T2 along all or the entire length thereof. Fig. 22 1908, is less than the thickness T1 of each strut 1912 of the inflow portion 1908. In one embodiment, the thickness T1 of the strut 1912 is at least two times greater than the thickness T2 of the strut 1926A. In another embodiment, the thickness T1 of the strut 1912 is at least three times greater than the thickness T2 of the strut 1926A. In yet another embodiment, the thickness T1 of the strut 1912 is at least four times greater than the thickness T2 of the strut 1926A. The wall thickness T2 of the strut 1926A can be reduced in the radial direction by micro-blasting and electro-polishing the target surface. As described above with respect to Figure 11-15 As described, the surface targeted to reduce the wall thickness T2 of commissure post 1926A may be the innermost radial surface of commissure post 1926A, the outermost radial surface of commissure post 1926A, or both the innermost and outermost radial surfaces of commissure post 1926A.

[0095] In addition to having a reduced thickness relative to adjacent struts 1912, commissure posts 1926A also have a width W2 in the circumferential direction that is relatively wider than the width W1 of struts 1912 of inflow portion 1908 adjacent to commissure posts 1926A. More specifically, each strut 1912 of inflow portion 1908 adjacent to commissure posts 1926A has a width W1 along all or the entire length thereof, and each commissure post 1926A has a width W2 along all or the entire length thereof. The width W1 of struts 1912 is less than the width W2 of commissure posts 1926A. In one embodiment, width W2 is at least two times greater than the width W1 of struts 1912. In another embodiment, width W2 is at least three times greater than the width W1 of struts 1912. In yet another embodiment, width W2 is at least four times greater than the width W1 of struts 1912. The relatively wide commissure post 1926A helps to distribute the loads experienced by the commissure post over a wider area and also allows the cross-section of the commissure post 1926A to be modified to flex radially inwardly.

[0096] In addition to having a reduced thickness and increased width relative to adjacent struts 1912, commissure posts 1926A also have an overall or entire length L2 along the longitudinal direction that is relatively longer than an overall or entire length L1 of struts 1912 of inflow portion 1908 adjacent to commissure posts 1926A. More specifically, each strut 1912 of inflow portion 1908 adjacent to commissure posts 1926A has a length L1 along its length, and each commissure post 1926A has a length L2 along its length. The length L1 of struts 1912 is less than the length L2 of commissure posts 1926A. In one embodiment, length L2 is at least two times greater than length L1 of struts 1912. In another embodiment, length L2 is at least three times greater than length L1 of struts 1912. In yet another embodiment, length L2 is at least four times greater than length L1 of struts 1912. For example, in one embodiment, the length L1 of struts 1912 may be in a range between 3 mm and 4 mm, while the length L2 of commissure posts 1926A may be in a range between 5 mm and 7 mm. The relatively long commissure posts 1926A further allow the cross-section of commissure posts 1926A to be modified to be radially inwardly bent.

[0097] In one embodiment of the present invention, in addition to being relatively longer, wider and thinner than the struts 1912 of the inflow portion 1910, each commissure post 1926A also has a strength greater than the strength of each strut 1912 of the inflow portion 1910. The strength of the commissure post 1926A can also be increased by post-processing after the stent 1902 is formed by a laser cutting manufacturing method and / or another conventional stent forming method. More specifically, the yield strength of the material of the commissure post 1926A is increased due to cold working (forging) or other post-processing methods. The increased yield strength increases fatigue resistance. In addition, the yield strength of the material of the commissure post 1926A is also increased due to cold working (forging) or other post-processing methods. For example, in one embodiment, the commissure post 1926A can undergo forging and cold working to increase the yield strength of at least the commissure post 1926A, which in turn increases the fatigue resistance of the commissure post 1926A. In another embodiment, the yield strength of at least the commissure posts 1926A and struts 1912 in the most distal rows of struts of the inflow portion of the stent 1902 can be increased by post-processing after the stent 1902 is formed by a laser cutting manufacturing method and / or another conventional stent forming method. In yet another embodiment, the yield strength of at least the commissure posts 1926A and struts 1912 in the inflow portion of the stent 1902 that form the endmost gem-shaped opening can be increased by post-processing after the stent 1902 is formed by a laser cutting manufacturing method and / or another conventional stent forming method. In other words, for this embodiment, the yield strength of at least the commissure posts 1926A and struts 1912 in the two most distal rows of struts of the inflow portion of the stent 1902 can be increased by post-processing after the stent 1902 is formed by a laser cutting manufacturing method and / or another conventional stent forming method.

[0098] In another embodiment of the present invention, now refer to Figure 24-25 , the commissures can be formed of a different material than the inflow portion, such that each commissure 2426A of stent 2402 is configured to flex radially inwardly during transcatheter valve prosthesis loading. Similar to stent 102, stent 2402 has an expanded configuration and a non-expanded or crimped configuration, wherein the expanded configuration is Fig.24 The non-expanded or curled configuration is shown in the side view of Fig.25 2402 is shown in a side view. Although only stent 2402 is shown, stent 2402 is configured to be used with a prosthetic valve assembly to form a transcatheter valve prosthesis similar to transcatheter valve prosthesis 100 described above. Stent 2402 has an inflow portion 2408 and an outflow portion 2418. Stent 2402 is a portion defining a central lumen or channel (not shown). Figure 24-252406 and the outflow end 2416 of the tubular stent 2402. The inflow portion 2408 forms the general tubular shape of the stent 2402, and the outflow portion 2418 includes three connecting rods 2426A extending longitudinally from the inflow portion 2408, as will be described in more detail herein. The inflow portion 2408 of the stent 2402 has the same structure or configuration as the inflow portion 108 of the stent 102 described above, and therefore the details thereof are not repeated. When expanded, the diameter of the inflow end 2406 of the stent 2402 is the same as the diameter of the outflow end 2416 of the tubular stent 2402. In one embodiment, the diameter of the inflow end and the outflow end can be in a range between 18 mm and 30 mm to accommodate the size of the natural valve anatomy. The inflow portion 2408 of the stent 2402 can be formed by a laser cutting manufacturing method and / or another conventional stent forming method, as understood by a person of ordinary skill in the art. The cross-section of stent 2402 may be circular, oval, rectangular, hexagonal, square, or other polygonal shapes, but it is presently believed that a circular or oval shape may be preferred in the context of providing a transcatheter valve prosthesis for aortic valve replacement.

[0099] The outflow portion 2418 includes three commissure posts 2426A extending longitudinally or axially from the inflow portion 2408 and substantially parallel to the central longitudinal axis of the tubular stent 2402. Similar to the commissure posts 126A, each commissure post 2426A is a relatively rigid axial segment or planar rod having a first end 2428 connected to the crown 2410 of the inflow portion 2408 and a second end 2430 that is unattached or free. The three commissure posts 2426A are circumferentially spaced apart and aligned with and attached to the corresponding commissures of the three leaflets of the prosthetic valve. A prosthetic valve similar to the prosthetic valve 132 described above (in Figure 24-25 The three commissure posts 2426A are disposed within the outflow portion 2418 of the stent 2402 and are fixed to at least the outflow portion. The three commissure posts 2426A facilitate valve alignment and coaptation. More specifically, the three commissure posts 2426A strengthen or reinforce the commissure area of ​​the prosthetic valve by shaping the leaflets and supporting the leaflets during opening and closing of the leaflets, thereby providing more secure leaflet coaptation. The shape or configuration of the commissure posts 2426A is not limited to Figure 24-25 For example, in another embodiment herein (not shown), the commissure post 2426A can be in the form of an upside-down Y-shape having two legs extending longitudinally or axially from the inflow portion 2408, wherein each leg of the upside-down Y-shape is connected to the crown 2410 of the inflow portion 2408, and the base of the upside-down Y-shape forms the unattached or free second end of the commissure post.

[0100] exist Figure 24-25 In the depicted embodiment, three commissure posts 2426A are the only structures formed at the outflow end 2418 of the stent 2402. The configuration of the stent 2402 maximizes access to the coronary arteries because the commissure posts 2426A are the only structures close to the coronary arteries at the outflow portion 2418 of the tubular stent 2402. It is very unlikely that the right coronary artery and / or the left main coronary artery will be blocked or blocked by the commissure posts 2426A, and therefore, unimpeded access to the coronary arteries will be provided by the coronary guide catheter when the transcatheter valve prosthesis is deployed in situ. In addition, with the elimination of any outflow crown at the outflow portion 2418 of the stent 2402, the overall height of the stent 2402 is reduced relative to a tubular stent having an outflow crown formed away from the commissure posts 2426A. The shorter overall height minimizes interaction with the aortic anatomy, thereby producing less vascular trauma or valve deformation. In another embodiment herein (not shown), in addition to the three commissure posts 2426A, the outflow portion 2418 of the stent 2402 may further include axial struts disposed between adjacent commissure posts 2426A. Figure 9-10 The axial strut 126B described in the embodiment is similar.

[0101] As previously described, the commissure posts 2426A can be formed of a material different from the inflow portion 2408, so that each commissure post 2426A is configured to be radially inwardly flexed during transcatheter valve prosthesis loading. More specifically, the inflow portion 2408 of the stent 2402 is made of a first or plastically deformable material so that when expanded by an expansion balloon, the inflow portion 2408 of the tubular stent 2402 maintains its radially expanded configuration. The inflow portion 2408 of the stent 2402 can be formed of stainless steel or other suitable metals, such as platinum iridium, cobalt chromium alloys, such as MP35N, or various types of polymers or other materials known to those skilled in the art, including the materials coated with various surface deposits for improving clinical function. The inflow portion 2408 of the stent 2402 is configured to be hard so that it does not deflect or move when subjected to intracorporeal forces, or so that deflection or movement is minimized when subjected to intracorporeal forces. In one embodiment, the radial stiffness of the inflow portion 2408 of the stent 2402 (i.e., a measure of how much the inflow portion 2408 of the stent 2402 deflects when subjected to an internal force) is between 80 N / m and 120 N / m, and the radial stiffness of the inflow portion 2408 of the stent 2402 is scaled across its deployed height to approximately 5 N / mm 2In one embodiment, the radial stiffness of the inflow portion 2408 of the tubular stent 2402 is greater than 100 N / m. Further, in one embodiment, the device recoil force (i.e., a measurement of how much the inflow portion 2408 of the tubular stent 2402 relaxes after balloon deployment) is less than 15%, and the approximate recoil force after deployment is between 1 mm and 2 mm. Further, in one embodiment, the device squeeze force or yield force (i.e., the radial force at which the inflow portion 2408 of the stent 2402 yields) is approximately 200N.

[0102] The commissure posts 2426A are made of a second or superelastic material, such as, but not limited to, nitinol. The superelastic commissure posts 2426A are configured to be slightly radially inwardly flexed to reduce the stress observed during valve loading, and thereby improve or increase the tissue durability of the valve leaflets attached to the stent due to the strain experienced during valve loading being transferred to the commissure posts 2426A. More specifically, the balloon-expandable material of the inflow portion 2408 is more rigid and stronger than the superelastic material of the commissure posts 2426A. The valve leaflets formed by tissue are usually more durable when the portion of the stent to which they are attached is more flexible. Therefore, the superelastic commissure posts 2426A achieve a balance between stent durability and tissue durability because the inflow portion 2408 allows the superelastic commissure posts 2426A to be flexed inwardly to increase tissue durability while maintaining its strength and durability. In other words, superelastic commissure posts 2426A extend the useful life of the balloon-expandable transcatheter valve prosthesis.

[0103] After the inflow portion 2408 is formed by a laser cutting manufacturing method and / or another conventional stent forming method, the superelastic commissure posts 2426A are attached or secured to the distal-most crown 2410 of the inflow portion 2408. Each superelastic commissure post 2426A can be attached or secured to the distal-most crown 2410 of the inflow portion 2408 by a rivet 2454, such as Figure 24-25 As shown, or may be attached by another suitable method, such as but not limited to welding. Rivet 2454 may be formed of titanium, nickel, or any other suitable metal or alloy.

[0104] Commissure post 2426A may have a uniform thickness in the radial direction along its length, or may alternatively be Figure 11-15 Further, in another embodiment herein, the commissure posts 2426A can be relatively longer, wider, and thinner than the struts of the inflow portion, such that each commissure post 2426A of the stent 2402 is configured to flex radially inwardly during loading of the transcatheter valve prosthesis 100, as described above with respect to Figure 19-23 As described.

[0105] Although various embodiments according to the present invention have been described above, it should be understood that the embodiments are presented only by way of illustration and example and in a non-restrictive manner. It is apparent to those skilled in the relevant art that various changes may be made to form and details therein without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the present invention should not be limited to any of the exemplary embodiments described above, but should only be defined according to the attached claims and their equivalents. It should also be understood that each feature of each embodiment discussed herein and each feature of each reference cited herein can be used in combination with the features of any other embodiment. All patents and public documents discussed herein are incorporated herein by reference as a whole.

Claims

1. A transcatheter valve prosthesis, comprising: A stent having a crimped configuration for delivery within a vasculature and an expanded configuration for deployment within a native heart valve, the stent having: an inflow portion formed proximate an inflow end of the stent, the inflow portion comprising a plurality of crowns and a plurality of struts, wherein each crown is formed between a pair of opposing struts, the plurality of crowns and the plurality of struts defining a plurality of side openings, wherein the inflow portion is formed of a first material; and an outflow portion formed proximate an outflow end of the stent and coupled to the inflow portion, wherein the outflow portion of the tubular stent has exactly three commissure posts, each commissure post extending longitudinally from a crown of the inflow portion, and the three commissure posts are circumferentially spaced apart, and wherein each commissure post is formed of a second material that is different from the first material; as well as A prosthetic valve is disposed within and secured to at least the outflow portion of the stent, the prosthetic valve being configured to block blood flow in one direction to regulate blood flow through the central lumen of the tubular stent.

2. A transcatheter valve prosthesis according to claim 1, wherein the prosthetic valve comprises three leaflets and three commissures, each commissure being formed by attached adjacent side ends of adjacent pairs of the three leaflets, and wherein the three commissure posts are aligned with and attached to corresponding commissures of the three leaflets of the prosthetic valve.

3. A transcatheter valve prosthesis according to claim 1 or 2, wherein each commissure post is a planar rod, and wherein each commissure post has a length greater than the length of each strut of the inflow portion, each commissure post has a thickness along its length, the thickness is less than the thickness of each strut of the inflow portion along its length, and each commissure post has a width greater than the width of each strut of the inflow portion.

4. The transcatheter valve prosthesis of any one of claims 1 to 3, wherein the first material is plastically deformable and the second material is superelastic.

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