Artificial heart valves

Abstract

An embodiment of a radially contractible and expandable artificial heart valve is disclosed. When mounted on a delivery shaft, the valve frame may have a tapered profile, with the inflow end portion having a smaller diameter than the outflow end portion. The valve may include a generally V-shaped leaflet, reducing material in the inflow end of the frame. An outer skirt may be fixed to the outside of the inflow end portion of the frame, the outer skirt having a longitudinal slack when the valve is expanded and lying flat against the frame when the valve is contracted. The diagonally braided inner skirt may be axially elongated with the frame. Side protrusions adjacent to the leaflets may extend through and be fixed to the window frame portion of the frame to form a commissure. When the valve is creased on the delivery shaft, the window frame portion may be radially recessed inward relative to the surrounding frame portion.

Description

[0001] This application is a divisional application based on the divisional application No. 201510850059.4. The application date of the original application is October 5, 2011, the Chinese application number is 201180058439.4, the international application number is PCT / US2011 / 054973, and the invention name is “Artificial Heart Valve”. Technical Field

[0002] The present disclosure relates to embodiments of prosthetic heart valves and delivery systems for implanting the heart valves. Background Art

[0003] The human heart can suffer from various valvular diseases. These valvular diseases can lead to severe malfunction of the heart and ultimately require replacement of the natural valve with an artificial valve. There are many known artificial valves and many known methods of implanting these artificial valves in humans.

[0004] Various surgical techniques can be used to replace or repair diseased or damaged valves. Due to stenosis and other valvular heart diseases, thousands of patients undergo surgery each year in which the defective native heart valve is replaced with an artificial valve. Another less drastic method for treating defective valves is by repair or reconstruction, which is usually used on minimally calcified valves. The problem with surgical therapy is the significant risk of high morbidity and mortality associated with surgical repair imposed on these chronic patients.

[0005] When replacing a native valve, surgical implantation of an artificial valve typically requires an open-chest surgery during which the heart is stopped and the patient is placed on an extracorporeal circulation machine (the so-called "heart-lung machine"). In one common surgical procedure, the diseased native valve leaflets are excised and an artificial valve is sutured to the surrounding tissue at the valve annulus. Because of the trauma associated with the procedure and the duration of the accompanying extracorporeal blood circulation, some patients do not survive the surgical procedure or die soon thereafter. It is well known that the risk to the patient increases with the amount of time required for extracorporeal circulation. Due to these risks, a large number of patients with defective valves are considered inoperable because their condition is too frail to withstand the procedure. By some estimates, greater than 50% of subjects over the age of 80 who suffer from valvular stenosis cannot undergo valve replacement surgery.

[0006] Because of the disadvantages associated with conventional open heart surgery, percutaneous and minimally invasive surgical approaches have attracted great attention. In one technique, an artificial valve is configured to be implanted in a much less invasive procedure by catheter insertion. For example, U.S. Patent Nos. 5,411,522 and 6,730,118, which are incorporated herein by reference, describe a collapsible transcatheter heart valve that can be introduced percutaneously in a compressed state over a catheter and expanded in a desired position by balloon inflation or by using a self-expanding frame or stent.

[0007] An important design parameter for a transcatheter heart valve is the diameter of the folded or pleated profile. The diameter of the pleated profile is important because it directly affects the physician's ability to guide the transcatheter heart valve through the femoral artery or vein. More specifically, a smaller profile allows a greater number of patients to be treated with enhanced safety. Summary of the invention

[0008] The present disclosure relates to methods and devices relating to prosthetic valves, such as heart valves, delivery devices, and kits of heart valves mounted on delivery devices.

[0009] An exemplary embodiment of a kit for implanting an artificial heart valve in a patient includes a delivery device comprising an elongated shaft and a radially expandable artificial heart valve mounted on the shaft in a radially contracted configuration for delivery into the body. The artificial heart valve comprises an annular frame having an inflow end portion and an outflow end portion, and a leaflet structure located within the frame. The outer diameter of the inflow end portion of the frame is less than the outer diameter of the outflow end portion of the frame. The reduced diameter of the inflow end may be due to the reduced amount of material located within the inflow end portion of the frame. The reduced diameter at the inflow end portion may make room for an outer skirt located around the inflow end portion.

[0010] In some embodiments, the heart valve may further include an outer skirt arranged around the outer surface of the inflow end portion of the frame, so that the outer diameter of the inflow end portion of the artificial valve - including the outer skirt - is still less than or equal to the outer diameter of the outflow end portion of the artificial valve.

[0011] In some embodiments, the leaflet structure may include a plurality of leaflets, each of which includes opposing side protrusions on opposing sides of the leaflet. The side protrusions may be fixed to the outflow end portion of the frame. Each leaflet may further include a free outflow edge portion extending between the side protrusions adjacent to the outflow end of the frame; and an inflow edge portion extending between the side protrusions adjacent to the inflow end of the frame. The inflow edge portion may include opposing axial edge portions extending in a generally axial direction from the side protrusions toward the inflow end; and an intermediate edge portion extending between the axial edge portions. The intermediate edge portion may include a curved top portion adjacent to the inflow end of the frame, and a pair of inclined portions extending between the axial edge portions and the top portion. The inclined portion may have a larger radius of curvature than the top portion, forming a generally V-shaped leaflet.

[0012] In some embodiments, the frame includes a plurality of angularly spaced commissure windows, each including a closed opening between first and second axially oriented side struts. In these embodiments, the leaflet structure includes a plurality of leaflets, each including two opposing side projections, each side projection being paired with an adjacent side projection of an adjacent leaflet to form a commissure of the leaflet structure. Each commissure extends radially outward through a corresponding commissure window of the frame to a position outside the frame and is sutured to the side struts of the commissure window. In some of these embodiments, when the artificial valve is in a collapsed configuration on the axis, the commissure windows of the frame are radially recessed inwardly relative to the portion of the frame extending between the adjacent commissure windows.

[0013] In some embodiments, the frame includes an inflow row of openings at an inflow end portion of the frame, an outflow row of openings at an outflow end portion of the frame, and at least one intermediate row of openings between the inflow row of openings and the outflow row of openings. The openings of the inflow row of openings are larger than the openings of the at least one intermediate row of openings.

[0014] In some embodiments, when in the collapsed configuration on the shaft, portions of the leaflet structure protrude through the openings in the frame.

[0015] In some embodiments, the inflow end portion of the frame includes a frame thickness that is less than a frame thickness of a middle portion of the frame between the inflow end portion and the outflow end portion.

[0016] Embodiments disclosed herein may include an implantable artificial valve that is radially contractible to a contracted configuration and radially expandable to an expanded configuration. Such an artificial valve may include an annular frame, a leaflet structure located within the frame, and an annular outer skirt located around the outer surface of the frame. The outer skirt may include an inflow edge fixed to the frame at a first position, an outflow edge fixed to the frame at a second position, and an intermediate portion between the inflow edge and the outflow edge. When the valve is in an expanded configuration, the intermediate portion of the outer skirt includes a slack portion between the inflow edge of the outer skirt and the outflow edge of the outer skirt in an axial direction, and when the valve is contracted to a contracted configuration, the axial distance between the inflow edge of the outer skirt and the outflow edge of the outer skirt increases, reducing the slack portion in the outer skirt in an axial direction.

[0017] In some of these embodiments, the outer skirt does not stretch in the axial direction when the valve radially contracts to the contracted configuration and slack is eliminated from the middle portion of the outer skirt.

[0018] Some embodiments of an implantable artificial valve include an annular frame including a plurality of leaflet attachment portions; and a leaflet structure located within the frame and fixed to the leaflet attachment portions of the frame. The leaflet structure includes a plurality of leaflets, each leaflet including a main body portion, two opposing main side projections extending from opposite sides of the main body portion, and two opposing secondary projections extending from the main body adjacent to the main side projections. The secondary projections are folded around radially extending folds so that a first portion of the secondary projections lies flat against the main body portion of the respective leaflet, and the secondary projections are folded around axially extending folds so that a second portion of the secondary projections extends in a plane different from the first portion. The second portion of each secondary projection is sutured to the respective main projection and the secondary projections are located inside the frame.

[0019] In some of these embodiments, when the valve is contracted to the radially contracted configuration, the first portion of each secondary projection pivots about the axially extending fold and lies flat against the second portion of the secondary projection. The first portion of each secondary projection includes an inner edge radially spaced from the inner surface of the frame, and when the valve is operated in a patient, the main body portion of the leaflet pivots about the inner edges of the two secondary projections of the leaflet in response to blood flowing through the valve.

[0020] Some embodiments disclosed herein include an implantable artificial valve that can radially contract to a contracted structure and can radially expand to an expanded structure. The artificial valve includes an annular frame having an inflow end portion and an outflow end portion, a leaflet structure located within the frame, and an annular inner skirt located within the frame. The inner skirt is fixed to the inner side of the frame and the inner skirt includes a fabric of a first group of threads and a second group of threads, and neither the first group of threads nor the second group of threads is parallel to the axial direction of the valve. When the valve contracts from the expanded structure to the contracted structure, the axial length of the frame increases and both the first group of threads and the second group of threads rotate toward the axial direction of the valve, so that the inner skirt extends along the axial direction with the frame.

[0021] In some of these embodiments, when the valve is in an expanded configuration, the first set of threads is substantially perpendicular to the second set of threads. In some embodiments, the first set of threads forms a first angle with the axial direction of the valve, and the second set of threads forms a second angle with the axial direction of the valve, and the first and second angles are substantially equal. In some of these embodiments, the first set of threads and the second set of threads comprise 20 denier yarn.

[0022] Some embodiments of the implantable artificial valve include a radially contractible and expandable annular frame including a plurality of angularly spaced commissure windows, each including a closed opening between first and second axially oriented side pillars. The valve also includes a leaflet structure, which is located within the frame and includes a plurality of leaflets, each leaflet including two opposing side projections. Each side projection is paired with an adjacent side projection of an adjacent leaflet to form a commissure of the leaflet structure. Each pair of side projections extends radially outward through a corresponding commissure window to a position outside the frame, and the portions of the projections outside the frame extend circumferentially away from each other and along the outer surface of the side pillars. The valve further includes a plurality of wedges, each wedge being located between the side pillars of the commissure window and separating the side projections extending through the commissure window, the wedges being forced radially inward against the side projections.

[0023] The wedge-shaped portion may be elongated in the axial direction and have an axial length that is consistent with the axial length of the commissure window side struts. The wedge-shaped portion may further limit the rotational movement of the side tab pair relative to the commissure window. Each wedge-shaped portion may be sutured to a flexible reinforcement sheet that is also sutured to each pair of side tabs, and each may be sutured to the side tab pair. The wedge-shaped portion may include a non-metallic material, such as a suture material.

[0024] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description, which is described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1-3 An exemplary embodiment of a prosthetic heart valve is shown.

[0026] Figure 4-10 show Figure 1 An exemplary frame for a heart valve.

[0027] Figure 11-15B Another exemplary frame for a prosthetic heart valve is shown.

[0028] Fig.16A and 16B show Figure 1 An exemplary inner skirt of a heart valve.

[0029] Fig.17 Another embodiment of a prosthetic heart valve showing frame deformation in a compressed (crimped) condition.

[0030] Fig.18 Shown in a compressed state and mounted on an exemplary balloon catheter Figure 1 of the heart valves.

[0031] Figure 19-20 shows Fig.16A The inner skirt and Figure 4of the framework.

[0032] Figure 21-28 A kit showing exemplary leaflet structures.

[0033] Figure 29-35 A kit showing the commissure portions of the leaflet structure and the window frame portion of the frame.

[0034] Figure 36-40 Shown along the lower edge of the leaflet, the set of leaflet structures with the inner skirt.

[0035] Fig.41 An exemplary outer skirt is shown flattened outwardly.

[0036] Fig.42 and 43 show Figure 1 An exemplary artificial heart valve of .

[0037] Figures 44-48 An alternative embodiment of a prosthetic heart valve is shown.

[0038] Figure 49-52 Portions of an alternative implementation of a framework are shown.

[0039] Fig.53 Shown in radial compression Figure 4 part of the frame.

[0040] Fig.54 show Figure 4 A cross-sectional profile of a frame showing a general taper from the outflow end to the inflow end.

[0041] Fig.55 Shown in its expanded, flat configuration Figure 4 framework.

[0042] Fig.56 Shown in a compressed state and mounted on an exemplary balloon catheter Figure 1 of the heart valves.

[0043] Fig.57 and 58 An embodiment is shown having leaflets having a generally V-shaped configuration.

[0044] Fig.59 A cross-sectional view showing an alternative embodiment of a prosthetic valve having a variable thickness frame.

[0045] Fig.60 is a side view of an embodiment of a valve frame having commissure windows prior to mounting the leaflet structure to the frame.

[0046] Fig.60A yes Fig.60An enlarged side view of a commissure window.

[0047] Fig.61 Yes Fig.60 A perspective view of an embodiment of a prosthetic valve having a frame and leaflet structures mounted to the valve.

[0048] Fig.62 yes Fig.61 An enlarged side view of one of the commissures of the valve.

[0049] Figure 63-71 yes Fig.61 Cross-sectional views of the commissures of a valve showing various techniques for suturing a pair of leaflet side projections to the commissure windows using reinforcement tabs.

[0050] Figures 72-74 Balloon expansion of an alternative embodiment of a frame is shown for use with a prosthetic valve having inflow and outflow end portions of reduced thickness. DETAILED DESCRIPTION

[0051] According to one embodiment, Figure 1-3 Various views of an artificial heart valve 10 are shown. The illustrated valve is adapted for implantation in the native aortic annulus, although in other embodiments it may be adapted for implantation in other native annuli of the heart. The valve 10 may have four major components: a stent or frame 12, a valve structure 14, an inner skirt 16, and an outer skirt 18.

[0052] The valve structure 14 may include three leaflets 400 that together form a leaflet structure, which may be arranged to collapse in a tricuspid arrangement, such as Figure 2 The lower edge of the leaflet structure 14 desirably has a wavy, curved fan-like shape ( Figure 1 The suture 154 shown in the scalloped shape follows the leaflet structure). By forming leaflets with this scalloped geometry, stresses on the leaflets are reduced, which in turn improves the durability of the valve. Moreover, due to the scalloped shape, creases and corrugations in the middle of each leaflet (the middle region of each leaflet) can be eliminated or at least minimized, which can cause early calcification in those areas. The scalloped geometry also reduces the amount of tissue material used to form the leaflet structure, thereby allowing a smaller, flatter pleated profile at the inflow end of the valve. The leaflet 400 can be formed from pericardial tissue (e.g., bovine pericardial tissue), a biocompatible synthetic material, or various other suitable natural or synthetic materials, as known in the art and described in U.S. Patent No. 6,730,118, which is incorporated herein by reference.

[0053] Bare frame 12 is shown in Figure 4In. The frame 12 may be composed of a plurality of circumferentially spaced slits or commissure windows 20 (three in the illustrated embodiment) that are suitable for mounting the commissures of the valve structure 14 to the frame, as described in more detail below. The frame 12 may be made of any of a variety of suitable plastic expansion materials (e.g., stainless steel, etc.) or self-expanding materials (e.g., nitinol) known in the art. When constructed of a plastic expansion material, the frame 12 (and therefore the valve 10) may be creased to a radially compressed state on a delivery catheter and then expanded in the patient by an inflatable balloon or equivalent expansion mechanism. When constructed of a self-expanding material, the frame 12 (and therefore the valve 10) may be creased to a radially compressed state and maintained in a compressed state by a sheath or equivalent mechanism inserted into a delivery catheter. Once in the body, the valve may be advanced from the delivery sheath so that the valve expands to its functional size.

[0054] Suitable plastic expansion materials that can be used to form the frame 12 include, but are not limited to, stainless steel, nickel-based alloys (e.g., cobalt-chromium alloys or nickel-cobalt-chromium alloys), polymers, or combinations thereof. In a specific embodiment, the frame 12 is made of a nickel-cobalt-chromium-molybdenum alloy such as MP35N. TM (trademark of SPS Technologies), which is equivalent to UNS R30035 (covered by ASTM F562-02). MP35N TM / UNS R30035 includes 35% nickel, 35% cobalt, 20% chromium and 10% molybdenum by weight. It has been found that using MP35N to form the frame 12 provides structural effects superior to stainless steel. Specifically, when MP35N is used as the frame material, less material is required to achieve the same or better performance in terms of radial force and compression force resistance, fatigue resistance and corrosion resistance. Moreover, because less material is required, the frame crimping profile can be reduced, thereby providing a smaller profile valve kit for percutaneous delivery to the treatment site in the body.

[0055] refer to Figure 4 and 5, the frame 12 in the illustrated embodiment includes a first lower row I of angled struts 22 arranged end to end and extending circumferentially at the inflow end of the frame; a second row II of angled struts 24 extending circumferentially; a third row III of angled struts 26 extending circumferentially; a fourth row IV of angled struts 28 extending circumferentially; and a fifth row V of angled struts 32 extending circumferentially at the outflow end of the frame. A plurality of substantially straight axially extending struts 34 may be used to interconnect the struts 22 of the first row I with the struts 24 of the second row II. The angled struts 32 of the fifth row V are connected to the angled struts 28 of the fourth row IV by a plurality of axially extending window frame portions 30 (which define the commissure windows 20) and a plurality of axially extending struts 31. Each axial strut 31 and each frame portion 30 extends from a position defined by the intersection of the lower ends of two angled struts 32 to another position defined by the intersection of the upper ends of two angled struts 28. Figure 6 , 7 , 8, 9 and 10 are Figure 5 An enlarged view of the portions of the frame 12 represented by letters A, B, C, D and E in FIG.

[0056] Each commissure window frame portion 30 houses a respective commissure of the leaflet structure 14. As can be seen, each frame portion 30 is fixed at its upper and lower ends to adjacent rows of struts to provide a robust structure that has enhanced fatigue resistance under cyclic loading of the valve compared to known cantilever struts for supporting the commissures of the leaflet structure. This construction enables a reduction in frame wall thickness to achieve a smaller pleat diameter of the valve. In a specific embodiment, the thickness T of the frame 12 measured between the inner diameter and the outer diameter is Figure 4 ) is about 0.48 mm or less.

[0057] The struts and frame portions of the frame together define a plurality of open meshes of the frame. At the inflow end of the frame 12, struts 22, struts 24, and struts 34 define a lower row of meshes that define openings 36. The struts 24, 26, and 28 of the second, third, and fourth rows define two intermediate rows of meshes that define openings 38. The struts 28 and 32 of the fourth and fifth rows, together with the frame portion 30 and struts 31, define an upper row of meshes that define openings 40. The openings 40 are relatively large and are sized so that portions of the leaflet structure 14 protrude or bulge into and / or through the openings 40 when the frame 12 is creased to minimize the creased profile.

[0058] like Figure 7 As best shown in FIG. 4 , the lower end of strut 31 is connected to two struts 28 at a node or junction 44, and the upper end of strut 31 is connected to two struts 32 at a node or junction 46. The thickness S1 of strut 31 may be less than the thickness S2 of junctions 44, 46. Fig.53A portion of the frame 12 is shown in a creased state. The ties 44, 46, together with the ties 64, prevent the aperture 40 from being completely closed. Fig.18 The valve 10 is shown crimped onto a balloon catheter. It can be seen that the geometry of the struts 31 and the junctions 44, 46 and 64 help create sufficient space in the opening 40 in the crimped state to allow portions of the leaflets to protrude (i.e., bulge) outwardly through the opening. This allows the valve to be crimped to a relatively smaller diameter than would be assumed if all of the leaflet material were confined within the crimped frame.

[0059] The frame 12 is configured to prevent or at least minimize possible over-expansion of the valve at a predetermined balloon pressure, particularly at the outflow end portion of the frame supporting the leaflet structure 14. In one aspect, the frame is configured to have relatively large angles 42a, 42b, 42c, 42d, 42e between struts. The larger the angle, the greater the force required to open (expand) the frame. This phenomenon is schematically illustrated in Fig.15A and 15B middle. Fig.15A The struts 32 are shown when the frame 12 is in its compressed state (e.g., mounted on an air bag). When the frame is compressed, the vertical distance d1 between the strut ends is greatest, providing a relatively large moment between the forces F1 and F2 acting on the strut ends in opposite directions when an opening force is applied from inflation of the air bag (or expansion of another expansion device). When the frame is radially expanded, the vertical distance between the strut ends decreases to a distance d2, as shown in FIG. Fig. 15B As depicted in . As the vertical distance decreases, the moment between forces F1 and F2 also decreases. Therefore, it can be seen that as the vertical distance and moment between the ends of the struts decrease, a relatively larger expansion force is required. Moreover, as the frame expands, the strain hardening (hardening) at the ends of the struts increases, which increases the expansion force required to cause further plastic deformation at the ends of the struts. In this way, the angles between the struts of the frame can be selected to limit the radial expansion of the frame at a given opening pressure (e.g., the inflation pressure of the airbag). In specific embodiments, these angles are at least 110 degrees or greater when the frame is expanded to its functional size, and even more specifically, these angles are at least 120 degrees or greater when the frame is expanded to its functional size.

[0060] In addition, due to the "dumbbell" effect of the balloon used to inflate the valve, the inflow and outflow ends of the frame generally tend to over-inflate than in the middle portion of the frame. To avoid over-inflation of the leaflet structure 14, it is desirable to secure the leaflet structure to the frame 12 below the upper row of struts 32, such as Figure 1 Best displayed in . Fig.55 Display and Figure 5A similar plan view of the frame 12 but showing lines 176 superimposed on the frame to indicate the location of the upper edge of the leaflets 400. Thus, in the event of over-expansion of the outflow end of the frame, the leaflet structure is located below a level where over-expansion would occur, thereby avoiding over-expansion of the leaflet structure.

[0061] In known valve configurations, if the leaflets are mounted too close to the distal end of the frame, the leaflets may protrude outwardly beyond the outflow end of the frame when the valve is crimped. If the delivery catheter that mounts the crimped valve includes a push mechanism or stop element that pushes toward or against the outflow end of the valve (e.g., to maintain the crimped valve in position on the delivery catheter), the push element or stop element may damage the exposed leaflets that extend beyond the outflow end of the frame. Another benefit of mounting the leaflets at a location spaced apart from the outflow end 178 of the frame is that when the valve is crimped on the delivery catheter, such as Fig.56 As shown in FIG. 1 , the leaflets 400 do not protrude in the axial direction beyond the outflow end 178 of the frame. Thus, if the delivery catheter includes a push mechanism or stop element that pushes toward or against the outflow end of the valve, the push mechanism or stop element may contact the end 178 of the frame instead of the leaflets 400, thereby avoiding damage to the leaflets.

[0062] Moreover, in Figure 5 As can be seen in the figure, the openings 36 in the bottom row of openings in the frame are relatively larger than the openings 38 in the two middle rows of openings. Fig.54 , this allows the frame to assume an overall tapered shape when creased, tapering from a maximum diameter D1 at the outflow end of the valve to a minimum diameter D2 at the inflow end of the valve. When creased, the frame 12 has a region of reduced diameter extending along a portion of the frame adjacent the inflow end of the frame indicated by reference numeral 174, which generally corresponds to the region of the frame covered by the outer skirt 18. The diameter of region 174 is reduced compared to the diameter of the upper portion of the frame (not covered by the outer skirt) so that the outer skirt 18 does not add to the overall creased shape of the valve. When the valve is deployed, the frame can expand to Figure 4 In one example, when crimped, the frame of a 26 mm valve has a diameter D1 of 14 French at the valve outflow end and a diameter D2 of 12 French at the valve inflow end.

[0063] Fig.11 and 12An optional frame 50 is shown that can be incorporated into the valve 10. The frame 50 includes multiple rows of circumferentially extending, angled struts 52 that are connected to each other at nodes or connecting portions 54 and 56. The uppermost row of struts 52 is connected to the struts of the adjacent row by multiple axially extending struts 58 and commissure window frame portions 60. Each commissure frame portion 60 defines a slit or commissure window 62 for mounting a respective commissure of the valve structure, as described in more detail below. In a specific embodiment, the thickness T of the frame 50 is about 0.45 mm or less. Fig.13 and 14 yes Fig.12 1 and 12 are enlarged views of the frame portions 50 indicated by letters A and B, respectively.

[0064] The main function of the inner skirt 16 is to help fix the valve structure 14 to the frame 12, and to help form a good seal between the valve and the natural ring by blocking blood flow through the open mesh of the frame 12 below the lower edge of the leaflet. The inner skirt 16 desirably includes a tough, tear-resistant material, such as polyethylene terephthalate (PET), although various other synthetic or natural materials can be used. The thickness of the skirt is desirably less than 6 mils, and desirably less than 4 mils, and even more desirably about 2 mils. In a specific embodiment, the skirt 16 may have a variable thickness, for example, the skirt may be thicker at its edge than at its center. In one implementation, the skirt 16 may include a PET skirt having a thickness of about 0.07 mm at its edge and about 0.06 mm at its center. A thinner skirt can provide better pleating performance while still providing a good seal around the valve.

[0065] The skirt 16 may be secured to the interior of the frame 12 by stitching 70, such as Fig.39 The valve structure 14 may be attached to the skirt (which may together form a sleeve) via one or more thin PET reinforcing bands 72 discussed below, which ensure secure suturing and avoid tearing of the pericardial tissue of the leaflet structure. The valve structure 14 may be sandwiched between the skirt 16 and the thin PET band 72, as shown in FIG. Fig.38 The sutures 154 that secure the PET band and the leaflet structure 14 to the skirt 16 may be any suitable sutures, such as Ethibond sutures. The sutures 154 are desirably along the curvature of the bottom edge of the leaflet structure 14, as described in more detail below.

[0066] Known fabric skirts include a fabric of warp and weft fibers that extend perpendicular to each other and one set of fibers extends perpendicular to the upper and lower edges of the skirt. When the metal frame to which the fabric skirt is secured is radially compressed, the overall axial length of the frame increases. Unfortunately, the fabric skirt, which inherently has limited elasticity, cannot extend with the frame and therefore tends to deform the struts of the frame and prevent uniform pleating.

[0067] Fig.17 An example of a pleated valve is shown in which the struts have been deformed in several places due to the skirt having fibers extending perpendicular to the upper and lower edges of the skirt, as indicated by reference numeral 100. Also, the fabric tends to bunch or form bulges of excess material in certain locations, which limits the minimum pleat profile and prevents uniform pleating.

[0068] refer to Fig. 16B In contrast to known fabric skirts, the skirt 16 is desirably woven from a first group of fibers, or yarns, or threads 78 and a second group of fibers, or yarns, or threads 80, neither of which is perpendicular to the upper edge 82 and the lower edge 84 of the skirt. In a specific embodiment, the fibers 78 of the first group and the fibers 80 of the second group extend at an angle of approximately 45 degrees relative to the upper and lower edges 82, 84. The skirt 16 may be formed by weaving the fibers at a 45 degree angle relative to the upper and lower edges of the fabric. Alternatively, the skirt may be cut diagonally from a vertically woven fabric (where the fibers extend perpendicular to the edges of the material) so that the fibers extend at a 45 degree angle relative to the upper and lower cut edges of the skirt. As Fig. 16B As further shown in FIG. 1 , the relatively short edges 86, 88 of the skirt are desirably not perpendicular to the upper and lower edges 82, 84. For example, the short edges 86, 88 desirably extend at an angle of about 45 degrees relative to the upper and lower edges and are thus aligned with the first group of fibers 78. Therefore, the overall shape of the skirt is a rhombus shape.

[0069] Fig.19A and 19B The skirt 16 is shown after the opposing edge portions 90, 92 have been sewn together to form the annular shape of the skirt. As shown, the edge portion 90 can be arranged in an overlapping relationship relative to the opposing edge portion 92, and the two edge portions can be sewn together with a stitching line 94 extending parallel to the diagonal of the edges 86, 88. The upper edge portion of the skirt 16 can be formed by a plurality of protrusions 96 that define a wavy shape that generally follows the shape of the fourth row of struts 28 adjacent the lower end of the axial struts 31. In this manner, as shown in FIG. Fig. 20 As best shown in the figure, the upper edge of the skirt 16 can be tightly secured to the pillars 28 with sutures 70. The skirt 16 can also be formed with a slit 98 to facilitate attachment of the skirt to the frame. The size of the slit 98 is such that the upper edge portion of the skirt partially wraps around the pillars 28 and reduces stress in the skirt during the attachment process. For example, in the illustrated embodiment, the skirt 16 is placed inside the frame 12 and the upper edge portion of the skirt wraps around the upper surface of the pillars 28 and is secured in place with sutures 70. Wrapping the upper edge portion of the skirt around the pillars 28 in this manner provides the skirt with a stronger and more durable attachment to the frame. The skirt 16 can also be secured to the pillars 22, 24 and 26 of the first, second and third rows, respectively, with sutures 70.

[0070] Reference again Fig. 16B Due to the orientation of the fibers relative to the upper and lower edges, the skirt may experience greater elongation in the axial direction (ie, the direction from the upper edge 82 to the lower edge 84).

[0071] Therefore, when the metal frame 12 is creased (eg Fig.18 ), the skirt 16 can be stretched along the axial direction with the frame and thus provide a more uniform and predictable crimping profile. In the illustrated embodiment, each mesh of the metal frame includes at least 4 angled struts that are rotated in the axial direction (i.e., the angled struts are more aligned with the length of the frame). The angled struts of each mesh serve as a mechanism to rotate the fibers of the skirt in the same direction as the struts, so that the skirt stretches along the length of the struts. This allows the skirt to stretch more and avoids undesirable deformation of the struts when the valve is crimped.

[0072] In addition, the spacing between the woven fibers or yarns can be increased so that the skirt can be stretched in the axial direction. For example, for a PET skirt 16 formed of 20 denier yarn, the yarn density can be about 15% to about 30% less than a conventional PET skirt. In some instances, the yarn spacing of the skirt 16 can be from about 155 yarns per foot to about 180 yarns per foot, such as about 160 yarns per foot, while in a conventional PET skirt, the yarn spacing can be from about 217 yarns per foot to about 247 yarns per foot. The inclined edges 86, 88 promote uniform and consistent distribution of the fabric material along the inner circumference of the frame during pleating, thereby minimizing the bundling of the fabric to promote uniform pleating to the smallest possible diameter. In addition, cutting the diagonal seam in a perpendicular manner may leave loose fringes along the cut edge. The inclined edges 86, 88 help minimize the occurrence of this situation. As described above, Fig.17 Shows a pleated valve with a conventional skirt, with the fibers running perpendicular to the upper and lower edges of the skirt. Fig.17 and 18 It will be apparent that the construction of the skirt 16 avoids undesirable deformation of the frame struts and provides for more uniform frame crimping.

[0073] In an alternative embodiment, the skirt may be formed of woven elastic fibers that may stretch in the axial direction during crimping of the valve. The warp and weft fibers may be perpendicular and parallel to the upper and lower edges of the skirt, or alternatively, they may extend at an angle between 0 and 90 degrees relative to the upper and lower edges of the skirt, as described above.

[0074] The inner skirt 16 may be sewn to the frame 12 at a location away from the stitching line 154 so that the skirt may be more flexible in this area (see FIG. Fig.28 ). This avoids stress concentration on the suture 154 attaching the lower edge of the leaflet to the skirt 16.

[0075] As described above, the illustrated embodiment includes three flexible leaflets 400 (although a greater or lesser number of leaflets may be used). Fig.21 As best shown in the illustrated construction, each leaflet 400 has an upper (outflow) free edge 110 extending between opposing upper projections 112 on opposite sides of the leaflet. A notch 114 is located below each upper projection 112, separating the upper projection from a corresponding lower projection 116. The leaflet lower (inflow) edge portion 108 extending between the respective ends of the lower projections 116 includes a vertical or axial edge portion 118 on opposite sides of the leaflet, extending downwardly from the corresponding lower projection 116; and a substantially V-shaped middle edge portion 120 having a smooth, curved top portion 119 at the lower end of the leaflet and a pair of inclined portions 121 extending between the axial edge portions and the top portion. The inclined portions may have a larger radius of curvature than the top portion. Each leaflet 400 may have a reinforcing band 72 secured (e.g., sutured) to the inner surface of the lower edge portion 108, such as Fig. 22 as shown in the .

[0076] The leaflets 400 may be secured to each other at their proximal sides to form commissures 122 of the leaflet structure. A plurality of flexible connectors 124 (one of which is shown in FIG. Fig.23 The flexible connectors 124 may be formed from a woven PET fabric sheet, although other synthetic and / or natural materials may be used. Each flexible connector 124 may include a wedge 126 extending from a lower edge to an upper edge in the center of the connector. The wedge 126 may include a non-metallic material, such as a rope or a sheet of Ethibond 2-0 suture material, secured to the connector with a temporary suture 128. The wedge 126 helps prevent rotational movement of the leaflet protrusions when they are secured to the commissure window frame portion 30. The connector 124 may have a series of inner notches 130 and outer notches 132 formed along its upper and lower edges.

[0077] Fig.24 The adjacent sides of two leaflets 400 are shown connected to each other by a flexible connector 124. Opposite end portions of the flexible connector 124 can be placed in overlapping relationship with the lower projection 116, with the inner notch 130 aligned with the vertical edge of the projection 116. Each projection 116 can be secured to a corresponding end portion of the flexible connector 124 by suturing along a line extending from the outer notch 132 on the lower edge to the outer notch 132 on the upper edge of the connector. Three leaflets 400 can be secured to each other end-to-end using three flexible connectors 124, as shown. Fig.25 as shown in the .

[0078] Reference Fig.26 and 27 , the adjacent subcommissure portions 118 of the two leaflets can be sutured directly to each other. In the example shown, PTFE-6-0 suture material is used to form in-and-out sutures 133 and comb-like sutures 134, which extend through the subcommissure portions 118 and the reinforcing band 72 on the two leaflets. The remaining two adjacent pairs of subcommissure portions 118 are sutured together in the same manner to form a combined leaflet structure 14, which can then be fixed to the frame 12 in the following manner.

[0079] As described above, the inner skirt 16 can be used to assist in suturing the leaflet structure 14 to the frame. Fig.28 , the skirt 16 may have a wavy temporary marking suture 136 to guide the attachment of the lower edge of each leaflet 400. The skirt 16 itself can be sutured to the struts of the frame 12 using sutures 70, as described above, and then the leaflet structure 14 is secured to the skirt 16. The struts that intersect the marking suture 136 are desirably not attached to the skirt 16. This makes the skirt 16 more flexible in areas not secured to the frame and minimizes stress concentration along the sutures that secure the lower edge of the leaflet to the skirt. The portion of the skirt 16 initially bounded by the rectangle 140 is not secured to the frame 12 and is later secured to the frame after the leaflet structure 14 is secured to the skirt, as further described below. As described above, when the skirt is secured to the frame, the fibers 78, 80 (see Fig. 16B ) are roughly aligned with the angled struts of the frame to promote uniform crimping and expansion of the frame.

[0080] Fig.29 is a cross-sectional view of a frame portion and leaflet structure showing adjacent projection portions of two leaflets secured to corresponding window frame portions 30 . Figure 30-36 One specific method for securing the commissure portions 122 of the leaflet structure 14 to the commissure window frame portion 30 of the frame is shown. First, as Fig.30 As shown in FIG. 1 , the flexible connector 124 securing the two adjacent sides of the two leaflets is folded laterally and the upper protrusion portion 112 is folded downwardly against the flexible connector. Fig.30 and 31 As best shown in FIG. 1 , each upper projection portion 112 is folded longitudinally (vertically) to assume an L-shape with the inner portion 142 folded against the inner surface of the leaflet and the outer portion 144 folded against the connector 124. The outer portion 144 may then be sutured to the connector 124 along suture line 146. Next, as shown in FIG. Fig.31 As shown in , the commissure tab assembly (consisting of a pair of lower tab portions 116 connected by a connector 124 ) is inserted through the commissure window 20 of the corresponding window frame portion 30 . Fig.32is a side view of the frame 12 showing the commissure tab set extending outwardly through the window frame portion 30 .

[0081] like Fig.29 and 33 As best shown in FIG. 1 , the commissure tab set is compressed radially inward at the wedge 126 so that one lower tab portion 116 and a portion of the connector 124 are folded against the frame 12 on one side of the window frame portion 30 and the other lower tab portion 116 and a portion of the connector 124 are folded against the frame 12 on the other side of the window frame portion 30. A pair of sutures 148 are formed to hold the lower tab portion 116 in place with the Fig.29 Each suture 148 extends through the connector 124, the lower protrusion portion 116, the wedge 126 and another portion of the connector 124. Next, as shown in Fig.29 and 34 As shown in FIG. 1 , each lower protrusion portion 116 is secured to a corresponding upper protrusion portion 112 with a main suture 150 extending through a layer of connectors 124, lower protrusion portion 116, another layer of connectors 124, another layer of connectors 124, and upper protrusion portion 112. Finally, as shown in FIG. Fig.29 and 35 As shown in FIG. 1 , the suture material used to form the main suture 150 can be used to further form a lock stitch 152 at the edge of the tab portions 112 , 116 , which extends through the two layers of connector 124 sandwiched between the tab portions 112 , 116 .

[0082] like Fig.29 and 30 As shown in , the downwardly folded upper protrusion portion 112 forms a double layer of leaflet material at the commissure. The inner portion 142 of the upper protrusion portion 112 is arranged as a flat layer adjacent to the two leaflets 400 that form the commissure, so that each commissure includes only four layers of leaflet material inside the window frame 30. This four-layer portion of the commissure can be more resistant to bending or pivoting than the portion of the leaflet 400 that is only radially inward from the relatively more rigid four-layer portion. This allows the leaflet 400 to pivot primarily at the inner edge 143 of the downwardly folded inner portion 142 in response to blood flowing through the valve during in vivo operation, rather than pivoting about the axial struts of the window frame 30. Because the leaflets are pivoted at a position radially inward from the window frame 30, the leaflets can avoid contacting and damaging the frame. However, under high forces, the four-layer portion of the commissure can pivot about the longitudinal axis 145 ( adjacent the window frame 30) . Fig.29) is unfolded, each inner portion 142 folds outwardly against a respective outer portion 144. This may occur, for example, when the valve 10 is compressed and mounted on a delivery shaft, allowing for a smaller pleat diameter. When the balloon catheter is inflated during expansion of the valve, the four-layer portion of the commissure may also unfold around shaft 145, which may relieve some of the pressure on the commissure caused by the balloon and thus the commissure is not damaged during expansion.

[0083] After all three commissure tab sets are secured to the window frame portion 30, the lower edges of the leaflets 400 between the commissure tab sets can be sutured to the inner skirt 16. For example, Figure 36-38 As shown in FIG. 1 , each leaflet 400 can be sutured to the skirt 16 along suture line 154 using, for example, an Ethibond thread. The suture line can be a through suture line that extends through each leaflet 400, the skirt 16, and each reinforcement band 72. Each leaflet 400 and the respective reinforcement band 72 can be sutured to the skirt 16, respectively. In this way, the lower edge of the leaflet is fixed to the frame 12 via the skirt 16. As shown in FIG. Fig.38 , the leaflets can be further secured to the skirt with lock stitch sutures 156 that extend through each reinforcement band 72, the leaflets 400, and the skirt 16 while looping around the edges of the reinforcement bands 72 and leaflets 400. The sutures 156 can be formed of a PTFE suture material. Fig.39 and 40 The frame 12, leaflet structure 14 and skirt 16 are shown after securing the leaflet structure and skirt to the frame and securing the leaflet structure to the skirt.

[0084] Fig.41 16. A plan view of the outer skirt 18 is shown before it is attached to the frame 12. The outer skirt 18 may be laser cut or otherwise formed from a sheet of a strong, durable material such as woven PET, although other synthetic or natural materials may be used. The outer skirt 18 may have a substantially straight lower edge 160 and an upper edge 162 that define a plurality of alternating protrusions 164 and indentations 166. Fig.42 As best shown in FIG. 1 , the lower edge 160 of the skirt 18 may be sutured to the lower edge of the inner skirt 16 at the inflow end of the valve. Fig.43 As shown in FIG. 1 , each protrusion 164 can be sewn to the second rail II support 24 of the frame 12. The corners 162 of the protrusions 164 can be folded over the respective support of the rail II and secured with sutures 168.

[0085] As in Figure 1 , 3As can be seen in FIGS. 4 and 43 , the outer skirt 18 is secured to the frame 12 such that when the frame is in its expanded state, there is excess material or slack between the lower and upper edges 160, 162 of the outer skirt that is not flat against the outer surface of the frame 12. In other words, the outer skirt is configured with excess material that causes the outer skirt to bulge outwardly as the frame shortens (i.e., becomes shorter in length) during radial expansion. Therefore, when the valve 10 is deployed in vivo, the excess material of the outer skirt 18 can fill the gap between the frame 12 and the surrounding native annulus, helping to form a good fluid seal between the valve and the native annulus. The outer skirt 18 thus cooperates with the inner skirt 16 to avoid leakage around the valve after the valve 10 is implanted. In another advantageous feature, the slack between the lower and upper edges of the outer skirt 18 allows the frame 12 to elongate axially during crimping without any resistance from the outer skirt, and the outer skirt does not substantially affect the outer diameter of the prosthetic valve in the crimped condition.

[0086] Fig.56 The elongated shaft 180 of the delivery device is shown mounted on Figure 1-3 The valve 10 of 42-43 is formed into a delivery kit for implanting the valve 10 in a patient. The valve 10 is installed in a radially collapsed configuration for delivery into the body. The shaft 180 includes an inflatable balloon 182 for expanding the balloon in the body, and the pleated valve 10 is located above the deflated balloon. When in the radially compressed installation configuration, the frame 12 of the valve 10 includes an inflow end portion 174 (see Fig.54 ), whose outer diameter D2 is less than the outer diameter D1 of the outflow end portion of the frame. The tapering of the frame can be due at least in part to the V-shaped leaflets 400, as the V-shaped leaflets have less leaflet material within the inflow end portion of the frame 12 than the more rounded U-shaped leaflets. Due to the tapered shape of the frame 12 in the installed state, even with the thickness of the outer skirt 18 located around the inflow end portion 174 of the frame 12, the overall outer diameter of the inflow end portion of the valve 10 can be approximately equal to or less than the overall outer diameter of the outflow end portion of the valve.

[0087] Moreover, if Fig.56As shown in , the valve 10 includes a commissure portion of the leaflet that extends radially outward through a corresponding window frame portion 30 to a position outside the frame and is sutured to the side struts of the commissure window frame. In order to minimize the pleated profile of the valve, when the valve is radially compressed on the axis to a contracted configuration, the window frame portion 30 can be radially recessed inward relative to a surrounding portion of the frame, such as a frame portion extending between adjacent commissure windows. For example, when the valve is radially contracted, the commissure windows 30 of the frame can be recessed inwardly by a radial distance of between 0.2 mm and 1.0 mm relative to the frame portion extending between adjacent commissure windows. In this way, the outer diameter of the outflow end portion of the valve including the commissure portion can be generally consistent, in contrast to the commissure portion protruding outward from the surrounding portion of the valve, which can hinder delivery of the valve to the body. Even with the radially recessed commissure window frames 30, when the valve is radially collapsed on the shaft, the outer diameter of the frame inflow end portion can still be less than or approximately equal to the outer diameter of the frame outflow end portion, allowing for a minimal maximum overall diameter of the valve. By minimizing the diameter of the valve when mounted on the delivery shaft, the kit can be accommodated in smaller diameter catheters and therefore can pass through smaller vessels in the body and can be generally minimally invasive.

[0088] Fig.44 An artificial heart valve 200 according to another embodiment is illustrated. The heart valve 200 includes a frame or stent 202 and a leaflet structure 204 mounted on the stent. The leaflet structure 204 may include a plurality of leaflets 218 (e.g., 3 as depicted), which may be sutured to each other and to the frame 202 using suitable techniques and / or mechanisms. The frame 202 may be adapted to include a commissure frame portion 30 (e.g., Figure 4 ) to help suturing the leaflets to the frame.

[0089] Frame 202 has some of the design features of frame 12 described above. Specifically, like frame 12, frame 202 has relatively large frame openings 206 along the region of the frame that supports the leaflet structure, such as Fig.45 . The opening 206 is defined by a row of angled struts 208 at the outflow end of the frame, a plurality of axially extending, circumferentially spaced struts 210, and an intermediate row of angled struts 212. As shown, the axial struts 210 are desirably thinner than the junctions 214 that connect the opposite ends of the axial struts 210 to the intersection of two struts 212 and the intersection of two struts 208. Due to this construction, when the valve is radially compressed to the delivery configuration, the width of the opening 206 remains large enough to allow portions of the leaflet structure 204 to protrude outwardly through the opening, as shown. Fig.46 and 47 This allows the valve to be crimped to a relatively smaller diameter than would be possible assuming that all leaflet material was confined within the crimped frame.

[0090] For comparison purposes, Fig.48 2 is a cross-section of a known artificial valve 250 showing the valve in a creased state. When the valve is radially compressed, the spacing between adjacent struts is relatively small and does not allow portions of the leaflet structure to protrude outward through the frame. As a result, the presence of all leaflet material confined within the interior of the frame limits the creased diameter of the valve.

[0091] Fig.49 and 50 A plan view of an alternative frame configuration is shown that may allow portions of the leaflets to protrude outwardly through the frame in a creased state. This frame configuration may be implemented in the valve 10 described above. Fig.49 A cross section of the frame showing radial compression, while Fig.50 A cross section of the frame is shown in a radially expanded state. The frame (only a portion of which is shown) includes a first row of angled struts 442 extending circumferentially and at least a second row of angled struts 444 extending circumferentially. Some of the openings in the frame are diamond-shaped openings 446, which are formed by adjacent struts 442 connected to each other at their upper ends and adjacent struts 444 connected to each other at their lower ends. The frame also includes larger openings 448, which are formed by adjacent struts 442 connected to respective ends of horizontal struts 450 at their upper ends and adjacent struts 444 connected to respective ends of horizontal struts 452 at their lower ends. When the frame is radially compressed, the horizontal struts 450, 452 keep the width W of the openings 448 large enough to allow portions of the valve leaflets to protrude outward through the frame. Therefore, when the frame is creased, the width of the openings 448 is greater than the width of the openings 446. The frame can be formed so that the openings 446, 448 alternate around the circumference of the frame. Optionally, the openings 448 may be located at selected locations along the length and circumference of the frame to correspond to areas where leaflet material tends to accumulate within the frame, such as between commissures.

[0092] Fig.51 and 52 A plan view of another frame configuration is shown that allows portions of the leaflets to protrude outwardly through the frame in a creased state. This frame configuration may be implemented in the valve 10 described above. Fig.51 A cross section of the frame showing radial compression, while Fig.52A cross section of the frame is shown in a radially expanded state. The frame (only a portion of which is shown) includes a first row of angled struts 402 extending circumferentially and at least a second row of angled struts 404 extending circumferentially. Some of the openings in the frame are diamond-shaped openings 406, which are formed by adjacent struts 402 connected to each other at their upper ends and adjacent struts 404 connected to each other at their lower ends. The frame also includes openings 408, which are formed by adjacent struts 402 connected to enlarged nodes or junctions 410 at their upper ends and adjacent struts 404 connected to enlarged nodes or junctions 412 at their lower ends. The junctions 410, 412 add rigidity to the frame at those locations so that when the frame is radially compressed, the width W of the openings 408 remains large enough to allow the leaflet portion of the valve to protrude outward through the frame. Therefore, when the frame is creased, the width of the openings 408 is greater than the width of the openings 406. The frame can be formed with openings 406, 408 alternating around the circumference of the frame. Optionally, the openings 408 can be located at selected locations along the length and circumference of the frame to correspond to areas where leaflet material tends to accumulate within the frame, such as between commissures.

[0093] Fig.57 A leaflet 500 of an artificial valve (e.g., valve 10 or 200) according to another embodiment is shown. Leaflet 500 has an overall V-shape similar to leaflet 400 described above. Leaflet 500 has two tab portions 502 on opposite sides of the leaflet that are fixed to adjacent tab portions of another leaflet to form commissures of the leaflet structure. The subcommissure portion of leaflet 500 (the portion below tab 502) includes two substantially straight edges 504 that extend from respective positions just below tab 502 to a curved lower edge 506. Fig.58 The general shape of the leaflets 500 is shown when the valve is creased. When creased, the frame (not shown) Figure 57-58 middle) is slightly elongated, causing leaflet 500 to become slightly elongated.

[0094] The tapered profile of the subcommissure portion of the leaflet reduces the amount of leaflet material in the lower half of the pleated valve, minimizing the pleated diameter of that portion of the valve. Thus, if additional components are attached to that portion of the valve, such as the outer skirt 18, the reduced profile of that portion of the valve can help offset or minimize the increase in diameter caused by the additional components. Additionally, the commissure tabs 502 are relatively short and require fewer sutures than known leaflet designs (such as T-shaped and scalloped leaflets) for forming the commissures of the leaflet structure, which better distributes and reduces the volume of leaflet material when the valve is pleated.

[0095] Fig.59A cross-sectional view of a valve 500 according to another embodiment is shown. The valve 500 includes a frame 502, leaflets 504, and an outer skirt 18 mounted (e.g., by suturing) to the outer surface of the frame 502. The frame 502 has a thickness that varies along its length to optimize strength in selected areas of the frame when needed, but to minimize material (and therefore minimize the pleated profile). In the embodiment shown, the outflow end portion 506 of the frame has a maximum thickness T1 (measured from the inner diameter to the outer diameter of that portion of the frame) and the inflow end portion 508 of the frame has a minimum thickness T2 (measured from the inner diameter to the outer diameter of that portion of the frame). It should be noted that the struts of the frame 502 (which are not shown) that form the outflow end portion 506 are not shown in the figure. Fig.59 502 may have the same construction as frame 12 described above, except for the variable thickness of the frame. The area of ​​reduced thickness may be formed using a variety of manufacturing techniques, such as electro-polishing selected portions of the frame (which may mask non-polished portions), grinding selected portions of the frame, wire cutting, or other suitable techniques.

[0096] The outflow end portion 502 generally corresponds to the commissures that support the leaflets 504 and is generally subject to the greatest loads of the valve frame. Therefore, the outflow end portion 502 of the frame has a greater thickness T1 selected to provide the required strength under the expected load. Due to the outer skirt 18, the inflow end portion 508 supports an additional layer of material. The reduced thickness of the inflow end portion 508 allows the inflow end portion to be pleated to a smaller diameter than the outflow end portion. This offsets or minimizes the increase in the pleated diameter caused by the addition of the outer skirt 18.

[0097] Figure 60-62 Another embodiment of an implantable prosthetic valve 310 is shown, which includes a leaflet structure 314 and a radially contractible and expandable frame 312 (with Fig.11 310 has a plurality of radially spaced commissure windows 318 for securing the leaflet structure within the frame. The valve 310 also includes a skirt 316 secured between the inner surface 312 of the leaflet structure 314 frame and the curved lower edge 364. The valve 310 has a lower inflow end 340 and an upper outflow end 342.

[0098] like Fig.60A As shown in FIG. 1 , each window 318 includes a closed opening 334 between two axially extending side struts 320. Each side strut includes a generally rectangular, for example, square, cross-sectional profile, such as Fig.63Each rectangular side strut 320 includes four surfaces: an outer surface 324 on the radially outward facing side, an inner surface 326 on the radially inward facing side, an intermediate surface 328 on the side facing the other side strut, and a lateral surface 330 on the side away from the other side strut. In other embodiments, the side struts may include other cross-sectional shapes, such as circular or hexagonal.

[0099] The leaflet structure includes a plurality of leaflets 360, each including a pair of side tabs 366 secured to the frame 312, a curved lower edge 364 secured to the skirt 316, and a pivoting portion 372 between the side tabs and the lower edge. Each side tab 366 mates with an adjacent side tab of another leaflet 360 to form a commissure 376 of the leaflet structure 314. Each pair of side tabs 366 extends radially outward through a corresponding commissure window 318 to a location outside the frame 312 and is secured to the side struts 320 of the window, such as with sutures, such as Fig.62 In some embodiments, each side protrusion 366 includes an end portion 368 (see Fig.64 ) and the two side protrusion end portions 368 of each joint 376 are away from each other and extend circumferentially along the outer surface 324 of the respective side pillars 320 of the window 318.

[0100] In some embodiments, each commissure 376 further includes at least one non-rigid reinforcement sheet 378, which is sutured to the side protrusions 366 and to the side struts 320. The sheet 378 may include a flexible tear-resistant material, including various natural and / or synthetic biocompatible materials. Exemplary synthetic materials may include polymers such as nylon, silicone, and polyester, including PET. In one embodiment, the sheet 378 includes a woven PET fabric.

[0101] Each reinforcement sheet 378 may be generally rectangular (when laid flat) and may include a middle portion 380 and opposing end portions 386. In some embodiments, the first end portion 386 of the sheet is secured to the first side brace 320 and the second end portion 386 of the sheet is secured to the second side brace 320, such as Fig.64 As shown in FIG. 378, the sheet separates the side protrusion 366 from the side pillar 320 so that the side protrusion does not contact the side pillar. For example, each end portion 386 of the sheet may completely wrap around the respective side pillar 320, such as Fig.64 as shown in the .

[0102] The side tabs 366 and the reinforcement tabs 378 may be secured to the side pillars 320 at multiple stages. For example, Fig.63An exemplary first suturing stage is shown in which the sheet is placed so that the middle portion 380 of the sheet extends circumferentially across the outer surface of the end portions 368 of the side tabs 366 and each end portion 386 of the sheet extends between the respective outer, middle and inner surfaces 324, 328, 326 of the respective side tabs 366 and the respective side struts 320. The sheet 378 surrounds the side tabs 366 and protects the side tabs from the edges of the side struts 320. A pair of through stitches 390 may secure each side tab 366 and one end of the sheet 378 to the respective struts 320. As shown in FIG. Fig.63 , each suture 390 can be oriented substantially perpendicular to the circumference of the frame 312 along the side surface 330 of the side pillar 320 and can pass radially back and forth through the commissure 376 at a plurality of different longitudinal positions. Each suture 390 can intersect the sheet 378 of the first layer, the side projection end portion 368, the sheet of the second layer, and the sheet of the third layer, moving radially inward in that order. The suture 390 secures the sheet 378 to the side projection end portion 368 and secures the sheet end portion 386 around the side pillar 320, thereby securing the side projection 366 to the side pillar 320 and securing the leaflet structure 314 to the frame 312.

[0103] Fig.64 An exemplary second suturing stage is shown, in which a second pair of sutures 392 are used to tie off the slack in the reinforcement sheet 378. For example, the second sutures 392 may cross the portion of the middle portion 380 extending laterally beyond the first sutures 390 and the end portions 386 of the sheet. The second sutures 392 may be spiral overlock sutures that cross the commissures 376 at a plurality of different longitudinal locations, such as Fig.62 , and secure the slack portion of sheet 378 tightly against the side surface 330 of the side support.

[0104] Both the first suture 390 and the second suture 392 can be arranged adjacent to the side surface 330 of the strut 320 and spaced away from the window opening 334. This arrangement of the sutures can reduce the stress on the sutures caused by movement of the hinged portion 372 of the leaflet. Instead, much of this stress is transferred from the elastic hinge 370 of the leaflet to the side strut 320 near the inner-medial edge 332 of the strut.

[0105] The reinforcing sheet 378 protects the resilient hinge 370 from damage caused by the inner-medial edge 332 of the strut 320 when the leaflet is pivoted between the open and closed positions, such as Fig.64 In addition, some embodiments may also include a longitudinally extending padding strip 374 located between the elastic hinge 370 and the support 320, such as adjacent to the inner-medial edge 332, such as Fig.64, to further protect the elastic hinge from damage caused by the struts. The cushioning strip 374 may include a flexible, compressible material, such as PET fabric, pericardial tissue, or various other biocompatible materials. In some embodiments, the cushioning strip may include a tube filled with an elastic material. For example, the cushioning strip may include a PET tube filled with pericardial tissue. In other embodiments, the outer tubular covering of the cushioning strip may be formed by a sheet 378 and may be filled with an elastic material. The sheet may be secured with sutures around the elastic material to keep the cushioning strip properly positioned, such as Fig.64 In other embodiments, a separate cushioning strip 374 may be sewn to the reinforcement sheet 378. The cushioning strip 374 may have a thickness similar to the window sash 62 to provide radial clearance between the side struts 320 and the hinged portion 372 of the leaflet to prevent or minimize contact between the leaflet and the inner surface of the frame during the cardiac cycle.

[0106] Fig.65 Displays something like Fig.63 and 64 but with a different stitching pattern. Fig.65 320, the sutures 390 are replaced by sutures 398 that secure the sheet 378 around the end portions 368 of the side tabs. Each suture 398 crosses the middle portion 380 of the sheet, one of the side tabs 366, and the second layer of the sheet adjacent the middle-outer edge 324 of each side strut. The sutures 398 may include through sutures that cross the commissures at a plurality of different longitudinal locations. Each end portion of the sheet 378 may include a folded portion 388 that folds underneath to form a double layer of the sheet 378 along the surface of the respective side strut 320. The sutures 392 secure the sheet end portions 386 and the end portions 368 of the side tabs tightly around the side surfaces 330 of the side struts.

[0107] Fig.66 and 67 An alternative method for sewing the side tabs 366 and flaps 378 to the side struts 320 is shown. Fig.66 A stitch line 394 is shown arranged along the outer surface 324 of the side pillar and generally perpendicular to the radius of the frame. The stitch line 394 intersects the two side tabs 366 and the two end portions 386 of the sheet 378. The stitch line 394 secures each end portion 386 of the sheet tightly around the middle surface, inner surface and side surface 328, 326, 330 of the respective side pillar 320, and also secures the sheet middle portion 380 loosely around the end portions 368 of the side tabs 366. Fig.66 In the illustrated embodiment, the stitching line 394 intersects the first ply A, the second ply B, the two side tabs 366, the third ply C, and the fourth ply D in that order.

[0108] After the first suture 394 is in place, the end portions 368 of the side projections are stretched and positioned adjacent to the exterior surface 324 of the side struts 320, as shown in FIG. Fig.67 This tightens the slack middle portion 380 of the sheet around the end portions 368 of the side tabs. A pair of sutures 396 can then secure the middle portion 380 of the sheet tightly to the end portions 386 of the sheet to hold the end portions 368 of the side tabs in place, as shown in FIG. Fig.67 Suture 396 may be a circular overlock suture that crosses commissure 376 at a plurality of different longitudinal positions. Fig.64 Similar to the stitching line 392 in .

[0109] Fig.68 and 69 Another alternative method for sewing the side tabs 366 and flaps 378 to the side struts 320 is shown. Fig.68 A stitching line 395 is shown, which is arranged along the outside of the window opening and is oriented generally perpendicular to the radius of the frame. The stitching line 395 intersects the two side tabs 366 and two portions of the sheet 378. The stitching line 395 secures the middle portion 380 of the sheet, which extends loosely around the end portions 368 of the side tabs 366. Fig.68 In the embodiment shown in FIG. 3 , the stitching line 395 crosses the first sheet A, the first side tab B, the second side tab C, and the second sheet D in this order.

[0110] After the first suture 395 is in place, the end portions 368 of the side projections are stretched and positioned adjacent to the exterior surface 324 of the side struts 320, as shown in FIG. Fig.69 This allows the loose middle portion 380 of the sheet to be tightened around the end portions 368 of the side tabs. A pair of sutures 397 can then secure the middle portion 380 of the sheet tightly to the end portions 386 of the sheet to hold the end portions 368 of the side tabs in place, as shown in FIG. Fig.69 The end portion 386 of the sheet may include a portion 388 folded under to form a double layer of sheet material to reinforce the suture 397. The suture 397 may be a circular overlock suture that crosses the commissure 376 at a plurality of different longitudinal positions and is Fig.62 Similar to the stitching line 392 in .

[0111] Fig.70 and 71 Yet another alternative method for sewing the side tabs 366 and flaps 378 to the side struts 320 is shown. Fig.70A stitching line 395 is shown, which is arranged along the outside of the window opening and is oriented generally perpendicular to the radius of the frame. The stitching line 395 intersects the two side tabs 366 and the four portions or layers of the sheet 378. Each end portion 386 of the sheet includes a folded portion 388 that forms a double layer of sheet material between the side tabs 366 and the middle surface 328 of the side struts. The stitching line 395 secures the middle portion 380 of the sheet loosely around the end portions 368 of the side tabs 366. As shown in FIG. Fig.70 As shown in FIG. 1 , each stitch of stitch line 395 crosses a first pair of plies including layers A and B, a first side tab C, a second side tab D, and a second pair of plies including layers E and F in that order.

[0112] After the first suture 395 is in place, the end portions 368 of the side projections are stretched and positioned adjacent to the exterior surface 324 of the side struts 320, as shown in FIG. Fig.71 This allows the middle portion 380 of the sheet to be pulled tight around the end portions 368 of the side tabs. A pair of sutures 397 can then secure the middle portion 380 of the sheet tightly to the end portions 386 of the sheet to hold the end portions 368 of the side tabs in place, as shown in FIG. Fig.71 The folded portion 388 of the sheet forms a double layer of sheet material to reinforce the suture line 397. The suture line 397 can be a circular overlock suture that crosses the joint 376 at multiple different longitudinal positions and Fig.62 Similar to the stitching line 392 in .

[0113] For attaching the leaflet structure 314 to Figures 61-71 Various configurations of the joints of the window frame 318 shown in FIG. 310 may also be used to Figure 1-3 Alternative ways of attaching the leaflet structure 14 of the valve 10 to the window frame portion 30 of the frame 12 .

[0114] Figures 72-74 A prosthetic heart valve kit 600 is shown that includes an embodiment of a frame 602 of a prosthetic valve mounted on a balloon 606 on a delivery shaft 604. The frame 602 can be similar in shape to the frame 12 and can include an inflow end portion 610, an outflow end portion 612, and a middle portion 614. For clarity, other components of the valve, such as the leaflets and skirt, are not shown. The frame 602 can have a reduced thickness at the inflow end portion 610 and the outflow end portion 612 relative to the thickness of the middle portion 614. Due to the thinner end portions, when the balloon 606 is inflated, the end portions 610, 612 offer less resistance to expansion and expand faster than the middle portion 614, as shown in FIG. Fig.73Because the end portions expand faster than the middle portion, the frame 602 is constrained on the airbag 606, inhibiting the frame from sliding toward either end of the airbag and reducing the risk of the frame sliding off the airbag prematurely. Fig.74 As shown in , further inflation of the balloon can cause the middle portion 614 of the frame to expand to the same final diameter as the end portions 610, 612 for implantation, after which the balloon can be deflated and removed. Controlling the position of the valve on the balloon during delivery can be important, especially for frames that shorten and move relative to the balloon during inflation. Figures 72-74 In the embodiment shown in FIG. 6 , the middle portion 614 of the frame can remain constant relative to the airbag, while the two end portions shorten toward the middle portion due to the "dumbbell" effect of the airbag. Any conventional means can be used to produce the frame 602 with reduced thickness at the end portions 610, 612, such as sanding the end portions or the like. In one embodiment, the thickness of the end portions 610, 614 of the frame is about 0.37 mm, while the thickness of the middle portion 614 is about 0.45 mm.

[0115] In view of the many possible embodiments applying the disclosed inventive principles, it should be recognized that the illustrated embodiments are merely preferred embodiments of the invention and should not be considered as limiting the invention. Rather, the scope of the invention is defined by the appended claims. We therefore claim protection for all of our inventions within the scope of these claims.

Claims

1. A kit for implanting a balloon expandable prosthetic aortic heart valve in a patient, comprising: A delivery device comprising an elongated shaft (180) having an inflatable balloon (182), and An artificial aortic heart valve (10) includes a balloon-expandable frame (12), wherein the frame (12) has a radially contracted state and a radially expanded state, and the frame (12) includes: an inflow row opening (36) at the inflow end portion of the frame (12), an outflow opening (40) at an outflow end portion of the frame (12); and at least one intermediate row of openings (38) between the inflow row of openings (36) and the outflow row of openings (40); wherein the inflow row openings (36) are formed by a lower row of angled struts (22) extending circumferentially arranged end to end and a first intermediate row of angled struts (24) extending circumferentially arranged end to end, the lower row of angled struts and the first intermediate row of angled struts (22, 24) being interconnected by a plurality of substantially straight axially extending struts (34); and wherein the outflow row opening (40) is formed by an upper row of angled struts (32) arranged end-to-end and extending circumferentially and a second middle row of angled struts (28) arranged end-to-end and extending circumferentially, wherein the upper row of angled struts and the second middle row of angled struts (28, 32) are interconnected by a plurality of axially extending struts (31) and a plurality of angularly spaced axially extending joint window frame portions (30), wherein each axially extending strut (31) and each joint window frame portion (30) of the outflow row opening (40) extends from a position defined by the intersection of the lower ends of the two angled struts (32) of the upper row of angled struts (32) to another position defined by the intersection of the upper ends of the two angled struts (28) of the second middle row of angled struts (28); wherein the plurality of commissure window frame portions (30) each include a closed opening between first and second axially oriented side struts; and Wherein the commissure window frame portions are configured to recess radially inwardly relative to a portion of the frame extending between adjacent commissure window frame portions when the valve radially contracts.

2. A kit according to claim 1, wherein each axially extending strut (34) of the inflow row opening extends from a position defined by the intersection of the lower ends of two angled struts (24) of the first middle row of angled struts (24) to another position defined by the intersection of the upper ends of two angled struts (22) of the lower row of angled struts (22).

3. A kit according to claim 1 or 2, wherein the first middle row angled struts (24) are connected to the second middle row of struts (28) at a position defined by the intersection of the upper ends of the two angled struts (24) of the first middle row of angled struts (24), and the second middle row of angled struts (28) are connected to the first middle row of angled struts (24) at a position defined by the intersection of the lower ends of the two angled struts (28) of the second middle row of angled struts (28).

4. The kit according to claim 1 or 2, wherein the opening (40) of the outflow row openings (40) is larger than the openings (36, 38) of the inflow row openings (36) and the at least one intermediate row openings (38).

5. The kit according to claim 3, wherein the opening (40) of the outflow row openings (40) is larger than the openings (36, 38) of the inflow row openings (36) and the at least one intermediate row openings (38).

6. The kit according to one of claims 1-2 and 5, wherein adjacent angled struts of the frame (12) form an angle of at least 120° when the frame is in a radially expanded state.

7. A kit according to one of claims 1-2 and 5, wherein the plurality of joint window frame portions (30) have upper ends and lower ends, wherein each upper end and lower end of the plurality of joint window frame portions (30) are fixed to an adjacent row of angled struts (28, 32).

8. The kit of one of claims 1-2 and 5, wherein the thickness (T) of the frame (50) measured between the inner diameter and the outer diameter of the frame is about 0.48 mm or less.

9. The kit of claim 8, wherein the thickness (T) of the frame (50) measured between the inner and outer diameters of the frame is about 0.45 mm or less.

10. A kit according to one of claims 1-2, 5 and 9, wherein the lower ends of two adjacent angled struts (24) of the angled strut row are connected by a joint having a U shape, and the upper ends of two adjacent angled struts (22) of the angled strut row are connected by a joint having an inverted U shape.

11. A kit according to one of claims 1-2, 5 and 9, further comprising an inner skirt (16), wherein an upper edge of the inner skirt (16) is sewn to the second middle row of angled struts (28), wherein the upper edge of the skirt (16) is formed with a plurality of protrusions (96), the protrusions (96) defining a wavy shape that substantially follows the shape of the second middle row of angled struts (28).

12. According to a kit according to one of claims 1-2, 5 and 9, the artificial aortic heart valve (10) further includes a leaflet structure (14), wherein each commissure window frame portion (30) is configured to mount a corresponding commissure of the leaflet structure (14).

13. According to a kit according to one of claims 1-2, 5 and 9, the artificial aortic heart valve (10) further includes a leaflet structure (14) having a leaflet (400), wherein the lower edge of the leaflet (400) has a wavy, curved fan-shaped shape and is sutured to the inner skirt (16) between corresponding joints of the leaflet structure (14).

14. According to a kit according to one of claims 1-2, 5 and 9, the artificial aortic heart valve (10) also includes an annular outer skirt (18), the annular outer skirt (18) including an inflow edge fixed to the frame (12) at a first position and an outflow edge fixed to the frame (12) at a second position.

15. A kit according to claim 14, wherein the outer skirt (18) has an upper edge (162), the upper edge (162) defining a plurality of alternating protrusions (164) and notches (166), the protrusions (164) being fixed to the second position, and the outer skirt (18) is not fixed to the frame (12) at the notches.

16. The kit of claim 14, wherein the artificial aortic heart valve (10) further comprises an inner skirt (16), wherein the outer skirt (18) has a substantially straight lower edge (160) sewn to a lower edge of the inner skirt (16) at the inflow end of the valve.

17. The kit of claim 15, wherein the artificial aortic heart valve (10) further comprises an inner skirt (16), wherein the outer skirt (18) has a substantially straight lower edge (160) sewn to a lower edge of the inner skirt (16) at the inflow end of the valve.

18. The kit of one of claims 1-2, 5, 9 and 15-17, the artificial aortic heart valve (10) further comprising a leaflet structure (14) secured to the frame (12) beneath an upper row of angled struts (32).

19. The kit according to any one of claims 1-2, 5, 9 and 15-17, wherein the frame (12) comprises a material selected from stainless steel and cobalt-chromium alloy.

20. A kit for implanting an artificial heart valve in a patient, comprising: a delivery device comprising an elongated shaft; and A radially expandable prosthetic heart valve adapted to be mounted on the shaft in a radially collapsed configuration for delivery into the body, the prosthetic heart valve comprising an annular frame (12) having an inflow end portion and an outflow end portion; a leaflet structure positioned within the frame; an inner fabric skirt disposed along an inner surface of the frame; and an outer fabric skirt disposed along an outer surface of the frame; wherein the outer fabric skirt is adapted to bulge radially outwardly during radial expansion of the prosthetic heart valve, The framework (12) comprises: an inflow row opening (36) at the inflow end portion of the frame (12), an outflow opening (40) at an outflow end portion of the frame (12); and at least one intermediate row of openings (38) between the inflow row of openings (36) and the outflow row of openings (40); wherein the inflow row openings (36) are formed by a lower row of angled struts (22) arranged end to end and extending circumferentially and a first intermediate row of angled struts (24) arranged end to end and extending circumferentially, the lower row of angled struts and the first intermediate row of angled struts (22, 24) being interconnected by a plurality of substantially straight axially extending struts (34); wherein the outflow row opening (40) is formed by an upper row of angled struts (32) arranged end-to-end and extending circumferentially and a second middle row of angled struts (28) arranged end-to-end and extending circumferentially, wherein the upper row of angled struts and the second middle row of angled struts (28, 32) are interconnected by a plurality of axially extending struts (31) and a plurality of angularly spaced axially extending joint window frame portions (30), wherein each axially extending strut (31) and each joint window frame portion (30) of the outflow row opening (40) extends from a position defined by the intersection of the lower ends of the two angled struts (32) of the upper row of angled struts (32) to another position defined by the intersection of the upper ends of the two angled struts (28) of the second middle row of angled struts (28); wherein the plurality of commissure window frame portions (30) each include a closed opening between first and second axially oriented side struts; and Wherein the commissure window frame portions are configured to recess radially inwardly relative to a portion of the frame extending between adjacent commissure window frame portions when the valve radially contracts.

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