Prosthetic heart valve

Abstract

This application relates to prosthetic heart valves. Disclosed are embodiments of a radially collapsible and expandable prosthetic heart valve. The valve frame can have a tapered profile when mounted on a delivery shaft, with a smaller diameter at the inflow end portion than at the outflow end portion. The valve can include generally V-shaped leaflets, reducing the amount of material in the inflow end of the frame. An outer skirt can be secured to the outside of the inflow end portion of the frame, with longitudinal slack when the valve is expanded and lying flat against the frame when the valve is collapsed. An angularly woven inner skirt can be axially elongated with the frame. Side tabs adjacent the leaflets can extend through and be secured to window frame portions of the frame to form commissures. The window frame portions can be recessed radially inward relative to the surrounding frame portions when the valve is crimped on a delivery shaft.

Description

[0001] This application is a divisional application based on application number 201810800907.4, which is based on application number 201510850059.4. The original application has an application date of October 5, 2011, Chinese application number 201180058439.4, international application number PCT / US2011 / 054973, and the title "Prosthetic Heart Valves." TECHNICAL FIELD

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

[0003] The human heart can suffer from a variety of valvular diseases. These valvular diseases can cause severe malfunctioning of the heart and eventually require replacement of the native valve with a prosthetic valve. There are many known prosthetic valves and many known methods of implanting these prosthetic valves in humans.

[0004] Various surgical techniques can be used to replace or repair diseased or damaged valves. Each year, thousands of patients undergo surgical procedures in which a defective native heart valve is replaced with a prosthetic valve due to stenosis and other heart valve diseases. Another, less drastic, method for treating defective valves is through repair or reconstruction, which is typically used on minimally calcified valves. A problem with surgical therapy is the significant risk of high morbidity and mortality associated with surgical repair imposed on these chronically ill patients.

[0005] Surgical implantation of a prosthetic valve when replacing a native valve typically requires open chest surgery during which the heart is stopped and the patient is placed on a heart-lung machine, also known as a "cardiopulmonary bypass machine." In a typical surgical procedure, the diseased native valve leaflets are excised and the prosthetic valve is sutured to the surrounding tissue at the valve annulus. Some patients do not survive the surgical procedure or die soon thereafter due to injury associated with the procedure and the attendant duration of extracorporeal blood circulation. It is well known that the patient's risk 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 weak to withstand the procedure. By some estimates, greater than 50% of those suffering from valvular stenosis over the age of 80 are unable to undergo a valve replacement procedure.

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

[0007] An important design parameter for transcatheter heart valves is the diameter of the collapsed or crimped profile. The diameter of the crimped profile is important because it directly impacts the ability of the physician to guide the transcatheter heart valve through the femoral artery or vein. More specifically, a smaller profile allows for treating a greater number of patients with enhanced safety. SUMMARY

[0008] The present disclosure relates to methods and devices related 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 a prosthetic heart valve in a patient includes a delivery device comprising an elongated shaft and a radially expandable prosthetic heart valve mounted in a radially collapsed configuration on the shaft for delivery into the body. The prosthetic heart valve includes 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 can be due to a reduced amount of material located within the inflow end portion of the frame. The reduced diameter at the inflow end portion can make room for an outer skirt located around the inflow end portion.

[0010] In some embodiments, the heart valve can further include an outer skirt disposed around the outer surface of the inflow end portion of the frame, such that the outer diameter of the inflow end portion of the prosthetic valve, including the outer skirt, is still less than or equal to the outer diameter of the outflow end portion of the prosthetic valve.

[0011] In some embodiments, the leaflet structure can include a plurality of leaflets each including opposing side tabs on opposite sides of the leaflet. The side tabs can be secured to the outflow end portion of the frame. Each leaflet can further include a free outflow edge portion extending between the side tabs adjacent the outflow end of the frame, and an inflow edge portion extending between the side tabs adjacent the inflow end of the frame. The inflow edge portion can include opposing axial edge portions extending in a generally axial direction from the side tabs toward the inflow end, and a middle edge portion extending between the axial edge portions. The middle edge portion can include a curved tip portion adjacent the inflow end of the frame, and a pair of sloped portions extending between the axial edge portions and the tip portion. The sloped portions can have a greater radius of curvature than the tip 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 aperture between first and second axially oriented side struts. In these embodiments, the leaflet structure includes a plurality of leaflets each including two opposing side tabs each paired with an adjacent side tab 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 location outside the frame and is sutured to the side struts of the commissure window. In some of these embodiments, the commissure windows of the frame are recessed radially inward relative to portions of the frame extending between adjacent commissure windows when the prosthetic valve is in a contracted configuration on the axis.

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

[0014] In some embodiments, portions of the leaflet structure protrude through the apertures in the frame when in a contracted configuration on the axis.

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

[0016] Embodiments disclosed herein can include a collapsible prosthetic valve that can be radially collapsed to a collapsed configuration and radially expanded to an expanded configuration. Such a prosthetic valve can include an annular frame, a leaflet structure located within the frame, and an annular outer skirt located around an outer surface of the frame. The outer skirt can include an inflow edge fixed to the frame at a first location, an outflow edge fixed to the frame at a second location, and an intermediate portion between the inflow edge and the outflow edge. When the valve is in the expanded configuration, the intermediate portion of the outer skirt includes a slack 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 collapsed to the collapsed configuration, an axial distance between the inflow edge of the outer skirt and the outflow edge of the outer skirt is increased, reducing the slack in the axial direction in the outer skirt.

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

[0018] Some embodiments of a collapsible prosthetic 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 body portion, two opposing primary side tabs extending from opposing sides of the body portion, and two opposing secondary tabs extending from the body portion adjacent to the primary side tabs. The secondary tabs are folded about a radially extending crease to lie flat against the body portion of the respective leaflet in a first portion of the secondary tabs, and the secondary tabs are folded about an axially extending crease to extend in a second portion of the secondary tabs in a different plane than the first portion. The second portion of each secondary tab is sewn to the respective primary tab and the secondary tab is located inside the frame.

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

[0020] Some embodiments disclosed herein include a collapsible prosthetic valve that is radially collapsible to a collapsed configuration and radially expandable to an expanded configuration. The prosthetic 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 secured to an inner side of the frame and includes a first set of threads and a second set of threads, neither of which are parallel to an axial direction of the valve. When the valve is collapsed from the expanded configuration to the collapsed configuration, an axial length of the frame increases and both the first set of threads and the second set of threads rotate toward the axial direction of the valve such that the inner skirt elongates along the axial direction with the frame.

[0021] In some of these embodiments, the first set of threads is substantially perpendicular to the second set of threads when the valve is in the expanded configuration. 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, the first and second angles being substantially equal. In some of these embodiments, the first set of threads and the second set of threads include 20 denier threads.

[0022] Some embodiments of a collapsible prosthetic valve include an annular frame that is radially collapsible and expandable, including a plurality of angularly spaced commissure windows each including a closed aperture between first and second axially oriented side struts. The valve also includes a leaflet structure located within the frame and including a plurality of leaflets each including two opposing side tabs. Each side tab is paired with an adjacent side tab of an adjacent leaflet to form a commissure of the leaflet structure. Each pair of side tabs extends radially outward through a respective commissure window to a location outside the frame, the portions of the tabs outside the frame extending away from each other circumferentially and along exterior surfaces of the side struts. The valve further includes a plurality of wedges each located between the side struts of a commissure window and separating the pair of side tabs extending through the commissure window, the wedges being forced radially inward against the side tabs.

[0023] The wedges can be elongatable in the axial direction and have an axial length coinciding with the axial length of the commissure window side struts. The wedges can further limit rotational motion of the pair of side tabs relative to the commissure window. Each wedge can be sewn to a flexible reinforcement patch that is also sewn to each pair of side tabs, and each can be sewn to the pair of side tabs. The wedges can include a non-metallic material, such as a sewing material.

[0024] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: BRIEF DESCRIPTION OF DRAWINGS

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

[0026] Figures 4-10 An example frame of a heart valve is shown. Figure 1 An example frame of a heart valve is shown.

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

[0028] Figure 16A And 16B An example frame of a heart valve is shown. Figure 1 An example inner skirt of a heart valve is shown.

[0029] Figure 17 Another embodiment of a prosthetic heart valve showing frame deformation under compression (crimping) conditions.

[0030] Figure 18 A heart valve shown in a compressed state and mounted on an example balloon catheter. Figure 1 A heart valve shown in a compressed state and mounted on an example balloon catheter.

[0031] Figures 19-20 show the inner skirt of Figure 16A with the frame of Figure 4 as a kit.

[0032] Figures 21-28 A kit showing example leaflet structures.

[0033] Figures 29-35 A kit showing commissure portions of leaflet structures with window frame portions of a frame.

[0034] Figures 36-40 A kit showing leaflet structures along lower edges of leaflets with an inner skirt.

[0035] Figure 41 An example outer skirt shown flattened outward.

[0036] Figure 42 And 43 An example prosthetic heart valve is shown. Figure 1 An example prosthetic heart valve is shown.

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

[0038] Figures 49-52 Portions of an alternative embodiment of a frame are shown.

[0039] Figure 53 Portions of a frame of Figure 4 shown in a radially compressed state.

[0040] Figure 54 A cross-sectional profile of a frame of Figure 4 is shown showing a general tapering from an outflow end to an inflow end.

[0041] Figure 55 frame in an expanded, flat configuration. Figure 4 frame.

[0042] Figure 56 heart valve in a compressed state and mounted on an exemplary balloon catheter. Figure 1 frame.

[0043] Figure 57 and 58 embodiment having a generally V-shaped configuration.

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

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

[0046] Figure 60A is a magnified side view of one commissure window of Figure 60

[0047] is a perspective view of an embodiment of a prosthetic valve including Figure 61 frame and a leaflet structure mounted to the valve. Figure 60

[0048] is a magnified side view of one commissure of Figure 62 Figure 61 is a cross-sectional view of a commissure of the valve of

[0049] Figures 63-71 Figure 61 is a cross-sectional view of a commissure of the valve of

[0050] Figures 72-74 balloon inflation showing an alternative embodiment of a frame for a prosthetic valve having reduced thickness inflow and outflow end portions. DETAILED DESCRIPTION

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

[0052] The valve structure 14 can include three leaflets 400 that collectively form a leaflet structure, which can be arranged in a collapsed tricuspid arrangement, as shown in Figure 2 ​​The optimal display is achieved by considering the lower edge of the leaflet structure 14, which ideally has a wavy, curved fan shape. Figure 1 The suture 154 shown follows the fan-shaped shape of the leaflet structure. By forming leaflets with this fan-shaped geometry, stress on the leaflets is reduced, which in turn improves valve durability. Moreover, due to the fan-shaped shape, creases and ripples in the middle of each leaflet (the central region of each leaflet) can be eliminated or at least minimized, as these creases and ripples can cause early calcification in those areas. The fan-shaped geometry also reduces the amount of tissue material used to form the leaflet structure, thereby allowing for a smaller, flatter pleated profile at the valve inflow end. The leaflet 400 may be formed from pericardial tissue (e.g., bovine pericardial tissue), biocompatible synthetic materials, 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] Exposed frame 12 is shown Figure 4 The frame 12 may consist of a plurality of circumferentially spaced slits or connecting windows 20 (three in the illustrated embodiment) adapted to mount the connecting portion 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-expanding materials (e.g., stainless steel, etc.) or self-expanding materials (e.g., nitinol) known in the art. When constructed of a plastic-expanding material, the frame 12 (and therefore the valve 10) may be folded into a radially compressed state on the delivery catheter and then inflated within the patient by an inflatable balloon or equivalent inflation mechanism. When constructed of a self-expanding material, the frame 12 (and therefore the valve 10) may be folded into a radially compressed state and held in a compressed state by a sheath or equivalent mechanism inserted into the delivery catheter. Once in the body, the valve may advance from the delivery sheath such 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 Composed of (a trademark of SPS Technologies), it 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 the use of MP35N to form frame 12 provides structural benefits over stainless steel. In particular, when MP35N is used as the frame material, less material is required to achieve the same or better performance in terms of resistance to radial and crush forces, fatigue resistance, and corrosion resistance. Moreover, because less material is required, the frame crush profile can be reduced, thereby providing a smaller profile valve assembly for percutaneous delivery to a treatment site in the body.

[0055] Reference is made to Figure 4 and 5 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 circumferentially extending angled struts 24; a third row III of circumferentially extending angled struts 26; a fourth row IV of circumferentially extending angled struts 28; and a fifth row V of circumferentially extending angled struts 32 at the outflow end of the frame. A plurality of substantially straight, axially extending struts 34 can 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 commissure frame portions 30, which define commissure windows 20, and a plurality of axially extending struts 31. Each axial strut 31 and each frame portion 30 extends from a location defined by the intersection of the lower ends of two angled struts 32 to another location defined by the intersection of the upper ends of two angled struts 28. Figure 6 , 7 , 8, 9, and 10 are Figure 5 enlarged views of portions of frame 12 identified by the letters A, B, C, D, and E in

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

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

[0058] As Figure 7 Best shown in FIG. 6, the lower end of the strut 31 is connected to two struts 28 at a node or junction 44, and the upper end of the strut 31 is connected to two struts 32 at a node or junction 46. The thickness S1 of the strut 31 can be less than the thickness S2 of the junctions 44, 46. Figure 53 Portions of the frame 12 in a crimped state are shown. The junctions 44, 46, along with the junction 64, prevent the apertures 40 from being completely closed. Figure 18 Valve 10 crimped on a balloon catheter is shown. As can be seen, the geometry of the strut 31 and the junctions 44, 46, and 64 help create sufficient space in the aperture 40 in the crimped state for portions of the leaflets to protrude (i.e., bulge) outward through the aperture. This allows the valve to be crimped to a relatively smaller diameter than would be the case 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 overexpansion of the valve at a predetermined balloon pressure, particularly at the frame outflow end portion that supports the leaflet structure 14. In one aspect, the frame is configured to have relatively large angles 42a, 42b, 42c, 42d, 42e between the struts. The larger the angle, the greater the force required to open (expand) the frame. This phenomenon is illustrated schematically in Figure 15A and 15B . Figure 15A Strut 32 is shown when the frame 12 is in its compressed state (e.g., mounted on a balloon). When the frame is compressed, the vertical distance dl between the strut ends is maximized, providing a relatively large moment between the forces Fl and F2 acting on the strut ends in opposite directions when the aperture force is applied from inflation of the balloon (or expansion of another expansion device). When the frame is radially expanded, the vertical distance between the strut ends decreases to distance d2, as shown in Figure 15BAs the vertical distance decreases, the moment between forces Fl and F2 also decreases. Thus, it can be seen that as the vertical distance between the strut tips and the moment decreases, relatively greater expansion forces are required. Also, as the frame expands, the strain hardening (hardening) at the strut tips increases, which increases the expansion forces required to induce further plastic deformation at the strut tips. Thus, 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 balloon). In particular embodiments, these angles are at least 110 degrees or greater when the frame is expanded to its functional size, and even more particularly, 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 expand the valve, the inflow and outflow ends of the frame tend to over-expand more than the middle portion of the frame. To avoid over-expansion of the leaflet structure 14, it is desirable to secure the leaflet structure below the upper row of struts 32 of the frame 12, as Figure 1 is best shown in Figure 55 shows a plan view of the frame 12 similar to Figure 5 but shows lines 176 superimposed on the frame to indicate the position of the upper edge of the leaflet 400. Thus, in the event of over-expansion of the outflow end of the frame, the leaflet structure is positioned below the level at which over-expansion can occur, thereby avoiding over-expansion of the leaflet structure.

[0061] In known valve constructions, if the leaflets are mounted too close to the distal end of the frame, the leaflets can protrude outward beyond the outflow end of the frame when the valve is crimped. If the delivery catheter used to install the crimped valve includes a push mechanism or stop element that pushes against or abuts the outflow end of the valve (e.g., in order to maintain the position of the crimped valve on the delivery catheter), the push element or stop element can damage the exposed leaflets that extend beyond the outflow end of the frame. Another benefit of mounting the leaflets at a position spaced apart from the outflow end 178 of the frame is that, when the valve is crimped on the delivery catheter, as Figure 56 shown in , the leaflets 400 do not protrude beyond the outflow end 178 of the frame in the axial direction. Thus, if the delivery catheter includes a push mechanism or stop element that pushes against or abuts the outflow end of the valve, the push mechanism or stop element can contact the end 178 of the frame, rather than the leaflets 400, thereby avoiding damage to the leaflets.

[0062] Also, as can be seen in Figure 5 , the openings 36 of the lowermost row of openings of the frame are relatively larger than the openings 38 of the two middle rows of openings. As Figure 54As shown in FIG. 1, when crimped, this allows the frame to assume an overall tapered shape that tapers from a maximum diameter Dl at the outflow end of the valve to a minimum diameter D2 at the inflow end of the valve. When crimped, the frame 12 has a region of reduced diameter that extends 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 the 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 increase the overall crimped profile of the valve. When the valve is deployed, the frame can expand to the Figure 4 As shown in FIG. 1, when crimped, this allows the frame to assume an overall tapered shape that tapers from a maximum diameter Dl at the outflow end of the valve to a minimum diameter D2 at the inflow end of the valve. When crimped, the frame 12 has a region of reduced diameter that extends 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 the 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 increase the overall crimped profile of the valve. When the valve is deployed, the frame can expand to the

[0063] Figure 11 and 12 An alternative frame 50 that can be incorporated into the valve 10 is shown. The frame 50 includes a plurality of rows of circumferentially extending, angled struts 52 that are connected to one another at nodes or connection portions 54 and 56. The uppermost row of struts 52 is connected to the adjacent row of struts by a plurality of axially extending struts 58 and commissure window frame portions 60. Each commissure frame portion 60 defines a slot or commissure window 62 for mounting a respective commissure of the valve structure, as described in more detail below. In a particular embodiment, the frame 50 has a thickness T of about 0.45 mm or less. Figure 13 and 14 is Figure 12 Magnified views of the frame portions 50, respectively indicated by the letters A and B in FIG. 1.

[0064] The primary function of the inner skirt 16 is to help secure the valve structure 14 to the frame 12, and to help form a good seal between the valve and the native annulus by blocking blood flow through the lower edge of the leaflets under the open mesh of the frame 12. The inner skirt 16 desirably comprises 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 desirably is less than 6 mils, and desirably less than 4 mils, and even more desirably about 2 mils. In a particular embodiment, the skirt 16 can have a variable thickness, for example, the skirt can be thicker at its edges than at its center. In one implementation, the skirt 16 can comprise a PET skirt that is about 0.07 mm thick at its edges and about 0.06 mm thick at its center. A thinner skirt can provide better crimping performance while still providing a good seal around the valve.

[0065] The skirt 16 can be secured to the interior of the frame 12 by sutures 70, as Figure 39The valve structure 14 can be attached to the skirt (which can collectively form a hub) with one or more thin PET reinforcing bands 72 discussed below, which ensure reliable suturing and avoid pericardial tissue tearing of the leaflet structure. The valve structure 14 can be sandwiched between the skirt 16 and the thin PET bands 72, as shown in Figure 38 The sutures 154 that secure the PET bands and the leaflet structure 14 to the skirt 16 can be any suitable suture, such as Ethibond suture. The sutures 154 desirably follow 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 a limited elasticity, cannot elongate with the frame and thus tends to deform the struts of the frame and hinder uniform crimping.

[0067] Figure 17 An example of a crimped valve is shown in which the struts have deformed in several places, as indicated by reference numeral 100, due to the skirt having fibers that extend perpendicular to the upper and lower edges of the skirt. Also, in some locations the fabric tends to bunch or form excess material bulges, which limit the minimum crimp profile and hinder uniform crimping.

[0068] Reference is made to Figure 16B In contrast to known fabric skirts, the skirt 16 desirably is woven from a first set of fibers, or yarns or threads 78 and a second set of fibers, or yarns or threads 80, neither of which extend perpendicular to the upper and lower edges 82, 84 of the skirt. In a particular embodiment, the first set of fibers 78 and the second set of fibers 80 extend at an angle of about 45 degrees relative to the upper and lower edges 82, 84. The skirt 16 can be formed by weaving the fibers at a 45 degree angle relative to the upper and lower edges of the fabric. Alternatively, the skirt can be cut diagonally from a perpendicular woven fabric in which the fibers extend perpendicular to the edges of the material, such that the fibers extend at a 45 degree angle relative to the upper and lower cut edges of the skirt. As shown in Figure 16B As further shown in, the opposite short edges 86, 88 of the skirt desirably do not extend 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 thus are aligned with the first set of fibers 78. So the overall shape of the skirt is a long oblique square shape.

[0069] Figure 19A and 19BThe skirt 16 after the opposite edge portions 90, 92 have been sewn together to form the skirt's annular shape is shown. As shown, the edge portion 90 can be arranged in overlapping relation with respect to the opposite edge portion 92, and the two edge portions can be sewn together with a seam 94 that runs 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 wave shape that generally follows the shape of the fourth row of posts 28 immediately below the lower end of the axial post 31. In this manner, as Figure 20 The upper edge of the skirt 16 can be secured tightly to the posts 28 with the seam 70, as best shown in

[0070] Referring again to Figure 16B Due to the orientation of the fibers with respect to the upper and lower edges, the skirt can experience greater elongation in the axial direction (i.e., the direction from the upper edge 82 to the lower edge 84).

[0071] Thus, when the metal frame 12 is crimped (as shown in Figure 18 the skirt 16 can elongate in the axial direction with the frame and thus provide a more uniform and predictable crimp profile. In the illustrated embodiment, each cell of the metal frame includes at least four angled posts that rotate toward the axial direction (i.e., the angled posts are more aligned with the length of the frame). The angled posts of each cell act as a mechanism to rotate the fibers of the skirt in the same direction as the posts, such that the skirt elongates along the length of the posts. This causes the skirt to elongate more and avoids undesirable deformation of the posts as the valve is crimped.

[0072] Additionally, the spacing between the woven fibers or yarns can be increased to facilitate elongation of the skirt in the axial direction. For example, for a PET skirt 16 formed from 20 denier yarns, the yarn density can be about 15% to about 30% less than a conventional PET skirt. In some examples, 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 beveled edges 86, 88 facilitate even and consistent distribution of the fabric material along the inner circumference of the frame during crimping, thereby minimizing bunching of the fabric to facilitate even crimping to a minimum possible diameter. Additionally, cutting the diagonal stitching in a perpendicular manner can leave loose fringes along the cut edges. The beveled edges 86, 88 help minimize the occurrence of this. As described above, Figure 17 A crimped valve is shown having a conventional skirt with fibers perpendicular to the upper and lower edges of the skirt. In comparison Figure 17 and 18 It is apparent that the construction of the skirt 16 avoids undesirable deformation of the frame struts and provides a more even crimping of the frame.

[0073] In alternative embodiments, the skirt can be formed from woven elastic fibers that can stretch in the axial direction during crimping of the valve. The warp and weft fibers can be perpendicular and parallel to the upper and lower edges of the skirt, or alternatively, they can 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 can be stitched to the frame 12 at a location distal from the stitching 154, such that the skirt can be more flexible in this region (see Figure 28 This can avoid stress concentration at the stitching 154 that attaches the lower edge of the leaflet to the skirt 16.

[0075] As described above, the illustrated embodiment of the leaflet structure 14 includes 3 soft leaflets 400 (although a greater or lesser number of leaflets can be used). As Figure 21In the best shown configuration, each leaflet 400 has an upper (outflow) free edge 110 extending between opposing upper tabs 112 on opposite sides of the leaflet. Each upper tab 112 has a notch 114 below it that separates the upper tab from a corresponding lower tab 116. The lower (inflow) edge portion 108 of each leaflet extending between respective ends of the lower tabs 116 includes a vertical or axial edge portion 118 on opposite sides of the leaflet extending downward from the corresponding lower tab 116, and a substantially V-shaped intermediate edge portion 120 having a smooth, curved tip portion 119 at the lower end of the leaflet and a pair of sloped portions 121 extending between the axial edge portion and the tip portion. The sloped portions can have a greater radius of curvature than the tip portion. Each leaflet 400 can have a reinforcing band 72 secured (e.g., sewn) to the inner surface of the lower edge portion 108, as shown in Figure 22 .

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

[0077] Figure 24 Adjacent sides of two leaflets 400 connected to one another by a flexible connector 124 are shown. Opposing end portions of the flexible connector 124 can be placed in overlapping relation with the lower tabs 116, with the inner notches 130 aligned with the vertical edges of the tabs 116. Each tab 116 can be secured to a respective end portion of the flexible connector 124 by suturing along a line extending from an outer notch 132 on the lower edge to an outer notch 132 on the upper edge of the connector. Three leaflets 400 can be secured to one another end-to-end using three flexible connectors 124, as shown in Figure 25 .

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

[0079] As noted above, the inner skirt 16 can be used to help suture the leaflet structure 14 to the frame. As Figure 28 shown in the middle, the skirt 16 can have wavy temporary marker sutures 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 cross the marker sutures 136 are desirably not attached to the skirt 16. This makes the skirt 16 more flexible in areas that are not secured to the frame and minimizes stress concentration along the sutures that secure the lower edge of the leaflets to the skirt. The portion of the skirt 16 initially circumscribed 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 noted above, when the skirt is secured to the frame, the fibers 78, 80 (see Figure 16B ) of the skirt are generally aligned with the angled struts of the frame to facilitate uniform crimping and expansion of the frame.

[0080] Figure 29 is a cross-sectional view of the frame portion and leaflet structure showing the adjacent tab portions of two leaflets secured to the corresponding window frame portion 30. Figures 30-36 One particular method for securing the commissure portions 122 of the leaflet structure 14 to the frame is shown. First, as shown in Figure 30 the middle, the flexible connectors 124 that secure two adjacent sides of the two leaflets are folded laterally and the upper tab portions 112 are folded down against the flexible connectors. As best shown in Figure 30 and 31 , each upper tab 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 can then be sutured to the connector 124 along a suture 146. Next, as shown in Figure 31 , the commissure tab set (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. Figure 32 is a side view of the frame 12 showing the commissure tab set extending outwardly through the window frame portion 30.

[0081] like Figure 29 and 33 In the optimal configuration, the connecting protrusion kit is radially inwardly pressed at the wedge-shaped portion 126, such that one lower protrusion 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 protrusion 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 stitches 148 are formed to hold the lower protrusion portion 116 in place with... Figure 29 The same manner shown in the image rests against frame 12. Each suture 148 extends through connector 124, lower protrusion portion 116, wedge portion 126, and another portion of connector 124. Then, as... Figure 29 and 34 As shown, each lower protruding portion 116 is secured to the corresponding upper protruding portion 112 with a main suture 150, the main suture 150 extending through a connector 124, the lower protruding portion 116, another connector 124, another connector 124, and the upper protruding portion 112. Finally, as... Figure 29 and 35 As shown, the suture material used to form the main suture 150 can be used to further form a lockstitch 152 at the edges of the protruding portions 112, 116, which extends through the two-layer connector 124 sandwiched between the protruding portions 112, 116.

[0082] like Figure 29 and 30 As shown, the downwardly folded upper protrusion portion 112 forms a double layer of leaflet material at the joint. The inner portion 142 of the upper protrusion portion 112 is arranged flat adjacent to the two leaflets 400 forming the joint, so that each joint includes only four layers of leaflet material within the window frame 30. This four-layer portion of the joint is more resistant to bending or pivoting than the leaflet 400 portion that is only radially inward from the relatively more rigid four-layer portion. This allows the leaflets 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 around the axial strut of the window frame 30. Because the leaflets are pivoted at a position radially inward from the window frame 30, the leaflets avoid contact with and damage to the frame. However, under strong forces, the four-layer portion of the joint can pivot around the longitudinal axis 145 adjacent to the window frame 30. Figure 29) unfold, each inner portion 142 folds outward against the respective outer portion 144. This can occur, for example, when the valve 10 is compressed and mounted on a delivery shaft, allowing for a smaller crimped diameter. The four-layer portions of the commissures can also unfold about the shaft 145 when the balloon catheter is inflated during expansion of the valve, which can release some of the pressure on the commissures caused by the balloon and thus the commissures are not damaged during expansion.

[0083] After all three commissure tab sets are secured to the window frame portions 30, respectively, the lower edges of the leaflets 400 between the commissure tab sets can be sewn to the inner skirt 16. For example, as shown in Figures 36-38 each leaflet 400 can be sewn to the skirt 16 along a suture line 154 using, for example, Ethibond suture. The suture line can be a through suture that extends through each leaflet 400, the skirt 16, and each reinforcing band 72. Each leaflet 400 and the respective reinforcing band 72 can be sewn to the skirt 16, respectively. In this manner, the lower edges of the leaflets are secured to the frame 12 via the skirt 16. As shown in Figure 38 the leaflets can be further secured to the skirt with a lock stitch suture line 156 that extends through each reinforcing band 72, leaflet 400, and skirt 16 while looping around the edges of the reinforcing band 72 and leaflet 400. The suture line 156 can be formed of PTFE suture material. Figure 39 and 40 show the frame 12, leaflet structure 14, and skirt 16 after the leaflet structure and skirt are secured to the frame and the leaflet structure is secured to the skirt.

[0084] Figure 41 shows a plan view of the outer skirt 18 before it is attached to the frame 12. The outer skirt 18 can be formed of a piece of strong, durable material such as woven PET laser cut or otherwise, although other synthetic or natural materials can be used. The outer skirt 18 can have a substantially straight lower edge 160 and upper edge 162 that define a plurality of alternating tabs 164 and notches 166. As best shown in Figure 42 the lower edge 160 of the skirt 18 can be sewn to the lower edge of the inner skirt 16 at the inflow end of the valve. As shown in Figure 43 each tab 164 can be sewn to the second rung II strut 24 of the frame 12. The corner 162 of the tab 164 can be folded over the respective strut of the rung II and secured with a suture line 168.

[0085] As in Figure 1 , 3As seen in section 43, the outer skirt 18 is fixed 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, which is not flat against the outer surface of the frame 12. In other words, the outer skirt is configured with excess material, which causes the outer skirt to bulge outward as the frame shortens (i.e., its length decreases) during radial expansion. Therefore, when the valve 10 is placed in the body, the excess material of the outer skirt 18 can fill the gap between the frame 12 and the surrounding natural ring, contributing to the formation of a good fluid seal between the valve and the natural ring. Thus, the outer skirt 18 cooperates with the inner skirt 16 to prevent perivalvular leakage after valve 10 implantation. 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 folding without any resistance from the outer skirt, and the outer skirt substantially does not affect the outer diameter of the artificial valve in the folded state.

[0086] Figure 56 Display mounted on the slender shaft 180 of the conveyor device Figures 1-3 The valves 10, 42-43, form a delivery kit for implantation of the valve 10 in a patient. The valve 10 is mounted in a radially compressive configuration for delivery into the body. The shaft 180 includes an inflatable balloon 182 for inflating the balloon within the body, with the pleated valve 10 positioned above the deflated balloon. When in a radially compressive mounting configuration, the frame 12 of the valve 10 includes an inflow portion 174 (see...). Figure 54 The outer diameter D2 of the valve 10 is smaller than the outer diameter D1 of the outflow portion of the frame. The tapering of the frame may be at least partly due to the V-shaped leaflet 400, since the V-shaped leaflet has less leaflet material in the inflow portion of the frame 12 compared to the more rounded U-shaped leaflet. Due to the tapered shape of the frame 12 in the installed state, and even with the thickness of the outer skirt 18 located around the inflow portion 174 of the frame 12, the total outer diameter of the inflow portion of the valve 10 may be approximately equal to or smaller than the total outer diameter of the outflow portion of the valve.

[0087] Moreover, such as Figure 56As shown in the figures, the valve 10 includes coaptation portion of the leaflets that extend radially outward beyond the frame to a location outside the frame through a corresponding window frame portion 30 and are sutured to the side struts of the coaptation window frame. To minimize the crimped profile of the valve, the window frame portion 30 can be recessed radially inward relative to the surrounding portion of the frame, such as the frame portion extending between adjacent coaptation windows, when the valve is radially compressed to a collapsed configuration on the shaft. For example, the coaptation window 30 of the frame can be recessed inward relative to the frame portion extending between adjacent coaptation windows by a radial distance of between 0.2 mm and 1.0 mm when the valve is radially collapsed. In this manner, the outer diameter of the outflow portion of the valve including the coaptation portion can be substantially uniform, as opposed to the coaptation portion protruding outward from the surrounding portion of the valve, which can interfere with delivery of the valve to the body. Even with the radially recessed coaptation window frame 30, the outer diameter of the inflow portion of the frame can still be less than or approximately equal to the outer diameter of the outflow portion of the frame when the valve is radially collapsed on the shaft, allowing for a minimal overall maximum diameter of the valve. By minimizing the diameter of the valve when mounted on the delivery shaft, the kit can be accommodated in a smaller diameter catheter and thus can pass through smaller vessels in the body and can generally be less invasive.

[0088] Figure 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 can include a plurality of leaflets 218 (e.g., three as depicted) that can be sutured to each other and to the frame 202 using suitable techniques and / or mechanisms. The frame 202 can be adapted to include coaptation frame portions 30 (as shown in the Figure 4 figures) to assist in suturing the leaflets to the frame.

[0089] The frame 202 possesses some of the design features of the frame 12 described above. In particular, like the frame 12, the frame 202 has relatively large frame openings 206 along the area of the frame that supports the leaflet structure, as shown in the Figure 45 figures. The openings 206 are 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 opposite ends of the axial struts 210 to the intersection of two struts 212 and the intersection of two struts 208. As a result of this configuration, when the valve is radially compressed to a delivery configuration, the width of the openings 206 remains large enough for portions of the leaflet structure 204 to protrude outward through the openings, as indicated at 216 in the Figure 46 and 47 figures. This allows the valve to be crimped to a relatively smaller diameter compared to the case where all of the leaflet material is confined within the crimped frame.

[0090] For comparison purposes, Figure 48 is a cross-section of a known prosthetic valve 250 showing the valve in a crimped 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 outwardly through the frame. As a result, the presence of all the leaflet material confined within the frame limits the crimped diameter of the valve.

[0091] Figure 49 and 50 shows a cross-section of an alternative frame construction that can allow portions of the leaflets to protrude outwardly through the frame in a crimped state. This frame construction can be implemented in the valve 10 described above. Figure 49 shows a frame cross-section in a radially compressed state, while Figure 50 shows a frame cross-section in a radially expanded state. The frame, only a portion of which is shown, includes a first row of circumferentially extending angled struts 442 and at least a second row of circumferentially extending angled struts 444. Some of the openings in the frame are diamond-shaped openings 446 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 formed by adjacent struts 442 connected to respective ends of a horizontal strut 450 at their upper ends and adjacent struts 444 connected to respective ends of a horizontal strut 452 at their lower ends. When the frame is radially compressed, the horizontal struts 450, 452 maintain the width W of the openings 448 large enough to allow portions of the valve leaflets to protrude outwardly through the frame. Thus, the width of the openings 448 is larger than the width of the openings 446 when the frame is crimped. The frame can be formed with the openings 446, 448 alternating around the circumference of the frame. Alternatively, the openings 448 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.

[0092] Figure 51 and 52 shows a cross-section of an alternative frame construction that can allow portions of the leaflets to protrude outwardly through the frame in a crimped state. This frame construction can be implemented in the valve 10 described above. Figure 51 shows a frame cross-section in a radially compressed state, while Figure 52A frame cross-section is shown in a radially expanded state. The frame (only a portion of which is shown) includes a first row of circumferentially extending angled struts 402 and at least a second row of circumferentially extending angled struts 404. Some of the openings in the frame are diamond shaped openings 406 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 formed by adjacent struts 402 connected at their upper ends to enlarged nodes or junctions 410 and adjacent struts 404 connected at their lower ends to enlarged nodes or junctions 412. The junctions 410, 412 add rigidity to the frame at those locations so that the width W of the openings 408 remains large enough to allow leaflet portions of the valve to protrude outward through the frame when the frame is radially compressed. Thus, the width of the openings 408 is larger than the width of the openings 406 when the frame is crimped. The frame can be formed with the openings 406, 408 alternating around the circumference of the frame. Alternatively, 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 bunch up within the frame, such as between commissures.

[0093] Figure 57 A leaflet 500 of a prosthetic valve (e.g., valve 10 or 200) is shown according to another embodiment. The leaflet 500 has a generally V-shape similar to the leaflet 400 described above. The leaflet 500 has two tab portions 502 on opposite sides of the leaflet that are secured to adjacent tab portions of another leaflet to form a commissure of the leaflet structure. The sub-commisural portion of the leaflet 500 (the portion below the tab 502) includes two substantially straight edges 504 that extend from respective locations just below the tab 502 to a curved lower edge 506. Figure 58 The general shape of the leaflet 500 when the valve is crimped is shown. When crimped, the frame (not shown in Figures 57-58 ) is slightly elongated so that the leaflet 500 becomes slightly elongated.

[0094] The tapered profile of the sub-commisural portion of the leaflet reduces the amount of leaflet material in the lower half of the crimped valve, minimizing the crimping diameter of that portion of the valve. Thus, if additional components are mounted 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 diameter increase caused by the additional components. In addition, the commissure tabs 502 are relatively short and require less suturing for forming the commissures of the leaflet structure than known leaflet designs, such as T-shaped and scalloped leaflets, which better distribute and reduce the bulk of leaflet material when the valve is crimped.

[0095] Figure 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 varying thickness along its length to optimize the strength in selected areas of the frame, if desired, but to minimize the material (and thus the crimp profile). In the embodiment shown, the outflow end portion 506 of the frame has a maximum thickness Tl (measured from the inner diameter to the outer diameter of this 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 this portion of the frame). It should be noted that the thickness of the struts (not shown in Figure 59 the frame 502 forming the outflow end portion 506 is Tl and the thickness of the struts forming the inflow end portion 508 is T2. The frame 502 can have the same construction as the frame 12 described above, except for the varying thickness of the frame. The areas of reduced thickness can be formed using various manufacturing techniques, such as electro-polishing selected portions of the frame (which can mask the non-polished portions), sanding selected portions of the frame, wire cutting, or other suitable techniques.

[0096] The outflow end portion 502 generally corresponds to the commissure regions supporting the leaflets 504 and is typically the area of the frame that experiences the greatest load of the valve. Therefore, the outflow end portion 502 of the frame has a greater thickness Tl selected to provide the required strength under the expected load. The inflow end portion 508 supports an additional layer of material due to the outer skirt 18. The reduced thickness of the inflow end portion 508 causes the inflow end portion to crimp to a smaller diameter than the outflow end portion. This offsets or minimizes the increase in the crimped diameter caused by the addition of the outer skirt 18.

[0097] Figures 60-62 Another embodiment of a implantable prosthetic valve 310 is shown, which includes a leaflet structure 314 and a radially collapsible and expandable frame 312 (similar to the frame 50 shown in Figure 11

[0098] As shown in Figure 60A each window 318 includes a closed aperture 334 between two axially extending side struts 320, respectively. Each side strut includes a generally rectangular, e.g., square, cross-sectional profile, as shown in Figure 63 ​Each of the rectangular side struts 320 includes four surfaces: an outer surface 324 facing radially outward toward the side, and an inner surface 326 facing radially inward toward the side, a middle surface 328 on the side facing the other side strut, and a lateral surface 330 on the side facing away from the other side strut. In other embodiments, the side struts can 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 hinged portion 372 between the side tabs and the lower edge. Each side tab 366 pairs 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 respective commissure window 318 to a location 312 outside the frame, and is secured to the side strut 320 of the window, such as with sutures, as shown in FIG. 3B. Figure 62 In some embodiments, each side tab 366 includes a terminal portion 368 (see FIG. 3C) and the two side tab terminal portions 368 of each commissure 376 are distal from each other and extend circumferentially along the outer surface 324 of the respective side strut 320 of the window 318. Figure 64 ) and the two side tab terminal portions 368 of each commissure 376 are distal from each other and extend circumferentially along the outer surface 324 of the respective side strut 320 of the window 318.

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

[0101] Each stiffening patch 378 can be generally rectangular (when laid flat) and can include a middle portion 380 and opposite terminal portions 386. In some embodiments, a first terminal portion 386 of the patch is secured to a first side strut 320 and a second terminal portion 386 of the patch is secured to a second side strut 320, as shown in FIG. 3D. Figure 64 The patch 378 separates the side tabs 366 from the side strut 320, such that the side tabs do not contact the side strut. For example, each terminal portion 386 of the patch can completely wrap the respective side strut 320, as shown in FIG. 3E. Figure 64

[0102] The side tabs 366 and the stiffening patches 378 can be secured to the side struts 320 in multiple stages. For example, Figure 63 ​An exemplary first suturing stage is shown in which the patch is placed such that the middle portion 380 of the patch extends circumferentially across the outer surface of the side projection end portion 368 and each end portion 386 of the patch extends between the respective outer, middle, and inner surfaces 324, 328, 326 of the respective side projection 366 and the respective side strut 320. The patch 378 surrounds the side projection 366 and protects the side projection from the edges of the side strut 320. A pair of through-suturing lines 390 can secure each side projection 366 and one end of the patch 378 to the respective strut 320. As shown in Figure 63 Each suturing line 390 can be oriented approximately perpendicular to the circumference of the frame 312 along the side surface 330 of the side strut 320 and can pass radially back and forth through the commissure 376 at a plurality of different longitudinal positions. Each suturing line 390 can cross the first layer of patch 378, the side projection end portion 368, the second layer of patch, and the third layer of patch, moving radially inward in that order. The suturing lines 390 secure the patch 378 to the side projection end portion 368 and the patch end portion 386 around the side strut 320, thereby securing the side projection 366 to the side strut 320 and the leaflet structure 314 to the frame 312.

[0103] Figure 64 An exemplary second suturing stage is shown in which a second pair of suturing lines 392 are used to tie down loose portions of the reinforcing patch 378. For example, the second suturing lines 392 can cross portions of the middle portion 380 of the patch that extend laterally beyond the first suturing lines 390 and the end portions 386 of the patch. The second suturing lines 392 can be spiral whipstitch sutures that cross the commissure 376 at a plurality of different longitudinal positions, as shown in Figure 62 and secure the loose portions of the patch 378 tightly against the side surface 330 of the side strut.

[0104] Both the first suturing lines 390 and the second suturing lines 392 can be disposed proximate the side surface 330 of the strut 320 and spaced away from the window aperture 334. This arrangement of suturing lines can reduce stress on the suturing 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-middle edge 332 of the strut.

[0105] When the leaflet is hinged between the open and closed poses, the reinforcing patch 378 prevents the elastic hinge 370 from being damaged by the inner-middle edge 332 of the strut 320, as shown in Figure 64 Additionally, some embodiments can also include a longitudinally extending grommet band 374 between the elastic hinge 370 and the strut 320, such as proximate the inner-middle edge 332, as shown in Figure 64shown in FIG. 37 to further avoid damage to the flexible hinge from the strut. The grommet strap 374 can comprise a flexible, compressible material such as PET fabric, pericardial tissue, or various other biocompatible materials. In some embodiments, the grommet strap can comprise a tube filled with a flexible material. For example, the grommet strap can comprise a PET tube filled with pericardial tissue. In other embodiments, an outer tubular covering of the grommet strap can be formed from a sheet 378 and can be filled with a flexible material. The sheet can be secured around the flexible material with sutures to keep the grommet strap properly positioned, as shown in FIG. 37. Figure 64 shown in FIG. 37. In other embodiments, a separate grommet strap 374 can be sutured to the reinforcement sheet 378. The grommet strap 374 can have a thickness similar to the window frame 62 to provide a radial clearance between the side strut 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] Figure 65 shows an embodiment similar to Figure 63 and 64 but with a different suture pattern. Figure 65 In FIG. 38, the sutures 390 are replaced by sutures 398 that secure the sheet 378 around the end portion 368 of the side tab. Each suture 398 crosses the middle portion 380 of the sheet, one side tab 366, and a second layer of sheet adjacent to the middle-outer edge 324 of each side strut. The sutures 398 can comprise through-and-through sutures that cross the commissure at multiple different longitudinal positions. Each end portion of the sheet 378 can comprise a folded portion 388 that is folded underneath to form a double layer of the sheet 378 along the surface of the respective side strut 320. The suture 392 secures the sheet end portion 386 tightly around the side surface 330 of the side strut and the end portion 368 of the side tab.

[0107] Figure 66 and 67 shows an alternative method for suturing the side tab 366 and the sheet 378 to the side strut 320. Figure 66 shows a suture 394 that is disposed along the outer surface 324 of the side strut and is generally perpendicular to the radius of the frame. The suture 394 crosses both side tabs 366 and both end portions 386 of the sheet 378. The suture 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 strut 320, respectively, and also secures the middle portion 380 of the sheet loosely around the end portion 368 of the side tab 366. In Figure 66 In the embodiment shown in FIG. 39, the suture 394 crosses the first sheet layer A, the second sheet layer B, both side tabs 366, the third sheet layer C, and the fourth sheet layer D in that order.

[0108] After the first suture 394 is in place, the end portion 368 of the side tab is stretched out and disposed adjacent the outer surface 324 of the side strut 320, as shown in Figure 67 . This tightens the slack middle portion 380 of the sheet around the end portion 368 of the side tab. A pair of sutures 396 can then secure the middle portion 380 of the sheet tightly to the end portion 386 of the sheet to hold the end portion 368 of the side tab in place, as shown in Figure 67 . The sutures 396 can be circular lockstitch sutures that cross the commissure 376 at a plurality of different longitudinal positions, similar to the sutures 392 in Figure 64 .

[0109] Figure 68 and 69 shows another alternative method for suturing the side tab 366 and the sheet 378 to the side strut 320. Figure 68 shows sutures 395 disposed along the outside of the window opening and oriented generally perpendicular to the radius of the frame. The sutures 395 cross two portions of the side tab 366 and the sheet 378. The sutures 395 secure the middle portion 380 of the sheet that extends loosely around the end portion 368 of the side tab 366. In the embodiment shown in Figure 68 , the sutures 395 cross the first sheet layer A, the first side tab B, the second side tab C, and the second sheet layer D in that order.

[0110] After the first suture 395 is in place, the end portion 368 of the side tab is stretched out and disposed adjacent the outer surface 324 of the side strut 320, as shown in Figure 69 . This tightens the slack middle portion 380 of the sheet around the end portion 368 of the side tab. A pair of sutures 397 can then secure the middle portion 380 of the sheet tightly to the end portion 386 of the sheet to hold the end portion 368 of the side tab in place, as shown in Figure 69 . The end portion 386 of the sheet can include a portion 388 folded underneath, forming a double layer of sheet material, to reinforce the sutures 397. The sutures 397 can be circular lockstitch sutures that cross the commissure 376 at a plurality of different longitudinal positions, similar to the sutures 392 in Figure 62 .

[0111] Figure 70 and 71 shows yet another alternative method for suturing the side tab 366 and the sheet 378 to the side strut 320. Figure 70A suture line 395 is shown that is disposed along the outside of the window opening and is oriented generally perpendicular to the radius of the frame. The suture line 395 intersects two side tabs 366 and 4 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 tab 366 and the intermediate surface 328 of the side strut. The suture line 395 secures the intermediate portion 380 of the sheet loosely around the end portion 368 of the side tab 366. As shown in Figure 70 Each suture of the suture line 395 intersects, in that order, a first pair of sheet layers including layers A and B, a first side tab C, a second side tab D, and a second pair of sheet layers including layers E and F.

[0112] After the first suture line 395 is in place, the end portion 368 of the side tab is stretched out and disposed adjacent the outer surface 324 of the side strut 320, as shown in Figure 71 This causes the intermediate portion 380 of the sheet around the end portion 368 of the side tab to be taut. A pair of suture lines 397 can then secure the intermediate portion 380 of the sheet tightly to the end portion 386 of the sheet to hold the end portion 368 of the side tab in place, as shown in Figure 71 The folded portion 388 of the sheet forms a double layer of sheet material to reinforce the suture lines 397. The suture lines 397 can be circular lock stitch lines that intersect the commissure 376 at a plurality of different longitudinal positions, similar to the suture lines 392 in Figure 62

[0113] Various configurations for attaching the leaflet structure 314 to Figures 61-71 the commissures of the window frame 318 shown in Figures 1-3 may also be used as an alternative way of attaching the leaflet structure 14 of the valve 10 to the window frame portion 30 of the frame 12.

[0114] Figures 72-74 An artificial heart valve kit 600 is shown that includes an embodiment of a frame 602 of an artificial valve mounted on a balloon 606 of 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 an intermediate portion 614. Other components of the valve, such as the leaflets and skirt, are not shown for clarity. 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 intermediate portion 614. Because of the thinner end portions, the end portions 610, 612 provide less resistance to inflation when the balloon 606 is inflated and inflate more quickly than the intermediate portion 614, as shown in Figure 73 ​As shown in the diagram. Because the distal portion inflates faster than the middle portion, the frame 602 is restrained on the airbag 606, preventing the frame from sliding towards either end of the airbag and reducing the risk of the frame prematurely slipping out of the airbag. Figure 74 As shown, further inflation of the balloon causes the middle portion 614 of the frame to expand to the same final diameter as the distal 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 may be important, especially for frames that shorten and move relative to the balloon during inflation. Figures 72-74 In the embodiment shown, the middle portion 614 of the frame can remain constant relative to the airbag, while the two end portions shorten towards the middle portion due to the "dumbbell" effect of the airbag. Any conventional method can be used to produce the frame 602 with reduced thickness at the end portions 610, 612, such as sanding the end portions or similar methods. In one embodiment, the thickness of the end portions 610, 614 of the frame is approximately 0.37 mm, while the thickness of the middle portion 614 is approximately 0.45 mm.

[0115] Given the many possible implementations 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. Therefore, we claim protection for all our inventions within the scope of these claims.

Claims

1. Artificial heart valves, which include: A radially contractible and expandable annular frame, the frame comprising a plurality of angledly spaced connecting windows, each connecting window comprising a closed opening between first and second axially oriented side pillars; The leaflet structure is located within the frame and includes a plurality of leaflets, each leaflet including two opposing side protrusions, each side protrusion pairing with an adjacent side protrusion of a neighboring leaflet to form a ferrule of the leaflet structure, each pair of side protrusions extending radially outward through a corresponding ferrule window to a position outside the frame, wherein portions of the protrusions located outside the frame extend circumferentially away from each other and along the outer surface of the side support. and Multiple wedge-shaped portions, each wedge-shaped portion located between the side pillars of the connecting portion window and separating the pair of side protrusions extending through the connecting portion window, the wedge-shaped portions being forced radially inward between the side protrusions; Multiple connector pieces, each connector piece being sewn to a corresponding pair of side protrusions, wherein each of the wedge-shaped portions is sewn to a corresponding connector piece among the connector pieces.

2. The valve according to claim 1, wherein each wedge portion is elongated in the axial direction and the axial length corresponds to the axial length of the side strut of the connecting portion window.

3. The valve of claim 2, wherein the wedge-shaped portion restricts the movement of the lateral protrusion relative to the commissural window.

4. The valve of claim 1, wherein the wedge portion is sutured to the pair of lateral protrusions.

5. The valve of claim 1, wherein the wedge portion comprises suture material.

6. The valve according to claim 1, wherein the wedge portion is non-metallic.

7. The valve according to claim 1, wherein the wedge portion comprises a sheet of fabric material.

8. The valve of claim 1, wherein the connector piece extends along the radially outer surface of the wedge portion and the separated side protrusions extending through the connecting window.

9. Artificial heart valves, including: A radially contractible and expandable annular frame, the frame comprising a plurality of angledly spaced connecting windows, each connecting window comprising a closed opening between first and second axially oriented side pillars; The leaflet structure is located within the frame and includes a plurality of leaflets, each leaflet including two opposing side protrusions, each side protrusion pairing with an adjacent side protrusion of a neighboring leaflet to form a ferrule of the leaflet structure, each pair of side protrusions extending radially outward through a corresponding ferrule window to a position outside the frame, wherein portions of the protrusions located outside the frame extend circumferentially away from each other and along the outer surface of the side support. and Multiple wedges, each comprising a flexible, non-metallic material, are located between side pillars of the connecting window and separate a pair of side protrusions extending through the connecting window, the wedges being forced radially inward between the side protrusions.

10. The valve of claim 9, wherein the wedge portion comprises suture material.

11. The valve of claim 9, wherein the wedge portion comprises a cord.

12. The valve of claim 9, wherein the wedge portion comprises a sheet of flexible material.

13. The valve of claim 9, wherein each wedge is elongated in an axial direction and the axial length corresponds to the axial length of the side strut of the commissural window, wherein the wedge restricts the movement of the side protrusion relative to the commissural window.

14. The valve of claim 9, wherein each wedge portion is sutured to the pair of lateral protrusions.

15. The valve of claim 9, further comprising a plurality of flexible connectors, each connector being sutured to a corresponding pair of side protrusions, wherein each of the wedges is sutured to a corresponding connector of the connectors.

16. The valve of claim 15, wherein the flexible connector comprises a fabric sheet.

17. The valve of claim 16, wherein the flexible connector extends along the radial outer surface of the wedge portion and the separated side protrusions extending through the merging window.

Images