Transcatheter interventional polymer heart valve

Abstract

The invention provides a transcatheter interventional polymer heart valve which comprises a valve leaflet and a valve frame which are integrally injection-molded, the valve frame is of a hollow columnar grid structure, and the valve frame is provided with a first end and a second end; the integrally-injection-molded valve leaflet and the valve frame are integrally injection-molded, the integrally-injection-molded valve leaflet comprises a valve leaflet body, a surface film and a grid inner film which are integrally connected, and the surface film is attached to and wraps the inner surfaces and the outer surfaces of a plurality of sets of supporting rods forming the valve frame, so that the center of each grid is still kept hollow. The valve leaflets are arranged in the center of the valve frame, the number of the valve leaflets is multiple, the valve leaflets are sequentially arranged in the circumferential direction, and each valve leaflet comprises a free edge and a connecting edge connected with the surface film and the grid inner film; and the grid inner film is filled in the hollowed-out part of the grid from the connecting edge to the second end of the valve frame and is connected with the surface film.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a transcatheter interventional polymer heart valve. Background Art

[0002] Heart valves are the valves between the atria and ventricles, or between the ventricles and arteries. They play a crucial role in the heart's constant circulation: they act as gatekeepers, preventing blood from flowing back into the atria or ventricles it has just left. Prosthetic heart valves are implantable medical devices used to treat heart valve disease or defects.

[0003] Existing polymer valves still have certain limitations in manufacturing and molding technology. Summary of the Invention

[0004] An embodiment of the present invention provides a transcatheter polymer heart valve with an optimized structure, a valve frame with a grid gradient distribution and an integral injection-molded valve leaflet, which reduces stress concentration when the valve leaflet opens and closes, optimizes valve performance, reduces artificial valve sutures, and improves assembly efficiency.

[0005] A transcatheter interventional polymer heart valve provided by an embodiment of the present invention includes an integrally injected leaflet and a valve frame, wherein the valve frame is a hollow cylindrical grid structure, and the valve frame has a first end and a second end; the integrally injected leaflet and the valve frame are integrally injection-molded, and the integrally injected leaflet includes an integrally connected leaflet, a surface film and a grid inner film, the surface film fits and covers the inner and outer surfaces of multiple groups of struts that constitute the valve frame, so that the center of each grid remains hollow, and the leaflet is arranged in the center of the valve frame. There are multiple leaflets, and the multiple leaflets are arranged in sequence along the circumferential direction, and the leaflet includes a free edge and a connecting edge connecting the surface film and the grid inner film; the grid inner film fills the hollow part of the grid of the valve frame corresponding to the connecting edge to the second end and is connected to the surface film.

[0006] Preferably, the grids of the valve frame are distributed in a gradient manner along the axial direction, so that the stiffness of the valve frame gradually increases from the first end to the second end.

[0007] Preferably, the petal frame is provided with multiple groups of grids in sequence along the axial direction from the first end to the second end, and the multiple groups of grids are respectively surrounded by multiple groups of struts, and the multiple groups of grids include a first grid, a second grid, a third grid and a fourth grid; the first grid is surrounded by the first strut and the second strut; the second grid is surrounded by the second strut and the third strut, and the third grid is surrounded by the third strut and the fourth strut; the fourth grid is surrounded by the fourth strut, the fifth strut and the sixth strut; the stiffness of the first grid, the second grid, the third grid and the fourth grid increases in sequence; the stiffness of the grid is adjusted by adjusting the width and length of the struts that surround the grid.

[0008] Preferably, the lengths of the first support rod, the second support rod, the third support rod, the fourth support rod and the sixth support rod are L1, L2, L3, L4 and L6 respectively, and the lengths of the plurality of support rods satisfy the following relationship: L1≥L2>L3≥L4≥L6.

[0009] Preferably, a line connecting the midpoint of the free edge and the midpoint of the connecting edge forms a belly curve on the leaflet, and the leaflet frame is provided with a large grid opposite to the belly curve.

[0010] Preferably, the large grid occupies the position of one first grid, two second grids and one third grid connected in sequence; the large grid is formed by removing two second support rods and two third support rods surrounding the centers of the two second grids occupied by the large grid.

[0011] Preferably, the ends of the connecting edges of adjacent leaflets are connected at the first end of the flap frame to form a peak, and the connecting edge is an arc-shaped curve convex toward the second end, so that the connecting edge forms a trough in the middle, and the trough of the connecting edge extends to a position close to the bottom of the large grid.

[0012] Preferably, a rounded corner is provided at the connection point between the connection edge of the leaflet and the surface film.

[0013] Preferably, the ratio of the thickness of the thin film in the grid to the thickness of the flap frame is in the range of 1:2-10.

[0014] Preferably, it further comprises an outer sealing film, which is arranged at the second end of the valve frame and located outside the mesh inner film.

[0015] Preferably, the outer sealing film is attached to the outside of the mesh inner film by electrostatic spinning or hot melting.

[0016] Preferably, the outer sealing membrane is a porous film.

[0017] Compared with the prior art, the technical solution of the embodiment of the present invention has beneficial effects.

[0018] For example, an integral injection-molded leaflet is formed through an integral molding process, and a thin film is coated on the surface of the valve frame, thereby avoiding direct contact between the leaflet and the valve frame, reducing leaflet damage during the crimping process, and improving leaflet fatigue performance; the inner wall film within the valve frame grid blocks paravalvular leakage and reduces the valve crimping size; the setting of the outer sealing film further reduces paravalvular leakage and provides an endothelialization site; the overall suturing process is not used, thereby improving production efficiency; the valve frame adopts a grid gradient distribution design, so that the stiffness of the valve frame gradually increases from the first end to the second end, the high-stress peak area of ​​the leaflet is located at the first end with smaller stiffness, and the low-stress trough area is close to the second end with larger stiffness, matching the leaflet morphology, maintaining the required flexibility of the leaflet and providing the necessary stiffness of the anchoring area. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of a transcatheter polymer heart valve according to an embodiment of the present invention; Figure 2 is a schematic structural diagram of a valve frame according to an embodiment of the present invention; Figure 3 is a schematic diagram of a cutout portion of a valve frame according to an embodiment of the present invention; Figure 4 2. It is a schematic diagram comparing the positions of the valve frame and the valve leaflets in an embodiment of the present invention; Figure 5 Schematic diagram of the valve frame and integrally-injected valve leaflet structure in an embodiment of the present invention.

[0020] Description of reference numerals: 1- leaflet; 11- free edge; 12- connecting edge; 13- high stress area; 14- low stress area; 2-petal frame; 21-first end; 22-second end; 23-first grid; 24-second grid; 25-third grid; 26-fourth grid; 27-large grid; 281-first support rod; 282-second support rod; 283-third support rod; 284-fourth support rod; 285-fifth support rod; 286, sixth support rod; 3-Surface film; 4-mesh inner film; 5-Outer sealing film. DETAILED DESCRIPTION

[0021] In order to make the purpose, features and beneficial effects of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. It is understood that the specific embodiments described below are only used to explain the present invention, and are not intended to limit the present invention. In addition, the same or similar reference numerals may be used in the figures to refer to the same or similar elements in different embodiments, and the descriptions of the same or similar elements in different embodiments and the descriptions of the prior art elements, features, effects, etc. may be omitted. It should be noted that the axial, radial and circumferential directions described in the embodiments of the present invention respectively represent the axial, radial and circumferential directions of the valve frame 2.

[0022] Reference Figures 1 to 5 , an embodiment of the present invention provides a transcatheter polymer heart valve.

[0023] In a specific implementation, the transcatheter interventional polymer heart valve includes an integrally-injected leaflet and a valve frame 2, the valve frame 2 being a hollow cylindrical grid structure, the valve frame 2 having a first end 21 and a second end 22; the integrally-injected leaflet and the valve frame 2 are integrally-injected, and the integrally-injected leaflet includes an integrally-connected leaflet 1, a surface film 3, and a grid inner film 4, the surface film 3 adheres to and covers the inner and outer surfaces of the multiple groups of struts constituting the valve frame 2, so that the center of each grid remains hollow, the leaflet 1 is arranged at the center of the valve frame 2, the leaflet 1 is multiple, and the multiple leaflets 1 is arranged sequentially along the circumferential direction, and the leaflets 1 include a free edge 11 and a connecting edge 12 connecting the surface film 3 and the mesh inner film 4. The ends of the connecting edges 12 of adjacent leaflets 1 are connected at the first end 21 of the valve frame 2 to form a peak, and the middle of the connecting edges 12 forms a peak at the second end 22 of the valve frame 2. Specifically, the connecting edge 12 is an arc curve convex toward the second end 22, so that the connecting edge 12 forms a valley in the middle; the mesh inner film 4 fills the hollow part of the mesh of the valve frame 2 corresponding to the connecting edge 12 to the second end 22 and is connected to the surface film 3.

[0024] Specifically, when the free edges 11 of the multiple leaflets 1 are in contact, blood circulation is blocked, and when the free edges 11 of the multiple leaflets 1 are separated, blood is allowed to flow from the second end 22 to the first end 21; when the leaflet 1 is closed, the stress at the top of the leaflet 1 near the connection of the leaflet 1 is the greatest, and it is most likely to tear, and the stress at the bottom of the leaflet 1 is the least, and the risk of tearing is the lowest; therefore, the peak of the leaflet 1 near the connecting edge 12 is the high stress area 13, and the trough near the connecting edge 12 is the low stress area 14.

[0025] Specifically, when the leaflet 1 is closed, the inner mesh film 4 blocks blood reflux and reduces paravalvular leakage; at the same time, it strengthens the connection with the surface film 3 and the leaflet 1.

[0026] Specifically, the stiffness of different regions of the valve frame 2 is adjusted to match the stress changes under different motion states of the leaflet 1. For example, the struts of the valve frame 2 corresponding to the high-stress region 13 of the leaflet 1 are set to a low stiffness to facilitate stress transfer when the leaflet 1 closes. Meanwhile, the struts of the valve frame 2 corresponding to the low-stress region 14 of the leaflet 1, as they are located in the valve anchoring area, have their stiffness set to maximum to provide sufficient radial support.

[0027] Specifically, because the surface film 3 completely fits and covers the surfaces of each support rod of the valve frame 2, the surface film 3 can serve as a buffer layer, preventing direct contact between the leaflet 1 and the valve frame 2, facilitating stress transfer, and reducing the risk of tearing in the high stress area 13 caused by stress concentration. The relative position of the leaflet 1 and the surface film 3 can be adjusted by the mold, that is, the position of the connecting edge 12 can be adjusted. The connecting edge 12 is set slightly lower than the first end 21 of the valve frame 2 near the high stress area 13 of the leaflet 1. In this way, when the leaflet 1 is closed, the connecting edge 12 can transfer part of the stress to the film 4 inside the grid, reducing the possibility of separation of the surface film 3.

[0028] In some embodiments, the petal frame 2 is provided with multiple groups of grids in sequence along the axial direction from the first end 21 to the second end 22, and the multiple groups of grids are respectively surrounded by multiple groups of support rods, and the multiple groups of grids include a first grid 23, a second grid 24, a third grid 25 and a fourth grid 26; the first grid 23 is surrounded by a first support rod 281 and a second support rod 282; the second grid 24 is surrounded by a second support rod 282 and a third support rod 283, and the third grid 25 is surrounded by a third support rod 283 and a fourth support rod 284; the fourth grid 26 is surrounded by a fourth support rod 284, a fifth support rod 285 and a sixth support rod 286; the stiffness of the first grid 23, the second grid 24, the third grid 25 and the fourth grid 26 increases in sequence; the stiffness of the grid is adjusted by adjusting the width and length of the support rods surrounding the grid.

[0029] Specifically, the connecting edge 12 can be set close to the outflow end support rods of the second grid 24, the third grid 25 and the fourth grid 26; preferably, the connecting edge 12 is slightly lower than the outline of the outflow end support rods of the second grid 24, the third grid 25 and the fourth grid 26, so as to facilitate the transfer of part of the stress to the film 4 in the grid; for example, the area enclosed by the outflow end support rods of the second grid 24, the third grid 25 and the fourth grid 26 can account for 5% to 50% of the first grid 23, the second grid 24 and the third grid 25 respectively.

[0030] Specifically, the stiffness of the grid is determined by the stiffness of the struts that form the grid. Since the flap frame 2 is formed by laser engraving from tubular material, the thickness of the flap frame 2 is certain. The stiffness of the struts is proportional to the wall thickness t of the flap frame 2 and the strut width w, and inversely proportional to the strut length L; therefore, the stiffness of the grid can be adjusted by adjusting the width and length of the struts that form the grid.

[0031] In some embodiments, the lengths of the first support rod 281, the second support rod 282, the third support rod 283, the fourth support rod 284 and the sixth support rod 286 are L1, L2, L3, L4 and L6 respectively, and the lengths of the multiple support rods satisfy the following relationship L1≥L2>L3≥L4≥L6.

[0032] Specifically, the support rod length L1≥L2>L3≥L4≥L6 is preferably set, and the support rod width is appropriately adjusted according to actual usage to achieve the purpose of increasing the stiffness of the first grid 23, the second grid 24, the third grid 25 and the fourth grid 26 in sequence.

[0033] In some embodiments, a line connecting the midpoint of the free edge 11 and the midpoint of the connecting edge 12 forms an abdominal curve on the leaflet 1 , and the valve frame 2 is provided with a large grid 27 opposite to the abdominal curve.

[0034] In some embodiments, the large grid 27 occupies the position of a first grid 23, two second grids 24 and one third grid 25 connected in sequence; the large grid 27 is formed by removing two second support rods 282 and two third support rods 283 surrounding the centers of the two second grids 24 occupied by the large grid.

[0035] Specifically, after the valve is implanted in the heart, the large grid 27 corresponds to the coronary artery opening, reducing coronary artery obstruction and increasing coronary perfusion blood flow.

[0036] In some embodiments, the valley of the connecting edge 12 extends to a position close to the bottom of the large grid 27 .

[0037] In some embodiments, the connection between the connecting edge 12 of the leaflet 1 and the surface film 3 is provided with a rounded corner to enhance the connection reliability of the connection and improve the fatigue life of the valve.

[0038] In some embodiments, the ratio of the thickness of the inner mesh film 4 to the thickness of the valve frame 2 is in the range of 1:2 to 10. The inner mesh film 4 is set to a relatively small thickness. When the valve frame 2 is compressed, the inner mesh film 4 and the surface film 3 do not restrict the radial contraction of the valve frame 2, thereby minimizing the impact on the compression size of the valve frame 2 and reducing patient damage. When the valve frame 2 is compressed, the inner mesh film of each grid is squeezed, and the increased circumference during compression is twice the thickness of the inner mesh film 4. That is, if there are n grid waves in the circumferential direction, the compression circumference will increase by 2n grid inner mesh film 4 thicknesses, and the corresponding compression size will also increase. Therefore, it is necessary to reduce the thickness of the inner mesh film 4 to reduce the compression size. The inner mesh film 4 is obtained by injection molding and has a smooth and dense surface. After implantation, it will not form endothelialization, thrombosis, etc., and will not affect the size of the blood flow inlet. It will avoid reducing the valve opening and affecting the treatment effect.

[0039] In some embodiments, an outer sealing membrane 5 is further included. The outer sealing membrane 5 is disposed at the second end 22 of the valve frame 2 and is located outside the mesh inner film 4 .

[0040] Specifically, the outer sealing film 5 is attached to the outer surface of the thin film 4 within the grid of the fourth grid 26 of the valve frame 2 .

[0041] In some embodiments, the outer sealing film 5 is attached to the outside of the mesh inner film 4 by electrospinning or hot melting.

[0042] In some embodiments, the outer sealing membrane 5 is a porous film; the porous structure facilitates endothelialization after implantation. At the same time, the thickness of the outer sealing membrane 5 is thinner than that of a conventional valve sealing membrane to reduce the grip size.

[0043] Specifically, the porous structure provides a rough surface and tiny "pits", which greatly increases the surface area and contact points for cell attachment and anchoring, promotes cell "attachment", "migration", "infiltration" and "three-dimensional integration", thereby accelerating and optimizing the endothelialization process.

[0044] Specifically, the outer sealing film 5 is preferably made of the same material as the surface film 3 to improve the bonding strength with the surface film 3. The presence of the outer sealing film 5 further improves the sealing performance and reduces the risk of paravalvular leakage.

[0045] In some embodiments, a micropore array, regular grooves or flanges are engraved on the surface of the valve frame 2, or the surface of the valve frame 2 is subjected to surface activation treatment to improve the bonding strength between the surface of the valve frame 2 and the integrally injected leaflet.

[0046] In some embodiments, the material of the valve frame 2 is metal, the valve frame 2 is formed by laser engraving, and the material of the integrally-injected valve leaflets is a polymer material.

[0047] Specifically, the injection molding material of the integral injection-molded leaflet can be selected from styrene-ethylene-butylene-styrene block copolymer, polyether polyurethane material, polyester polyurethane material, polycarbonate or silane-modified polyurethane material.

[0048] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of the present disclosure, even when only a single embodiment is described with respect to specific features. The feature examples provided in the present disclosure are intended to be illustrative, not limiting, unless otherwise stated. In specific implementations, the technical features of one or more dependent claims may be combined with the technical features of the independent claims, depending on actual needs and where technically feasible, and the technical features from the corresponding independent claims may be combined in any appropriate manner rather than solely through the specific combinations listed in the claims.

[0049] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A transcatheter polymer heart valve, characterized in that: It includes an integrally injected flap and a flap frame, the flap frame is a hollow columnar grid structure, and the flap frame has a first end and a second end; the integrally injected flap and the flap frame are integrally injection-molded, and the integrally injected flap includes an integrally connected flap, a surface film and a grid inner film, the surface film fits and covers the inner and outer surfaces of multiple groups of struts that constitute the flap frame, so that the center of each grid remains hollow, and the flap is arranged at the center of the flap frame. There are multiple flaps, and multiple flaps are arranged in sequence along the circumferential direction. The flap includes a free edge and a connecting edge connecting the surface film and the grid inner film; the grid inner film fills the hollow part of the grid of the flap frame corresponding to the connecting edge to the second end and is connected to the surface film.

2. The transcatheter polymer heart valve according to claim 1, characterized in that: The grids of the valve frame are distributed in a gradient manner along the axial direction, so that the stiffness of the valve frame gradually increases from the first end to the second end.

3. The transcatheter polymer heart valve according to claim 2, characterized in that: The petal frame is provided with multiple groups of grids in sequence along the axial direction from the first end to the second end, and the multiple groups of grids are respectively surrounded by multiple groups of support rods, and the multiple groups of grids include a first grid, a second grid, a third grid and a fourth grid; the first grid is surrounded by the first support rod and the second support rod; the second grid is surrounded by the second support rod and the third support rod, and the third grid is surrounded by the third support rod and the fourth support rod; the fourth grid is surrounded by the fourth support rod, the fifth support rod and the sixth support rod; the stiffness of the first grid, the second grid, the third grid and the fourth grid increases in sequence; the stiffness of the grid is adjusted by adjusting the width and length of the support rods surrounding the grid.

4. The transcatheter polymer heart valve according to claim 3, characterized in that: The lengths of the first support rod, the second support rod, the third support rod, the fourth support rod and the sixth support rod are L1, L2, L3, L4 and L6 respectively, and the lengths of the plurality of support rods satisfy the following relationship: L1≥L2>L3≥L4≥L6.

5. The transcatheter polymer heart valve according to claim 3, characterized in that: A line connecting the midpoint of the free edge and the midpoint of the connecting edge forms an abdominal curve on the leaflet, and the leaflet frame is provided with a large grid facing the abdominal curve.

6. The transcatheter polymer heart valve according to claim 5, characterized in that: The large grid occupies the position of one first grid, two second grids and one third grid connected in sequence; the large grid is formed by removing two second support rods and two third support rods surrounding the centers of the two second grids occupied by the large grid.

7. The transcatheter polymer heart valve according to claim 5, characterized in that: The ends of the connecting edges of adjacent leaflets are connected at the first end of the flap frame to form a peak, and the connecting edge is an arc curve convex toward the second end, so that the connecting edge forms a trough in the middle; the trough of the connecting edge extends to a position close to the bottom of the large grid.

8. The transcatheter polymer heart valve according to claim 1, characterized in that: A fillet is provided at the connection between the connection edge of the leaflet and the surface film.

9. The transcatheter polymer heart valve according to claim 1, characterized in that: The ratio of the thickness of the thin film in the grid to the thickness of the flap frame is in the range of 1:2-10.

10. The transcatheter polymer heart valve according to claim 1, characterized in that: It also includes an outer sealing film, which is arranged at the second end of the valve frame and is located outside the mesh inner film.

11. The transcatheter polymer heart valve according to claim 10, characterized in that: The outer sealing film is attached to the outside of the film in the grid by electrostatic spinning or hot melting.

12. The transcatheter polymer heart valve according to claim 10, characterized in that: The outer sealing film is a porous film.

Images