An artificial heart valve

Abstract

The present invention relates to an artificial heart valve, which comprises a valve stent, a first sealing membrane, a second sealing membrane, valve leaflets and valve leaflet anchoring members. The valve stent includes an inflow section and an outflow section; the first sealing membrane is attached to the outer side of the valve stent and comprises a hydrophilic swelling material, which can absorb liquid and swell after contacting with blood, for reducing paravalvular leakage; the second sealing membrane is arranged on the outer side of the first sealing membrane and at least covers all regions corresponding to the outer surface of the inflow section, for increasing the friction with the native valve leaflets; the valve leaflets are arranged inside the valve stent for controlling the unidirectional flow of blood; the valve leaflet anchoring members are spiral and can be coiled outside the mitral / tricuspid chordae tendineae plexus and interact with the valve stent. By providing the first sealing membrane and the second sealing membrane, the artificial heart valve of the present invention can better fit with the native tissue after being implanted into the mitral / tricuspid valve, so as to effectively prevent the occurrence of paravalvular leakage.

Description

Technical Field

[0001] The present invention relates to the field of medical devices for cardiac surgery, and particularly to an artificial heart valve. Background Art

[0002] The heart includes four pumping chambers, namely the left atrium, the right atrium, the left ventricle, and the right ventricle. Each pumping chamber has a valve that controls its unidirectional outflow. Among them, the mitral valve is located between the left atrium and the left ventricle. When the ventricle contracts, the mitral valve tightly closes the atrioventricular orifice to prevent blood from flowing back into the left atrium. The tricuspid valve is located between the right atrium and the right ventricle. When the right ventricle contracts, it squeezes the blood in the ventricle to impact the tricuspid valve and close it, preventing blood from flowing back into the right atrium.

[0003] A functionally perfect mitral valve or tricuspid valve can ensure correct blood circulation during the cardiac cycle. However, when the leaflets of the valve cannot achieve complete contact (engagement) due to disease, mitral regurgitation (MR) or tricuspid regurgitation (TR) will occur. On the other hand, abnormal cardiac structure may also be the cause of regurgitation, and these two processes can accelerate abnormal cardiac function due to "synergistic effects".

[0004] Currently, the standard treatment for cardiac valve regurgitation usually requires surgical methods. Standard surgical repair or replacement operations require thoracotomy, the use of cardiopulmonary bypass, and cardiac arrest. Due to the invasive nature of these surgical operations, deaths, strokes, bleeding, respiratory problems, kidney problems, and other complications are common. Therefore, patients often refuse or are judged as unsuitable for traditional open surgery due to the high risks.

[0005] In recent years, due to the successful advancement of aortic valve replacement, it has inspired the exploration of transcatheter mitral / tricuspid valve replacement for the treatment of regurgitation. However, mitral / tricuspid valve replacement is much more difficult than aortic replacement in many aspects. For example, the spatial structure of the mitral / tricuspid valve is not a traditional circular shape, the mitral / tricuspid valve has a more complex organizational structure (annulus, leaflets, chordae tendineae, papillary muscles), the mitral / tricuspid valve is larger than the aorta and is more slender in shape, the leaflets of the mitral / tricuspid valve are soft in texture. Compared with aortic valve stenosis or calcification, the mitral / tricuspid valve cannot provide good retention for the replacement valve. At the same time, when the ventricle contracts, the pressure in the ventricle will rise sharply. If the replacement valve fails to establish sufficient anchoring at the annulus, there will be a risk of displacement. Therefore, to effectively perform mitral / tricuspid valve replacement for the treatment of regurgitation, not only must it withstand the large periodic loads from the mitral / tricuspid valve, but more importantly, establish stable and firm anchoring. Summary of the Invention

[0006] The present invention discloses an artificial heart valve, aiming to solve the technical problems existing in the prior art.

[0007] The present invention adopts the following technical solutions:

[0008] An artificial heart valve, comprising:

[0009] - A valve stent, the valve stent includes an inflow section and an outflow section;

[0010] - A first sealing membrane, the first sealing membrane is attached to the outer side of the valve stent, the first sealing membrane includes a hydrophilic swelling material, and the hydrophilic swelling material can absorb liquid and swell after contacting with blood, so as to reduce perivalvular leakage;

[0011] - A second sealing membrane, the second sealing membrane is arranged on the outer side of the first sealing membrane, and the second sealing membrane covers at least all the areas corresponding to the outer surface of the inflow section; the second sealing membrane is used to increase the friction force with the native leaflets;

[0012] - Leaflets, the leaflets are arranged inside the valve stent and are used to control the unidirectional flow of blood;

[0013] - Leaflet anchoring members, the leaflet anchoring members are spiral, can be coiled outside the mitral / tricuspid chordal plexus, and interact with the valve stent implanted in the mitral / tricuspid valve.

[0014] As a preferred technical solution, the valve stent is cylindrical; the valve stent includes a plurality of interconnected polygonal grid structures.

[0015] As a preferred technical solution, the lower edge of the first sealing membrane is sutured to the lower edge of the outer side of the inflow section, and the lower edge of the first sealing membrane matches the shape of the lower edge of the inflow section; the upper edge of the first sealing membrane is turned inwards from the upper edge of the inflow section and sutured to the upper part of the inner side of the inflow section.

[0016] As a preferred technical solution, the first sealing membrane covers the upper edge of the inflow section, and the first sealing membrane covering the upper edge of the inflow section is cylindrical.

[0017] As a preferred technical solution, the upper edge of the first sealing membrane is turned inwards in an arc shape, and an annular cavity is formed between the folded area of the first sealing membrane and the upper edge of the inflow section.

[0018] As a preferred technical solution, an elastic membrane-like material, a biocompatible sponge-like material or a fiber aggregate is provided in the annular cavity.

[0019] As a preferred technical solution, the thickness of the first sealing membrane is 0.3 - 1 mm; the length of the upper edge of the first sealing membrane turned inwards is 4 - 6 mm.

[0020] As a preferred technical solution, the valve leaflets are sutured to the inner side of the inflow section; the second sealing membrane is sutured to the outer surface of the first sealing membrane.

[0021] As a preferred technical solution, the lower edge of the second sealing membrane matches the shape of the lower edge of the first sealing membrane and / or the inflow section.

[0022] As a preferred technical solution, the hydrophilic swelling material includes a biohydrogel.

[0023] As a preferred technical solution, the second sealing membrane is made of a biocompatible fabric.

[0024] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0025] (1) The present invention provides an artificial heart valve. In a preferred technical solution of the present invention, a first sealing membrane is sutured to the outer side of the inflow section of the valve stent, and a second sealing membrane is sutured outside the first sealing membrane. The upper edge of the first sealing membrane is higher than the inflow section and is folded inward to form a roughly cylindrical structure; the first sealing membrane is preferably a biohydrogel, and the second sealing membrane allows blood to pass through. When the artificial heart valve is implanted into the native mitral / tricuspid valve, on the one hand, the first sealing membrane has excellent water-proof performance and can prevent blood from leaking out of the valve, effectively preventing paravalvular leakage; on the other hand, as the artificial heart valve is implanted into the human body for a longer time, the first sealing membrane can gradually increase the gap between the artificial heart valve and the surrounding native tissue by using its swelling property, further preventing the occurrence of paravalvular leakage.

[0026] (2) In a preferred solution, the part of the first sealing membrane folded outward is arc-shaped, and there is an annular cavity between the first sealing membrane and the valve stent. An elastic material, a spongy material or a fiber composite is provided in the annular cavity so that the folded area of the first sealing membrane can collapse or recover. During the process of delivering the valve stent, the cavity collapses to ensure smooth delivery, and after the valve stent is released, the cavity expands to increase the volume of the folded area, so that the inflow section can better fit the native valve annulus and enhance the fixing effect.

[0027] (3) In a preferred embodiment of the present invention, an anchor is further provided outside the chordae tendineae plexus of the mitral / tricuspid valve. The anchor can directly cooperate with the implanted valve stent to avoid deformation or displacement of the valve stent during the contraction or relaxation of the native tissue, effectively ensuring the fixed position of the valve stent and reducing its displacement risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments, which form a part of the present invention. The schematic embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0029] Figure 1 Schematic diagram of the structure of a valve stent in a preferred embodiment disclosed in Embodiment 1 of the present invention;

[0030] Figure 2 Schematic diagram of the structure of an artificial heart valve in a preferred embodiment disclosed in Embodiment 1 of the present invention;

[0031] Figure 3 Stereogram of an artificial heart valve in a preferred embodiment disclosed in Embodiment 1 of the present invention;

[0032] Figure 4 Bottom view of an artificial heart valve in a preferred embodiment disclosed in Embodiment 1 of the present invention;

[0033] Figure 5 Schematic diagram of the structure of a leaflet anchor in a preferred embodiment disclosed in Embodiment 1 of the present invention;

[0034] Figure 6 Schematic diagram of the structure after an artificial heart valve is implanted into the mitral valve in a preferred embodiment disclosed in Embodiment 1 of the present invention;

[0035] Figure 7 Cross-sectional view of an artificial heart valve in a preferred embodiment disclosed in Embodiment 2 of the present invention.

[0036] Explanation of reference numerals:

[0037] Valve stent 1, inflow section 11, outflow section 12, first sealing film 2, second sealing film 3, leaflet 4, leaflet anchor 5, native mitral valve 6, annular cavity 7. Detailed implementation manners

[0038] To make the objectives, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions of the present invention in conjunction with the specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is generally used in the sense of including "and / or", unless otherwise clearly specified in the content.

[0039] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of this application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0040] Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0041] To solve the problems existing in the prior art, the embodiments of this application provide an artificial heart valve. The main structure includes a valve stent, a first sealing film, a second sealing film, valve leaflets, and valve leaflet anchoring members; wherein, the valve stent includes an inflow section and an outflow section; the first sealing film is attached to the outside of the valve stent, and the first sealing film includes a hydrophilic swelling material which can absorb liquid and swell after contacting with blood, for reducing paravalvular leakage; the second sealing film is arranged on the outside of the first sealing film, and the second sealing film covers at least all the areas corresponding to the outer surface of the inflow section, for increasing the friction with the native valve leaflets; the valve leaflets are arranged inside the valve stent, for controlling the one-way flow of blood; the valve leaflet anchoring members are spiral-shaped and can be wound around the mitral / tricuspid chordal plexus and interact with the valve stent implanted in the mitral / tricuspid valve.

[0042] Example 1

[0043] The artificial heart valve provided by this embodiment can be used in the mitral or tricuspid valve. Preferably, taking the implantation of the mitral valve as an example, Embodiment 1 of this application provides an artificial heart valve to solve the technical problems existing in the prior art. According to Figures 1-6 , the above artificial heart valve includes a valve stent 1, a first sealing film 2, a second sealing film 3, and valve leaflets 4; in a preferred embodiment, the above artificial heart valve further includes a valve leaflet anchoring member 5. The valve stent 1 is positioned in the annulus of the native mitral valve 6, and the valve leaflet anchoring member 5 is spirally wound and positioned at the chordal plexus of the native mitral valve 6 to anchor the valve stent 1 implanted in the mitral valve and prevent the valve stent 1 from shifting during the cardiac cycle.

[0044] Refer to Figure 1, Optionally, the valve stent 1 is a self-expanding stent, a balloon-expandable stent, a mechanically expandable stent, etc. Preferably, the valve stent 1 is a self-expanding stent; in a preferred embodiment, the valve stent 1 is made of metal or polymer material, such as nitinol memory material or other memory polymer materials or alloys. In this embodiment, by processing the nitinol memory material, etc., a number of interconnected polygonal grid structures are formed; optionally, the above processing methods include but are not limited to weaving, laser cutting, welding, riveting, threading, etc.

[0045] In a more preferred embodiment, the valve stent 1 is a balloon-expandable stent; the valve stent 1 is made of materials such as medical stainless steel and cobalt-chromium alloy, and a number of interconnected polygonal grid structures are pre-formed by means of weaving, welding, riveting, threading, etc.

[0046] Preferably, the main body contour of the valve stent 1 is in a cylindrical structure or a structure similar to a cylindrical shape. Correspondingly, the main body of the valve stent 1 can be radially expanded and compressed, ensuring that it is in a compressed state during delivery in the blood vessel and then opened by self-expansion or balloon expansion after reaching the annulus of the native mitral valve 6.

[0047] Preferably, the valve stent 1 includes an inflow section 11 and an outflow section 12. According to the direction of blood flow, the outflow section 12 is located downstream of the inflow section 11. The inflow section 11 corresponds to the part where blood flows into the valve stent 1 after the artificial heart valve is implanted, and the outflow section 12 corresponds to the part where blood flows out of the valve stent 1 after the artificial heart valve is implanted; specifically, the inflow section 11 is positioned at the annulus of the native mitral valve 6, and the outflow section 12 is positioned at the connection transition area between the leaflets and chordae tendineae of the native mitral valve 6. Those skilled in the art should understand that when the valve stent 1 is a self-expanding stent, the inflow section 11 has a higher elastic modulus than the outflow section 12 and can undergo elastic deformation at least radially and axially after being implanted into the mitral valve to conform to the change in the annulus shape of the native mitral valve 6; if the valve stent 1 is a balloon-expandable stent, the process of its expansion and opening is plastic deformation, and neither the inflow section 11 nor the outflow section 12 exhibits elastic recoil.

[0048] In a preferred embodiment, both the inflow section 11 and the outflow section 12 of the valve stent 1 include a number of interconnected polygonal grid structures, and adjacent grid structures are connected by wave rods or nodes with a certain elasticity. Among them, the polygonal grid is preferably a rhombus, and pentagons, hexagons, etc. that can form closed shapes can also be selected; in a preferred embodiment, the inflow section 11 has a denser grid structure than the outflow section 12 to provide elastic deformation in more directions, such as axial elastic deformation, radial elastic deformation, and transverse elastic deformation; while the outflow section 12 can provide stronger anti-deformation ability to prevent the valve stent 1 from shifting during the cardiac cycle.

[0049] Preferably, the mesh structures at the free ends of the inflow section 11 and the outflow section 12 are continuously and completely distributed in the circumferential direction, so as not to affect the radial supporting force and avoid unexpected displacement of the valve stent 1 after being implanted into the mitral valve.

[0050] Such as Figures 2-4 , in a preferred embodiment, the first sealing film 2 is attached to the outer side surface of the valve stent 1, and the first sealing film 2 is sutured to the valve stent 1; the valve leaf 4 is sutured to the inner side of the valve stent 1 for controlling the unidirectional flow of blood; the second sealing film 3 is sutured to the outer surface of the first sealing film 2.

[0051] Preferably, multiple valve leaves 4 are sewn on the frame struts of the valve stent 1, and the multiple valve leaves 4 are completely wrapped within the first sealing film 2. When the valve leaves 4 are closed, the reflux blood is completely restricted within the space formed by the first sealing film 2, the second sealing film 3 and the closed valve leaves 4.

[0052] Preferably, the lower edge of the first sealing film 2 is sutured to the lower edge on the outer side of the inflow section 11. Since the lower edge of the inflow section 11 is formed by the edge of the mesh structure, it is generally in a continuous wave shape or zigzag shape and forms a loop. In order to better fit the first sealing film 2 with the inflow section 11, the lower edge of the first sealing film 2 has the same shape as the lower edge of the inflow section 11, that is, it is also in a continuous wave shape or zigzag shape.

[0053] Preferably, the upper edge of the first sealing film 2 covers the upper edge of the inflow section 11, and the length extends beyond the valve stent 1. The extended part is folded inward along the inflow section 11 of the valve stent 1 and sutured to the upper part on the inner side of the inflow section 11, such as Figures 3-4 ; Preferably, since the upper edge of the inflow section 11 is formed by the edge of the mesh structure, it is in a continuous wave shape or zigzag shape. When the first sealing film 2 is folded inward, it no longer completely fits the shape of the upper edge of the inflow section 11, but is directly folded inward in a cylindrical shape, that is, the folded upper edge is in a continuous circular ring shape. In particular, after the first sealing film 2 is folded inward, the upper edge of the first sealing film 2 is more tightly sutured to the valve stent 1. At the same time, since the thickness of the folded area increases, this part can better fit with the native mitral valve 6 annulus, which can not only better locate in the mitral valve, but also further prevent the occurrence of paravalvular leakage.

[0054] In particular, for different patients, the size and / or shape of their mitral valves will be different. Those skilled in the art should understand that the size of the inward folding of the first sealing film 2 can be adaptively changed according to the patient's situation. Preferably, the thickness of the first sealing film 2 is 0.3 - 1 mm, and the length of its inward folding is 4 - 6 mm to ensure that the folded area can be clamped on the native mitral valve 6 annulus to prevent the occurrence of paravalvular leakage.

[0055] In a preferred embodiment, the first sealing film 2 is made of a biocompatible hydrophilic swelling material, and the hydrophilic swelling material is required to be able to absorb liquid and swell after contacting with blood, so that the artificial heart valve can better fit with the mitral valve annulus.

[0056] Preferably, the first sealing film 2 is made of a biohydrogel material. Biohydrogel is a type of extremely hydrophilic three-dimensional network structure gel. It rapidly swells in water and can maintain a large volume of water in this swollen state without dissolving. By controlling the production process, the biohydrogel can be swollen by 2-3 times. As the valve stent 1 is implanted in the human body for a longer time, on the one hand, due to the liquid absorption and swelling characteristics of the biohydrogel itself, the cylindrical structure formed at the folded edge of the upper edge of the first sealing film 2 on the valve stent 1 can gradually fill the gap between the valve stent 1 and the native tissue, preventing the occurrence of paravalvular leakage. On the other hand, due to the excellent water-proof and permeation-proof performance of the biohydrogel, it can effectively prevent blood from permeating out of the artificial heart valve, further preventing the occurrence of paravalvular leakage. In other aspects, because the biohydrogel has a soft texture, it can act as a buffer layer when the valve stent 1 and the native mitral valve 6 are anchored by the leaflet anchor 5, preventing the native leaflets from being torn and damaged.

[0057] Reference Figures 2-3 , preferably, the second sealing film 3 is sutured to the outer surface of the first sealing film 2; the second sealing film 3 covers at least all the areas corresponding to the outer side surface of the inflow section 11 of the valve stent 1; preferably, the lower edge of the second sealing film 3 has the same shape as the lower edge of the inflow section 11, forming a continuous wavy or serrated shape; the upper edge of the second sealing film 3 is cylindrical.

[0058] Preferably, the second sealing film 3 is made of a biocompatible fabric and has a certain elasticity. The biocompatible fabric is preferably but not limited to any one or at least two combinations of PET (polyethylene terephthalate), PTFE (polytetrafluoroethylene), e-PTFE or PU (polyurethane). The second sealing film 3 can not only increase the friction force between the valve stent 1 and the leaflets of the native mitral valve 6 after the valve stent 1 is implanted to strengthen the fixing effect; after the first sealing film 2 absorbs liquid and swells, the second sealing film 3 can also expand to a certain extent with its swelling.

[0059] In this embodiment, it should be noted that when the above-mentioned first sealing film 2, second sealing film 3 and leaflets 4 are sutured, the sutures are all connected and fixed to the frame struts of the valve stent 1, rather than in other structures.

[0060] Preferably, there are also a plurality of radiopaque points on the valve stent 1. After the artificial heart valve is implanted into the human body, usually, doctors need to determine whether the implantation position is accurate through the radiopaque points provided on the implanted valve stent 1. Moreover, since the heart valve is a three-dimensional structure, it is usually necessary to determine whether its spatial position is accurate. Therefore, it is necessary to judge whether its spatial position is accurate through the positions of multiple radiopaque points.

[0061] Reference Figure 6 , in this embodiment, when the above artificial heart valve is surgically implanted, the valve stent 1 is delivered to the annulus of the native mitral valve 6 through a balloon catheter or a guiding catheter, and the valve stent 1 is opened and released by self-expansion or balloon dilation. When the valve stent 1 is positioned, the leaflet anchor 5 is released into the chordal plexus of the native mitral valve 6 through a delivery device. The valve stent 1 has a radially outward expanding force, while the leaflet anchor 5 has a radially inward tightening force, which can effectively pull the native leaflets towards the central position. Relying on the interference fit between the leaflet anchor 5 and the valve stent 1, the native leaflets are clamped to achieve fixation.

[0062] Since the outermost layer of the valve stent 1 is provided with a second sealing film 3, it can provide greater friction with the leaflet anchor 5 and strengthen the fixing effect; since the first sealing film 2 is made of biocompatible hydrogel material, it gradually expands with the extension of the implantation time of the valve stent 1, further tightening the gap between the valve stent 1, the native leaflets and the leaflet anchor 5, and strengthening the fixation of the valve; and the cylindrical structure formed by the folding of the first sealing film 2 at the upper edge of the valve stent 1 is positioned on the atrial side. This structure can further fill the gap with the native tissue, effectively prevent paravalvular leakage. At the same time, the biocompatible hydrogel has a soft texture and can act as a buffer layer when the valve stent 1 and the native mitral valve 6 are anchored by the leaflet anchor 5, preventing the native leaflets from being torn and damaged.

[0063] Example 2

[0064] Still taking the mitral valve implantation as an example, reference Figure 7 , in this embodiment, an artificial heart valve is provided, and its structure includes a valve stent 1, a first sealing film 2, a second sealing film 3 and leaflets 4; in a preferred embodiment, the above artificial heart valve further includes a leaflet anchor 5.

[0065] In this embodiment, the structure of the valve stent 1 is the same as that in Embodiment 1 and will not be described herein again; preferably, the first sealing film 2 is attached to the outer side surface of the valve stent 1; the leaflets 4 are sutured to the inner side of the valve stent 1; the second sealing film 3 is sutured to the outer surface of the first sealing film 2.

[0066] Preferably, the lower edge of the first sealing film 2 is sutured to the lower edge inside the inflow section 11, the upper edge of the first sealing film 2 covers the upper edge of the inflow section 11, and the length thereof is higher than that of the valve stent 1. The extended part is folded inward along the inflow section 11 of the valve stent 1 to cover a partial area at the upper end of the inflow section 11.

[0067] In a preferred embodiment, before bypassing the top end of the valve stent 1, the first sealing film 2 covers the outside of the upper end of the inflow section 11 in a substantially circular arc or semicircular shape. That is, there is an annular cavity 7 between the folding area of the first sealing film 2 and the outside of the upper end of the inflow section 11, as Figure 7 shown.

[0068] Preferably, an elastic film material or a biocompatible sponge material, such as a TPU film, a chitin porous body, a collagen sponge, PLGA, etc., is attached to the inside of the annular cavity 7, so that the annular cavity 7 of the first sealing film 2 can collapse or recover. During the process of delivering the valve stent 1, the annular cavity 7 collapses to ensure that the valve stent 1 can reach the mitral valve smoothly and be released. After the valve stent 1 expands and is fixed, the annular cavity 7 slowly recovers. Due to the existence of this cavity, the thickness / volume of the folding area is further increased, making the inflow section 11 of the valve stent 1 fit more closely with the native mitral valve 6.

[0069] In another preferred embodiment, before bypassing the top end of the valve stent 1, the first sealing film 2 is in a substantially circular arc or semicircular shape. After the first sealing film 2 bypasses the top end of the valve stent 1 and is folded, its end is fixed to the first sealing film 2 outside the valve stent 1 by means of pasting or the like. A fibrous complex with a certain volume, such as a diene elastic fiber, a polyether ester elastic fiber or a composite elastic fiber, etc., is filled in the annular cavity 7 formed therebetween, so that the folding area of the first sealing film 2 can collapse or recover. Those skilled in the art should understand that due to the bulkiness, elasticity and relatively high elastic recovery rate of the fiber aggregate, it can fit well with the outer surface of the inflow section 11 during the delivery process of the valve stent 1 to ensure the smooth delivery, and can slowly expand after the valve stent 1 is released and gradually fit with the native mitral valve 6.

[0070] Particularly, for different patients, the size and / or shape of the mitral valve will be different. Those skilled in the art should understand that the size of the annular cavity formed by the inward folding of the first sealing film 2 can be adaptively changed according to the situation of the patient. Preferably, the width of the annular cavity 7 is 4-6 mm.

[0071] Preferably, the first sealing film 2 is made of a biohydrogel material. Refer to the description in the above-mentioned Embodiment 1 and details will not be repeated here.

[0072] Preferably, the structure of the second sealing film 3 is the same as that in Embodiment 1 above, and will not be described herein again.

[0073] In this Embodiment 2, when the above artificial heart valve is surgically implanted, the valve stent 1 is delivered through a balloon catheter or a guiding catheter. At this time, both the valve stent 1 and the annular cavity 7 formed by the inward folding of the first sealing film 2 are in a collapsed state. When reaching the annulus of the native mitral valve 6, the valve stent 1 is opened and released by self-expansion or balloon dilation. At this time, the annular cavity also resumes its original volume; the expanded annular cavity 7 can be engaged above the annulus of the native mitral valve 6, enabling the valve stent 1 to better fit the annulus of the native mitral valve 6, which is also beneficial for the better positioning of the artificial heart valve; and the second sealing film 3 is arranged on the outermost side of the valve stent 1, which can increase the friction between the valve stent 1 and the annulus of the native mitral valve 6 after the valve stent 1 is implanted, so as to strengthen the fixing effect.

[0074] When the valve stent 1 is positioned, the leaflet anchor 5 is released into the mitral chordal plexus through the delivery device. The valve stent 1 has a radially outward expanding force, while the leaflet anchor 5 has a radially inward tightening force. The two cooperate with each other to anchor the valve stent 1 to prevent it from shifting, making the cooperation between the artificial heart valve and the native tissue structure safer and more stable.

[0075] Since the first sealing film 2 is made of biogel material, it gradually expands with the extension of the implantation time of the valve stent 1, further tightening the gap between the valve stent 1 and the native leaflets and the leaflet anchor 5, and strengthening the fixation of the valve; and the cylindrical structure formed at the folding edge of the upper edge of the valve stent 1 by the first sealing film 2 is positioned on the atrial side. This structure can further fill the gap with the native tissue, effectively preventing paravalvular leakage. At the same time, the biogel has a soft texture and can act as a buffer layer when the valve stent 1 and the native mitral valve 6 are anchored by the leaflet anchor 5, preventing the native leaflets from being torn and damaged.

[0076] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope protected by the present invention and the claims, and all of them belong to the protection scope of the present invention.

Claims

1. An artificial heart valve, characterized in that, it comprises: - A valve stent, the valve stent comprising an inflow section and an outflow section; - A first sealing film, the first sealing film being attached to the outer side of the valve stent, the first sealing film comprising a hydrophilic swelling material which can absorb liquid and swell after contacting with blood, for reducing paravalvular leakage; - A second sealing film, the second sealing film being disposed on the outer side of the first sealing film such that the first sealing film can gradually swell as the implantation time of the valve stent extends, the second sealing film at least covering all regions corresponding to the outer surface of the inflow section; after the first sealing film absorbs liquid and swells, the second sealing film can also expand to a certain extent along with its swelling, and the second sealing film is used for increasing the friction force with the native leaflets; - Leaflets, the leaflets being disposed inside the valve stent for controlling the unidirectional flow of blood; - Leaflet anchoring members, the leaflet anchoring members being spiral-shaped and capable of coiling outside the mitral / tricuspid chordal plexus and interacting with the valve stent implanted in the mitral / tricuspid valve.

2. The artificial heart valve according to claim 1, characterized in that, the valve stent is cylindrical; the valve stent comprises a plurality of interconnected polygonal grid structures.

3. The artificial heart valve according to claim 1, characterized in that, the lower edge of the first sealing film is sutured to the lower edge of the outer side of the inflow section, and the lower edge of the first sealing film matches the shape of the lower edge of the inflow section; the upper edge of the first sealing film is folded inwards from the upper edge of the inflow section and sutured to the upper part of the inner side of the inflow section.

4. The artificial heart valve according to claim 3, characterized in that, the first sealing film covers the upper edge of the inflow section, and the first sealing film covering the upper edge of the inflow section is in a cylindrical shape.

5. The artificial heart valve according to claim 3, characterized in that, the upper edge of the first sealing film is folded inwards in an arc shape, and an annular cavity is formed between the folded area of the first sealing film and the upper edge of the inflow section.

6. The artificial heart valve according to claim 5, characterized in that, an elastic film-like material, a sponge-like material with biocompatibility or a fiber aggregate is provided in the annular cavity.

7. The artificial heart valve according to claim 3, characterized in that, the thickness of the first sealing film is 0.3 - 1 mm; the length of the upper edge of the first sealing film folded inwards is 4 - 6 mm.

8. The artificial heart valve according to claim 3, characterized in that, the leaflets are sutured to the inner side of the inflow section; the second sealing film is sutured to the outer surface of the first sealing film.

9. The artificial heart valve according to claim 8, characterized in that, the lower edge of the second sealing film matches the shape of the first sealing film and / or the lower edge of the inflow section.

10. The artificial heart valve according to claim 1, characterized in that, the hydrophilic swelling material comprises a biohydrogel.

11. The artificial heart valve according to claim 1, Characterized in that, the second sealing film is made of a biocompatible fabric.

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