Balloon-Expandable Valve Tip Protection During Crimping

Abstract

According to one aspect of the present disclosure, an artificial heart valve system includes an artificial heart valve including a stent, a cuff, and a plurality of valve leaflets, wherein the cuff and the plurality of valve leaflets constitute a valve assembly, and an expandable balloon having a contracted state and an expanded state, configured and arranged to transition the artificial heart valve from a folded state to an expanded state and to protect a part of the valve assembly during crimping and delivery.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 349,241, filed Jun. 6, 2022, the disclosure of which is incorporated herein by reference.

Background Art

[0002] Valvular heart disease, specifically aortic valve disease and mitral valve disease, are significant health problems in the United States. Valve replacement is a primary option for the treatment of valvular heart disease. In the patent literature, prosthetic heart valves including surgical heart valves and collapsible / expandable heart valves for transcatheter aortic valve replacement ("TAVR") or transcatheter mitral valve replacement ("TMVR") are well known. Surgical or mechanical heart valves can be sutured, for example, to a patient's native annulus during open - heart surgery. Collapsible / expandable heart valves can be delivered to a patient via a tubular delivery device such as a catheter, trocar, laparoscopic instrument, etc. to avoid more invasive procedures such as full - sternotomy open - heart surgery. As used herein, the reference to a "collapsible / expandable" heart valve includes not only a heart valve formed with a small cross - section that enables delivery to a patient through a tubular delivery device in a minimally invasive procedure and expands once in place to an operable state, but also a heart valve that, after being configured, is folded to a small cross - section for delivery to a patient and then expands once in place at the annulus to an operable size.

[0003] Foldable / expandable heart valves are typically in the form of a one-way valve structure (often referred to herein as a valve assembly) that is mounted within an expandable stent / expandable stent. Generally, these foldable / expandable heart valves include self-expanding or balloon-expandable stents, which are often composed of shape memory metals or alloys such as nitinol (in the case of self-expanding stents) or steel or cobalt chrome (in the case of balloon-expandable stents). Existing foldable / expandable TAVR devices are known to use stent layouts of various configurations, including linear vertical struts connected by a "V" as exemplified in U.S. Patent No. 8,454,685 or a diamond-shaped cell layout as exemplified in U.S. Patent No. 9,326,856, both of which are incorporated herein by reference. The one-way valve assembly mounted within the stent / stent includes one or more valve leaflets and may also include a cuff or skirt. The cuff can be disposed on the inner surface or lumen inner surface, outer surface or lumen outer surface, and / or both surfaces of the stent. The cuff serves to prevent blood from flowing around the valve leaflets in the event that the valve or valve assembly is not properly positioned at the valve annulus. A portion of the cuff disposed outside the cuff or stent can help retard leakage around the outside of the valve (known as perivalvular leakage or "PV" leakage).

[0004] Balloon-expandable valves are typically delivered to the native valve annulus while folded (or "crimped") onto a deflated balloon of a balloon catheter. The folded valve may or may not be covered by an outer sheath. Once an artificial heart valve crimped within the annulus of the native heart valve to be replaced is positioned, inflation of the balloon causes the balloon-expandable valve to transition from the folded or crimped state to the expanded or deployed state, and the artificial heart valve assumes the shape expanded by the balloon. Typically, when the position of the folded artificial heart valve has been determined to be in the desired position relative to the native valve annulus (e.g., by visualization under fluoroscopy), a fluid such as saline (usually a liquid, but a gas can be used as well) is passed (manually, automatically, or semi-automatically) through a syringe into the balloon catheter, and upon initiation of balloon filling and expansion, the overlying artificial heart valve expands into the native valve annulus.

[0005] Self-expanding artificial heart valves are necessarily maintained in a folded state within a capsule of a delivery device when being delivered inside a patient to replace a failing native heart valve. The capsule can prevent premature self-expansion of the artificial heart valve, and such an outer capsule serves to prevent premature contact of the artificial heart valve with tissue, as well as to help the artificial heart valve maintain its desired position and orientation relative to the delivery device during delivery, whether or not there is an auxiliary inner retention function. However, balloon-expandable artificial heart valves are typically folded onto the balloon of the delivery device without a separate capsule covering and / or protecting the artificial heart valve. One reason for this is that in transcatheter artificial heart valve delivery devices and systems, space is always at a premium, and adding a capsule in addition to the artificial valve and underlying balloon may not be feasible considering the size profile requirements of these procedures.

[0006] During delivery and / or crimping, the valve assembly (e.g., valve tip and / or cuff) may be damaged. Specifically, when reducing the diameter of the valve frame to the desired delivery diameter, the valve tip of the valve may be pressed against a rigid metal stent by a large force. This may cause local stress and / or damage to the valve tip. Also, when the stent includes large open cells, there is a possibility that the compressed valve tip may protrude from the opening between the struts of the open cell and be pinched. SUMMARY OF THE INVENTION

[0007] In some embodiments, an artificial heart valve system includes an artificial heart valve including a stent, a cuff, and a plurality of valve tips, and an expandable balloon having a contracted state and an expanded state, wherein the cuff and the plurality of valve tips constitute a valve assembly, and the expandable balloon is configured and arranged to transition the artificial heart valve from a folded state to an expanded state and to protect a part of the valve assembly during crimping and delivery.

[0008] In some embodiments, a method of delivering an artificial heart valve system includes providing an artificial heart valve including a stent, a cuff, and a plurality of valve tips, wherein the cuff and the plurality of valve tips constitute a valve assembly, disposing an expandable balloon having features for protecting the artificial heart valve during crimping and delivery in a contracted state inside the artificial heart valve, and crimping the artificial heart valve and the expandable balloon while the features protect a part of the valve assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0009]

Figure 1A

Figures 1B - 1E

Figures 1F - 1H

Figures 1I - 1K

Figures 2A - 2B

Figures 3A - 3C

Figures 4A - 4B

Figure 5

Figures 6A - 6E

DETAILED DESCRIPTION OF THE INVENTION

[0010] As used herein, the term "inflow end" when used in connection with an artificial heart valve refers to the end of the artificial valve where blood first enters when the artificial valve is implanted in its intended position and orientation. On the other hand, the term "outflow end" refers to the end of the artificial valve where blood exits when the artificial valve is implanted in its intended position and orientation. Thus, in the case of an artificial aortic valve, the inflow end is the end closer to the left ventricle, while the outflow end is the end closer to the aorta. The intended position and orientation are used for the convenience of describing the valves disclosed herein, but it should be noted that the use of the valve is not limited to this intended position and orientation and can be deployed in any type of lumen or passage. For example, in this specification, an artificial heart valve is described as an artificial aortic valve, but the same or similar structures and features can also be adopted in other heart valves such as pulmonary valves, mitral valves, or tricuspid valves. Further, the term "proximal" when used in connection with a delivery device or system refers to the direction that is relatively closer to the user when the device or system is used as intended. On the other hand, the term "distal" refers to the direction that is relatively farther from the user of the device. In other words, the front end of the delivery device or system is disposed distally relative to the rear end of the delivery device or system when used as intended. As used herein, the terms "substantially", "Generally", "approximately", and "about" are intended to mean that a slight deviation from an absolute value is included within the scope of the term thus modified. As used herein, for a stent, an "expanded state" and a "folded state" are contemplated, which represent the relative radial size of the stent.

[0011] Figure 1A is a perspective view of a stent 100 of an artificial heart valve according to an embodiment of the present disclosure. The stent 100 may comprise a frame extending axially between an inflow end 101 and an outflow end 103. The stent 100 includes three substantially symmetric portions, each portion extending at approximately 120° in the circumferential direction of the stent 100. The stent 100 comprises three vertical struts 110a, 110b, 110c extending in an axial direction (central longitudinal axis) substantially parallel to the direction of blood flow through the stent. Each of the vertical struts 110a, 110b, 110c may extend substantially over the entire axial length between the inflow end 101 and the outflow end 103 of the stent 100 and may also be disposed between and shared by two portions. In other words, each portion is defined by the portion between two vertical struts of the stent 100. For this reason, each of the vertical struts 110a, 110b, 110c is spaced apart by approximately 120° in the circumferential direction of the stent 100. It will be understood that the stent 100 may include three portions as shown when used in an artificial heart valve having three valve leaflets. However, in other embodiments, if the artificial heart valve has two valve leaflets, the stent may include only two of these portions.

[0012] Figure 1B is a schematic diagram of the stent portion 107 of the stent 100, which will be described in more detail herein and is representative of all three parts. The stent portion 107 shown in Figure 1B includes a first vertical strut 110a and a second vertical strut 110b. The first vertical strut 110a extends axially between a first inflow node 102a and a first outer node 135a. The second vertical strut 110b extends axially between a second inflow node 102b and a second outer node 135b. As shown, the vertical struts 110a, 110b may extend over substantially the entire axial length of the stent 100. In some embodiments, the stent 100 may be formed as a single unit, for example, by laser cutting from a tube. The term "node" may represent a junction where two or more struts of the stent 100 meet. A pair of continuous inverted Vs extend between the inflow nodes 102a, 102b, which includes a first inflow inverted V 120a and a second inflow inverted V 120b that are joined to each other at the inflow node 105. The first inflow inverted V 120a includes a first outer lower strut 122a that extends between the first inflow node 102a and a first central node 125a. The first inflow inverted V 120a further includes a first inner lower strut 124a that extends between the first central node 125a and the inflow node 105. The second inflow inverted V 120b includes a second inner lower strut 124b that extends between the inflow node 105 and a second central node 125b. The second inflow inverted V 120b further includes a second outer lower strut 122b that extends between the second central node 125b and the second inflow node 102b. These structures have been described as inverted Vs, but could also be described as half-cells, where each half-cell is a half-diamond cell with an opening at the inflow end 101 of the stent 100.

[0013] The stent portion 107 further includes a first central strut 130a extending between the first central node 125a and the upper node 145. The stent portion 107 also includes a second central strut 130b extending between the second central node 125b and the upper node 145. The first central strut 130a, the second central strut 130b, the first inner lower strut 124a, and the second inner lower strut 124b form a rhombus-shaped cell 128. The stent portion 107 includes a first outer upper strut 140a extending between the first outer node 135 and the first outflow node 104a. The stent portion 107 further includes a second outer upper strut 140b extending between the second outer node 135b and the second outflow node 104b. The stent portion 107 includes a first inner upper strut 142a extending between the first outflow node 104a and the upper node 145. The stent portion 107 further includes a second inner upper strut 142b extending between the upper node 145 and the second outflow node 104b. The stent portion 107 includes an outflow reversal V-shaped member 114 extending between the first and second outflow nodes 104a, 104b. The first vertical strut 110a, the first outer upper strut 140a, the first inner upper strut 142a, the first central strut 130a, and the first outer lower strut 122a form a first substantially kite-shaped cell 133a. The second vertical strut 110b, the second outer upper strut 140b, the second inner upper strut 142b, the second central strut 130b, and the second outer lower strut 122b form a second substantially kite-shaped cell 133b. The first and second kite-shaped cells 133a, 133b are symmetric and opposed to each other in the stent portion 107. Although the term "kite-shaped" is used above, it should be understood that such a shape is not limited to the exact shape definition of a kite. The outflow reversal V-shaped member 114, the first inner upper strut 142a, and the second inner upper strut 142b form an upper cell 134. The upper cell 134 is substantially kite-shaped and is axially aligned with the rhombus-shaped cell 128 in the stent portion 107.Although the various struts described herein are designated as separate struts, it is understood that, as described above, they may be part of a single unit structure. However, in other embodiments, the stent 100 need not be formed as a single piece, and thus, the struts may be different structures (or parts of different structures) that are integrally joined.

[0014] Figure 1C is a schematic diagram of the stent portion 207 according to an alternative embodiment of the present disclosure. Unless otherwise stated, the same reference numbers represent the same elements of the stent 100 described above, but within the range of numbers in the 200s. The stent portion 207 is substantially similar to the stent portion 107 and includes inflow nodes 202a, 202b, vertical struts 210a, 210b, first and second inflow reversing Vs 220a, 220b, and outflow nodes 204a, 204b. The structure of the stent portion 207 differs from the structure of the stent portion 107 in that it does not include an outflow reversing V. The purpose of one embodiment having the structure of the stent portion 207 shown in such Figure 1C is to promote uniform expansion with respect to the inflow end 201 by reducing the force required for the expansion of the outflow end 203 of the stent 200 compared to the stent 100. The outflow nodes 204a, 204b are connected by a V of proper orientation constituted by a first inner upper strut 242a, an upper node 245, and a second inner upper strut 242b. In other words, the struts 242a, 242b may constitute a semi-diamond cell 234 whose open end is oriented toward the outflow end 203 side. The semi-diamond cell 234 is axially aligned with the diamond cell 228. By adding an outflow reversing V coupled between the outflow nodes 204a, 204b, the resistance to changes in the stent shape is increased and additional material that requires additional force for the expansion of the stent is provided. By removing material from the outflow end 203, the resistance to expansion at the outflow end 203 is reduced, so that uniform expansion of the inflow end 201 and the outflow end 203 can be promoted. In other words, the inflow end 201 of the stent 200 has a substantially open or fully open half-cell whose opening is oriented toward the inflow end 201 side, rather than including a continuous circumferential structure. On the other hand, most of the outflow end 203 includes a substantially continuous circumferential structure via struts corresponding to the struts 140a, 140b. All other things being equal, a substantially continuous circumferential structure may require more force for expansion compared to a similar opening structure. For this reason, the inflow end 101 of the stent 100 may require more force for radial expansion compared to the outflow end 103.By omitting the inverted V-shaped portion 114, the result is the stent 200, and the force required for the expansion of the outflow end 203 of the stent 200 can be suppressed to a magnitude close to that near the inflow end 201.

[0015] FIG. 1D is a front view of the stent portion 207 in the folded state, and FIG. 1E is a front view of the stent portion 207 in the expanded state. The stent 200 in FIGS. 1D and 1E is shown together with an opaque tube extending inside the stent only for the purpose of assisting in the illustration of the stent, and it is understood that this may represent a balloon by which the stent portion 207 is crimped. As described above, the stent includes three symmetric parts, and each part extends at approximately 120° around the circumference of the stent. The stent portion 207 shown in FIGS. 1D and 1E is defined by the region between the vertical struts 210a and 210b. The stent portion 207 represents all three parts of the stent. Also, the stent portion 207 has an arcuate structure such that when the three parts are connected, they form one complete cylindrical shape. FIGS. 1F and 1G show side views of a part of the stent. In other words, the views of the stent 200 in FIGS. 1F and 1G are rotated by approximately 60° compared to the views in FIGS. 1D and 1E. The views of the stent shown in FIGS. 1F and 1G are centered on the vertical strut 210b, and show approximately half of each of two adjacent stent portions 207a and 207b on both sides of the vertical strut 210b. The portions 207a and 207b surrounding the vertical strut 210b are mirror images of each other. FIG. 1F shows the stent portions 207a and 207b in the folded state. On the other hand, FIG. 1G shows the stent portions 207a and 207b in the expanded state.

[0016] Figure 1H is a plan view of a stent 200 including three stent portions 207a, 207b, and 207c, with the stent cut longitudinally and laid flat on a table. As shown, portions 207a, 207b, and 207c are symmetric with respect to each other, and adjacent portions share a common vertical strut. As described above, although the stent 200 is shown in a plan view, each portion 207a, 207b, and 207c has an arcuate shape that spreads at 120° to form a complete cylinder. Figure 1H further shows valve tips 250a, 250b, and 250c coupled to the stent 200. However, in Figure 1H, it should be understood that only the connection portions of the valve tips 250a - 250c are shown. In other words, each of the valve tips 250a - 250c typically includes a free edge, and these free edges act to prevent retrograde blood flow through the stent 200 by joining with each other, and allow antegrade blood flow through the stent by moving radially outward toward the inner surface of the stent. These free edges are not shown in Figure 1H, and the attachment edges of the valve tips 250a - 250c are shown by dashed lines. This attachment can be accomplished in any suitable manner, but it is preferably considered that the attachment edge is sutured to a cuff or skirt intervening between the stent 200 and / or the stent and the valve tips 250a - 250c. The three valve tips 250a, 250b, and 250c each extend approximately 120° around the stent 200 from end to end, and each valve tip includes a belly that can extend toward the radial center of the stent 200 when the valve tips are integrally joined. Each valve tip extends between the upper nodes of adjacent portions. The first valve tip 250a extends from the first upper node 245a of the first stent portion 207a to the second upper node 245b of the second stent portion 207b. The second valve tip 250b extends from the second upper node 245b to the third upper node 245c of the third stent portion 207c. The third valve tip 250c extends from the third upper node 245c to the first upper node 245a. Thus, each upper node includes the first end of the first valve tip and the second end of the second valve tip coupled thereto. In the illustrated embodiment, each end of each valve tip is coupled to its respective node by suturing.However, any coupling means may be used for attaching the valve leaflet to the stent. Further, it is also conceivable that the stent may include any number of portions and / or valve leaflets. For example, the stent may include two portions each extending at 180° around the circumference of the stent. Further, the stent may include two valve leaflets to mimic a bicuspid valve. Further, each valve leaflet may include a structure (not shown) such as a tab at the junction of the free edge and the attachment edge of the valve leaflet, and it should be noted that each tab of each valve leaflet may be coupled to the tab of an adjacent valve leaflet to form a joint. In the illustrated embodiment, the valve leaflet joint is shown as being attached to the node where the struts intersect. However, in other embodiments, the stent 200 may incorporate a joint attachment mechanism to facilitate such attachment. For example, the joint attachment mechanism may be formed in the stent 200 at nodes 245a to 245c and may include one or more openings to facilitate suturing of the valve leaflet joint to the stent. Further, the valve leaflets 250a to 250c may be formed of a biological material such as an animal pericardium or the like, or may be formed of a synthetic material such as ultra-high molecular weight polyethylene (UHMWPE).

[0017] Figures 1I and 1J show an artificial heart valve 206 comprising a stent 200, a cuff 260 coupled to the stent 200 (e.g., by suture), and valve leaflets 250a, 250b, 250c attached to the stent 200 and / or the cuff 260 (e.g., by suture). Although the artificial heart valve 206 is intended for use in replacement of the aortic valve, the same or similar structure may be used in artificial valves for replacement of other heart valves. The cuff 260 is disposed on the luminal or inner surface of the stent 200, but alternatively or additionally, it may be disposed on the outer luminal or outer surface of the stent. The cuff 260 may include an inflow end disposed substantially along the inflow end 201 of the stent 200. FIG. 1I is a front view of the valve 206 showing one stent portion 207 between vertical struts 210a, 210b that includes the cuff 260 and the contours of two valve leaflets 250a, 250b sutured to the cuff 260. In addition to suturing the valve leaflets to the cuff, various methods of suturing the valve leaflets and / or the cuff to the stent may be used, many of which are described in U.S. Patent No. 9,326,856, which is incorporated herein by reference. In the illustrated embodiment, the upper (or outflow) edge of the cuff 260 is sutured to the first central node 225a, the upper node 245, and the second central node 225b and extends along the first central strut 230a and the second central strut 230b. The upper (or outflow) edge of the cuff 260 extends substantially continuously between a portion of the second central node and a portion of the first central node adjacent thereto. The cuff 260 extends between the upper node 245 and the inflow end 201. Thus, the cuff 260 covers the cells (including the diamond-shaped cells 228) of the stent portion 207 formed by the struts between the upper node 245 and the inflow end 201. FIG. 1J is a side view of the stent 200 including the contour of the cuff 260 and the valve leaflet 250b. In other words, the view of the valve 206 in FIG. 1J is rotated approximately 60° compared to the view in FIG. 1I. The view shown in FIG. 1J is centered on the vertical strut 210b and shows substantially half of each of two adjacent stent portions 207a, 207b on both sides of the vertical strut 210b.The portions 207a, 207b surrounding the vertical strut 210b are mirror images of each other. As described above, the cuff can be disposed on the inner surface or the luminal inner surface, the outer surface or the luminal outer surface, and / or both surfaces of the stent. The cuff prevents blood from flowing around the valve tip when the valve or valve assembly is not optimally positioned at the valve annulus. A portion of the cuff disposed outside the cuff or the stent can help delay leakage around the outside of the valve (known as paravalvular leakage or "PV" leakage). In the embodiments shown in FIGS. 1I and 1J, the cuff 260 covers only about half of the stent 200, and about half of the stent is not covered by the cuff. This configuration reduces the amount of cuff material required compared to a cuff that covers more or all of the stent 200. By reducing the amount of cuff material, it may be possible to make the profile in which the artificial heart valve 206 is crimped during folding smaller. It is contemplated that the cuff may cover any amount of the surface area of the cylinder formed by the stent. For example, the upper edge of the cuff may extend straight along the circumference of any cross-section of the cylinder formed by the stent. The cuff 260 may be formed of any suitable material including biological materials such as animal pericardium or synthetic materials such as UHMWPE.

[0018] As described above, FIGS. 1I and 1J show the cuff 260 disposed inside the stent 200. And an example of an additional outer cuff 270 is shown in FIG. 1K. It is to be understood that the outer cuff 270 may have a shape other than that shown in FIG. 1K. The outer cuff 270 shown in FIG. 1K may be provided without the inner cuff 260, but is preferably additionally provided on the inner cuff 260. The outer cuff 270 may be integrally formed with the inner cuff 260 and folded back at the inflow edge of the stent (for example, may be wound). Or, it may be provided as a separate member from the inner cuff 260. The outer cuff 270 may be formed of any of the materials described herein in relation to the inner cuff 260. In the illustrated embodiment, the outer cuff 270 includes an inflow edge 272 and an outflow edge 274. When the inner cuff 260 and the outer cuff 270 are formed separately, the inflow edge 272 may be coupled to the inflow end of the stent 200 and / or the inflow edge of the inner cuff 260 by, for example, suturing, ultrasonic welding, or any other suitable attachment method. The connection between the inflow edge 272 of the outer cuff 270 and the stent 200 and / or the inner cuff 260 preferably serves as a seal between the inner cuff 260 and the outer cuff 270 at the inflow end of the artificial heart valve so that retrograde blood flowing into the space between the inner cuff 260 and the outer cuff 270 cannot cross the inflow edges of the inner cuff 260 and the outer cuff 270. The outflow edge 274 may be coupled to the struts of the stent 200 and / or the inner cuff 260, for example, by suturing, at a selected position on the circumference of the stent 200. With this configuration, an opening is formed circumferentially between adjacent connection points between the inner cuff 260 and the outer cuff 270, so that the retrograde blood flow can no longer continue to cross the inflow edges of the inner cuff 260 and the outer cuff 270 and tends to flow into the space between these cuffs through the opening. When blood flows into the space between the inner cuff 260 and the outer cuff 270, the outer cuff 270 bulges outward, and the space between the outer cuff 270 and the natural valve ring against which the outer cuff 270 is pressed can be better sealed.The outer cuff 270 may be provided as a continuous cylindrical member with side edges (which may or may not be parallel to the longitudinal central axis of the artificial heart valve) attached to each other so as to wrap around the entire circumference of the stent 200, or as a strip wound around the outer periphery of the stent 200.

[0019] The stent may be formed of a biocompatible material including a metal and an alloy such as cobalt chrome or cobalt chromium or stainless steel, but in some embodiments, it may be formed of a shape memory material such as nitinol. Thus, the stent is configured to be folded upon crimping to a smaller diameter and / or expanded upon forced opening such as by inflation of an internal balloon, and will substantially maintain the changed shape at rest. The stent is folded radially and (to some extent) lengthened axially by crimping, so that the profile in any given cross-section can be made smaller. Also, the stent can expand radially and (to some extent) shorten axially.

[0020] An artificial heart valve may be adapted to be delivered via any suitable transvascular route, including, for example, transapical or transfemoral. Generally, in transapical delivery, a relatively stiff catheter is utilized that penetrates the apex of the left ventricle through the patient's chest, resulting in a relatively high degree of trauma compared to transfemoral delivery. In transfemoral delivery, a delivery device containing the valve is inserted into the femoral artery and advanced against the blood flow into the left ventricle. In either delivery method, the valve may initially be folded onto an expandable balloon while the balloon is deflated. The balloon may be coupled to a delivery system that can transport the valve through the body and heart to reach the aortic valve, or may be disposed within the delivery system, and the valve is disposed on the balloon (or, depending on the situation, beneath an upper sheath). Upon reaching the aortic valve or adjacent thereto, the surgeon or operator of the delivery system may position the artificial valve as desired within the native valve annulus while the artificial valve is folded onto the balloon. Once the desired positioning is achieved, the upper sheath (if provided) may be withdrawn (or advanced) to expose the artificial valve, and then the balloon may be inflated to expand the artificial valve radially, with at least a portion of the artificial valve becoming axially shorter.

[0021] Referring to FIG. 2A, this figure shows an example of an artificial heart valve PHV that may include a stent similar to stent 100 or 200, with the balloon 380 of the balloon catheter 390 being crimped onto the balloon 380 while the balloon 380 is in a contracted state. In FIGS. 2A and 2B, it is to be understood that, in addition to the handle used for induction and / or deployment, other components of the delivery device, such as a syringe for inflating the balloon 380, are omitted. The artificial heart valve PHV may be delivered transvessel into the native aortic valve annulus, for example, through the femoral artery and around the aortic arch while in the folded state shown in FIG. 2A. Once the desired position is obtained, as shown in FIG. 2B, fluid may be pushed through the balloon catheter 390 to inflate the balloon 380. Although FIG. 2B omits the artificial heart valve PHV, it is to be understood that when the balloon 380 inflates, the artificial heart valve PHV expands into the native aortic valve annulus (however, it is to be understood that other heart valves may be replaced according to the concepts described herein). In the illustrated example, fluid flows from a syringe or inflation device (not shown) through the lumen within the balloon catheter 390 into the balloon 380 and also into one or more ports 385 disposed within the interior of the balloon 380. In the particular example shown in FIG. 2B, the first port 385 may be one or more openings in the sidewall of the balloon catheter 390, and the second port 385 may be the distal open end of the balloon catheter 390, terminating within the interior space of the balloon 380.

[0022] Figure 3A shows an example of an artificial heart valve PHV having a stent 400 and a plurality of valve leaflets 450 that together with a cuff form a valve assembly. For clarity, the valve skirt or cuff, as well as the sutures that attach the valve leaflets and skirt to the stent, are not shown. In this configuration, an expandable balloon 490 disposed inside the artificial heart valve PHV is shown. The expandable balloon 490 can have a contracted state as shown in Figure 3A and a substantially cylindrical expanded state. The expandable balloon 490 may have an interior configured to receive a fluid (e.g., a liquid such as saline or air) that provides sufficient radial force to expand the balloon and thereby expand the artificial heart valve PHV. Suitable materials for the balloon 490 include PEBAX® elastomers, nylon, polyester, PET, or multi-layers of these materials with various durometers. In the illustrated example, the expandable balloon 490 includes a plurality of pleats 492 that can result in a substantially star-shaped configuration when contracted. Specifically, the pleats 492 include a plurality of arms 494 that extend or wind radially, and a plurality of pockets 496 that are disposed between adjacent arms, receive a portion of the valve assembly (e.g., one or more portions of the valve leaflets), and protect the valve assembly during crimping and delivery. The pleats 492 may include V-shaped folds, and in one example, three pleats 492 are provided in the expandable balloon to form three arms 494. Alternatively, six pleats 492 are provided in the expandable balloon to form six arms 494. In at least some examples, the number of pleats is equal to or correlated with the number of valve leaflets of the valve assembly (e.g., the number of pleats is a multiple of the number of valve leaflets).

[0023] As described above, the plurality of pockets 496 are sized, configured, and arranged to receive portions of the plurality of valve leaflets, and the arm 494 can be configured and arranged to draw in and wind up portions of the plurality of valve leaflets 450. In FIG. 3B, the star-shaped balloon 490 is wound generally in a first direction (e.g., clockwise), and the plurality of valve leaflets 450 are arranged to be wound in the same direction (e.g., clockwise) in accordance with this pattern. Alternatively, it will be appreciated that both the balloon 490 and the valve leaflets 450 may be wound counterclockwise. This helical or winding pattern of the valve leaflets and / or the balloon can increase or become tighter when the prosthetic heart valve PHV is crimped for delivery and its radial size becomes smaller (FIG. 3C). Also, as shown in FIGS. 4A and 4B, it will be appreciated that the prosthetic heart valve PHV may include a star-shaped balloon 490 wound in a first direction (e.g., counterclockwise) and valve leaflets 450 wound in the opposite direction (e.g., clockwise).

[0024] Thus, the expandable balloon 490 itself can serve both to expand the prosthetic heart valve PHV and to provide valve leaflet protection during crimping and delivery by way of valve leaflet protection features (e.g., pleats and pockets). Rotation of the star-shaped or iris-shaped (iris diaphragm-shaped) balloon 490 can draw in portions of the valve leaflets during crimping, preventing or reducing the likelihood of damage to the valve leaflets or valve assembly during crimping and delivery. With the valve leaflets 450 drawn in or confined between the pleats, the balloon 490 acts as a protective barrier between a portion of the valve leaflets 450 and the interior of the stent 400. This drawing-in (pleating) process may include gradually twisting the balloon 490 relative to the stent while radially crimping the prosthetic heart valve PHV onto the balloon.

[0025] As an addition or alternative to the above-described protection feature portion of the balloon, a removable protection sleeve 575 may be disposed between a part of the stent 500 and the valve tip 550 and / or the cuff 560 (FIG. 5). The removable protection sleeve 575 may be arranged or introduced between the valve assembly and the stent in the crimping process, and may also be introduced into the body and removed together with the balloon at the time of delivery. In at least some examples, the protection sleeve 575 may be formed of PEBX (registered trademark) elastomer, nylon, polyethylene (HDPE or MWPE).

[0026] In an alternative embodiment shown in FIG. 6A, the balloon 690A may include an asymmetric configuration with a plurality of protrusions 694, and adjacent protrusions define an inner pocket 696 sized to protect the valve assembly during crimping and delivery by receiving a part of the valve assembly (e.g., one or more parts of the valve tip). The balloon may have a non-circular shape to form an area that offsets the peak area of the valve tip of the valve. Another example is shown in FIG. 6B, where the balloon 690B in this case includes a pair of fingers 698 that radially extend alternately with the pocket 696. Specifically, each of the pair of radially extending fingers includes a first finger 698a, a second finger 698b, and a small gap 699 formed therebetween. Here, three pairs of fingers 698 that are spaced approximately 120° apart from each other are shown. It is understood that the fingers 698 may be disposed alone or in pairs as shown. Also, the number of fingers 698 may correspond to the number of valve tips of the prosthetic heart valve PHV. For example, three fingers 698 may be used for three valve tips. Alternatively, the fingers 698 may be a multiple set for the number of valve tips (e.g., two fingers per valve tip, three fingers per valve tip, etc.). The spacing between the fingers or finger pairs may be adjusted as needed to set the pocket spacing for the valve tips of the PHV.

[0027] In FIG. 6C, the interior of the prosthetic heart valve PHV is shown, specifically, the balloon 690B disposed within the stent 600 and the plurality of valve leaflets 650. The fingers 698 are disposed between the folds 651 of the valve leaflets 650 and can enable a safer and more controlled crimp. In addition to preventing or suppressing damage to the valve leaflets, according to these configurations, the device can be crimped to a much smaller size. In this case, as in other embodiments, the balloon can rotate or twist during or prior to crimping to wind the valve leaflets and fingers of the balloon. As shown in FIG. 6D, the fingers 698 begin to wind counterclockwise and the leaflets 650 also begin to wind in the same direction. In at least some examples, after the balloon 690B is introduced into the interior of the prosthetic heart valve PHV, the valve leaflets are gathered and begin to wind by winding or rotation relative to the stent 600. After winding of the valve leaflets 650 and the balloon 690B, the device can be crimped so that the circumferential diameter becomes smaller. In another embodiment, instead of being part of a sequential process, the winding of the balloon 690B and the valve leaflets 650 is performed simultaneously with the crimping process. That is, the balloon 690B is rotatable relative to the stent 600, and this winding can occur when the prosthetic heart valve PHV is being reduced or crimped in the circumferential direction. Based on the material used for the balloon 690B and the configuration and spacing of the fingers 698, the crimped prosthetic heart valve 600 can assume a non-circular fully folded state as shown in FIG. 6D. For example, a prosthetic heart valve PHV' having a substantially triangular or guitar pick shape is shown as a result of the overall winding process of the size and configuration of the balloon 690B and both the balloon and the valve leaflets 650. According to this concept, larger pockets are formed within the balloon and most of the valve leaflet material and valve assembly can be received. Thus, the spacing and arrangement of these pockets maximize and control the separation of the outer sheath during crimping. Also, according to this configuration, the force acting on the valve leaflets can be reduced and the likelihood of damage can be lower, and the seams of the valve leaflets can be easily located, resulting in a non-circular pleated shape that is easier to implant, transport, and finally deploy.

[0028] In use, the artificial heart valve can be implanted and delivered according to either of the above-described configurations and states. First, a balloon-expandable artificial heart valve including a stent, a cuff, and a plurality of valve leaflets may be provided, with the cuff and the plurality of valve leaflets constituting a valve assembly. In a partially or fully expanded state of the artificial heart valve PHV, an expandable balloon in a substantially deflated state may be introduced through the interior of the artificial heart valve PHV. The artificial heart valve PHV and the balloon may together form an artificial heart valve system. The balloon may have pleats, fingers, or other valve leaflet protection features as described above, and in some cases, a portion of the balloon may be disposed between portions of the valve assembly, or a portion of the valve assembly may be received within a pocket or cavity of the balloon. Optionally, the balloon may be wound by rotation to gather the valve leaflets therewith. Subsequently, the wound balloon and valve leaflets may be crimped together with the stent, whereby the circumferential diameter of the artificial heart valve PHV can be reduced. Alternatively, the winding of the valve leaflets and / or the balloon may be accomplished during the crimping of the artificial heart valve PHV. It is understood that the winding of the balloon and the valve leaflets may be in the same direction (e.g., both clockwise or both counterclockwise) or in different directions (e.g., the first of the balloon and valve leaflets is wound clockwise and the second of the balloon and valve leaflets is wound counterclockwise).

[0029] According to one aspect of the present disclosure, an artificial heart valve system includes an artificial heart valve including a stent, a cuff, and a plurality of valve leaflets, with the cuff and the plurality of valve leaflets constituting a valve assembly, and an expandable balloon having a deflated state and an inflated state, configured and arranged to transition the artificial heart valve from a folded state to an expanded state and to protect a portion of the valve assembly during crimping and delivery.

[0030] According to another embodiment of the present disclosure, a method of delivering an artificial heart valve system includes providing an artificial heart valve including a stent, a cuff, and a plurality of valve leaflets, wherein the cuff and the plurality of valve leaflets constitute a valve assembly; disposing, in a contracted state, an expandable balloon having features for protecting the artificial heart valve during crimping and delivery inside the artificial heart valve; and crimping the artificial heart valve and the expandable balloon while the features protect a part of the valve assembly.

[0031] Although the invention has been described herein with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the invention. Accordingly, many modifications may be made to the illustrated embodiments and other configurations may be devised without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. An artificial heart valve system comprising: An artificial heart valve including a stent, a cuff, and a plurality of valve leaflets, wherein the cuff and the plurality of valve leaflets constitute a valve assembly; An expandable balloon having a contracted state and an expanded state, configured and arranged to transition the artificial heart valve from a folded state to an expanded state and to protect a part of the valve assembly during crimping and delivery; The artificial heart valve system comprising the above.

2. The artificial heart valve system according to claim 1, wherein the expandable balloon includes a plurality of pleats.

3. The artificial heart valve system according to claim 2, wherein the plurality of pleats includes three pleats.

4. The artificial heart valve system according to claim 2, wherein the plurality of pleats includes six pleats.

5. The artificial heart valve system according to claim 2, wherein the plurality of pleats corresponds to the plurality of valve leaflets.

6. The artificial heart valve system according to claim 2, wherein the plurality of pleats defines a plurality of inner pockets configured and arranged to receive a part of the plurality of valve leaflets.

7. The artificial heart valve system according to claim 1, wherein the expandable balloon is star-shaped and includes a plurality of arms in the contracted state.

8. The artificial heart valve system according to claim 7, wherein the plurality of arms are configured and arranged to draw in and wind up a part of the plurality of valve leaflets.

9. The artificial heart valve system according to claim 8, wherein the star-shaped balloon is wound in a first direction and the plurality of valve leaflets are wound in a second direction, and the first direction and the second direction are the same.

10. The artificial heart valve system according to claim 8, wherein the star-shaped balloon is wound in a first direction and the plurality of valve leaflets are wound in a second direction, and the first direction and the second direction are different.

11. The artificial heart valve system according to claim 1, further comprising a removable protective sleeve disposed between the valve assembly and the stent frame during delivery.

12. The artificial heart valve system according to claim 1, wherein the artificial heart valve has a non-circular folded state.

13. The artificial heart valve system according to claim 12, wherein the artificial heart valve has a substantially triangular folded state.

14. A method for delivering an artificial heart valve system, comprising: An artificial heart valve including a stent, a cuff, and a plurality of valve leaflets, wherein the cuff and the plurality of valve leaflets constitute a valve assembly, the step of providing an artificial heart valve; The step of disposing, in a contracted state, an expandable balloon having features for protecting the artificial heart valve during crimping and delivery inside the artificial heart valve; The step of crimping the artificial heart valve and the expandable balloon while the features are protecting a part of the valve assembly; A method comprising.

15. The method according to claim 14, further comprising rotating the expandable balloon relative to the stent of the artificial heart valve before or during crimping of the artificial heart valve.

16. The method according to claim 14, wherein the step of disposing the expandable balloon includes disposing an expandable balloon having a plurality of pleats inside the artificial heart valve.

17. The method according to claim 16, wherein the step of disposing the expandable balloon includes disposing an expandable balloon having a plurality of pleats and a plurality of inner pockets, and further includes disposing a part of the plurality of valve leaflets in the inner pockets of the expandable balloon.

18. The method according to claim 14, further comprising the step of spirally winding the expandable balloon.

19. The method according to claim 14, further comprising the step of winding the expandable balloon in a first direction and winding the plurality of valve leaflets in a second direction, wherein the first direction and the second direction are the same.

20. The method according to claim 14, further comprising the step of winding the expandable balloon in a first direction and winding the plurality of valve leaflets in a second direction, wherein the first direction and the second direction are different.

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