Double-layer valve stent and heart valve prosthesis

Abstract

The invention relates to a double-layer valve stent and an artificial heart valve comprising the double-layer valve stent. The double-layer valve stent comprises an outer stent body, an inner stent body arranged in the outer stent body and a connecting line used for binding the outer stent body and the inner stent body. The outer frame comprises a first connecting part, and the inner frame comprises a second connecting part correspondingly attached to the first connecting part; the first connecting part is provided with at least one first transverse straight rod perpendicular to the axial direction of the double-layer valve support. The second connecting part is correspondingly provided with at least one second transverse straight rod perpendicular to the axial direction of the double-layer valve support. And the connecting lines are at least bound and wound on the peripheries of the first transverse straight rods and the corresponding second transverse straight rods which are attached to each other. According to the double-layer valve stent, the inner stent body and the outer stent body can be stably connected only through the connecting wires with few turns.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a double-layer valve stent and an artificial heart valve. Background Art

[0002] Some existing artificial heart valves include a double-layer valve stent, which includes an outer frame and an inner frame arranged in the outer frame and connected to the outer frame. Conventional connection methods between the outer frame and the inner frame include welding, crimping, riveting, pin connection, etc. Welding connection has high strength, but it will cause irreversible damage to the connecting struts of the outer frame and the inner frame; during subsequent use, the connecting struts are prone to breakage. Although crimping, riveting, pin connection, etc. have high connection strength, because they are rigid connections, the stress on the connecting struts of the inner and outer frames is relatively large, and the risk of the connecting struts breaking is also relatively large. At present, there is a technology that uses sutures to tie the connecting struts of the inner and outer frames. However, in order for the sutures to sufficiently resist the shear force or separation force generated by the inner and outer frames under the action of factors such as blood flow, it is often necessary to tie a large number of turns of sutures, which will result in a larger crimping size of the double-layer valve stent, which is not conducive to delivery. Summary of the invention

[0003] In view of this, the present invention aims to provide a double-layer valve stent and an artificial heart valve that can solve the above-mentioned problems.

[0004] To this end, on one hand, the present invention provides a double-layer valve stent, comprising an outer frame, an inner frame arranged in the outer frame, and a connecting line for binding the outer frame and the inner frame; the outer frame comprises a first connecting part, the inner frame comprises a second connecting part corresponding to the first connecting part, and the first connecting part is abutted against the second connecting part; the first connecting part has at least one first transverse straight rod perpendicular to the axial direction of the double-layer valve stent; the second connecting part corresponds to at least one second transverse straight rod perpendicular to the axial direction of the double-layer valve stent; the connecting line is at least tied around the periphery of the first transverse straight rod and the corresponding second transverse straight rod abutting against each other.

[0005] On the other hand, the present invention also provides an artificial heart valve, comprising the aforementioned double-layer valve stent, a coating connected to the inner surface and / or outer surface of the double-layer valve stent, and at least two leaflets that can open and close relative to each other and are connected to the inner frame of the double-layer valve stent.

[0006] In an embodiment of the present invention, the connecting wire is tied around the first transverse straight rod of the first connecting part of the outer frame and the second transverse straight rod of the second connecting part of the inner frame, which can directly generate a connecting force concentrated in the axial direction, that is, the axial connecting force generated by the connecting wire is directly used to resist the axial shear force generated by the outer frame and the inner frame during loading, delivery and use, rather than using the axial component force formed by the connecting force generated by the connecting wire to resist the axial shear force. Therefore, only a small number of turns of connecting wire are required to generate a connecting force that can resist the axial shear force. Therefore, the overall size of the first connecting part and the second connecting part connected together by the connecting wire is smaller, thereby effectively reducing the compression grip size of the artificial heart valve and improving the delivery passability of the artificial heart valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a three-dimensional schematic diagram of an artificial heart valve according to a first embodiment of the present invention;

[0008] Figure 2 yes Figure 1 A three-dimensional schematic diagram of a double-layer valve stent of an artificial heart valve;

[0009] Figure 2A yes Figure 2 A schematic diagram showing that the first connection portion and the second connection portion of the double-layer valve stent are tied together by a connection line;

[0010] Figure 3 yes Figure 2 An exploded view of the double-layer valve stent shown;

[0011] Figure 3A yes Figure 3 An enlarged view of a first connection portion of an outer frame of the double-layer valve stent;

[0012] Figure 3B yes Figure 3 An enlarged view of the second connection portion of the inner frame of the double-layer valve stent;

[0013] Figure 4A yes Figure 2A A schematic diagram of a variation in which the first connecting portion and the second connecting portion are tied together by a connecting line;

[0014] Figure 4B yes Figure 4A Comparative example of:

[0015] Figure 4C yes Figure 2A Another variant schematic diagram showing that the first connecting portion and the second connecting portion are tied together by a connecting line;

[0016] Figure 4D yes Figure 2AA schematic diagram of another variation in which the first connecting portion and the second connecting portion are tied together by a connecting line;

[0017] Figure 4E yes Figure 2A A schematic diagram of another variation in which the first connecting portion and the second connecting portion are tied together by a connecting line;

[0018] Figure 5 is a three-dimensional schematic diagram of a double-layer valve stent of an artificial heart valve according to a second embodiment of the present invention;

[0019] Figure 6 It is a three-dimensional schematic diagram of a double-layer valve stent of an artificial heart valve according to the third embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In addition, the embodiments described below can be combined with each other as long as there is no contradiction or conflict, and the same or similar concepts, structures or processes may not be repeated in some embodiments.

[0021] First of all, it should be noted that, in this article, the "inflow end" / "inflow side" and "outflow end" / "outflow side" of the valve stent and its components, the artificial heart valve and its components are defined according to the blood flow direction in the ventricular diastolic state, wherein the "inflow end" / "inflow side" refers to the end or side close to the blood inflow side or close to the atrium side; the "outflow end" / "outflow side" refers to the end or side close to the blood outflow side or close to the ventricle side. "Axial" refers to the direction parallel to the line connecting the center of the outflow end and the center of the inflow end. "Radial" refers to the direction perpendicular to or approximately perpendicular to the axial direction, the diameter or radius of the component. "Circumferential" refers to the direction surrounding the axial direction. The "central axis" refers to the line connecting the centers of the outflow end and the inflow end.

[0022] It is worth noting that the above-mentioned terms indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0023] The artificial heart valve of the present invention is suitable for replacing a diseased native mitral valve or tricuspid valve. Figure 1 and Figure 2The artificial heart valve of the first embodiment includes a double-layer valve stent 100, a coating 200 and a leaflet 300. The double-layer valve stent 100 includes an outer frame 110, an inner frame 120 arranged in the outer frame 110, and a connecting line 130 for binding the outer frame 110 and the inner frame 120. The coating 200 is connected to the inner surface and / or outer surface of the outer frame 110 and the inner frame 120 (for example, by suture), and is used to block and block blood flow, effectively prevent paravalvular leakage, and facilitate rapid endothelialization of the double-layer valve stent 100 after implantation. The leaflets 300 are fixed in the inner frame 120 (for example, by suture), and the number can be two, three or more. Each leaflet 300 can open and close relative to each other to form a one-way valve, which only allows blood to flow from the atrium to the ventricle, and blocks blood from flowing from the ventricle to the atrium.

[0024] In this embodiment, the outer frame 110 and the inner frame 120 are both self-expanding stents made of shape memory material (e.g., nickel-titanium alloy). The self-expanding stent can be delivered to the diseased native valve by a delivery device in a compressed state, and can self-expand to its expanded state after being released from the delivery device to replace the native valve. In other embodiments, the outer frame 110 and the inner frame 120 can also both be balloon-expandable stents, and the outer frame 110 and the inner frame 120 are driven to expand by an expansion balloon.

[0025] refer to Figure 2 and Figure 2A In this embodiment, the outer frame 110 includes a first connecting portion 111, and the inner frame 120 includes a second connecting portion 121 corresponding to the first connecting portion 111. The first connecting portion 111 and the second connecting portion 121 are abutted against each other and are tied together by the connecting line 130.

[0026] In this embodiment, the first connecting portion 111 includes at least one first transverse straight rod 1110 perpendicular to the axial direction of the double-layer valve stent 100 and at least one first vertical straight rod 1111 parallel to the axial direction of the double-layer valve stent 100. Figure 2A As shown, the first connection portion 111 includes two opposite first transverse straight rods 1110 and two opposite first vertical straight rods 1111 (due to angle reasons, only one first transverse straight rod 1110 and one first vertical straight rod 1111 are shown in the figure).

[0027] In this embodiment, the second connecting portion 121 includes at least one second transverse straight rod 1210 perpendicular to the axial direction of the double-layer valve stent 100 and at least one second vertical straight rod 1211 parallel to the axial direction of the double-layer valve stent 100. Figure 2AAs shown, in this embodiment, the second connecting portion 121 includes two opposite second transverse straight rods 1210 and two opposite second vertical straight rods 1211. The second transverse straight rods 1210 are attached to the corresponding first transverse straight rods 1110, and the second vertical straight rods 1211 are attached to the corresponding first vertical straight rods 1111.

[0028] The connecting line 130 includes a first portion 131 tied around the periphery of the second horizontal straight rod 1210 and the corresponding first horizontal straight rod 1110 abutting against each other, and a second portion 132 tied around the periphery of the second vertical straight rod 1211 and the corresponding first vertical straight rod 1111 abutting against each other. Figure 2A As shown, in this embodiment, the connecting line 130 includes a first part 131 and two second parts 132, wherein the first part 131 is tied around the periphery of the first transverse straight rod 1110 at the inflow end of the first connecting part 111 and the second transverse straight rod 1210 at the inflow end of the second connecting part 121, while the first transverse straight rod 1110 at the outflow end of the first connecting part 111 and the second transverse straight rod 1210 at the outflow end of the second connecting part 121 are not tied around the connecting line, and the two second parts 132 are respectively tied around the peripheries of the two first vertical straight rods 1111 of the first connecting part 111 and the corresponding second vertical straight rods 1211 of the second connecting part 121.

[0029] The outer frame 110 and the inner frame 120 of the double-layer valve stent 100 may be affected by various factors (including but not limited to blood flow dynamics). Figure 2 As shown in FIG. 1 , the axial shear force F1 (i.e., the shear force generated by the displacement of the outer frame 110 and the inner frame 120 in opposite axial directions) is generated. Since the first portion 131 of the connecting wire 130 of this embodiment is tied around the outer periphery of the second transverse straight rod 1210 and the first transverse straight rod 1110 which are close to each other, each turn of the first portion 131 of the connecting wire 130 can generate a concentrated axial connecting force f1 in response to the axial shear force F1. z (like Figure 2A As shown), the connection force f z Will not be decomposed into components in other directions, the connection force f z All of them are used to resist the axial shear force F1 generated by the outer frame 110 and the inner frame 120 during loading, delivery, and use, so the first part 131 of the connecting line 130 only needs to form a smaller number of turns to provide a reliable and sufficient connection force to resist the axial shear force F1.

[0030] Similarly, even if the outer frame 110 and the inner frame 120 of the double-layer valve stent 100 are subjected to Figure 2As shown in the radial separation force F2 (i.e., the separation force generated by the displacement of the outer frame 110 and the inner frame 120 in opposite radial directions), since the second portion 132 of the connecting wire 130 of this embodiment is tied around the outer periphery of the second vertical straight rod 1211 and the first vertical straight rod 1111 which are close to each other, each turn of the second portion 132 of the connecting wire 130 can generate a concentrated radial connection force f y (like Figure 2A As shown), the connection force f y Will not be decomposed into components in other directions, the connection force f y All of them are used to resist the radial separation force F2 generated by the outer frame 110 and the inner frame 120 during loading, delivery, and use, so the second part 132 of the connecting line 130 only needs to form a smaller number of turns to provide a reliable and sufficient connection force.

[0031] Since the number of turns of the first part 131 and the second part 132 of the connecting wire 130 are both small, the overall size of the first connecting part 111 and the second connecting part 121 connected together by the connecting wire 130 is smaller, thereby effectively reducing the compression grip size of the artificial heart valve and improving the delivery passability of the artificial heart valve.

[0032] Preferably, the first portion 131 of the connecting wire 130 includes at least two turns, and specifically may include two, three or more turns. Figure 2A As shown, in this embodiment, the first part 131 of the connecting wire 130 includes two turns of wire to prevent the first part 131 from breaking, and the two ends of the first part 131 of the connecting wire 130 can be knotted for fixing. Each of the second parts 132 of the connecting wire 130 also preferably includes at least two turns of wire, and can specifically include two, three or more turns of wire. For example, Figure 2A As shown, each second portion 132 of the connecting wire 130 in this embodiment includes five turns of wire, and both ends of the second portion 132 of the connecting wire 130 can be knotted respectively for fixation.

[0033] Preferably, the connecting line 130 is a flexible line, more preferably a medical suture, such as a PTFE (polytetrafluoroethylene) suture or a PET (polyethylene terephthalate) suture with good biocompatibility. Medical suture has a certain elasticity, and its elongation at break is greater than 150% and can be stretched slightly. Therefore, the connection between the first connecting portion 111 of the outer frame 110 and the second connecting portion 121 of the inner frame 120 can be regarded as a flexible connection, which can reduce the stress on the first transverse straight rod 1110 and the first vertical straight rod 1111 of the first connecting portion 111, and the second transverse straight rod 1210 and the second vertical straight rod 1211 of the second connecting portion 121, reduce the risk of fracture of the above-mentioned rods, and improve the safety and durability of the connection parts.

[0034] It is worth noting that the straight rod in this article refers to a rod whose axis extending along its length direction is straight or substantially straight, for example, it can be a straight rectangular rod.

[0035] refer to Figure 3 as well as Figure 3A-3B In this embodiment, the first transverse straight rod 1110 of the first connecting portion 111 includes two opposite first transverse straight sides 1112 ( Figure 3A The second transverse straight rod 1210 of the second connecting portion 121 also includes two opposite second transverse straight sides 1212 ( Figure 3B The straight side in this article refers to the side extending in the same plane or substantially in the same plane. Thus, the turns of the first part 131 of the connecting wire 130 can be vertically wound on the first transverse straight side 1112 of the first transverse straight rod 1110 and the second transverse straight side 1212 of the second transverse straight rod 1210, so as to facilitate the connection force generated by the turns of the first part 131 of the connecting wire 130 to be concentrated and extended in the axial direction. Optionally, in order to gather the turns of each circle of the first part 131 of the connecting wire 130, one of the first transverse straight side 1112 of the first transverse straight rod 1110 and one of the second transverse straight side 1212 of the second transverse straight rod 1210 can be slightly concave.

[0036] Preferably, in this embodiment, the first transverse straight rod 1110 of the first connecting portion 111 further includes two opposite third transverse straight sides 1113 (from Figure 3A From the perspective of the reader, one of the visible third horizontal straight sides 1113 faces the reader, and the other third horizontal straight side 1113 is invisible due to the perspective), so that the cross section of the first horizontal straight rod 1110 (perpendicular to the axial direction of the first horizontal straight rod 1110) is rectangular. The second horizontal straight rod 1210 of the second connecting portion 121 also includes two opposite fourth horizontal straight sides 1213 (from Figure 3BFrom the perspective of the invention, one of the visible fourth transverse straight side surfaces 1213 faces the reader, and the other fourth transverse straight side surface 1213 is invisible due to the perspective), so that the cross section of the second transverse straight rod 1210 (perpendicular to the axial direction of the second transverse straight rod 1210) is rectangular. Thus, the first transverse straight rod 1110 of the first connecting portion 111 and the second transverse straight rod 1210 of the second connecting portion 121 can be closely attached to each other through the third transverse straight side surface 1113 and the fourth transverse straight side surface 1213 facing each other, and the turns of the first portion 131 of the connecting wire 130 can also be vertically wound on the third transverse straight side surface 1113 and the fourth transverse straight side surface 1213 of the first transverse straight rod 1110 and the second transverse straight rod 1210 that are away from each other.

[0037] Similarly, the first vertical straight rod 1111 of the first connecting portion 111 includes two opposite first vertical straight sides 1114 (from Figure 3A From the perspective of the first vertical straight side 1114, one of the visible first vertical straight sides 1114 faces the reader, and the other first vertical straight side 1114 is invisible due to the perspective. The second vertical straight rod 1211 of the second connecting portion 121 also includes two opposite second vertical straight sides 1214 (from Figure 3B From the perspective of the first connecting portion 111, one of the visible second vertical straight side surfaces 1214 faces the reader, and the other second vertical straight side surface 1214 is invisible due to the perspective). Thus, the first vertical straight rod 1111 of the first connecting portion 111 and the second vertical straight rod 1211 of the second connecting portion 121 can be closely attached to each other through the first vertical straight side surface 1114 and the second vertical straight side surface 1214 opposite to each other, and the turns of the second portion 132 of the connecting wire 130 can also be vertically wound on the first vertical straight side surface 1114 and the second vertical straight side surface 1214 of the first vertical straight rod 1111 and the second vertical straight rod 1211 that are away from each other, so as to facilitate the connecting force generated by the turns of the second portion 132 of the connecting wire 130 to be concentrated and extended radially.

[0038] Preferably, in this embodiment, the first vertical straight rod 1111 of the first connecting portion 111 further includes two opposite third vertical straight sides 1115 ( Figure 3A The second vertical straight rod 1211 of the second connecting portion 121 also includes two opposite fourth vertical straight sides 1215 ( Figure 3BThe left and right sides in the perspective shown in the figure) are arranged so that the cross section of the second vertical straight rod 1211 (perpendicular to the axial direction of the second vertical straight rod 1211) is rectangular. Thus, the turns of the second portion 132 of the connecting wire 130 can also be vertically wound on the third vertical straight side 1115 of the first vertical straight rod 1111 and the fourth vertical straight side 1215 of the second vertical straight rod 1211.

[0039] Preferably, the first connecting portion 111 includes a first through portion 1116, which may be a through hole / groove, and the two first transverse straight rods 1110 and the two first vertical straight rods 1111 are the constituent edges of the first through portion 1116, that is, the two first transverse straight rods 1110 and the two first vertical straight rods 1111 jointly enclose the first through portion 1116. Corresponding to the first transverse straight side surface 1112 of the first transverse straight rod 1110 and the third vertical straight side surface 1115 of the first vertical straight rod 1111, in this embodiment, the first through portion 1116 is also rectangular.

[0040] Correspondingly, the second connecting portion 121 includes a second through portion 1216, which may be a through hole / groove, and the two second transverse straight rods 1210 and the two second vertical straight rods 1211 are the constituent edges of the second through portion 1216, that is, the two second transverse straight rods 1210 and the two second vertical straight rods 1211 are enclosed together to form the second through portion 1216. Corresponding to the second transverse straight side surface 1212 of the second transverse straight rod 1210 and the fourth vertical straight side surface 1215 of the second vertical straight rod 1211, in this embodiment, the second through portion 1216 is also rectangular.

[0041] When connecting the outer frame 110 and the inner frame 120, the first part 131 of the connecting line 130 can be tied around the first horizontal straight rod 1110 of the first connecting part 111 and the corresponding second horizontal straight rod 1210 of the second connecting part 121 through the first through portion 1116 and the second through portion 1216, and the second part 132 of the connecting line 130 can be tied around the first vertical straight rod 1111 of the first connecting part 111 and the corresponding second vertical straight rod 1211 of the second connecting part 121 through the first through portion 1116 and the second through portion 1216. The operation is convenient, and because the two first horizontal straight rods 1110 and the two first vertical straight rods 1111 of the first connecting part 111 form a closed structure, and the two second horizontal straight rods 1210 and the two second vertical straight rods 1211 of the second connecting part 121 form a closed structure, the turns of the connecting line 130 can be effectively prevented from falling off, so that the connection is stable and reliable.

[0042] In order to improve the connection stability and force uniformity of the outer frame 110 and the inner frame 120, as Figure 3 As shown, preferably, the outer frame 110 includes a plurality of first connection parts 111 evenly spaced along the circumferential direction, and the inner frame 120 includes a plurality of second connection parts 121 evenly spaced along the circumferential direction. Accordingly, the connection line 130 includes a plurality of first parts 131 and a plurality of second parts 132 tied around the plurality of first connection parts 111 and the corresponding second connection parts 121. In this embodiment, the plurality of first connection parts 111 are arranged on the inflow side of the outer frame 110, and the plurality of second connection parts 121 are correspondingly arranged on the inflow side of the inner frame 120.

[0043] Specifically, in this embodiment, the outer frame 110 includes an atrial segment 112, a ventricular segment 113, a transition segment 114 connected between the atrial segment 112 and the ventricular segment 113, and a connecting segment 115 connected at the connection between the transition segment 114 and the ventricular segment 113. The connecting segment 115 is located radially inside the transition segment 114, and its inflow side extends toward the inflow side of the atrial segment 112 relative to the outflow side of the atrial segment 112 (from Figure 3 From the perspective shown, that is, the inflow side of the connecting segment 115 is higher than the outflow side of the atrial segment 112). More specifically, the connecting segment 115 includes a corrugated rod, which has a plurality of troughs 1150 connected to the ventricular segment 113 and a plurality of crests 1151 facing away from the ventricular segment 113. The plurality of first connecting portions 111 are respectively arranged at the corresponding crests 1151 on the inflow side of the connecting segment 115. This helps to lift the leaflet 300 arranged in the inner frame 120 (which is connected to the first connecting portion 111 through the second connecting portion 121) toward the atrial side, reduce the height of the outer frame 110 and the inner frame 120 in the ventricle and the occupation of the ventricular space, and reduce the risk of obstructing the left ventricular outflow tract.

[0044] The transition section 114 is suitable for extending from the ventricular side across the valve ring to the atrial side, and includes a plurality of transition struts 1140 distributed along the circumferential direction, each transition strut 1140 being connected to a corresponding trough 1150 of the wave-shaped rod of the connecting section 115. Preferably, in the expanded state, the transition strut 1140 extends axially from the ventricular section 113 and also bends radially outward to extend to the atrial section 112, and at least a portion of the transition strut 1140 also bends circumferentially, thereby presenting a spatially curved structure. In other words, each transition strut 1140 bends radially and circumferentially while extending axially.

[0045] This transition strut 1140 with a spatially curved structure is in sharp contrast to the transition strut extending axially and radially in the same plane. When the transition strut extending axially and radially in the same plane is subjected to the force transmitted from the atrial segment (derived from the squeezing force of the atrial tissue on the atrial segment), the force will be concentrated in the radial direction, and the inflow end of the leaflet is usually close to the transition strut, so this concentrated radial inward squeezing force will often squeeze the inflow end of the leaflet, thereby affecting the opening and closing of the leaflet. However, when the artificial heart valve of the present embodiment is implanted into the diseased native mitral valve or tricuspid valve, even if the atrial segment 112 of the double-layer valve stent 100 is subjected to squeezing force from the atrial tissue, since the transition strut 1140 of the transition segment 114 presents a spatially curved structure and has a circumferentially curved section, the force transmitted to the transition segment 114 by the atrial segment 112 can be dispersed in the circumferential direction, so that the radial force on the transition segment 114, i.e., the force affecting the opening and closing shape of the leaflets, will be reduced accordingly, and the spatially curved structure of the transition strut 1140 helps to reduce its own stress and strain. Therefore, the squeezing effect of the double-layer valve stent 100 on the internal leaflets 300 will be greatly weakened, thereby effectively reducing the influence on the opening and closing shape of the leaflets 300.

[0046] The atrial segment 112 is roughly disc-shaped or flange-shaped, and gradually extends away from the transition segment 14 in the axial and radial outward directions from the inflow end of the transition segment 114, so as to be adaptively attached to the valve ring on the atrial side. Specifically, the atrial segment 112 includes a plurality of units 1120 distributed along the circumferential direction, and each unit 1120 includes a first strut 1121 and a second strut 1122, one end of the first strut 1121 and one end of the second strut 1122 are respectively connected to two adjacent transition struts 1140, and the other end of the first strut 1121 and the other end of the second strut 1122 are connected to each other and preferably smoothly transition to reduce damage to the atrial tissue. Preferably, the adjacent first struts 1121 and the second struts 1122 between two adjacent units 1120 are connected to the same transition strut 1140.

[0047] Preferably, in the expanded state, the first strut 1121 and the second strut 1122 are both bent circumferentially, and the bending directions are consistent. This is advantageous. First, this can improve the compliance of the atrial segment 112, so that the synchronization of the atrial segment 112 with the movement of the cardiac cycle is improved, thereby reducing the damage of the atrial segment 112 to the atrial tissue. Secondly, the first strut 1121 and the second strut 1122 that are bent circumferentially also have the ability to disperse the squeezing force from the atrial tissue, and the force transmitted to the transition strut 1140 will also be reduced, which will also help to reduce the impact on the opening and closing shape of the leaflet 300. Furthermore, the first strut 1121 and the second strut 1122 that are bent circumferentially have a larger physical length to contact the atrial side of the valve ring, and the anti-paravalvular leakage effect is better.

[0048] Also preferably, in the expanded state, the circumferential bending directions of the first support rod 1121 and the second support rod 1122 are opposite to or diverge from the circumferential bending direction of the transition support rod 1140. Figure 3 From the perspective shown, the transition strut 1140 is bent in the counterclockwise direction, but the first strut 1121 and the second strut 1122 are bent in the clockwise direction. This helps the circumferential forces on the first strut 1121 and the second strut 1122 to offset or balance the circumferential forces on the transition strut 1140, thereby preventing the double-layer valve stent 100 from rotating due to the superimposed circumferential forces in the same direction.

[0049] The ventricular segment 113 is located on the ventricular side and has a mesh structure. Preferably, at least a portion of the ventricular segment 113 protrudes radially outward relative to the outflow end of the transition segment 114, so as to define an annular groove 1130 together with the transition segment 114 for accommodating and limiting an anchoring ring (not shown). Before implanting an artificial heart valve, an anchoring ring can be implanted first, and then the artificial heart valve is placed in the anchoring ring so that the anchoring ring is embedded in the annular groove 1130, and the leaflets and / or chordal plexus between the two are tightened by the anchoring ring and the artificial heart valve to achieve stable limiting of the artificial heart valve.

[0050] Also preferably, the ventricular segment 113 is provided with a barb 1131, which extends radially outward from the inflow end of the ventricular segment 113 toward the outflow end of the ventricular segment 113 for a certain distance and then bends and extends toward the inflow end of the ventricular segment 113 until the free end of the barb 1131, and is used for hooking the native valve leaflet to prevent the native valve leaflet from blocking the left ventricular outflow tract.

[0051] The inner frame 120 includes a substantially straight cylindrical mesh structure 122. The mesh structure 122 includes multiple layers of corrugated rods connected in the axial direction, wherein the plurality of second connection portions 121 are respectively arranged at corresponding crests 1220 of the inflow side corrugated rods of the mesh structure 122. Optionally, one or more of the plurality of second connection portions 121 are also respectively connected to a loading rod 1221 for connecting to a delivery device (for loading and delivering an artificial heart valve, not shown). The plurality of loading rods 1221 are preferably evenly spaced and distributed in the circumferential direction.

[0052] It is understandable that the above embodiments are only preferred embodiments of the present invention, and those skilled in the art can make modifications, substitutions, etc. on this basis to obtain other embodiments. For example, the first connection part 111 and the second connection part 121 of the outer frame 110 and the inner frame 120 can be modified to obtain other embodiments, or the structures of the outer frame 110 and the inner frame 120 can also be changed to obtain other embodiments.

[0053] For example, in other embodiments, the first connection portion 111 may also include other numbers of first transverse straight rods 1110 and first vertical straight rods 1111, the second connection portion 121 may also include other numbers of second transverse straight rods 1210 and second vertical straight rods 1211, and the numbers of the first part 131 and the second part 131 of the connection line 130 may also be changed accordingly. Alternatively, in other embodiments, the first connection portion 111 may also include only one or more first transverse straight rods 1110 or one or more first vertical straight rods 1111, the second connection portion 121 may also include only one or more second transverse straight rods 1210 or one or more second vertical straight rods 1211, and accordingly, the connection line 130 may also include only one or more first parts 131 or one or more second parts 132.

[0054] Or, if Figure 4A As shown, in some embodiments, the connecting wire 2130 can be tied only around the first horizontal straight rod 1110 on the inflow side of the first connecting part 111 and the second horizontal straight rod 1210 on the inflow side of the second connecting part 121, and the first vertical straight rod 1111 of the first connecting part 111 and the second vertical straight rod 1211 of the second connecting part 121 are not tied with the connecting wire.

[0055] exist Figure 4A In the example shown, when the outer frame and the inner frame of the double-layer valve stent are subjected to axial shear force, since the connecting wire 2130 of this example is tied around the periphery of the first transverse straight rod 1110 and the second transverse straight rod 1210 that are close to each other, each turn of the connecting wire 2130 can generate a concentrated axial connecting force f z , the connection force f z Will not be decomposed into components in other directions, the connection force f z All of them are used to resist the axial shear force generated by the outer frame and the inner frame during loading, delivery, and use, so the connecting wire 2130 only needs to form a small number of turns to provide a reliable and sufficient connection force to resist the axial shear force. Therefore, the overall size of the first connecting part 111 and the second connecting part 121 connected together by the connecting wire 2130 is small, thereby effectively reducing the compression grip size of the artificial heart valve (i.e., the radial size of the artificial heart valve compressed and accommodated in the delivery device), and improving the delivery passability of the artificial heart valve.

[0056] In contrast, Figure 4BAs shown, assuming that the first connecting portion 111' and the second connecting portion 121' of the outer frame and the inner frame adopt a circular hole structure, the connecting force f' generated by the connecting wire 130' tied around the first connecting portion 111' and the second connecting portion 121' will extend radially along the circular hole structure, and the axial shear force of the outer frame and the inner frame can only be resisted by the axial component f1' of the connecting force f', which requires the connecting wire 130' to form a large number of turns to provide sufficient connecting force components to resist the axial shear force of the outer frame and the inner frame. Therefore, the overall size of the first connecting portion 111' and the second connecting portion 121' connected together by the connecting wire 130' is larger, resulting in a larger crimping size of the artificial heart valve.

[0057] also, Figure 4A In the illustrated embodiment, since each coil of the connecting wire 130 is also vertically wound around the third transverse straight side surface 1113 (not visible in the figure) and the fourth transverse straight side surface 1213 of the first transverse straight rod 1110 and the second transverse straight rod 1210 that are away from each other, each coil can actually generate a connecting force f concentrated in the radial direction in response to the radial separation force on the outer frame and the inner frame. y , to resist the radial separation force.

[0058] Or, if Figure 4C As shown, in other embodiments, the first connecting portion 3111 and the second connecting portion 3121 may not adopt a rectangular structure, but may adopt other shapes, such as Figure 4C Specifically, the first connecting portion 3111 includes two first transverse straight rods 1110, a first vertical straight rod 1111 and a first inclined straight rod (not visible in the figure), and the second connecting portion 3121 includes two second transverse straight rods 1210, a second vertical straight rod 1211 and a second inclined straight rod 31211, wherein the first inclined straight rod and the second inclined straight rod 31211 no longer extend along the axial direction, but extend obliquely relative to the axial direction. The connecting line 3130 includes a first portion 131 tied around the first horizontal straight rod 1110 on the inflow side of the first connecting portion 3111 and the second horizontal straight rod 1210 on the inflow side of the second connecting portion 3121, a second portion 3132 tied around the first inclined straight rod 31211 of the first connecting portion 3111 and the second inclined straight rod 31211 of the second connecting portion 3121, and a third portion 3133 tied around the first vertical straight rod 1111 of the first connecting portion 3111 and the second vertical straight rod 1211 of the second connecting portion 3121.

[0059] In this case, the first connection portion 3111 still includes the first through portion (not visible in the figure), and the second connection portion 3121 still includes the second through portion 31216. The first portion 131, the second portion 3132, and the third portion 3133 of the connecting wire 3130 can still generate sufficient connection force in the axial direction and connection force in the radial direction with a small number of turns to resist the axial shear force and radial separation force generated by the outer frame and the inner frame during loading, delivery, and use.

[0060] Or, if Figure 4D As shown, in other embodiments, the first connection portion 4111 and the second connection portion 4121 may also adopt a double D-shaped structure. Specifically, the first connection portion 4111 includes a first vertical straight rod 1111, two first transverse straight rods 1110 respectively connected to the two ends of the first vertical straight rod 1111, a third transverse straight rod (not visible in the figure) connected to the approximate middle of the first vertical straight rod 1111, and two arc-shaped rods (not visible in the figure) respectively connecting the two first transverse straight rods 1110 and the third transverse straight rod, wherein each first transverse straight rod 1110 and the corresponding arc-shaped rod, the corresponding section of the first vertical straight rod 1111, and the third transverse straight rod together enclose a first through portion, that is, the first connection portion 4111 includes two first through portions.

[0061] Correspondingly, the second connecting portion 4121 includes a second vertical straight rod 1211, two second transverse straight rods 1210 respectively connected to the two ends of the second vertical straight rod 1211, a fourth transverse straight rod 1217 connected to the approximate middle of the second vertical straight rod 1211, and two arc-shaped rods 1218 respectively connecting the two second transverse straight rods 1210 and the fourth transverse straight rod 1217, wherein each second transverse straight rod 1210 and the corresponding arc-shaped rod 1218, the corresponding section of the second vertical straight rod 1211, and the fourth transverse straight rod 1217 together enclose a second through portion 41216, that is, the second connecting portion 41211 includes two first through portions 41216.

[0062] The connecting line 4130 includes a first portion 4131 tied around the first transverse straight rod 1110 on the inflow side of the first connecting portion 4111 and the second transverse straight rod 1210 on the inflow side of the second connecting portion 4121, a second portion 4132 tied around the first vertical straight rod 1111 of the first connecting portion 4111 and the second vertical straight rod 1211 of the second connecting portion 4121, a third portion 4133 tied around the third transverse straight rod 1217 of the first connecting portion 4111 and the fourth transverse straight rod 1217 of the second connecting portion 4121, and a fourth portion 4134 tied around the two arc-shaped rods 1218 of the first connecting portion 4111 and the second connecting portion 4121. In this case, the first part 4131, the second part 4132, the third part 4133, and the fourth part 4134 of the connecting wire 4130 can still generate sufficient connecting force in the axial direction and the connecting force in the radial direction with a smaller number of turns to resist the axial shear force and radial separation force generated by the outer frame and the inner frame during loading, delivery, and use.

[0063] Even, if Figure 4E As shown, in other embodiments, the first connection portion 5111 and the second connection portion 5121 may no longer include the first through portion and the second through portion. Specifically, the first connection portion 5111 is roughly T-shaped, including a first horizontal straight rod 1110 and a first vertical straight rod 1111 vertically connected to the middle of the first horizontal straight rod 1110. The second connection portion 5121 is also roughly T-shaped accordingly, including a second horizontal straight rod 1210 and a second vertical straight rod 1211 vertically connected to the middle of the second horizontal straight rod 1210. The connecting line 5130 includes a first portion 5131 tied around the first horizontal straight rod 1110 of the first connection portion 5111 and the second horizontal straight rod 1210 of the second connection portion 5121, and a second portion 5132 tied around the first vertical straight rod 1111 of the first connection portion 5111 and the second vertical straight rod 1211 of the second connection portion 5121. In this case, the first part 5131 and the second part 5132 of the connecting wire 5130 can also generate sufficient connecting force in the axial direction and the connecting force in the radial direction with a smaller number of turns to resist the axial shear force and radial separation force generated by the outer frame and the inner frame during loading, delivery, and use.

[0064] refer to Figure 5Similar to the double-layer valve stent 100 of the first embodiment, the first connection portion 6111 of the outer frame 6110 and the second connection portion 6121 of the inner frame 6120 of the double-layer valve stent 6100 of the artificial heart valve of the second embodiment of the present invention are also roughly rectangular, that is, the first connection portion 6111 also includes a first transverse straight rod 61110 and a first vertical straight rod 61111, and the second connection portion 6121 also includes a second transverse straight rod 61210 and a second vertical straight rod 61211. Therefore, the first connection portion 6111 is tied around the first connection portion 6111. The connecting wires (not shown) on the first transverse straight rod 61110 and the corresponding second transverse straight rod 61210 of the second connecting part 6121, and the first vertical straight rod 61111 and the corresponding second vertical straight rod 61211 of the first connecting part 6111 and the second connecting part 6121 can also generate sufficient connecting force in the axial direction and the radial direction with a small number of turns to resist the axial shear force and radial separation force generated by the outer frame 6110 and the inner frame 6120 during loading, delivery and use.

[0065] However, different from the double-layer valve stent 100 of the first embodiment, the first connection portion 6111 of the outer frame 6110 in this embodiment is no longer arranged on the inflow side of the outer frame 6110, but is arranged between the inflow side and the outflow side of the outer frame 6110, and correspondingly, the second connection portion 6121 of the inner frame 6120 is no longer arranged on the inflow side of the inner frame 6120, but is arranged between the inflow side and the outflow side of the inner frame 6120. Moreover, the structures of the outer frame 6110 and the inner frame 6120 of this embodiment are also different from those of the outer frame 110 and the inner frame 120 of the first embodiment.

[0066] Specifically, the outer frame 6110 includes a first atrial segment 6112 and a first ventricular segment 6113 connected to the first atrial segment 6112, and the first connecting portion 6111 is provided at the connection between the first atrial segment 6112 and the first ventricular segment 6113. The first atrial segment 6112 is generally disc-shaped, and includes a plurality of first units 61120 distributed along the circumferential direction, each first unit 61120 includes a first strut 61121 and a second strut 61122, one end of the first strut 61121 and one end of the second strut 61122 are connected to each other, and the other end of the first strut 61121 and the other end of the second strut 61122 are respectively connected to the second strut 61122 and the first strut 61121 of the adjacent first unit 61120. The first ventricular segment 6113 extends axially from the outflow end of the first atrial segment 6112 and extends radially outward. Preferably, the first ventricular segment 6113 is also provided with a plurality of barbs 61131 distributed along the circumferential direction for puncturing the valve leaflets, or cooperating with the anchoring ring to limit the position of the artificial heart valve.

[0067] The inner frame 6120 includes a second ventricle segment 6122 and a second atrium segment 6123 connected to the second ventricle segment 6122, and the second connection portion 6121 is provided at the connection between the second atrium segment 6123 and the second ventricle segment 6122. The second atrium segment 6123 is generally disc-shaped, and includes a plurality of second units 61230 distributed along the circumferential direction, each second unit 61230 includes a third support rod 61231 and a fourth support rod 61232, one end of the third support rod 61231 and one end of the fourth support rod 61232 are connected to each other, and the other end of the third support rod 61231 and the other end of the fourth support rod 61232 are respectively connected to the fourth support rod 61232 and the third support rod 61231 of the adjacent second unit 61230. Preferably, the multiple second units 61230 of the inner frame 6120 and the multiple first units 61120 of the outer frame 6110 are staggeredly arranged along the circumferential direction to enhance the effect of preventing paravalvular leakage.

[0068] refer to Figure 6 Similar to the double-layer valve stent 100 of the first embodiment, the first connection portion 7111 of the outer frame 7110 and the second connection portion 7121 of the inner frame 7120 of the double-layer valve stent 7100 of the artificial heart valve of the third embodiment of the present invention are also roughly rectangular, that is, the first connection portion 7111 also includes a first transverse straight rod and a first vertical straight rod, and the second connection portion 7121 also includes a second transverse straight rod and a second vertical straight rod. Therefore, the connecting wires (not shown) tied around the first transverse straight rods of the first connection portion 7111 and the corresponding second transverse straight rods of the second connection portion 7121, as well as the first vertical straight rods of the first connection portion 7111 and the corresponding second vertical straight rods of the second connection portion 7121 can also generate sufficient connecting force in the axial direction and connecting force in the radial direction with a small number of turns to resist the axial shear force and radial separation force generated by the outer frame 7110 and the inner frame 7120 during loading, delivery, and use.

[0069] However, different from the double-layer valve stent 100 of the first embodiment, the first connection portion 7111 of the outer frame 7110 in this embodiment is no longer arranged on the inflow side of the outer frame 7110, but is arranged on the outflow side of the outer frame 7110, and correspondingly, the second connection portion 7121 of the inner frame 7120 is no longer arranged on the inflow side of the inner frame 7120, but is arranged on the outflow side of the inner frame 7120. Moreover, the structures of the outer frame 7110 and the inner frame 7120 of this embodiment are also different from those of the outer frame 110 and the inner frame 120 of the first embodiment.

[0070] Specifically, the outer frame 7110 includes a first ventricular segment 7113, but no longer includes an atrial segment. The first ventricular segment 7113 extends radially outward from its outflow end toward its inflow end to its maximum diameter and then slightly extends radially inward to its inflow end, and the inflow end of the first ventricular segment 7113 is a free end. The first ventricular segment 7113 has a mesh structure, and the mesh structure includes multiple layers of corrugated rods connected in the axial direction, wherein the first connecting portion 7111 is arranged at the corresponding trough 71130 of the corrugated rod on the outflow side of the mesh structure. One or several of the multiple first connecting portions 7111 are also respectively connected to a loading rod 71131 for connecting to a delivery device. The multiple loading rods 71131 are preferably evenly spaced along the circumferential direction. Preferably, the first ventricular segment 7113 is also provided with a plurality of limiting protrusions 71132 distributed along the circumferential direction.

[0071] The inner frame 7120 includes a second ventricular segment 7122 and an atrial segment 7123 connected to the second ventricular segment 7122. The second ventricular segment 7122 has a mesh structure, and the mesh structure includes multiple layers of corrugated rods connected in the axial direction, wherein the second connecting portion 7121 is provided at the corresponding trough 71220 of the outflow side corrugated rods of the mesh structure. The atrial segment 7123 is generally disc-shaped, and includes a plurality of units 71230 distributed in the circumferential direction, each unit 71230 includes a first support rod 71231 and a second support rod 71232, one end of the first support rod 71231 and one end of the second support rod 71232 are connected to each other, and the other end of the first support rod 71231 and the other end of the second support rod 71232 are respectively connected to the second support rod 71232 and the first support rod 71231 of the adjacent unit 71230.

[0072] When the artificial heart valve of this embodiment is implanted in the heart, the native valve ring can be received by the annular groove 71133 formed by the atrial segment 7123 of the inner frame 7120, the multiple limiting protrusions 71132 on the first ventricular segment 7113 of the outer frame 7110, and the section of the first ventricular segment 7113 located between the atrial segment 7123 and the multiple limiting protrusions 71132, so as to limit the artificial heart valve.

[0073] The above description is only a preferred specific implementation manner of the present invention, and the protection scope of the present invention is not limited to the embodiments listed above. Any simple change or equivalent replacement of the technical solution that can be obviously obtained by any technician familiar with the technical field within the technical scope disclosed in the present invention falls within the protection scope of the present invention.

Claims

1. A double-layer valve stent, characterized in that: It includes an outer frame, an inner frame arranged in the outer frame, and a connecting line for binding the outer frame and the inner frame; the outer frame includes a first connecting part, the inner frame includes a second connecting part corresponding to the first connecting part, and the first connecting part is adjacent to the second connecting part; the first connecting part has at least one first transverse straight rod perpendicular to the axial direction of the double-layer valve stent; the second connecting part corresponds to at least one second transverse straight rod perpendicular to the axial direction of the double-layer valve stent; the connecting line is at least tied around the periphery of the first transverse straight rod and the corresponding second transverse straight rod adjacent to each other.

2. The double-layer valve stent according to claim 1, characterized in that: The first connecting part also has at least one first vertical straight rod parallel to the axial direction of the double-layer valve stent; the second connecting part also has at least one second vertical straight rod parallel to the axial direction of the double-layer valve stent; the connecting line is also tied around the periphery of the first vertical straight rod and the corresponding second vertical straight rod which are abutting each other.

3. The double-layer valve stent according to claim 2, characterized in that: The first transverse straight rod and the corresponding second transverse straight rod each have at least two opposite transverse straight sides, and the first vertical straight rod and the corresponding second vertical straight rod each have at least two opposite vertical straight sides.

4. The double-layer valve stent according to claim 2 or 3, characterized in that: The cross-sectional shapes of the first transverse straight rod and the corresponding second transverse straight rod are both rectangular, and the cross-sectional shapes of the first vertical straight rod and the corresponding second vertical straight rod are both rectangular.

5. The double-layer valve stent according to claim 2 or 3, characterized in that: The first connecting portion includes a first through hole / slot, and the first horizontal straight rod and the first vertical straight rod are the constituent edges of the first through hole / slot; correspondingly, the second connecting portion includes a second through hole / slot, and the second horizontal straight rod and the second vertical straight rod are the constituent edges of the second through hole / slot.

6. The double-layer valve stent according to claim 5, characterized in that: The first through hole / slot is in a rectangular shape; correspondingly, the second through hole / slot is in a rectangular shape.

7. The double-layer valve stent according to claim 1, characterized in that: The first connection portion is arranged at the inflow side, outflow side or between the inflow side and the outflow side of the outer frame, and the second connection portion is correspondingly arranged at the inflow side, outflow side or between the inflow side and the outflow side of the inner frame.

8. The double-layer valve stent according to claim 7, characterized in that: The outer frame includes an atrial segment, a ventricular segment connected to the atrial segment, and a connecting segment connected to the ventricular segment, wherein the inflow side of the connecting segment extends toward the inflow side of the atrial segment relative to the outflow side of the atrial segment, the first connecting portion is arranged on the inflow side of the connecting segment, and the second connecting portion is arranged on the inflow side of the inner frame.

9. The double-layer valve stent according to claim 8, characterized in that: The connecting segment includes a corrugated rod having a plurality of troughs connected to the ventricular segment and a plurality of crests away from the ventricular segment, and a first connecting portion is disposed at a corresponding crest of the corrugated rod.

10. The double-layer valve stent according to claim 8, characterized in that: The outer frame also includes a transition section connected between the atrial segment and the ventricular segment, and the transition section includes a plurality of transition struts distributed along the circumferential direction. In an expanded state, the transition struts extend axially from the ventricular segment and also bend radially outward to extend to the atrial segment, and at least a portion of the transition struts also bends circumferentially, thereby presenting a spatially curved structure.

11. The double-layer valve stent according to claim 1, characterized in that: The connecting wire is a flexible wire.

12. The double-layer valve stent according to claim 1, characterized in that: The connecting wire tied around the periphery of the first transverse straight rod and the corresponding second transverse straight rod which are close to each other includes at least two turns of wire.

13. An artificial heart valve, characterized in that: It comprises a double-layer valve stent according to any one of claims 1 to 12, a coating connected to the inner surface and / or outer surface of the double-layer valve stent, and at least two leaflets that can open and close relative to each other and are connected to the inner frame of the double-layer valve stent.

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