Peripheral Leakage Protection of Balloon-Expandable Valve

Abstract

The artificial heart valve system comprises a balloon-expandable artificial heart valve and a delivery catheter. The artificial heart valve has an inflow end portion, an outflow end portion, and a central portion. The delivery catheter has a balloon assembly having a proximal portion, a distal portion, and a central portion at its distal end. In the delivery state of this system, the artificial heart valve is pleated onto the balloon while the balloon assembly is deflated. In the deployed state of this system, the balloon assembly expands such that the distal portion of the balloon assembly has a diameter larger than the diameter of the central portion of the balloon assembly, and the outflow end portion of the artificial heart valve extends radially outward with respect to the central portion of the artificial heart valve.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 63 / 343,492, filed on May 18, 2022, the disclosure of which is incorporated herein by reference.

Background Art

[0002] Cardiac valve diseases, 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 cardiac valve diseases. In the patent literature, artificial heart valves including surgical heart valves and foldable / 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 valve annulus during open - heart surgery. Foldable / 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. For the purposes of use herein, the reference to a "foldable / 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 valve annulus to an operable size.

[0003] Foldable / expandable heart valves are typically in the form of a one-way valve structure (also referred to herein as a valve assembly) attached to / within an expandable stent. Generally, these foldable / expandable heart valves include a self-expanding or balloon-expandable stent, which is often composed of a shape memory metal or alloy such as nitinol (in the case of a self-expanding stent) or steel or cobalt chromium (in the case of a balloon-expandable stent). Existing foldable / expandable TAVR devices are known to use stent layouts of various configurations, including straight 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 attached to / within the 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 when the valve or valve assembly is not optimally positioned at the valve annulus. A portion of the cuff or a cuff disposed outside the stent can help delay 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, and the folded valve may or may not be covered by an outer sheath. Once the crimped artificial heart valve is positioned within the annulus of the native heart valve to be replaced, inflation of the balloon causes the balloon-expandable valve to transition from a folded or crimped state to an 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 inflation and initiation of expansion of the balloon causes the overlying artificial heart valve to expand into the native valve annulus.

[0005] When an artificial heart valve expands within the native valve annulus of the valve to be replaced, it is considered difficult to completely seal the space between the outside of the artificial heart valve and the inner circumference of the native valve annulus. As described above, when complete sealing is not possible, there is a possibility that blood may flow through any space or gap between the outside of the artificial heart valve and the inside of the native valve annulus. For this reason, even if the valve assembly of the artificial heart valve functions completely and blood does not flow backward through the valve assembly, blood may flow backward due to PV leakage, which may reduce the effectiveness of the artificial heart valve replacement procedure. When a patient is a candidate for an artificial heart valve replacement, the patient is more likely than average to have severe calcification in the native valve annulus. Such calcification can make it difficult to achieve complete sealing with the artificial heart valve deployed inside. Some features of the artificial heart valve, such as an outer cuff, may help reduce the likelihood and / or severity of PV leakage. In the case of a balloon-expandable artificial heart valve, specific improvements to the balloon (including the manner in which the artificial heart valve is crimped onto the balloon or the manner in which the balloon expands the artificial heart valve) or specific improvements to the artificial heart valve itself can further reduce the likelihood and / or severity of PV leakage. SUMMARY OF THE INVENTION

[0006] According to one aspect of the present disclosure, an artificial heart valve system includes a balloon-expandable artificial heart valve and a delivery catheter. The artificial heart valve has an inflow end, an outflow end, and a central portion between the inflow end and the outflow end. The delivery catheter has a proximal portion, a distal portion, and a balloon assembly having a central portion between the proximal portion and the distal portion at the distal end. In the delivery state of this system, the artificial heart valve is pleated onto the balloon while the balloon assembly is deflated. In the deployed state of this system, the balloon assembly expands such that the distal portion of the balloon assembly has a diameter larger than the diameter of the central portion of the balloon assembly, and the outflow end of the artificial heart valve expands radially outward relative to the central portion of the artificial heart valve.

[0007] According to another aspect of the present disclosure, a method of implanting an artificial heart valve includes delivering the artificial heart valve to a native valve annulus while the artificial heart valve is pleated on a balloon assembly of a balloon catheter and the balloon assembly is deflated. The method also includes expanding the balloon assembly to expand the artificial heart valve such that the central portion of the artificial heart valve contacts the native valve annulus and the inflow end of the artificial heart valve expands radially outward relative to the central portion of the artificial heart valve.

[0008] According to yet another aspect of the present disclosure, an artificial heart valve system includes an artificial heart valve, a delivery catheter, and a first outer cuff. The artificial heart valve includes a balloon-expandable stent and an artificial valve assembly attached within the stent. The delivery catheter has a balloon at its distal end, and the system has (i) a delivery state in which the artificial heart valve is pleated onto the balloon while the balloon is deflated, (ii) a partial deployment state in which the artificial heart valve is partially expanded and the balloon is partially inflated, and (iii) a full deployment state in which the artificial heart valve is fully expanded and the balloon is fully inflated. The first outer cuff is formed by a thread having a first end coupled to the balloon and a second end coupled to the stent, and in the delivery state, has an intermediate portion that wraps around the stent and wraps around a portion of the balloon disposed beyond a first end of the stent.

Brief Description of the Drawings

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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 the absolute value is included within the scope of the term so 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] FIG. 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 generally symmetric portions, each portion extending approximately 120° around the circumference of the stent 100. The stent 100 comprises three vertical struts 110a, 110b, 110c extending in an axial direction (sometimes referred to as a 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 the entire axial length between the inflow end 101 and the outflow end 103 of the stent 100 and may be disposed between and shared by two of the 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 separated by approximately 120° around the circumference of the stent 100. It is to 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 for 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 location 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 they could also be described as half-cells, where each half-cell is a semi-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 reversing 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 generally 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 generally 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 is understood that such a shape is not limited to the exact shape definition of a kite. The outflow reversing 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 generally 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 an integral structure, 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 are 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-rhombus cell 234 whose open end is oriented toward the outflow end 203 side. The semi-rhombus cell 234 is axially aligned with the rhombus 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 else being equal, a substantially continuous circumferential structure may require greater force for expansion compared to a similar opening structure. For this reason, the inflow end 101 of the stent 100 may require greater 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 in which the stent portion 207 is formed into a pleated shape. 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, which is obtained by cutting the stent in the longitudinal direction and flattening it on a table. As shown, the portions 207a, 207b, and 207c are symmetric 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 of the portions 207a, 207b, and 207c has an arcuate shape that spreads at 120°, thereby forming a complete cylinder. Figure 1H further shows valve tips 250a, 250b, and 250c coupled to the stent 200. However, in Figure 1H, it is understood that only the connection portions of the valve tips 250a to 250c are shown. In other words, each of the valve tips 250a to 250c usually includes a free edge, and these free edges act to prevent the retrograde flow of blood passing through the stent 200 by joining with each other, and by moving radially outward toward the inner surface of the stent, enable the antegrade flow of blood through the stent. These free edges are not shown in Figure 1H, and the attachment edges of the valve tips 250a to 250c are shown by dashed lines. This attachment can be done 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 to 250c. The three valve tips 250a, 250b, and 250c each extend around the stent 200 at about 120° 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 tip is 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. For this reason, 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 the 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 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 junction. In the illustrated embodiment, the valve leaflet junction is shown as being attached to the node where the struts intersect. However, in other embodiments, the stent 200 may have a junction attachment mechanism incorporated into the stent to facilitate such attachment. For example, the junction attachment mechanism may be formed in the stent 200 at nodes 245a to 245c and may include one or more openings that facilitate suturing of the valve leaflet junction 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 abluminal 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. Figure 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 continuously substantially 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. Figure 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 Figure 1J is rotated approximately 60° compared to the view in Figure 1I.The figure shown in Fig. 1J shows, centered on the vertical strut 210b, approximately 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 retard leakage around the outside of the valve (known as perivalvular 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 pleated 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 the pericardium of an animal 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 selected circumferential positions 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 retrograde blood flow tends to flow into the space between the inner cuff 260 and the outer cuff 270 through the opening and can no longer continuously cross the inflow edges of these cuffs. 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 having 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 metal and alloys such as cobalt chrome or cobalt chromium or stainless steel, but in some embodiments may be formed of a shape memory material such as nitinol. Thus, the stent is configured to be folded upon pleating 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, upon pleating, is folded radially and (to some extent) lengthened axially, 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] The prosthetic heart valve may be adapted to be delivered via any suitable transvascular route, including, for example, transapical or transfemoral. Generally, in transapical delivery, since a relatively stiff catheter that penetrates the apex of the left ventricle through the patient's chest is utilized, the degree of trauma is relatively severe compared to transfemoral delivery. In transfemoral delivery, a delivery device containing the valve is inserted into the femoral artery and advances against the blood flow to the left ventricle. In either delivery method, the valve may initially be folded onto the expandable balloon while the expandable 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, under the upper sheath). When reaching the aortic valve or adjacent thereto, the surgeon or operator of the delivery system may align the prosthetic valve as desired within the native annulus while the prosthetic valve is folded onto the balloon. When the desired alignment is achieved, the upper sheath (if provided) may be withdrawn (or advanced) to expose the prosthetic valve, and then the balloon may be inflated to radially expand the prosthetic valve, and at least a portion of the prosthetic valve becomes 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, wherein the artificial heart valve PHV is corrugated on balloon 380 while balloon 380 of balloon catheter 390 is in a deflated state. In FIGS. 2A and 2B, it is to be understood that other components of the delivery device, such as a syringe for inflating balloon 380, are omitted in addition to the handle used for induction and / or deployment. The artificial heart valve PHV may be delivered transvessularly through, for example, the femoral artery, around the aortic arch, and into the native aortic valve annulus 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 balloon catheter 390 to inflate balloon 380. Although FIG. 2B omits the artificial heart valve PHV, it is to be understood that when 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 (not shown) through the lumen within balloon catheter 390 into balloon 380 and also into one or more ports 385 disposed inside balloon 380. In the specific example shown in FIG. 2B, the first port 385 may be one or more openings in the sidewall of balloon catheter 390, and the second port 385 may be the distal open end of balloon catheter 390 and may terminate in the internal space of balloon 380.

[0022] Figure 3A is a highly schematic view of an artificial heart valve PHV that has been expanded into the native aortic valve annulus VA of a patient by balloon 480. In this particular embodiment, balloon catheter 490 traverses the aortic arch through the patient's femoral artery and advances through aorta A, in which case the distal tip of the delivery device is present within left ventricle LV and the artificial heart valve PHV is expanded into the native aortic valve annulus VA by balloon 480, pushing back native valve leaflets VL. The artificial heart valve PHV may be similar to those described in connection with FIGS. 1A - 1K and may include an outer cuff similar to outer cuff 270 or may omit such an outer cuff. It is understood that the concepts described in connection with this aspect of the present disclosure may be used with other balloon-expandable artificial heart valves of different configurations than those specifically described herein.

[0023] Referring further to FIG. 3A, when balloon 480 expands to expand the artificial heart valve PHV into the native aortic valve annulus VA, the inflow end of the artificial heart valve PHV spreads radially outward relative to the outflow end of the artificial heart valve PHV. After balloon 480 deflates, the artificial heart valve PHV maintains its outward spread at its inflow end, thereby providing a better seal against the native aortic valve annulus VA and reducing the likelihood or severity of PV leakage. Through the implementation of various options, balloon 480 may be capable of achieving a desired shape upon inflation to spread the artificial heart valve PHV outward at its inflow end.

[0024] A first option for achieving the desired balloon shape shown in FIG. 3A is shown in FIGS. 3B and 3C. FIG. 3B is a side view of the distal end of a balloon catheter 490 that includes a balloon 480 that can be inflated via two ports 485, similar to the balloon catheter of FIG. 2B. However, the balloon catheter includes an auxiliary inner balloon 481 that shows the deflated state in FIG. 3B and the inflated state in FIG. 3C. The inner balloon 481 may be disposed on a separate inflation port 486 that can be isolated from the lumen leading to the inflation port 485. The end of the inner balloon 481 may be coupled to the shaft of the balloon catheter 490 so that the inner balloon 481 does not inflate even when fluid flows into the balloon 480 through the port 485. The inner balloon 481 may be disposed within the distal end (e.g., the distal half, the distal third, or the distal quarter) along the length of the balloon 480. In use, when the prosthetic heart valve PHV is fluted on the deflated balloons 480, 481 of the balloon catheter 490, the inflow end of the prosthetic heart valve PHV may be disposed on the inner balloon 481. At the time of delivery, when the prosthetic heart valve PHV is disposed within the native annulus, the balloon 480 may first be inflated (as shown in FIG. 3B) by passing fluid through the balloon catheter 490 and the port 485. After the balloon 480 is inflated, fluid passes through the balloon catheter 490 (e.g., via another lumen that does not reach the port 485) and exits from the port 486, causing the inner balloon 481 to inflate to a diameter larger than the proximal side of the balloon 480. When the inner balloon 481 expands, the distal end of the outer balloon 480 also increases in diameter, causing the inflow end of the prosthetic heart valve PHV to expand radially outward as shown in FIG. 3A. The second balloon 481 is illustrated and described as an inner balloon within the balloon 480, but other configurations may achieve similar results.For example, the second balloon 481 can be arranged around the outside of the first balloon 480 at approximately the same axial position as shown in FIGS. 3B and 3C, but so that the second balloon can be inflated separately after the first balloon has inflated, a portion of the second outer balloon is coupled to the shaft of the balloon catheter 490 at a location having a dedicated port. In this embodiment, the second balloon does not push the first balloon outward; rather, after the first balloon pushes the second balloon outward when the first balloon inflates, the second balloon inflates in a separate second step, expanding the inflow end of the artificial heart valve PHV outward as shown in FIG. 3A. Instead of arranging the first balloon 480 and the second balloon 481 such that one is inside the other, the second balloon 481 may be provided as a separate (e.g., consecutive) balloon axially distal to the first balloon 480, in which case the two balloons will hardly or not at all radially overlap. In an embodiment, the second balloon 481 may be configured to expand to a larger diameter than the first balloon 480, and the balloons 480, 481 may be configured to inflate simultaneously, or the first (in this case, proximal) balloon 480 may inflate first and the second (in this case, distal) balloon 481 may inflate second, sequentially. Regardless of whether the inflation is sequential or simultaneous, since the second balloon 481 expands to a larger diameter than the first balloon 480, the inflow end of the artificial heart valve PHV will expand radially outward relative to the other portions of the artificial heart valve PHV as shown in FIG. 3A.

[0025] Instead of using two balloons 480, 481 to achieve the expansion of the inflow end of the artificial heart valve PHV shown in FIG. 3A, a single balloon 480' may be used instead to achieve the desired effect. For example, as shown in FIG. 3D, the balloon 480' may be formed of a uniform material along the axial length of the balloon 480', but the distal end 480b' of the balloon 480' may be shaped to have a slightly spherical shape compared to the generally cylindrical shape of the proximal portion 480a' of the balloon 480' (e.g., the proximal three-quarters, proximal two-thirds, or proximal half), and the spherical shape 480b' on the distal side has a larger diameter than the cylindrical portion 480a' on the proximal side when inflated.

[0026] As shown in FIGS. 3E and 3F, in another option, the balloon 480'' is configured to have a proximal portion 480a'' formed of a semi-compliant material and a distal portion 480b'' formed of a less-compliant material. With this configuration, when fluid is pushed into the balloon 480'', the two portions 480a'', 480b'' expand until the balloon 480'' has a diameter that causes the artificial heart valve PHV to expand into the native valve annulus VA, as shown in FIG. 3E. However, when additional fluid is pushed into the balloon 480'', the less-compliant distal portion 480b'' continues to expand while the more-compliant proximal portion 480a'' tends not to expand significantly further. Thus, as shown in FIG. 3A, the inflow end of the artificial heart valve PHV expands radially outward relative to the other parts of the artificial heart valve PHV.

[0027] Figures 4A - 4D illustrate different stages of deployment of an artificial heart valve PHV using a balloon catheter 590, according to another embodiment of the present disclosure. Figure 4A shows the balloon catheter 590 positioned within or adjacent to the native valve annulus VA (the annulus shown in Figures 4B - 4D but omitted in Figure 4A), with an artificial heart valve PHV (which may be any balloon-expandable artificial heart valve, including those described herein) being pleated onto the balloon 580 of the balloon catheter 590 and the balloon 580 being in a deflated state. As shown in Figure 4A, the band 510 circumscribes the artificial heart valve PHV while being on top of the balloon 580 in the illustrated state. In the illustrated example, the band 510 circumscribes each component at or near the axial midpoint of the artificial heart valve PHV and the balloon 580. In other words, as shown, the artificial heart valve PHV has an axial center along the length of the balloon 580, and the band 510 has an axial center along the lengths of the balloon 580 and the artificial heart valve PHV. It is understood that in some embodiments, other arrangements may also satisfy the conditions. In other words, the band 510 may be positioned offset from the axial center of the balloon 580 and / or the artificial heart valve PHV, but it is considered undesirable for the band 510 to deviate significantly from the axial center of one or both of these components.

[0028] Figure 4B shows balloon 580 that is beginning to expand. In the illustrated embodiment, balloon 580 may be formed of a substantially uniform material and / or configuration such that it expands into a generally cylindrical shape when there is no contracting force. Balloon 580 may be configured to begin expanding by a fluid, such as a liquid (e.g., saline solution), that is pushed into a lumen of balloon catheter 590 that is in fluid communication with the internal volume of balloon 580. Except for band 510, it is understood that balloon catheter 590 and balloon 580 may have any of the configurations described above or any common balloon catheter configuration. When balloon 580 begins to expand, band 510 limits the expansion of both balloon 580 and artificial heart valve PHV at its axial position compared to other axial positions. As a result, both balloon 580 and artificial heart valve PHV begin to have a generally canine bone shape, for example, by the proximal and distal ends of balloon 580 expanding to a larger diameter than the axial center of balloon 580. Similarly, the inflow and outflow ends of artificial heart valve PHV first expand to a larger diameter than the axial center of artificial heart valve PHV (or the location where band 510 is disposed relative to artificial heart valve PHV).

[0029] Figure 4C shows the balloon 580 after the first expansion has begun, where the prosthetic heart valve PHV expands in a generally canine bone shape such that the inflow and outflow ends of the prosthetic heart valve PHV spread radially outward with respect to the axial center of the prosthetic heart valve PHV, and the expanded portions generally surround or seal the inflow and outflow sides of the native valve annulus VA (in this case, the native aortic valve annulus). The band 510 is preferably designed to perforate, tear, or break when the balloon 580 reaches a predetermined pressure. For example, the band 510 may have a generally continuous ring shape and may be provided with perforations that partially interrupt the continuity of the ring shape. In one example, a plurality of holes or openings are provided in the band 510, each hole being spaced a distance from adjacent holes and the holes may be aligned with each other in a direction parallel to the longitudinal axis of the prosthetic heart valve PHV. These holes may form preferential break lines in the band 510, and when sufficient pressure is applied to the balloon 580 to begin generally surrounding or sealing the native valve annulus VA at the expanded end of the prosthetic heart valve PHV, the band 510 is torn along the perforation line. Although one perforation line has been described, it is understood that a plurality of perforation lines may be provided. In other embodiments, the perforations may be omitted and the band 510 may simply break when the expansion force of the balloon 580 exceeds the winding strength of the band 510. In some embodiments, the band 510 is configured to break when the pressure of the balloon 580 reaches from about 3 atm to about 6 atm. In some embodiments, the band 510 may be formed of a thermoplastic resin or elastomer such as that provided under the trade name Tecothane™ or ChronoPrene™.

[0030] As shown in FIGS. 4C and 4D, the axial center of the prosthetic heart valve PHV may be in contact with or substantially in contact with the native valve annulus VA at the time of breakage of the band 510. When the band 510 breaks (as shown in FIG. 4C), it stops restricting the expansion of the balloon 580, so that the balloon 580 can expand rapidly if its axial center is not in contact with the native valve annulus VA. In other words, immediately before or after the breakage of the band 510, the axial center of the prosthetic heart valve PHV is in contact with the native valve annulus VA, and the inflow and outflow ends of the prosthetic heart valve PHV contact and surround or seal (e.g., expand radially outwardly) the inflow and outflow sides of the native valve annulus VA. The resulting arrangement is shown in FIG. 4D, where the band 510 remains trapped between the outside of the prosthetic heart valve PHV and the anatomical structure of the native valve annulus VA. In some embodiments, the band 510 may have one or more portions fixed to the prosthetic heart valve PHV, for example by tack sutures, to hold the band 510 in place after breakage so that the broken band 510 does not enter the circulatory system.

[0031] The above-described embodiments of the band 510 illustrate that temporary constriction can be achieved by breakage or perforation of the band 510, but it is to be understood that the band 510 may provide a similar function by expansion or elongation after application of a threshold pressure or threshold force rather than by breakage. For example, the band 510 may be formed of an extendable urethane without the need for breakage. In some embodiments, the band 510 may be formed of an elastomer provided under the trade name polyethylene or PRBAX®. In one embodiment of the extendable band 510, the band 510 may be configured to begin to extend or expand only after the prosthetic heart valve PHV has expanded from the balloon. For example, in FIG. 4B, the band 510 still shows no significant extension or expansion, and as shown in FIGS. 4C and 4D, extension or expansion begins when additional force is applied by the balloon.

[0032] As shown in FIG. 4D, according to the configuration of the band 510 that temporarily restricts the expansion of the center of the artificial heart valve PHV and / or the balloon 580, the artificial heart valve PHV can be formed to surround along the surface of the natural valve annulus VA. This can help suppress or eliminate the possibility of PV leakage, for example, by a very close fit between the artificial heart valve PHV and the natural valve annulus VA. Since the balloon-expandable artificial heart valve PHV is usually formed with a stent having plastic expansion characteristics (e.g., stainless steel or cobalt chrome), it is understood that the shape forced on the artificial heart valve PHV by the balloon and / or the patient's anatomy. For this reason, unlike a self-expandable artificial heart valve, the balloon-expandable artificial heart valve often has a generally cylindrical shape at the time of implantation, at least in part because the balloon becomes generally cylindrical when expanded. The above-described temporarily restricting band 510 can, instead, allow the spreading shape of the balloon-expandable artificial heart valve PHV as described above, potentially suppressing or eliminating PV leakage after implantation.

[0033] FIGS. 4A-4D are illustrated and described as if a single band were used at the axial center of the balloon / valve assembly, but it is understood that two or more bands may be used, and one or more bands may be arranged differently than shown. In some embodiments, it may be desirable or sufficient to use a band configuration in which only the outflow end of the artificial heart valve PHV spreads outward during implantation, or a band configuration in which only the inflow end of the artificial heart valve PHV spreads outward during implantation.

[0034] Similar effects to those shown in FIGS. 4A-4D can be provided by other mechanisms besides the band 510. For example, the frame or stent of the prosthetic heart valve PHV may be designed to have variable deployment characteristics. As an example, the strut shape of the frame near the axial center may be different from the strut shape near one or both end portions of the stent, such that the frame near the axial center requires a greater force to expand. Thus, when the balloon 580 expands, one or both end portions of the frame of the prosthetic heart valve PHV begin to expand as shown in FIG. 4B, but the different strut shapes near the axial center of the stent resist expansion until additional force is applied from the balloon 580. In some examples, the struts may be thicker near the axial center of the frame and / or the cell area may be smaller near the axial center of the frame to achieve a greater resistance to expansion at the axial center of the frame compared to one or both end portions of the frame. Further, while much of the present disclosure is directed to preventing or reducing PV leakage, alternatively or additionally, the expanded outflow profile of the prosthetic heart valve PHV as shown in FIG. 4D may result in better hemodynamics than an equivalent prosthetic heart valve that does not include such outflow expansion.

[0035] FIGS. 5A-5C show the prosthetic heart valve 600 at different stages of deployment by the balloon catheter 690, and the prosthetic heart valve 600 includes a PV leakage reduction mechanism in the form of an unravelling cuff. In particular, FIG. 5A shows the prosthetic heart valve 600 in a folded or pleated state on the deflated balloon 680 of the balloon catheter 690. The prosthetic heart valve 600 may be in any form of the other prosthetic heart valves described herein, but may include additional components in the form of one or more unravelling cuffs. Thus, the prosthetic heart valve 600 may comprise an inner cuff and / or an outer cuff similar to those described in connection with FIGS. 1A-1K, and the unravelling cuff may be provided as an additional PV leakage reduction mechanism, although it is considered preferable to omit the outer cuff in the manner of the outer cuff 270 with respect to the prosthetic heart valve 600.

[0036] Referring further to FIG. 5A, the artificial heart valve 600 may include a first outer cuff 670a at the inflow end of the artificial heart valve 600 and a second outer cuff 670b at the outflow end of the artificial heart valve 600. In some embodiments, the first outer cuff 670a may be omitted, or the second outer cuff 670b may be omitted. Different from the outer cuff 270, the outer cuffs 670a and 670b are each preferably in the form of a thread, cord, or other string having a plush or fuzzy texture. In some examples, the thread, cord, or other string may be in the form of a suture thread, and in some examples, it may be twisted and fuzzy and may also be formed of PET, PE, or UHMWPE. In some embodiments, the thread, cord, or other string may be formed as a multi-filament multi-structure. Each outer cuff 670a, 670b may include first ends 671a, 671b coupled (e.g., fastened or sutured) to the stent of the artificial heart valve 600. Each outer cuff 670a, 670b may extend to second opposite ends 672a, 672b reversibly fixed to the balloon 680. The length of each outer cuff 670a, 670b extending between the two opposing ends generally wraps around the circumference of the stent of the artificial heart valve 600, and a portion of it is woven (and / or wrapped around the struts constituting the cells) to enter and exit the cells constituting the stent of the artificial heart valve 600. In some embodiments, the outer cuffs 670a, 670b may each be woven with the frame one to ten times. Although the artificial heart valve 600 is in a pleated state as shown in FIG. 5A, the extra length of each outer cuff 670a, 670b may be wrapped around the balloon 680, including positions beyond the terminal ends of the artificial heart valve 600.

[0037] As shown in FIG. 5B, when fluid (e.g., liquid (including physiological saline)) passes through the lumen of balloon catheter 690 and enters balloon 680, balloon 680 begins to expand and expand artificial heart valve 600. When this occurs, due to the circumferential expansion of artificial heart valve 600, outer cuffs 670a, 670b are released. FIG. 5B shows balloon 680 and artificial heart valve 600 in a partially deployed state. When balloon 680 reaches full inflation and artificial heart valve 600 reaches full expansion as shown in FIG. 5C, the outer circumference of artificial heart valve 600 becomes equal to or substantially equal to the length of each outer cuff 670a, 670b, so each outer cuff 670a, 670b forms a substantially circular thread at the inflow / outflow end of artificial heart valve 600 respectively. The material of outer cuffs 670a, 670b helps to reduce or eliminate PV leakage, especially when it has a plush and / or fuzzy texture. This is because when artificial heart valve 600 is fully expanded, outer cuffs 670a, 670b are pushed into the native valve annulus. Some materials have been described above as suitable examples of plush and / or fuzzy materials / textures, but other suitable examples include multifilament polyester suture, polyurethane, nylon, or polyethylene. In some examples, depending on the profile of balloon 680 when folded, outer cuffs 670a, 670b can protrude sufficiently outward to act as an edge protector during delivery, especially when balloon 680 crosses the aortic arch. In other words, when balloon 680 passes through the vasculature with the artificial heart valve mounted, the presence of one or both outer cuffs 670a, 670b can prevent unwanted contact between the leading edge of the artificial heart valve and the anatomical structure (which may also cause the artificial valve to come off from balloon 680). Put another way, if during dissection the leading edge of balloon 680 contacts the patient's anatomical structure, that contact may preferentially occur at the placement of one or both outer cuffs 670a, 670b respectively rather than at the edge of the artificial heart valve.

[0038] Referring again to FIG. 5B, the second ends 672a, 672b of the outer cuffs 670a, 670b may be releasably coupled to the balloon 680 or the nose cone of the delivery device. For example, the second ends 672a, 672b may be tied within the nose cone or at the proximal or distal ends of the balloon attachment region, or may be lightly captured. With these configurations, when the artificial heart valve 600 is in the folded state of FIG. 5A, the lengths of the outer cuffs 670a, 670b that need to overlap the artificial heart valve 600 are only a very small portion, and at least half, at least two-thirds, or at least three-quarters of the lengths of the outer cuffs 670a, 670b are disposed beyond each end of the artificial heart valve 600. Thereby, in particular, compared with other outer cuffs that are always disposed directly above the stent of the artificial heart valve, the bulk due to the outer cuffs 670a, 670b can be made relatively small, whether in the folded state or the expanded state. When the balloon 680 is expanded, the frame of the artificial heart valve will also expand, and due to the pressure, the tacks fixing the second ends 672a, 672b of the outer cuffs may break. In some embodiments, both ends of the thread or cord constituting the outer cuff may be attached to the frame of the artificial heart valve. After the slack of the thread or cord is pulled onto the balloon and tightened during inflation, the PV leakage is prevented or reduced by pulling the thread or cord in place.

[0039] According to one aspect of the present disclosure, an artificial heart valve system includes a balloon-expandable artificial heart valve having an inflow end, an outflow end, and a central portion between the inflow end and the outflow end, a delivery catheter having a balloon assembly with a proximal portion, a distal portion, and a central portion between the proximal portion and the distal portion at the distal end and in the delivery state of the system, the artificial heart valve is pleated onto the balloon while the balloon assembly is deflated, In the deployed state of the system, the balloon assembly has a diameter at the distal portion of the balloon assembly that is greater than the diameter of the central portion of the balloon assembly, and the outflow end portion of the artificial heart valve expands such that it extends radially outward from the central portion of the artificial heart valve, and / or The balloon assembly includes a first balloon and a second balloon, and / or The second balloon is disposed within the first balloon, the second balloon is disposed only at the distal portion of the balloon assembly, and in the deployed state of the system, the second balloon is expanded to have a diameter greater than the diameter of the central portion of the balloon assembly, and / or The first balloon is disposed within the second balloon, the second balloon is disposed only at the distal portion of the balloon assembly, and in the deployed state of the system, the second balloon is expanded to have a diameter greater than the diameter of the central portion of the balloon assembly, and / or The balloon assembly includes only a single balloon, and / or The single balloon has a uniform compliance along the length of the single balloon, and is formed such that when the single balloon is inflated, the distal portion of the single balloon has a diameter greater than the diameter of the central portion of the single balloon, and / or The single balloon has a proximal portion with a first compliance and a distal portion with a second compliance that is less than the first compliance such that when the single balloon is inflated while the central portion of the single balloon is disposed within the patient's native valve annulus, the distal portion of the single balloon has a diameter greater than the diameter of the central portion of the single balloon, and / or In the delivery state of the system, a band circumscribes the central portion of the artificial heart valve, and / or In the deployed state of the system, the band restricts the expansion of the balloon assembly so as to maintain the diameter of the central portion of the balloon assembly, and / or The system has a final implanted state in which the band is configured such that (i) it does not circumscribe the central portion of the artificial heart valve and breaks during transition from the deployed state, or (ii) it circumscribes the central portion of the artificial heart valve and is configured to elongate during transition from the deployed state.

[0040] According to another aspect of the present disclosure, a method of implanting an artificial heart valve comprises pleating the artificial heart valve onto a balloon assembly of a balloon catheter and delivering the artificial heart valve to the native valve annulus while the balloon assembly is deflated, expanding the artificial heart valve by inflating the balloon assembly such that the central portion of the artificial heart valve contacts the native valve annulus and the inflow end of the artificial heart valve spreads radially outwardly relative to the central portion of the artificial heart valve, and / or inflating the balloon assembly includes inflating a first balloon of the balloon assembly to a first diameter and a second balloon of the balloon assembly to a second diameter greater than the first diameter such that the second balloon of the balloon assembly spreads the inflow end of the artificial heart valve radially outwardly relative to the central portion of the artificial heart valve, and / or the balloon assembly includes a single balloon having a uniform compliance, and inflating the balloon assembly includes inflating the single balloon to a predetermined shape in which the distal end of the single balloon has a diameter greater than the central portion of the single balloon, and / or the balloon assembly includes a single balloon having a proximal portion with a first compliance and a distal portion with a second compliance less than the first compliance, and inflating the balloon assembly includes inflating the single balloon until the proximal portion presses the artificial heart valve into the native valve annulus and continuing inflation of the balloon assembly such that the distal portion of the single balloon has a diameter greater than the diameter of the central portion of the single balloon, and / or Inflating the balloon assembly includes initiating inflation of the balloon assembly while the band circumscribes the center of the artificial heart valve and the center of the balloon assembly, and continuing inflation of the balloon assembly such that the distal portion of the balloon assembly inflates to a diameter greater than the diameter of the center of the balloon assembly while the band still circumscribes the center of the artificial heart valve and the center of the balloon assembly, and / or rupturing the band and further inflating the balloon assembly until the band no longer circumscribes the center of the artificial heart valve and the center of the balloon assembly, and / or The artificial heart valve includes a frame formed of struts having a strut shape, and the strut shape of the frame at the center of the artificial heart valve is different from the strut shape of the frame at the inflow end of the artificial heart valve such that a greater force is required for expansion of the frame at the center of the artificial heart valve than for expansion of the frame at the inflow portion of the artificial heart valve.

[0041] According to yet another aspect of the present disclosure, an artificial heart valve system includes an artificial heart valve including a balloon-expandable stent and an artificial valve assembly mounted within the stent, a delivery catheter having a balloon at its distal end, the system having (i) a delivery state in which the artificial heart valve is pleated on the balloon while the balloon is deflated, (ii) a partial deployment state in which the artificial heart valve is partially expanded and the balloon is partially inflated, and (iii) a full deployment state in which the artificial heart valve is fully expanded and the balloon is fully inflated, the delivery catheter a first outer cuff formed by a thread having a first end coupled to the balloon and a second end coupled to the stent, the first outer cuff having an intermediate portion that, in the delivery state, wraps around the stent and wraps around a portion of the balloon disposed beyond a first end of the stent, and / or As the system transitions from the delivery state to the partially deployed state and then to the fully deployed state, the first outer cuff unfolds, and / or In the fully deployed state of the system, the length of the first outer cuff is substantially equal to the circumference of the stent, and / or A second outer cuff formed by a thread having a first end coupled to the balloon and a second end coupled to the stent, the second outer cuff having an intermediate portion that, in the delivery state, wraps around the stent and wraps around a portion of the balloon disposed beyond the second end of the stent, the first outer cuff being disposed at the inflow end of the artificial heart valve and the second outer cuff being disposed at the outflow end of the artificial heart valve.

[0042] Although the invention has been described herein with reference to specific embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the invention. Accordingly, many modifications are possible to the illustrated embodiments, and other configurations can 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: a balloon-expandable artificial heart valve having an inflow end portion, an outflow end portion, and a central portion between the inflow end portion and the outflow end portion; a delivery catheter having a proximal portion, a distal portion, and a balloon assembly having a central portion between the proximal portion and the distal portion at the distal end; wherein, in the delivery state of the system, the artificial heart valve is formed into a pleated shape on the balloon while the balloon assembly is deflated; in the deployed state of the system, the balloon assembly expands such that the distal portion of the balloon assembly has a diameter larger than the diameter of the central portion of the balloon assembly, and the outflow end portion of the artificial heart valve expands radially outward with respect to the central portion of the artificial heart valve. An artificial heart valve system.

2. The artificial heart valve system according to claim 1, wherein the balloon assembly includes a first balloon and a second balloon.

3. The artificial heart valve system according to claim 2, wherein the second balloon is disposed within the first balloon, the second balloon is disposed only at the distal portion of the balloon assembly, and in the deployed state of the system, the second balloon is expanded to have a diameter larger than the diameter of the central portion of the balloon assembly.

4. The artificial heart valve system according to claim 2, wherein the first balloon is disposed within the second balloon, the second balloon is disposed only at the distal portion of the balloon assembly, and in the deployed state of the system, the second balloon is expanded to have a diameter larger than the diameter of the central portion of the balloon assembly.

5. The artificial heart valve system according to claim 1, wherein the balloon assembly includes only a single balloon.

6. The artificial heart valve system according to claim 5, wherein the single balloon has a uniform compliance along the length of the single balloon, and the distal portion of the single balloon has a diameter larger than the diameter of the central portion of the single balloon when the single balloon is expanded.

7. The artificial heart valve system according to claim 5, wherein when the single balloon expands while the central portion of the single balloon is disposed within the natural valve annulus of the patient, the distal portion of the single balloon has a diameter larger than the diameter of the central portion of the single balloon, and the proximal portion has a first compliance and the distal portion has a second compliance smaller than the first compliance.

8. The artificial heart valve system according to claim 1, wherein in the delivery state of the system, the band circumscribes the central portion of the artificial heart valve.

9. The artificial heart valve system according to claim 8, wherein in the deployed state of the system, the band restricts the expansion of the balloon assembly so as to maintain the diameter of the central portion of the balloon assembly.

10. The artificial heart valve system according to claim 9, wherein the system has a final implanted state in which the band is configured to (i) not circumscribe the central portion of the artificial heart valve and break during transition from the deployed state, or (ii) circumscribe the central portion of the artificial heart valve and elongate during transition from the deployed state.

11. A method of implanting an artificial heart valve, comprising: delivering the artificial heart valve to the natural valve annulus while the artificial heart valve is pleated on a balloon assembly of a balloon catheter and the balloon assembly is deflated; expanding the balloon assembly to expand the artificial heart valve such that the central portion of the artificial heart valve contacts the natural valve annulus and the inflow end portion of the artificial heart valve extends radially outward with respect to the central portion of the artificial heart valve. A method comprising.

12. The method according to claim 11, wherein expanding the balloon assembly comprises expanding a first balloon of the balloon assembly to a first diameter and expanding a second balloon of the balloon assembly to a second diameter larger than the first diameter such that the second balloon of the balloon assembly spreads the inflow end portion of the artificial heart valve radially outward with respect to the central portion of the artificial heart valve.

13. The balloon assembly includes a single balloon having a uniform compliance, and inflating the balloon assembly includes inflating the single balloon into a predetermined shape in which a distal end of the single balloon has a diameter greater than a central portion of the single balloon, the method of claim 11.

14. The balloon assembly includes a single balloon having a proximal portion with a first compliance and a distal portion with a second compliance that is less than the first compliance, and inflating the balloon assembly includes inflating the single balloon until the proximal portion pushes the artificial heart valve into the native valve annulus, and continuing to inflate the balloon assembly such that the distal portion of the single balloon has a diameter greater than a diameter of the central portion of the single balloon, the method of claim 11.

15. Inflating the balloon assembly includes initiating inflation of the balloon assembly while a band circumscribes a central portion of the artificial heart valve and a central portion of the balloon assembly, and continuing to inflate the balloon assembly such that a distal portion of the balloon assembly inflates to a diameter greater than a diameter of the central portion of the balloon assembly while the band still circumscribes the central portion of the artificial heart valve and the central portion of the balloon assembly, the method of claim 11.

16. The method of claim 15, further comprising further inflating the balloon assembly until the band breaks and no longer circumscribes the central portion of the artificial heart valve and the central portion of the balloon assembly.

17. The artificial heart valve includes a frame formed of struts having a strut shape, and the strut shape of the frame at the central portion of the artificial heart valve requires a greater force for expansion of the frame at the central portion of the artificial heart valve than for expansion of the frame at an inflow portion of the artificial heart valve, different from the strut shape of the frame at an inflow end of the artificial heart valve, the method of claim 11.

18. An artificial heart valve system, comprising An artificial heart valve comprising a balloon-expandable stent and an artificial valve assembly attached within the stent, A delivery catheter having a balloon at its distal end, the system having: (i) a delivery state in which the artificial heart valve is pleated onto the balloon while the balloon is deflated; (ii) a partial deployment state in which the artificial heart valve is partially expanded and the balloon is partially inflated; and (iii) a full deployment state in which the artificial heart valve is fully expanded and the balloon is fully inflated, the delivery catheter; A first outer cuff formed by a thread having a first end coupled to the balloon and a second end coupled to the stent, the first outer cuff having an intermediate portion that wraps around the stent and wraps around a portion of the balloon disposed beyond a first end of the stent in the delivery state, the first outer cuff; An artificial heart valve system comprising.

19. The artificial heart valve system according to claim 18, wherein the first outer cuff unfolds when the system transitions from the delivery state to the partial deployment state and then to the full deployment state.

20. The artificial heart valve system according to claim 19, wherein in the full deployment state of the system, the length of the first outer cuff is substantially equal to the circumference of the stent.

21. A second outer cuff formed by a thread having a first end coupled to the balloon and a second end coupled to the stent, the second outer cuff having an intermediate portion that wraps around the stent and wraps around a portion of the balloon disposed beyond a second end of the stent in the delivery state, further comprising the second outer cuff, the first outer cuff being disposed at an inflow end of the artificial heart valve, and the second outer cuff being disposed at an outflow end of the artificial heart valve, the artificial heart valve system according to claim 18.

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