Artificial heart valve and transcatheter heart valve replacement system

Abstract

The invention relates to an artificial heart valve and a transcatheter heart valve replacement system.The artificial heart valve comprises a valve support and an outer skirt part, the valve support is provided with an inflow end and an outflow end, and the valve support is sequentially provided with a plurality of grid sets arranged in the circumferential direction from the outflow end to the inflow end; wherein the grid group closest to the inflow end is suitable for being matched with the position below the annulus plane, and the size of a net opening of at least one non-end grid group matched with the annulus plane is larger than that of a net opening of at least one axially adjacent grid group; the outer skirt part covers the outer surface of the valve stent, the outer skirt part at least covers the two adjacent grid groups close to the inflow end, and the position, close to the inflow end, of the outer skirt part is configured to be of a structure with the thickness gradually increased in the direction from the outflow end to the inflow end.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices for heart surgery, and in particular to an artificial heart valve and a transcatheter heart valve replacement system. BACKGROUND

[0002] Aortic valve disease is a common heart disease, including aortic valve stenosis and insufficiency. In recent years, transcatheter aortic valve replacement has become a new method for the treatment of severe aortic valve stenosis.

[0003] During the transcatheter aortic valve replacement procedure, it is crucial to implant the artificial aortic valve into the pre-set ideal position and replace the native aortic valve to function. However, during the implantation of the artificial valve, paravalvular leakage (PVL) is easily generated between the native valve tissue and the artificial valve support, i.e., a blood flow leakage is formed between the artificial valve and the surrounding tissue. The causes of this paravalvular leakage are various, in addition to the inevitable reasons such as the inability to remove the patient's original degenerated, decaying, and damaged valve, and the patient's own anatomical structure (such as the non-circularity of the valve annulus plane and other factors), it is also closely related to the design characteristics of the current transcatheter valve intervention surgical equipment. A number of studies have shown that paravalvular leakage after surgery is directly related to the degree of recovery of patients, reoperation rate, readmission rate, early and long-term mortality, etc.

[0004] The existing balloon-expandable artificial aortic valve usually sets an external sealing member on the outside of the inflow end to improve paravalvular leakage by increasing the contact area with the heart valve annulus plane. However, these existing valve structures still have problems, due to the implantation position of the artificial valve, the anatomical structure difference of the native aortic valve, and calcification, etc., resulting in a certain amount of paravalvular leakage after implantation of the artificial valve.

[0005] In order to prevent the balloon-expandable artificial aortic valve from being implanted too high and being subjected to blood flow impact force, resulting in the risk of displacement towards the ascending aorta, the inflow end of the artificial valve is usually located below the annulus of the aortic valve after expansion and release. Therefore, the outer skirt corresponding to the first set of circumferential grid structures of the valve support near the inflow end is usually not in contact with the surrounding valve tissue, which further reduces the protection ability of the existing valve design against paravalvular leakage.

[0006] In view of the above problems, there is a need for an artificial aortic valve that can effectively prevent paravalvular leakage to improve the surgical prognosis of patients. SUMMARY

[0007] The present application discloses an artificial heart valve and a transcatheter heart valve replacement system, aiming to solve the technical problems existing in the prior art. The present application adopts the following technical solutions: In a first aspect, the present application provides an artificial heart valve, comprising: - a valve stent having an inflow end and an outflow end, the valve stent being provided with a plurality of circumferentially arranged mesh groups in sequence from the outflow end to the inflow end, wherein the mesh group closest to the inflow end is adapted to match a position below the annulus plane, and at least one mesh group of the non-end mesh groups matching the annulus plane has a mesh opening size larger than that of at least one mesh group axially adjacent thereto; - an outer skirt covering the outer surface of the valve stent, the outer skirt covering at least two adjacent mesh groups close to the inflow end, and the outer skirt is configured to have a structure of increasing thickness from the outflow end to the inflow end at a position close to the inflow end.

[0008] As a preferred technical solution, the valve stent comprises a first mesh group to an Nth mesh group arranged in sequence from the outflow end to the inflow end, wherein N≥3; The non-end mesh group corresponds to a position abutting against the surrounding tissue after implantation, and the mesh opening size thereof is larger than that of the mesh group closest to the inflow end axially adjacent thereto.

[0009] As a preferred technical solution, the valve stent comprises a first mesh group, a second mesh group, a third mesh group and a fourth mesh group arranged in sequence from the outflow end to the inflow end; The third mesh group corresponds to a position abutting against the surrounding tissue after implantation, and the mesh opening size of the third mesh group is larger than that of the second mesh group and the fourth mesh group.

[0010] As a preferred technical solution, the outer skirt covers at least the third mesh group and the fourth mesh group, and the thickness of the outer skirt on the outer surface of the fourth mesh group is greater than that on the outer surface of other mesh groups.

[0011] As a preferred technical solution, the outer skirt covers at least the second mesh group to the fourth mesh group, and the thickness of the outer skirt on the outer surface of at least the third mesh group is less than that on the outer surface of the fourth mesh group.

[0012] As a preferred technical solution, at least one side of the outer skirt corresponding to the third mesh group is provided with a liquid-absorbing and swelling material, which is configured to absorb blood and slowly swell after implantation to adapt to the annulus structure; In the delivery state of the artificial heart valve, the liquid-absorbing and swelling material is arranged in the mesh opening of the third mesh group to reduce the radial size of the artificial heart valve in the compressed state.

[0013] As a preferred technical solution, the liquid-absorbing and swelling material is arranged in the mesh opening area of the third mesh group, and a thickness-reduced area or a liquid-absorbing and swelling material-free area of the liquid-absorbing and swelling material is provided on the stent skeleton of the third mesh group.

[0014] As a preferred technical solution, the liquid-absorbing and swelling material comprises a biological hydrogel.

[0015] As a preferred technical solution, the inner skirt is arranged on the inner surface of the valve stent and is used for connecting and supporting the artificial valve leaflets. The inner skirt and the outer skirt form an annular cavity, and the inner skirt is provided with a plurality of first openings distributed in the circumferential direction, which are used for allowing blood to flow into the annular cavity.

[0016] As a preferred technical solution, the artificial valve leaflets are made of bovine pericardium or porcine pericardium.

[0017] As a preferred technical solution, the first openings are arranged in the region corresponding to the third mesh group.

[0018] As a preferred technical solution, the inner skirt outside the region corresponding to the third mesh group and / or the inner side of the outer skirt is provided with a liquid-absorbing expansion material.

[0019] As a preferred technical solution, the outer skirt corresponding to the region of the third mesh group is provided with a plurality of second openings, and the second openings and the first openings are arranged in a circumferential direction.

[0020] As a preferred technical solution, the structure of the second opening is configured such that when the valve stent is in a compressed state, the second opening is in a closed state due to the tension of the outer skirt, so as to prevent blood from entering the annular cavity.

[0021] As a preferred technical solution, the second opening includes a flap structure that partially overlaps each other, and the flap structure covers each other to form a sealing structure when the valve stent is in a compressed state, and the flap structure separates to form an opening after the valve stent is expanded and released.

[0022] As a preferred technical solution, the first mesh group is provided with three joint fixing windows in the circumferential direction, which are used for fixing the connection of adjacent artificial valve leaflets; and the valve stent is further provided with three developing marks, which correspond to the three joint fixing windows in the axial direction.

[0023] In a second aspect, the embodiments of the present application provide a transcatheter heart valve replacement system, which comprises a delivery device and an artificial heart valve releasably connected to the distal end of the delivery device, and the artificial heart valve is the artificial heart valve according to any one of the above.

[0024] An embodiment of the above-mentioned application has the following advantages or beneficial effects: The present application mainly provides an artificial heart valve and a transcatheter heart valve replacement system, which effectively solves the problems of paravalvular leakage and annulus matching of the artificial heart valve in the prior art by the combination of the plurality of mesh groups on the valve stent and the outer skirt.

[0025] In one embodiment of the present application, the valve stent is provided with four groups of mesh structures from the outflow end to the inflow end, wherein the third mesh group has a larger mesh opening size, which can provide more accommodation space for the outer skirt in the crimped state, so as to reduce the outer diameter of the artificial heart valve during delivery. In addition, the larger mesh opening size also reduces the interference of the stent skeleton with the outer skirt fitting, so that the outer skirt can better fit the irregular or calcified tissue surface.

[0026] In one embodiment of the present application, the outer skirt adopts a thickness gradient change design, the thickness of the outer surface of the fourth mesh group is the largest, and the thickness of the outer surface of the third mesh group is smaller. This can not only avoid scratching the surrounding tissue or the balloon during the delivery process of the inflow end of the valve stent, but also can provide a buffer effect during the expansion of the artificial heart valve, prevent the apex of the inflow end from puncturing the balloon to cause the failure of valve implantation, and further reduce the risk of open chest surgery to remove the valve. In addition, the deformation adaptability of the outer skirt at the position of the third mesh group is improved, which can better adapt to the anatomic structure of the valve annulus of different patients.

[0027] In one embodiment of the present application, the inner side or the outer side of the outer skirt is also provided with a liquid-absorbing expansion material, which can absorb blood and slowly expand after release, thereby improving the fit of the artificial heart valve and the valve annulus. The liquid-absorbing expansion material can also be compressed in the mesh opening in the delivery state, thereby avoiding the problem of excessive compression size.

[0028] In one embodiment of the present application, an inner skirt is further provided, which surrounds the outer skirt to form an annular cavity. A plurality of first openings are arranged on the inner skirt corresponding to the third mesh group, so that the initially regurgitated blood can enter the annular cavity through the first openings to form a bulging sealing structure, thereby filling the irregular tissue gap. Arranging the first openings on the inner skirt can also avoid the risk of the outer skirt being inflated too early due to accidental filling of blood during the delivery of the artificial heart valve.

[0029] As a balloon-expandable aortic valve, the present application is suitable for transcatheter aortic valve replacement. The structural design can effectively enhance the sealing effect of the artificial heart valve and the original valve, reduce paravalvular leakage, thereby improve the implant success rate and long-term effect, and provide a safer and more effective scheme for clinical treatment. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows, which form a part of the present application. The schematic embodiments of the present application and their description and explanation do not constitute an improper limitation on the present application. In the drawings: Figure 1 The structural schematic diagram of the valve stent disclosed in one embodiment of the present application; Figure 2Cross-sectional view of a valve stent disclosed in one embodiment of the present invention; Figure 3 Structure diagram of a prosthetic heart valve disclosed in one embodiment of the present invention; Figure 4 Structure diagram of a prosthetic heart valve disclosed in one embodiment of the present invention; Figure 3 Front view of Figure 5 A-A cross-sectional view of Figure 4 Figure 6 Structure diagram of a prosthetic heart valve disclosed in one embodiment of the present invention; Figure 7 Cross-sectional view of Figure 6 Figure 8 Structure diagram of a prosthetic heart valve disclosed in one embodiment of the present invention; Figure 9 Cross-sectional view of Figure 8 Figure 10 Structure diagram of a prosthetic heart valve disclosed in one embodiment of the present invention; Figure 11 Cross-sectional view of Figure 10 Figure 12 Structure diagram of a prosthetic heart valve disclosed in one embodiment of the present invention; Figure 13 Front view of Figure 12 Figure 14 B-B cross-sectional view of Figure 13 Figure 15 Structure diagram of a prosthetic heart valve disclosed in one embodiment of the present invention; Figure 16 Cross-sectional view of Figure 15 Figure 17 Structure diagram of a prosthetic heart valve disclosed in one embodiment of the present invention; Figure 18 Structure diagram of a prosthetic heart valve disclosed in one embodiment of the present invention; Figure 19 Cross-sectional view of Figure 18

[0031] BRIEF DESCRIPTION OF THE DRAWINGS Valve stent 10, first mesh group 11, leaflet joint fixing window 111, second mesh group 12, third mesh group 13, fourth mesh group 14, outer skirt 20, second opening 21, inner skirt 30, first opening 31, liquid absorbing expansion material 40.​​​​​​​​ DETAILED DESCRIPTION

[0032] In order to make the objects, technical solutions and advantages of the present application clearer, the following will clearly and completely describe the technical solutions of the present application with specific embodiments of the present application and corresponding drawings. In the description of the present application, it should be noted that the term "or" is generally used in the sense of including "and / or" unless the content clearly dictates otherwise.

[0033] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection" should be understood in a broad sense. In addition, in the description of the present application, the terms "first", "second", etc. are only used for distinguishing description and cannot be understood as indicating or implying relative importance. The "proximal end" herein refers to an end close to the operator along the length direction of the prosthetic heart valve or the delivery device; the "distal end" refers to an end away from the operator along the length direction of the prosthetic heart valve or the delivery device.

[0034] It can be known by those skilled in the art that in order to realize respective functions and meet the requirements of surgical operation, the specific shape / size / angle of each structure can be adjusted adaptively. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0035] In order to solve the technical problems existing in the prior art, in one embodiment, the present application provides a prosthetic heart valve, which is preferably suitable for transcatheter aortic valve replacement, and is preferably configured as a balloon-expandable prosthetic valve. The valve stent 10 of the prosthetic heart valve is made of medical stainless steel or cobalt-chromium alloy by laser cutting. The prosthetic heart valve can be compressed and delivered to the target position through the delivery catheter, and the radial expansion and anchoring of the valve stent 10 are realized through balloon expansion. After balloon expansion is completed, the balloon is immediately retracted and withdrawn, and the prosthetic heart valve is fixed at the target position in an expanded state, supporting the normal opening and closing of the artificial valve leaflet and restoring the one-way blood flow function of the heart.

[0036] Compared with the self-expanding prosthetic valve, the balloon-expandable prosthetic valve is easier to control in positioning, which can reduce the risk of valve displacement. In addition, the expansion is more uniform during release, and a greater radial force can be applied, so that the native valve annulus is closer to the ideal circle, thereby reducing the incidence of paravalvular leakage, and it is especially suitable for patients with calcification or specific anatomical structures (such as transverse heart).

[0037] As Figures 3-5In some embodiments, the prosthetic heart valve comprises a valve stent 10 and an outer skirt 20, wherein the valve stent 10 is configured in a compressed state for delivery and is balloon-expanded to a deployed state after release, and the axial length of the valve stent 10 is shortened after radial expansion, and the profile of the valve stent 10 is cylindrical; the outer skirt 20 is a membrane material, which can be PET or ePTFE material, and is arranged on the outer surface of the valve stent 10 to conform to the annulus to reduce paravalvular leakage.

[0038] Reference Figure 1 , Figure 2 In some embodiments, the valve stent 10 has an inflow end and an outflow end along its axial direction; for example, for aortic valve replacement, when the prosthetic heart valve is released in the heart, the inflow end corresponds to the left ventricular side for blood pumping in, and the outflow end corresponds to the aortic side for blood pumping out; the valve stent 10 is provided with a plurality of circumferentially arranged mesh groups from the outflow end to the inflow end, each mesh group comprises a plurality of polygonal mesh structures connected to each other, and each mesh structure encloses a mesh opening; adjacent mesh structures are preferably connected by wave rods or nodes, wherein the polygonal mesh can be selected from a closed shape unit formed by a rhombus, a pentagon, a hexagon, etc., and the mesh structures in the same mesh group preferably have the same polygonal shape, and the mesh structures in adjacent mesh groups can have the same or different polygonal shape.

[0039] In some embodiments, the mesh group closest to the inflow end is suitable for matching a position below the annulus plane, and the specific release depth can be adjusted according to clinical needs and specific anatomical structures of the patient. When the mesh group closest to the inflow end is matched to a position below the annulus plane, this state can provide more stable anchoring effect to prevent the prosthetic heart valve from moving in the direction of the aorta after implantation due to blood flow impact, thereby enhancing the positional stability of the prosthetic heart valve.

[0040] In some embodiments, the mesh opening size of at least one non-end mesh group is larger than the mesh opening size of at least one mesh group adjacent to it in the axial direction. The larger mesh opening size can provide more accommodation space for the outer skirt 20 in the crimped state to reduce the outer diameter of the prosthetic heart valve during delivery. In addition, the larger mesh opening size also reduces the interference of the stent skeleton with the fitting of the outer skirt 20, so that the outer skirt 20 can better conform to irregular or calcified tissue surfaces.

[0041] In some embodiments, the outer skirt 20 covers at least two adjacent mesh groups close to the inflow end, and the positions corresponding to these mesh groups are the areas in contact with the annulus tissue and below the annulus plane. Covering the outer skirt 20 at least in these areas can prevent paravalvular leakage.

[0042] In some embodiments, the outer skirt 20 is configured to have an increasing thickness from the outflow end to the inflow end, and the mesh groups at the inflow end are configured to have a relatively sharp apex. The thickened outer skirt 20 can effectively cover the apex of the mesh groups at the inflow end, so as to avoid scratching the surrounding tissue or the balloon during the delivery process. In addition, the outer skirt 20 at the inflow end can provide a buffer effect during the expansion of the prosthetic heart valve, so as to prevent the mesh groups from piercing the balloon and causing the failure of the prosthetic heart valve implantation.

[0043] In some embodiments, the outer skirt 20 corresponding to the mesh groups in direct contact with the annulus is configured to have a relatively thin thickness, so as to enhance the deformation adaptability and facilitate the fitting of the irregular annulus surface. The mesh groups are preferably the non-end mesh groups with a larger mesh opening, and the relatively thin thickness of the outer skirt 20 and the relatively large mesh opening size can greatly reduce the risk of cardiac conduction block when the outer skirt 20 is in contact with the annulus tissue, thereby avoiding the implantation of a permanent pacemaker in the patient.

[0044] In some embodiments, the valve stent 10 comprises first mesh groups 11 to Nth mesh groups arranged in sequence from the outflow end to the inflow end, wherein N≥3; the non-end mesh groups correspond to the positions in contact with the surrounding tissue after implantation, and the mesh opening size of the non-end mesh groups is larger than that of the mesh groups adjacent to the inflow end in the axial direction.

[0045] Specifically, N can be 3, 4, 5 or more, and different N values correspond to different axial distribution densities of the mesh groups. A larger N value means that the mesh groups of the valve stent 10 are arranged more densely in the axial direction, so as to provide more precise mechanical performance zoning. A smaller N value means that the mesh groups of the valve stent 10 are arranged more sparsely in the axial direction, and the span of each mesh group in the axial direction is relatively large, so as to realize a larger mesh opening size while ensuring the overall strength of the valve stent 10. When multiple mesh groups are in contact with the surrounding tissue after implantation, the non-end mesh groups in contact with the tissue can be simultaneously configured to have a larger mesh opening size, so as to improve the fitting with the tissue.

[0046] As Figure 2In some embodiments, N is 4, i.e. the valve stent 10 comprises a first mesh group 11, a second mesh group 12, a third mesh group 13 and a fourth mesh group 14 arranged in sequence from the outflow end to the inflow end, wherein the third mesh group 13 corresponds to the position abutting against the surrounding tissue after implantation, i.e. the position of the annular plane, and the fourth mesh group 14 corresponds to the position of the left ventricular outflow tract below the annulus; the mesh opening size of the third mesh group 13 is preferably greater than the mesh opening size of the second mesh group 12 and the fourth mesh group 14, so as to reduce the interference of the stent skeleton outer skirt 20 fitting, and enable the outer skirt 20 to more fully adapt to the irregular or calcified annular surface.

[0047] In some embodiments, the outer skirt 20 covers at least the third mesh group 13 and the fourth mesh group 14, and the thickness of the outer skirt 20 on the outer surface of the fourth mesh group 14 is greater than the thickness of the outer skirt 20 on the outer surface of the other mesh groups; the thickness of the outer skirt 20 can adopt two different configuration modes, one is a continuous increasing trend along the direction from the third mesh group 13 to the fourth mesh group 14; the other is that the outer skirt 20 corresponding to the third mesh group 13 maintains a uniform thickness, and the outer skirt 20 corresponding to the fourth mesh group 14 also maintains a uniform thickness, but the thickness of the outer skirt 20 on the outer surface of the fourth mesh group 14 is greater than the thickness of the outer skirt 20 on the outer surface of the third mesh group 13.

[0048] As shown in FIG. 1, the outer skirt 20 is arranged on the outer surface of the valve stent 10, and the outer skirt 20 covers at least the third mesh group 13 and the fourth mesh group 14. Figures 3-5 In some embodiments, the outer skirt 20 covers at least the second mesh group 12 to the fourth mesh group 14, so as to further improve the overall sealing performance of the artificial heart valve, especially for patients with anatomical structure variation or uneven calcification distribution, and the larger coverage range enables the outer skirt 20 to form a sealed contact with a larger area of the surrounding tissue, so as to reduce the risk of paravalvular leakage. Preferably, the thickness of the outer skirt 20 on the outer surface of the third mesh group 13 is less than the thickness of the outer skirt 20 on the outer surface of the fourth mesh group 14, and the thickness configuration mode of the outer skirt 20 can adopt a continuous transition structure gradually increasing from the second mesh group 12 to the fourth mesh group 14, or the outer skirt 20 corresponding to the second mesh group 12 and the third mesh group 13 maintains a uniform thickness, but a stepped increasing transition structure is formed between the two and the fourth mesh group 14.

[0049] In some embodiments, the upper edge of the outer skirt 20 can be arranged along the edge of the mesh, as shown in FIG. 1. Figures 3-5 ; or can be arranged straight along the circumference of the valve stent 10, as shown in FIG. 2. Figure 6 and Figure 7 At this time, the upper edge of the outer skirt 20 can only cover half or other proportion of the axial length of the second mesh group 12.

[0050] In some embodiments, the outer skirt 20 corresponding to the third mesh group 13 is further provided with a liquid-absorbing and swelling material 40, which can be arranged on the outer side of the outer skirt 20, as shown in FIG. 3.Figure 8 and Figure 9 , also can be arranged at the inner side, such as Figure 10 , Figure 11 The liquid-absorbing swelling material 40 is configured to absorb blood and slowly swell after implantation.

[0051] When the artificial heart valve is released to the target position, the liquid-absorbing swelling material 40 gradually absorbs the surrounding blood, increases in volume and fills the gap between the valve stent 10 and the irregular calcified tissue, and cooperates with the excellent deformation performance of the outer skirt 20 of the section to further form a sufficient seal with the irregular calcified tissue around, which is of great significance to reduce the risk of paravalvular leakage for patients with severe calcification of the valve ring and valve leaflets.

[0052] In some embodiments, when the artificial heart valve is compressed and loaded into the delivery system, the liquid-absorbing swelling material 40 is arranged in the mesh opening of the third mesh group 13, which can effectively utilize the mesh opening space and reduce the radial size of the artificial heart valve in the compressed state. In addition, this arrangement can also ensure the stability of the liquid-absorbing swelling material 40 during delivery, prevent the material from swelling due to premature contact with blood or falling off due to shear force during delivery, and when the artificial heart valve is released by balloon expansion, the liquid-absorbing swelling material 40 compressed in the mesh opening is unfolded, restores its original structure and prepares to perform the sealing function.

[0053] As Figure 8 , Figure 9 In some embodiments, the liquid-absorbing swelling material 40 is arranged corresponding to the mesh opening area of the third mesh group 13, and the stent skeleton directly opposite the area is provided with a thickness-thinned area or an area without liquid-absorbing swelling material 40.

[0054] Specifically, the stent skeleton itself is in direct contact with the tissue and provides radial support force, and these areas are usually not the main paravalvular leakage passage, so no or only a small amount of liquid-absorbing swelling material 40 is needed; while the mesh opening area is a potential paravalvular leakage passage, more liquid-absorbing swelling material 40 is needed to form an effective seal; secondly, the liquid-absorbing swelling material 40 in the stent skeleton area is thinned or missing, which can reduce the cladding thickness of the skeleton strut, and help to further reduce the overall diameter of the artificial heart valve in the compressed state. In the actual manufacturing process, this regionalized material distribution can be realized by precise coating, molding or hot pressing and other process methods, to ensure that the liquid-absorbing swelling material 40 provides the best sealing effect at the key position, while maintaining the compactness and compressibility of the overall structure.

[0055] In some embodiments, the liquid-absorbing and swelling material 40 comprises a biological hydrogel, which is a kind of three-dimensional network structure composed of hydrophilic polymer chains, capable of absorbing a large amount of water in an aqueous solution environment without dissolving, while maintaining structural integrity. After liquid-absorbing and swelling, the soft elastomer formed thereby can dynamically adapt to the morphological changes of the surrounding tissue, especially providing a sustained sealing effect during the systole and diastole of the heart.

[0056] In some embodiments, by adjusting the degree of chemical cross-linking of the biological hydrogel, a controllable swelling rate and swelling ratio can be achieved to accurately match the clinical requirements. In this embodiment, a biological hydrogel formulation with slow swelling kinetic characteristics is preferably used. By controlling the cross-linking reaction parameters, the hydrogel exhibits a gradual swelling behavior within a few hours after contacting blood, allowing sufficient time for the surrounding tissue to adapt to the morphological changes, while the hemodynamic parameters can be maintained stable, avoiding the application of sudden mechanical pressure on the annulus tissue, thereby inducing or exacerbating the heart failure state of the patient. In addition, this slow swelling characteristic also promotes the gradual adaptation and integration between the biological hydrogel and the surrounding tissue, forming a more stable long-term sealing interface. In this embodiment, the specific swelling rate and swelling ratio of the biological hydrogel are no longer limited, and those skilled in the art can make adaptive choices according to the actual needs of the patient and the clinic.

[0057] As Figures 12-14 In some embodiments, the artificial heart valve further comprises an inner skirt 30, which can be made of the same membrane material as the outer skirt 20, covering the inner surface of the valve stent 10, for connecting and supporting the artificial valve leaflets (for the sake of clear structure display, the shape of the artificial valve leaflets is not further shown in the figure).

[0058] Clinically used biological valves are usually stored in glutaraldehyde solution, which not only can kill microorganisms, but also has good cross-linking effect, making the biological membrane structure stable, but at the same time, there are the following problems: the aldehyde group causes the calcification of the biological valve, affecting the service life; the storage of the biological valve is inconvenient, and the transportation cost is high; before clinical use, it needs to be rinsed, and the operation is complicated.

[0059] To avoid the above problems, in some embodiments, the artificial valve leaflets are preferably made of dry valve leaflets made of bovine or porcine pericardium. Compared with traditional wet biological valve, dry valve leaflets have the advantages of convenient storage, low transportation cost, no need to rinse before clinical use, etc., at the same time, due to the avoidance of long-term soaking in glutaraldehyde solution, the risk of calcification caused by aldehyde group is effectively reduced, the service life of the valve is potentially prolonged, and good hemodynamic performance is maintained.

[0060] In some embodiments, the inner skirt 30 and the outer skirt 20 enclose an annular cavity. Specifically, the inner skirt 30 and the outer skirt 20 can adopt an integrated structure, or adopt a split structure and be connected by sewing; the coverage of the inner skirt 30 on the inner side of the valve stent 10 at least includes the third mesh group 13 to the fourth mesh group 14, so as to ensure that the annular cavity enclosed by the inner skirt 30 and the outer skirt 20 can correspond to the position of the valve annulus, so as to ensure the sealing of the valve annulus.

[0061] The upper end edge of the outer skirt 20 can adopt a flat structure along the circumference of the valve stent 10, such as Figure 18 , Figure 19 , or can be configured as a wave-shaped profile along the mesh structure, such as Figures 15-17 ; the upper end edge of the inner skirt 30 can also adopt a flat or wave-shaped profile, and the upper end edges of the inner skirt 30 and the outer skirt 20 can adopt the same or different profiles, and the sewing fixing point position of the outer skirt 20 / inner skirt 30 and the valve stent 10 can be flexibly configured according to the specific sealing requirements and the structure of the valve stent 10, and the core purpose is to ensure that the outer skirt 20 can form a controlled protruding sealing structure in the radial direction during the expansion of the valve stent 10 by the balloon, so as to improve the adaptability to irregular valve annulus shapes.

[0062] In some embodiments, a plurality of first openings 31 are arranged on the inner skirt 30 in a circumferential direction, and the first openings 31 are used for blood to flow into the annular cavity, such as Figure 15 , Figure 16 .

[0063] In some embodiments, the first openings 31 are uniformly or non-uniformly distributed in the circumferential direction, and are preferably arranged in the region corresponding to the third mesh, so that the annular cavity corresponds to the valve annulus plane. When the valve is closed in diastole, a plurality of first openings 31 allow regurgitant blood to enter the annular cavity through a controlled path, so that the outer side of the annular cavity presents a radial bulging state, so as to effectively fill the irregular gap or calcified depression around the valve annulus, and form a dynamic self-adaptive sealing structure.

[0064] Specifically, during the delivery of the artificial heart valve, the outer skirt 20 is directly exposed to the blood flow environment, and if the outer skirt 20 is provided with openings, it may cause blood to enter the annular cavity in advance before the artificial heart valve reaches the target position, causing the outer skirt 20 to expand too early. This not only increases the through resistance of the delivery system, but also may cause the valve to be deviated or damage the blood vessel wall. By arranging the first openings 31 only on the inner skirt 30, it can ensure that the annular cavity can be filled with blood only after the artificial heart valve is completely released and starts to work, so as to realize a controllable timing activation sealing mechanism.

[0065] In some embodiments, the inner skirt 30 preferably adopts a material with a lower elastic modulus, or adopts a smaller coverage size compared to the outer skirt 20. When the balloon expands to release the valve stent 10 to the target diameter, the inner skirt 30 material is stretched to near its elastic limit state, forming a highly pre-tensioned membrane structure. When the diastolic blood enters the annular cavity through the first apertures 31 of the inner skirt 30, the outer skirt 20 can flexibly expand radially outward due to its higher elasticity and compliance, forming an effective sealing barrier, while the inner skirt 30 maintains a stable form, avoiding the inner skirt 30 from inflating inward, which would reduce the effective orifice area (EOA) of the valve, increase the transvalvular pressure difference, and possibly interfere with the normal opening and closing function of the valve leaflets. By ensuring that the inner skirt 30 maintains a stable form, the geometric continuity and fluid dynamics performance of the blood flow passage are effectively guaranteed, while still allowing the outer skirt 20 to fully exert its sealing function and form a dynamic adaptation to the irregular annulus tissue.

[0066] In other embodiments, the inner skirt 30 outside the area corresponding to the third mesh group 13 is provided with a liquid-absorbing and swelling material 40, as shown by the dashed line in Figure 17 , and / or the outer skirt 20 inside the area corresponding to the third mesh group 13 is provided with a liquid-absorbing and swelling material 40, as shown by the dashed line in Figure 18 , Figure 19 . Preferably, the outer skirt 20 corresponding to the area of the third mesh group 13 is provided with a plurality of second apertures 21 to improve the opportunity for the liquid-absorbing and swelling material 40 to contact blood; the second apertures 21 are preferably arranged in a circumferential staggered manner with the first apertures 31 to avoid direct blood loss therebetween, thereby ensuring that the liquid-absorbing and swelling material 40 can fully contact blood and function.

[0067] Specifically, the inner skirt 30 outside and the outer skirt 20 inside the area corresponding to the third mesh group 13 essentially define the internal space of the annular cavity. Therefore, the liquid-absorbing and swelling material 40 is actually configured inside the annular cavity to ensure that the liquid-absorbing and swelling material 40 inside the annular cavity can efficiently absorb blood and be locked within the cavity, forming a dynamic self-adaptive sealing system, and effectively and actively filling the irregular gaps and small gaps around the annulus by transmitting pressure outward through the outer skirt 20, significantly reducing the risk of paravalvular leakage.

[0068] In some embodiments, the structure of the second apertures 21 is configured such that when the valve stent 10 is in a compressed state, the second apertures 21 are in a closed state due to the tension on the outer skirt 20 to prevent blood from entering the annular cavity.

[0069] Specifically, when the valve stent 10 is in a radially compressed state within the delivery system, the outer skirt 20 is subjected to a high degree of axial tension, which can tighten the second opening 21 to a closed state, effectively blocking the possibility of blood entering the annular cavity through the second opening 21, thereby avoiding the difficulty of delivery or deviation of positioning caused by premature increase in the volume of the valve. When the valve stent 10 is released to the target diameter by balloon expansion, the axial tension of the outer skirt 20 is significantly reduced, at which time the second opening 21 automatically changes to an open state, allowing blood to enter the annular cavity and contact the liquid-absorbing swelling material 40 to activate the sealing function.

[0070] In some embodiments, the second opening 21 includes a flap structure that partially overlaps each other, the flap structure covers each other to form a sealing structure when the valve stent 10 is in a compressed state, and the flap structure separates to form an opening after the valve stent 10 is expanded and released.

[0071] Specifically, the flaps are configured as semi-elliptical or crescent-shaped, with their long axis direction consistent with the principal stress direction of the valve stent 10 in a compressed state. The overlapping area of the flaps is functionally similar to the structure of the front and back fly of a garment. When the valve stent 10 is in a compressed state, the circumferential contraction of the entire artificial valve causes these flaps to overlap to a greater extent, forming a barrier structure that effectively prevents blood from penetrating; when the valve stent 10 begins to expand, the circumferential tension decreases, and the overlapping area between the flaps gradually decreases until, in the fully released state, the flap structure automatically separates along the pre-set separation line to form a clear opening profile to allow blood to flow from the external environment into the annular cavity.

[0072] As Figure 1 In some embodiments, the first mesh group 11 is provided with three flap joint fixing windows 111 in the circumferential direction, which are used to fix the connection of adjacent artificial valve flaps; the valve stent 10 is also provided with three radiographic markers, which correspond one-to-one with the three flap joint fixing windows 111 in the axial direction, for aligning with the joint of the native valve flap under intraoperative X-ray fluoroscopy, thereby avoiding the artificial valve flap from blocking the coronary artery opening, and thus reducing the risk of postoperative coronary artery occlusion.

[0073] Specifically, the radiographic markers can be provided on the stent structure, or on the corresponding positions of the outer skirt 20 or the inner skirt 30, and can be made of tantalum, platinum-iridium alloy or other biocompatible materials with good X-ray opacity, and can be in the shape of a dot, a ring or a line, so as to facilitate accurate identification during surgery. Compared with the prior art, the above embodiments can effectively enhance the sealing effect of the artificial heart valve and the original valve, reduce paravalvular leakage, thereby improving the success rate of implantation and long-term effect, and providing a safer and more effective solution for clinical treatment.

[0074] In another embodiment of the present application, there is also provided a transcatheter heart valve replacement system comprising a delivery device and the above-mentioned artificial heart valve, the artificial heart valve being releasably connected to the distal end of the delivery device and preferably configured as a balloon-expandable artificial valve suitable for transcatheter aortic valve replacement.

[0075] Since the artificial heart valve of the present application is compatible with the prior art in terms of key parameters such as peripheral profile size, stent contraction-expansion characteristics, and proximal-distal connection structure, the delivery device of the present embodiment can adopt any of the technical solutions in the existing mature transcatheter valve delivery systems. The specific structural form of the delivery device does not constitute the limiting technical features of the present application, and can be selected according to clinical needs, surgical approach (such as transfemoral, transapical, or transaortic), and operator preference. The technical innovation of the present application is mainly embodied in the artificial heart valve structure itself, especially its anti-paravalvular leakage design, while the delivery device is designed with functional interoperability as the principle, ensuring seamless integration with the existing clinical workflow, reducing the learning curve and clinical adoption threshold.

[0076] Although example embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the above description is merely of example embodiments and is not intended to limit the scope of the present application. Various changes and modifications can be made thereto by those of ordinary skill in the art without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as claimed in the appended claims.

Claims

1. A prosthetic heart valve, characterized in that, The artificial heart valve comprises: a valve stent having an inflow end and an outflow end, the valve stent being provided with a plurality of circumferentially arranged mesh groups in sequence from the outflow end to the inflow end, wherein the mesh group closest to the inflow end is adapted to match a position below the annular plane of the valve annulus, and the mesh opening size of at least one non-end mesh group matching the annular plane is greater than that of at least one mesh group axially adjacent thereto; an outer skirt covering the outer surface of the valve stent, the outer skirt covering at least two adjacent mesh groups close to the inflow end, and the outer skirt being configured as a structure with increasing thickness from the outflow end to the inflow end at a position close to the inflow end.

2. The prosthetic heart valve of claim 1, wherein, The valve stent comprises a first mesh group to an Nth mesh group arranged in sequence from the outflow end to the inflow end, wherein N≥3; The mesh opening size of the non-end mesh group corresponding to a position abutting against the surrounding tissue after implantation is greater than that of the mesh group closest to the inflow end axially adjacent thereto.

3. The prosthetic heart valve of claim 2, wherein, The valve stent comprises a first mesh group, a second mesh group, a third mesh group and a fourth mesh group arranged in sequence from the outflow end to the inflow end; The mesh opening size of the third mesh group corresponding to a position abutting against the surrounding tissue after implantation is greater than that of the second mesh group and the fourth mesh group.

4. The prosthetic heart valve of claim 3, wherein, The outer skirt covers at least the third mesh group and the fourth mesh group, and the thickness of the outer skirt on the outer surface of the fourth mesh group is greater than that on the outer surface of other mesh groups.

5. The prosthetic heart valve of claim 4, wherein, The outer skirt covers at least the second mesh group to the fourth mesh group, and the thickness of the outer skirt on the outer surface of at least the third mesh group is less than that on the outer surface of the fourth mesh group.

6. The prosthetic heart valve of claim 5, wherein, At least one side of the outer skirt corresponding to the third mesh group is provided with a liquid-absorbing and swelling material configured to absorb blood and slowly swell after implantation to adapt to the structure of the valve annulus. In the delivery state of the artificial heart valve, the liquid-absorbing and swelling material is arranged in the mesh opening of the third mesh group in a compressed state to reduce the radial size of the artificial heart valve in the compressed state.

7. The prosthetic heart valve of claim 6, wherein, The liquid-absorbing and swelling material is arranged in the mesh opening area of the third mesh group, and a thickness reduction area or a liquid-absorbing and swelling material-free area of the liquid-absorbing and swelling material is provided on the stent skeleton of the third mesh group.

8. The prosthetic heart valve of claim 6, wherein, The liquid-absorbing and swelling material comprises a biological hydrogel.

9. The prosthetic heart valve of claim 4, wherein, Further comprising an inner skirt covering the inner surface of the valve stent for connecting and supporting artificial valve leaflets; The inner skirt and the outer skirt form an annular cavity, and the inner skirt is provided with a plurality of first openings distributed circumferentially, which are used for blood to flow into the annular cavity.

10. The prosthetic heart valve of claim 9, wherein, The artificial valve leaflets comprise dry valve leaflets made of bovine pericardium or porcine pericardium.

11. The prosthetic heart valve of claim 9, wherein, The first openings are arranged in the area corresponding to the third mesh group.

12. The prosthetic heart valve of claim 11, wherein, The outer side of the inner skirt and / or the inner side of the outer skirt in the area corresponding to the third mesh group is provided with a liquid-absorbing and swelling material.

13. The prosthetic heart valve of claim 12, wherein, The third mesh group is located in an area corresponding to the outer skirt, and the outer skirt is provided with a plurality of second openings, and the second openings are arranged in a circumferential direction staggered with the first openings.

14. The prosthetic heart valve of claim 13, wherein, The structure of the second openings is configured to be in a closed state when the valve stent is in a compressed state, so as to prevent blood from entering the annular cavity.

15. The prosthetic heart valve of claim 14, wherein, The second openings comprise flap structures that partially overlap each other, and the flap structures cover each other to form a sealing structure when the valve stent is in a compressed state, and the flap structures are separated to form openings after the valve stent is released.

16. The prosthetic heart valve of claim 9, wherein, The first mesh group is provided with three joint fixing windows in a circumferential direction, for fixing the connection of adjacent artificial valve leaves. The valve stent is further provided with three developing markers, and the three developing markers correspond to the three joint fixing windows in an axial direction.

17. A transcatheter heart valve replacement system comprising a delivery device and a prosthetic heart valve releasably connected to a distal end of the delivery device, characterized in that, The artificial heart valve is the artificial heart valve according to any one of claims 1-16; and the artificial heart valve is configured as a balloon-expandable artificial valve, and is suitable for transcatheter aortic valve replacement.

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