Balloon-expandable valve leaflet 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 priority to 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. For the purposes of use 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 artificial heart valves typically take the form of a one-way valve structure (often referred to herein as a valve assembly) installed within an expandable stent / expandable stent. Generally, these foldable / expandable heart valves include self-expanding or balloon-expanding stents, which are often made of shape-memory metals or alloys such as nitinol (in the case of self-expanding stents) or steel or cobalt-chromium (in the case of balloon-expanding stents). Existing foldable / expandable TAVR devices are known to use a variety of stent layouts, including linear vertical struts connected by a "V" shape 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 stent / one-way valve assembly installed within the stent includes one or more valve leaflets and may also include a cuff or skirt. The cuff may be positioned on the inner surface or inner surface, outer surface or outer surface of the stent, or / or both surfaces. The cuff helps prevent blood from flowing around the valve leaflets when the valve or valve assembly is not properly positioned in the valve annulus. The cuff or a portion of the cuff positioned outside the stent may help slow perivalvular leakage (known as perivalvular leakage or "PV" leakage) outside the valve.

[0004] Balloon-expandable valves are typically delivered to the natural valve annulus while folded (or "crimped") on the deflated balloon of a balloon catheter, with or without the folded valve being covered by an upper sheath. Once the crimped prosthetic valve is positioned within the annulus of the natural heart valve to be replaced, inflating the balloon causes the balloon-expandable valve to transition from folded or crimped to expanded or unfolded, maintaining the balloon-expanded shape. Usually, once the position of the folded prosthetic valve is determined to be the desired position relative to the natural annulus (for example, by visualization under fluoroscopy), a fluid such as saline (usually a liquid, but gases can also be used) is injected into the balloon catheter (manually, automatically, or semi-automatically) via a syringe, initiating balloon inflation and expansion, which expands the upper prosthetic valve into the natural annulus.

[0005] When self-expanding artificial heart valves are delivered inside a patient to replace a malfunctioning natural heart valve, they are almost always kept folded within the capsule of the delivery device. The capsule can prevent premature self-expansion of the artificial heart valve, and such an upper capsule (with or without additional internal retention assistance) helps prevent premature contact of the artificial heart valve with tissue and helps maintain the desired position and orientation relative to the delivery device during delivery. However, balloon-expanding artificial heart valves are usually 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 space is always precious in transcatheter artificial heart valve delivery devices and systems, and adding a capsule in addition to the artificial valve and the lower balloon is not feasible given the size profile requirements of these procedures.

[0006] During delivery and / or crimping, the valve assembly (e.g., the valve leaflets and / or cuff) may be damaged. Specifically, the large forces required to shrink the valve frame to the desired delivery diameter may press the valve leaflets against the rigid metal stent. This can cause localized stress and / or damage to the leaflets. Also, if the stent contains a large open cell, the compressed leaflets may protrude and become pinched through the opening between the struts of the open cell. [Overview of the project]

[0007] In some embodiments, the artificial heart valve system comprises 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 deflated state and an inflated state, which is configured and positioned 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.

[0008] In some embodiments, a method for delivering an artificial heart valve system includes preparing an artificial heart valve comprising a stent, a cuff, and a plurality of leaflets, wherein the cuff and the plurality of leaflets constitute a valve assembly; positioning a deflated inflatable balloon inside the artificial heart valve, which has a feature for crimping and protecting the artificial heart valve during delivery; and crimping the artificial heart valve and the inflatable balloon while the feature protects a portion of the valve assembly. [Brief explanation of the drawing]

[0009] [Figure 1A] This is a perspective view of an artificial heart valve stent according to one embodiment of the present disclosure. [Figure 1B-1E] Figure 1B is a schematic front view of a portion of the stent in Figure 1A, Figure 1C is a schematic front view of a portion of the stent in an alternative embodiment of the artificial heart valve in Figure 1A, and Figures 1D-1E are front views of the stent portion in Figure 1C in a folded state and an expanded state. [Figure 1F-1H]Figure 1F-1G shows a side view of a portion of the stent in the folded state and a side view of the expanded state according to the embodiment of Figure 1C, and Figure 1H is a plan view of the stent cut and flattened according to the embodiment of Figure 1C. [Figure 1I-1K] Figures 1I-1J show the front and side views of the artificial heart valve including the stent in Figure 1C, and Figure 1K shows the additional lateral cuff attached to the stent in Figure 1H. [Figure 2A-2B] This figure shows an artificial heart valve (PHV) crimped onto a balloon in both its deflated and inflated states. [Figure 3A-3C] This is a schematic top view of an artificial heart valve used with an expandable balloon having a leaflet protection feature. [Figure 4A-4B] This is a schematic top view of another example of an artificial heart valve used with an expandable balloon having a valve leaflet protection mechanism. [Figure 5] This is a schematic side view of an artificial heart valve with a protective sleeve. [Figures 6A-6E] Figure 6A is a schematic top view of an expandable balloon with protrusions and a pocket, and Figures 6B-6E are schematic top views of another example of the use of an expandable balloon in combination with an artificial heart valve. [Modes for carrying out the invention]

[0010] In its use herein, the term "inflow end," as used in relation to an artificial heart valve, refers to the end of the valve into which blood first enters when the valve is implanted in its intended position and orientation. Conversely, the term "outflow end" refers to the end of the valve from which blood exits when the valve is implanted in its intended position and orientation. Therefore, 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 convenience in describing the valve 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 extended to 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 structure and features can be employed in other heart valves such as the pulmonary valve, mitral valve, or tricuspid valve. Furthermore, when used in relation to a delivery device or system, the term "proximal" refers to the direction relatively close to the user when the device or system is used as intended. Conversely, the term "distal" refers to the direction relatively farther from the user of the device. In other words, the front end of a delivery device or system is located distal 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 slight deviations from absolute values ​​fall within the range of the thus modified terms. As used herein, a stent can be described as having an "expanded state" and a "folded state," representing the relative radial size of the stent.

[0011] Figure 1A is a perspective view of a stent 100 for an artificial heart valve according to one embodiment of the present disclosure. The stent 100 may comprise a frame extending axially between an inlet end 101 and an outlet end 103. The stent 100 comprises three substantially symmetrical portions, each portion extending at approximately 120° in the circumferential direction of the stent 100. The stent 100 comprises three vertical struts 110a, 110b, and 110c extending axially (central longitudinal axis) substantially parallel to the direction of blood flow through the stent. Each vertical strut 110a, 110b, and 110c may extend substantially over the entire axial length between the inlet end 101 and the outlet end 103 of the stent 100, or may be positioned between two portions and shared by two portions. In other words, each portion is defined by the portion between two vertical struts of the stent 100. Therefore, each vertical strut 110a, 110b, and 110c is separated by approximately 120° in the circumferential direction of the stent 100. When the stent 100 is used in an artificial heart valve having three leaflets, it will be understood that it may include three parts as shown in the figure. However, in other embodiments, if the artificial heart valve has two leaflets, the stent may include only two of these parts.

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

[0013] The stent portion 107 further includes a first central strut 130a extending between a first central node 125a and an upper node 145. The stent portion 107 also includes a second central strut 130b extending between a second central node 125b and an 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 constitute a rhombic cell 128. The stent portion 107 includes a first outer upper strut 140a extending between a first outer node 135 and a first outflow node 104a. The stent portion 107 further includes a second outer upper strut 140b extending between a second outer node 135b and a 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 inversion V-shape 114 extending between the first and second outflow nodes 104a and 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 constitute the 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 constitute the second roughly kite-shaped cell 133b. The first and second kite-shaped cells 133a and 133b are symmetrical and opposite 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 strict definition of a kite shape. The outflow inverted V-shape 114, the first inner upper strut 142a, and the second inner upper strut 142b constitute the upper cell 134. The upper cell 134 is roughly kite-shaped and is axially aligned with the rhombic cell 128 in the stent portion 107.Although the various struts described herein are designated as separate struts, it should be understood that, as stated above, they may be part of a single unit structure. However, in other embodiments, the stent 100 does not need to be formed as a single structure, and therefore the struts may be different structures (or parts of different structures) that are integrally connected.

[0014] Figure 1C is a schematic diagram of a stent portion 207 according to an alternative embodiment of the present disclosure. Unless otherwise noted, the same reference numerals represent the same elements of the stent 100 described above, but within the range of 200s. The stent portion 207 is substantially similar to the stent portion 107 and includes inlet nodes 202a, 202b, vertical struts 210a, 210b, first and second inlet inversion V-shaped sections 220a, 220b, and outlet nodes 204a, 204b. The structure of the stent portion 207 differs from that of the stent portion 107 in that it does not include the outlet inversion V-shaped sections. The object of one embodiment having the structure of the stent portion 207 shown in Figure 1C is to promote uniform expansion to the inlet end 201 by reducing the force required to expand the outlet end 203 of the stent 200 compared to the stent 100. The outflow nodes 204a and 204b are connected by a properly oriented V-shape, which consists of a first inner upper strut 242a, an upper node 245, and a second inner upper strut 242b. In other words, the struts 242a and 242b may constitute a semi-rhombic cell 234 whose open end is oriented toward the outflow end 203. The semi-rhombic cell 234 is axially aligned with the rhombic cell 228. Adding an outflow inversion V-shape coupled between the outflow nodes 204a and 204b increases resistance to changes in the stent shape and provides additional material that requires additional force to expand the stent. By removing material from the outflow end 203, resistance to expansion at the outflow end 203 is reduced, which can promote uniform expansion of the inflow end 201 and the outflow end 203. In other words, the inlet end 201 of the stent 200 does not include a continuous circumferential structure, but rather has a substantially open or fully open half-cell with the opening oriented toward the inlet end 201. On the other hand, most of the outlet end 203 includes a substantially continuous circumferential structure via struts corresponding to struts 140a, 140b. All else equal, a substantially continuous circumferential structure may require greater force to expand compared to a similar open structure. For this reason, the inlet end 101 of the stent 100 may require greater force to expand radially compared to the outlet end 103.By omitting the inverted V-shape 114, the result is the stent 200, but the force required to expand the outflow end 203 of the stent 200 can be reduced to a size close to that of the inflow end 201.

[0015] Figure 1D is a front view of the stent portion 207 in a folded state, and Figure 1E is a front view of the stent portion 207 in an extended state. The stent 200 in Figures 1D and 1E is shown with an opaque tube extending inside the stent, solely for the purpose of illustrating the stent, and it is understood that this may represent a balloon into which the stent portion 207 is crimped. As described above, the stent consists of three symmetrical portions, each extending at approximately 120° around the circumference of the stent. The stent portion 207 shown in Figures 1D and 1E is defined by the region between the vertical struts 210a and 210b. The stent portion 207 represents all three portions of the stent. The stent portion 207 also has an arched structure such that when the three portions are connected, they form a single complete cylindrical shape. Figures 1F and 1G show side views of a portion of the stent. In other words, the diagrams of stent 200 in Figures 1F and 1G are rotated by approximately 60° compared to the diagrams in Figures 1D and 1E. The diagrams of the stent shown in Figures 1F and 1G are centered on the vertical strut 210b, with approximately half of each of the two adjacent stent portions 207a and 207b shown on either side of the vertical strut 210b. The portions 207a and 207b surrounding the vertical strut 210b are mirror images of each other. Figure 1F shows the stent portions 207a and 207b in a folded state. On the other hand, Figure 1G shows the stent portions 207a and 207b in an expanded state.

[0016] Figure 1H is a plan view of stent 200 including three stent sections 207a, 207b, and 207c, obtained by cutting the stent longitudinally and spreading it flat on a table. As shown, sections 207a, 207b, and 207c are symmetrical to each other, and adjacent sections share a common vertical strut. As mentioned above, although stent 200 is shown in a plan view, each section 207a, 207b, and 207c has an arched shape that spreads at 120°, thus forming a complete cylinder. Figure 1H further shows valve leaflets 250a, 250b, and 250c connected to stent 200. However, it should be understood that Figure 1H only shows the connection points of valve leaflets 250a to 250c. In other words, each valve leaflet 250a–250c typically includes a free edge, which acts to prevent retrograde blood flow through the stent 200 by joining with each other, and also allows antegrade blood flow through the stent by moving radially outward toward the inner surface of the stent. Figure 1H does not show these free edges, but the attachment edges of the valve leaflets 250a–250c are shown by dashed lines. This attachment is possible in any preferred manner, but it is considered preferable that the attachment edges are sutured to the stent 200 and / or to a cuff or skirt interposed between the stent and the valve leaflets 250a–250c. Each of the three valve leaflets 250a, 250b, and 250c extends approximately 120° from end to end around the stent 200, and each valve leaflet includes an abdomen that can extend toward the radial center of the stent 200 if the leaflets are joined integrally. Each valve leaflet extends between the upper nodes of adjacent portions. The first valve leaflet 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 leaflet 250b extends from the second upper node 245b to the third upper node 245c of the third stent portion 207c. The third valve leaflet 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 leaflet and the second end of the second valve leaflet connected thereto. In the illustrated embodiment, each end of each valve leaflet is connected to its respective node by suture.However, any coupling means may be used to attach the valve leaflets to the stent. Furthermore, the stent may include any number of parts and / or valve leaflets. For example, the stent may include two parts extending 180° from the circumference of the stent. Furthermore, the stent may include two valve leaflets to mimic a bicuspid valve. It should be noted that each valve leaflet may include a structure such as a tab (not shown) at the joint between the free edge and the attachment edge of the valve leaflet, and 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 a node where the struts intersect. However, in other embodiments, the stent 200 may have a joint attachment mechanism incorporated into the stent 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 the valve leaflet joint to the stent. Furthermore, the valve leaflets 250a to 250c may be formed from biological materials such as animal pericardium, or from synthetic materials 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 (for example by sutures), and valve leaflets 250a, 250b, 250c attached to the stent 200 and / or the cuff 260 (for example by sutures). Although the artificial heart valve 206 is intended for use in aortic valve replacement, the same or similar structure may be used for artificial valves to replace other heart valves. The cuff 260 is disposed on the inner surface or surface of the lumen of the stent 200, but may also be disposed on the outer surface or surface of the lumen of the stent as an alternative or addition. The cuff 260 may include an inlet substantially disposed along the inlet end 201 of the stent 200. Figure 1I is a front view of a valve 206 showing one stent portion 207 between vertical struts 210a, 210b, including a cuff 260, and the contours of two valve leaflets 250a, 250b sutured to the cuff 260. Various methods may be used to suture the valve leaflets to the cuff, as well as to suture the valve leaflets and / or the cuff to the stent, 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 a first central node 225a, upper node 245, and a 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 continues substantially between the second central node of one portion and the first central node of the adjacent portion. The cuff 260 extends between the upper node 245 and the inlet end 201. Thus, the cuff 260 covers the cells (including the rhombic cells 228) of the stent portion 207 formed by the strut between the upper node 245 and the inlet end 201. Figure 1J is a side view of the stent 200 including the contours of the cuff 260 and the valve leaflets 250b. In other words, the diagram of the valve 206 in Figure 1J is rotated by approximately 60° compared to the diagram in Figure 1I. The diagram shown in Figure 1J is centered on the vertical strut 210b, with approximately half of two adjacent stent portions 207a and 207b shown on either side of the vertical strut 210b.The portions 207a and 207b surrounding the vertical strut 210b are mirror images of each other. As described above, the cuff may be positioned on the inner surface or inner surface of the lumen, outer surface or outer surface of the lumen, and / or both surfaces of the stent. The cuff prevents blood from flowing around the valve leaflets when the valve or valve assembly is not optimally positioned in the annulus. The cuff or a portion of the cuff positioned outside the stent may help to slow periphery leakage (known as perivalvular leakage or "PV" leakage) outside the valve. In the embodiments shown in Figures 1I and 1J, the cuff 260 covers only about half of the stent 200, leaving about half of the stent uncovered. This configuration reduces the amount of cuff material required compared to a cuff that covers more or all of the stent 200. Reducing the amount of cuff material may allow for a smaller crimped profile of the artificial heart valve 206 during folding. The cuff may cover any portion of the surface area of ​​the cylinder formed by the stent. For example, the upper edge of the cuff may extend straight around the circumference of any cross-section of the cylinder formed by the stent. The cuff 260 may be made of any suitable material, including biological materials such as animal pericardium or synthetic materials such as UHMWPE.

[0018] As described above, Figures 1I and 1J show the cuff 260 located inside the stent 200. An example of an additional outer cuff 270 is shown in Figure 1K. It should be understood that the outer cuff 270 may have a shape other than that shown in Figure 1K. The outer cuff 270 shown in Figure 1K may be provided without the inner cuff 260, but it is preferable that it is provided in addition to the inner cuff 260. The outer cuff 270 may be formed integrally with the inner cuff 260 and folded back over (for example, wrapped around) the inlet edge of the stent. Alternatively, it may be provided as a separate component 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 inlet edge 272 and an outlet edge 274. If the inner cuff 260 and the outer cuff 270 are formed separately, the inlet edge 272 may be joined to the inlet end of the stent 200 and / or the inlet edge of the inner cuff 260 by, for example, suture, ultrasonic welding, or any other preferred attachment method. The joining of the inlet edge 272 of the outer cuff 270 and the stent 200 and / or the inner cuff 260 preferably forms a seal between the inner cuff 260 and the outer cuff 270 at the inlet 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 pass over the inlet edges of the inner cuff 260 and the outer cuff 270. The outlet edge 274 may be joined to the strut of the stent 200 and / or the inner cuff 260 at a selected position on the circumference of the stent 200, for example by suture. This configuration creates an opening between the inner cuff 260 and the outer cuff 270 in the circumferential direction between adjacent connection points, so that retrograde blood flow can no longer continue to flow over 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 expands outward, which can further improve the seal between the outer cuff 270 and the natural valve annulus against which the outer cuff 270 is pressed.The outer cuff 270 may be provided as a continuous cylindrical member whose lateral edges (which may or may not be parallel to the longitudinal central axis of the artificial heart valve) are attached to each other so as to enclose the entire circumference of the stent 200, or as a strip wrapped around the outer circumference of the stent 200.

[0019] The stent may be formed from a biocompatible material including metal and alloys such as cobalt chromium or stainless steel, but in some embodiments it may be formed from a shape memory material such as nitinol. Thus, the stent is configured to fold when crimped to a smaller diameter and / or expand when forcibly released, such as by the inflation of an internal balloon, and substantially maintains its modified shape when at rest. When crimped, the stent folds radially and lengthens (to some extent) axially, so that the profile at any given cross-section can be reduced. Also, the stent may expand radially and shorten (to some extent) 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, 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 proceeds against the blood flow to the left ventricle. In either delivery method, the valve may initially be folded onto the 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 (and, depending on the situation, beneath the upper sheath). When reaching the aortic valve or adjacent thereto, the surgeon or operator of the delivery system may position the prosthetic valve as desired within the native valve annulus while the prosthetic valve is folded on the balloon. When the desired positioning 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 expand the prosthetic valve radially, with at least a portion of the prosthetic valve becoming axially shorter.

[0021] Referring to Figure 2A, this figure shows an example of a PHV (Plug-in Hypoallergenic Valve), which may include a stent similar to stent 100 or 200, and is crimped onto the balloon 380 of a balloon catheter 390 while the balloon 380 is in a deflated state. It should be noted that in Figures 2A and 2B, other components of the delivery device, such as a syringe for inflating the balloon 380, as well as the handles used for guidance and / or deployment, are omitted. The PHV may be delivered transvascularly into the natural aortic annulus, for example, by passing through the femoral artery and bypassing the aortic arch, while in the folded state shown in Figure 2A. Once the desired position is achieved, fluid may be pushed through the balloon catheter 390 to inflate the balloon 380, as shown in Figure 2B. Figure 2B omits the artificial heart valve PHV, but it is understood that when the balloon 380 is inflated, the artificial heart valve PHV expands into the natural aortic annulus (however, it is understood that other heart valves may be replaced by the concepts described herein). In the illustrated example, fluid flows from a syringe or inflation device (not shown) through the lumen of the balloon catheter 390 into the balloon 380 and into one or more ports 385 located inside the balloon 380. In the particular example shown in Figure 2B, the first port 385 may be one or more openings in the side wall of the balloon catheter 390, and the second port 385 may be the distal open end of the balloon catheter 390 terminating in the internal 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 skirt or cuff of the valve, as well as the sutures that attach the 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 inflated 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 a 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 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 the number of leaflets of the valve assembly or correlates with the number of leaflets (e.g., the number of pleats is a multiple of the number of leaflets).

[0023] As described above, the multiple pockets 496 are sized, configured, and positioned to receive portions of multiple valve leaflets, and the arms 494 may be configured and positioned to pull in and wind portions of multiple valve leaflets 450. In Figure 3B, the star-shaped balloon 490 is wound overall in a first direction (e.g., clockwise), and the multiple valve leaflets 450 are positioned to be wound in the same direction (e.g., clockwise) to match this pattern. Alternatively, it is understood that both the balloon 490 and the valve leaflets 450 may be wound counterclockwise. This helical or winding pattern of the leaflets and / or balloon may increase or tighten when the artificial heart valve PHV is crimped for delivery and its radial size becomes smaller (Figure 3C). Furthermore, as shown in Figures 4A and 4B, the artificial heart valve PHV may include a star-shaped balloon 490 wound in a first direction (e.g., counterclockwise) and a valve leaflet 450 wound in the opposite direction (e.g., clockwise).

[0024] Thus, the expandable balloon 490 itself can serve both the function of expanding the artificial heart valve PHV and the function of providing leaflet protection during crimping and delivery through leaflet protection features (e.g., pleats and pockets). The rotation of the star-shaped or iris-shaped balloon 490 can pull in a portion of the leaflets during crimping, preventing or suppressing the possibility of damage to the leaflets or valve assembly during crimping and delivery. When the leaflets 450 are pulled in or trapped between the pleats, the balloon 490 acts as a protective barrier between a portion of the leaflets 450 and the interior of the stent 400. This pulling (folding) process may include gradually twisting the balloon 490 relative to the stent while crimping the artificial heart valve PHV radially onto the balloon.

[0025] As an addition to or alternative to the protective features of the balloon described above, a removable protective sleeve 575 may be provided between a portion of the stent 500 and the valve leaflets 550 and / or cuff 560 (Figure 5). The removable protective sleeve 575 may be positioned or introduced between the valve assembly and the stent during the crimping process, and may also be introduced into the body and removed together with the balloon upon delivery. In at least some examples, the protective sleeve 575 may be made of PEBX® elastomer, nylon, or polyethylene (HDPE or MWPE).

[0026] In an alternative embodiment shown in Figure 6A, the balloon 690A may include an asymmetric configuration with a number of projections 694, where adjacent projections define an inner pocket 696 sized to protect the valve assembly during crimping and delivery by receiving a portion of the valve assembly (e.g., one or more portions of the valve leaflets). The balloon may be non-circular in shape to form an area that offsets the peak area of ​​the valve leaflets. Another example is shown in Figure 6B, in which the balloon 690B includes a pair of fingers 698 that extend radially alternately from the pocket 696. Specifically, each pair of radially extending fingers includes a first finger 698a, a second finger 698b, and a small gap 699 formed between them. Here, three pairs of fingers 698 are shown, each spaced approximately 120° apart from one another. It is understood that the fingers 698 may be arranged individually or in pairs as shown. Furthermore, the number of fingers 698 may correspond to the number of leaflets of the artificial heart valve (PHV). For example, three fingers 698 may be used for three leaflets. Alternatively, the number of fingers 698 may be a multiple of the number of leaflets (for example, two fingers per leaflet, three fingers per leaflet, etc.). The spacing between fingers or pairs of fingers may be adjusted as needed to set the pocket spacing for the PHV leaflets.

[0027] Figure 6C shows the inside of the artificial heart valve PHV, specifically the balloon 690B positioned within the stent 600 and multiple leaflets 650. Fingers 698 may be positioned between the folds 651 of the leaflets 650 to allow for safer and more controlled crimping. In addition to preventing or suppressing leaflet damage, these configurations may allow the device to be crimped to a much smaller size. In this case, as with other embodiments, the balloon may rotate or twist during or before crimping to wrap around the leaflets and fingers of the balloon. As shown in Figure 6D, the fingers 698 begin to wrap counterclockwise, and the leaflets 650 also begin to wrap in the same direction. In at least some examples, after the balloon 690B is introduced into the artificial heart valve PHV, the leaflets begin to gather and wrap due to winding or rotation relative to the stent 600. After the wrapping of the leaflets 650 and balloon 690B, the device can be crimped to a smaller circumference. In another embodiment, the winding of the balloon 690B and the valve leaflets 650 is performed simultaneously with the crimping process, rather than as part of a sequential process. That is, the balloon 690B is rotatable relative to the stent 600, and this winding can occur when the artificial heart valve PHV is circumferentially reduced or crimped. Based on the material used for the balloon 690B and the configuration and spacing of the fingers 698, the crimped artificial heart valve 600 can be in a non-circular, fully folded state, as shown in Figure 6D. For example, an artificial heart valve PHV' with a roughly triangular or guitar-pick shape is shown, depending on the size and configuration of the balloon 690B and the overall result of the winding process of both the balloon and the valve leaflets 650. According to this concept, larger pockets are formed within the balloon, where the majority of the valve leaflet material and valve assembly can be accommodated. Thus, the spacing and arrangement of these pockets maximize and control the separation of the outer sheaths during crimping. Furthermore, this configuration reduces the force acting on the valve leaflets, potentially lowering the likelihood of damage, and allows for a non-circular, pleated shape that facilitates installation, transport, and final deployment, as the joints of the valve leaflets are easily locatable.

[0028] When in use, the artificial heart valve may be fitted and delivered according to any of the above-described manners and configurations. First, an artificial heart valve may be provided that is a balloon-expandable artificial heart valve including a stent, a cuff, and multiple leaflets, wherein the cuff and multiple leaflets constitute a valve assembly. In the partially or fully expanded state of the artificial heart valve PHV, a substantially deflated expandable balloon may be introduced through the interior of the artificial heart valve PHV. The artificial heart valve PHV and balloon may integrally constitute an artificial heart valve system. The balloon may have pleats, fingers, or other leaflet protection features as described above, and in some cases, a portion of the balloon may be positioned between portions of the valve assembly, or a portion of the valve assembly may be gathered within a pocket or cavity of the balloon. Optionally, the balloon may be rolled up by rotation to gather the leaflets together. Subsequently, the rolled balloon and leaflets may be crimped together with the stent to reduce the circumference of the artificial heart valve PHV. Alternatively, the winding of the valve leaflets and / or balloon may be completed during the crimping of the artificial heart valve PHV. It is understood that the winding of the balloon and valve leaflets may be in the same direction (e.g., both clockwise or both counterclockwise) or in different directions (e.g., the first balloon and valve leaflet winds clockwise, and the second balloon and valve leaflet winds counterclockwise).

[0029] According to one aspect of the present disclosure, the artificial heart valve system comprises 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 deflated state and an inflated state, which is configured and positioned 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 for delivering an artificial heart valve system includes preparing an artificial heart valve comprising a stent, a cuff, and a plurality of leaflets, wherein the cuff and the plurality of leaflets constitute a valve assembly; positioning a deflated inflatable balloon inside the artificial heart valve having a feature for crimping and protecting the artificial heart valve during delivery; and crimping the artificial heart valve and the inflatable balloon while the feature protects a portion of the valve assembly.

[0031] In this specification, the present invention has been described with reference to specific embodiments, but it is understood that these embodiments are merely illustrative of the principles and applications of the present invention. Therefore, it is understood that many improvements are possible to the illustrated embodiments, and that other configurations can be devised without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. An artificial heart valve system, An artificial heart valve comprising a stent, a cuff, and a plurality of valve leaflets, wherein the cuff and the plurality of valve leaflets constitute a valve assembly, The invention comprises an expandable balloon having a deflated state and an expanded state, configured and positioned 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, An artificial heart valve system wherein the expandable balloon includes a plurality of pleats defining a plurality of inner pockets configured and in which a portion of the plurality of valve leaflets is positioned, and each of the plurality of inner pockets corresponds to one of the plurality of valve leaflets.

2. The artificial heart valve system according to claim 1, wherein the plurality of pleats include three pleats.

3. The artificial heart valve system according to claim 1, wherein the plurality of pleats include six pleats.

4. An artificial heart valve system, An artificial heart valve comprising a stent, a cuff, and a plurality of valve leaflets, wherein the cuff and the plurality of valve leaflets constitute a valve assembly, The invention comprises an expandable balloon having a deflated state and an expanded state, configured and positioned 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, An artificial heart valve system in which the expandable balloon is star-shaped and includes a plurality of arms in the contracted state, the plurality of arms being configured and arranged to pull in and wind up a portion of the plurality of valve leaflets.

5. The artificial heart valve system according to claim 4, 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 and second directions are the same.

6. The artificial heart valve system according to claim 4, 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.

7. An artificial heart valve system, An artificial heart valve comprising a stent, a cuff, and a plurality of valve leaflets, wherein the cuff and the plurality of valve leaflets constitute a valve assembly, The invention comprises an expandable balloon having a deflated state and an expanded state, configured and positioned 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, An artificial heart valve system further comprising a removable protective sleeve that is positioned between the valve assembly and the stent frame during delivery.

8. An artificial heart valve system, An artificial heart valve comprising a stent, a cuff, and a plurality of valve leaflets, wherein the cuff and the plurality of valve leaflets constitute a valve assembly, The invention comprises an expandable balloon having a deflated state and an expanded state, configured and positioned 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, An artificial heart valve system in which the artificial heart valve has a non-circular folded state.

9. The artificial heart valve system according to claim 8, wherein the artificial heart valve has a substantially triangular folded state.

10. A method for preparing an artificial heart valve system for delivery, The steps include preparing an artificial heart valve comprising a stent, a cuff, and a plurality of valve leaflets, wherein the cuff and the plurality of valve leaflets constitute a valve assembly, The steps include: positioning an expandable balloon, having a feature for crimping and protecting the artificial heart valve during delivery, inside the artificial heart valve in a deflated state; The steps include crimping the artificial heart valve and the expandable balloon while the feature portion protects a part of the valve assembly, The steps include rotating the expandable balloon relative to the stent of the artificial heart valve before or during the crimping of the artificial heart valve, Methods that include...

11. The method according to claim 10, wherein the step of positioning the expandable balloon includes positioning an expandable balloon having a plurality of pleats inside the artificial heart valve.

12. The method according to claim 11, wherein the step of positioning an expandable balloon includes positioning an expandable balloon having a plurality of pleats and a plurality of inner pockets, and further includes positioning a portion of the plurality of valve leaflets in the inner pockets of the expandable balloon.

13. The method according to claim 10, further comprising winding the expandable balloon in a spiral shape.

14. The method according to claim 10, further comprising 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.

15. The method according to claim 10, further comprising 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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