Prosthetic heart valve stent and prosthetic heart valve

Abstract

The invention relates to a heart valve prosthesis stent and a heart valve prosthesis. The artificial heart valve stent has a compression state and an expansion state and comprises an atrial section, a ventricular section and a transition section located between the atrial section and the ventricular section, the transition section comprises a plurality of transition supporting rods distributed in the circumferential direction, and each transition supporting rod comprises a first end connected with the ventricular section and a second end connected with the atrial section. In the expanded state, the transition supporting rod extends from the first end in the axial direction and meanwhile bends outwards in the radial direction to extend to the second end, and at least part of the transition supporting rod is bent in the circumferential direction, so that the space bending structure is formed. The heart valve prosthesis comprises the heart valve prosthesis support, a covering film connected to the inner surface and / or the outer surface of the heart valve prosthesis support and at least two valve leaflets which are fixedly arranged in the heart valve prosthesis support and can be opened and closed oppositely. The artificial heart valve stent has small influence on the opening and closing form of valve leaflets in the artificial heart valve stent.

Description

Technical Field

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

[0002] Existing artificial heart valves usually include an artificial heart valve stent and artificial valve leaflets fixed in the artificial heart valve stent. When the existing artificial heart valve used for mitral valve replacement or tricuspid valve replacement is implanted in the human body, the atrial disk of the artificial heart valve stent will be squeezed by the atrial tissue, and then the artificial heart valve stent will squeeze the artificial valve leaflets, affecting the opening and closing shape of the artificial valve leaflets, and in severe cases, may even cause the artificial heart valve to fail. Summary of the invention

[0003] In view of this, the present invention aims to provide an artificial heart valve stent and an artificial heart valve that can effectively reduce the impact on the opening and closing morphology of the valve leaflets.

[0004] To this end, the present invention provides, on one hand, an artificial heart valve stent having a compressed state and an expanded state, comprising an atrial segment, a ventricular segment and a transition segment located between the atrial segment and the ventricular segment, wherein the transition segment comprises a plurality of transition struts distributed along the circumferential direction, each transition strut comprising a first end connected to the ventricular segment and a second end connected to the atrial segment, wherein in the expanded state, the transition strut extends axially from the first end while also bending radially outward to extend to the second end, and at least a portion of the transition strut is also bent circumferentially, thereby presenting a spatially curved structure.

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

[0006] When the artificial heart valve of the embodiment of the present invention is implanted into the diseased native mitral valve or tricuspid valve, even if the atrial segment of the artificial heart valve stent is subjected to squeezing force from the atrial tissue, since the transition struts of the transition segment present a spatially curved structure and have a circumferentially curved section, the force transmitted to the transition segment from the atrial segment can be dispersed in the circumferential direction, so that the radial force on the transition segment, that is, the force affecting the opening and closing morphology of the leaflets, will be reduced accordingly, and the spatially curved structure of the transition struts helps to reduce their own stress and strain. Therefore, the squeezing effect of the artificial heart valve stent on the internal leaflets will be greatly weakened, thereby effectively reducing the influence on the opening and closing morphology of the leaflets. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0008] Figure 1B yes Figure 1A A front view of the artificial heart valve shown;

[0009] Figure 2A Figure 1A A three-dimensional schematic diagram of an artificial heart valve stent of the artificial heart valve shown;

[0010] Figure 2B yes Figure 2A A front view of the artificial heart valve stent shown;

[0011] Figure 2C yes Figure 2A A top view of the artificial heart valve stent shown;

[0012] Figure 3A yes Figure 2A A three-dimensional schematic diagram of the atrial segment and transition segment of the artificial heart valve stent shown;

[0013] Figure 3B yes Figure 3A A top view of the atrial segment and transition segment is shown;

[0014] Figure 4A yes Figure 3A A three-dimensional schematic diagram of one transition support rod of the transition section and a first support rod and a second support rod connected thereto;

[0015] Figure 4B yes Figure 4A A top view of the transition support rod and the first support rod and the second support rod connected thereto;

[0016] Figure 5 is a top view of an artificial heart valve stent of an artificial heart valve according to a second embodiment of the present invention;

[0017] Figure 6 is a top view of an atrial segment and a transition segment of an artificial heart valve stent of an artificial heart valve according to a third embodiment of the present invention;

[0018] Figure 7 is a top view of an atrial segment and a transition segment of an artificial heart valve stent of an artificial heart valve according to a fourth embodiment of the present invention;

[0019] Figure 8 is a three-dimensional schematic diagram of an artificial heart valve stent of an artificial heart valve according to a fifth embodiment of the present invention;

[0020] Fig. 9 yes Figure 8 A three-dimensional schematic diagram of the atrial segment and transition segment of the artificial heart valve stent shown;

[0021] Fig. 10A yes Fig. 9 A three-dimensional schematic diagram of one transition support rod of the transition section and a first support rod and a second support rod connected thereto;

[0022] Fig. 10B yes Fig. 10A The transitional support rod shown is a top view of the first support rod and the second support rod connected thereto;

[0023] Fig.11 It is a three-dimensional schematic diagram of one transitional strut and a first strut and a second strut connected thereto of an artificial heart valve stent of an artificial heart valve of a sixth embodiment of the present invention;

[0024] Fig. 12A yes Fig.11 AA section view of the transition support rod shown;

[0025] Fig. 12B yes Fig.11 A BB section view of the transition support rod shown;

[0026] Fig.13A is a perspective schematic diagram of an artificial heart valve according to a seventh embodiment of the present invention;

[0027] Fig. 13B yes Fig.13A A front view of the artificial heart valve shown;

[0028] Fig.14A Fig. 13B A front view of an artificial heart valve stent of the artificial heart valve shown;

[0029] Fig. 14B yes Fig.14A An exploded view of the artificial heart valve stent shown;

[0030] Fig. 14C yes Fig. 14B A three-dimensional schematic diagram of the outer frame of the artificial heart valve stent shown;

[0031] Fig.15 It is a stereoscopic view of the outer frame of the artificial heart valve stent of the artificial heart valve of the eighth embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 or processes may not be repeated in some embodiments.

[0033] First of all, it should be noted that, in this article, the "inflow end" and "outflow end" of the artificial heart 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, where the "inflow end" refers to the end close to the blood inflow side or close to the atrium side; the "outflow end" refers to the end 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. "Central axis" refers to the center line connecting the outflow end and the inflow end.

[0034] 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.

[0035] refer to Figure 1A and Figure 1B The artificial heart valve 1000 of the first embodiment of the present invention is suitable for replacing the diseased native mitral valve or tricuspid valve. The artificial heart valve 1000 includes an artificial heart valve stent 1100, a coating 1200 and a leaflet 1300. The artificial heart valve stent 1100 preferably adopts a self-expanding stent, and is more preferably made of a shape memory material (such as a nickel-titanium alloy). The self-expanding stent can be delivered to the diseased native valve by a delivery device in a compressed form, and can self-expand to its expanded state after being released from the delivery device to replace the native valve. The coating 1200 is connected to the inner surface and / or outer surface of the artificial heart valve stent 1100 (for example, by suture suturing), which helps to prevent paravalvular leakage and facilitates rapid endothelialization of the artificial heart valve stent 1100 after implantation. The leaflets 1300 are fixed in the artificial heart valve stent 1100 (for example, by sutures), and the number can be two, three or more. Their function is similar to 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.

[0036] Also refer to Figures 2A-2C The artificial heart valve stent 1100 includes a ventricular segment 1110, a transition segment 1120 and an atrial segment 1130, wherein the transition segment 1120 is connected between the ventricular segment 1110 and the atrial segment 1130. As the name implies, after the artificial heart valve 1000 is implanted, the ventricular segment 1110 is located on the ventricular side, the atrial segment 1130 is located on the atrial side, and the transition segment 1120 extends from the ventricular side across the valve ring to the atrial side.

[0037] In this embodiment, the overall height h of the artificial heart valve stent 1100 (i.e., the axial distance between the inflow end and the outflow end of the artificial heart valve stent 1100) is preferably greater than or equal to 15 mm. The ventricular segment 1110 is roughly in the shape of a hollow cylinder, and has a mesh structure formed by multiple layers (four layers in the figure) of corrugated rods 1111 connected in sequence along the axial direction. The leaflets 1300 are sutured in the ventricular segment 1110 ( Figure 1B Visible). Optionally, the height of the ventricular segment 1110 (i.e., the axial distance between the inflow end and the outflow end of the ventricular segment 1110) h1 is in the range of 10mm-30mm, such as 19mm. The outer diameter d1 of the ventricular segment 1110 may be in the range of 23mm-35mm, such as 27mm. The transition segment 1120 extends axially and radially outward from the inflow end of the ventricular segment 1110 gradually away from the ventricular segment 1110, and its height (i.e., the axial distance between the inflow end and the outflow end of the transition segment 1120) h2 may be in the range of 3mm-10mm, such as 4mm. The atrial segment 1130 is roughly disc-shaped or flange-shaped, and extends axially and radially outward from the inflow end of the transition segment 1120 gradually away from the transition segment 1120. Optionally, the inclination angle θ of each part of the atrial segment 1130 relative to the ventricular segment 1110 (i.e., the angle of deflection of the tangent line of each part of the atrial segment 1130 relative to the axis of the ventricular segment 1110) is in the range of 90°-160°. The height h3 of the atrial segment 1130 (i.e., the axial distance between the inflow end and the outflow end of the atrial segment 1130) is usually greater than or equal to 3 mm, such as 6 mm. Figure 2C As shown, in this embodiment, the circumferential outer contour of the atrial segment 1130 is circular, and its maximum outer diameter d2 can be in the range of 35mm-65mm, such as 50mm. It is worth noting that the shapes, sizes, etc. of the artificial heart valve stent 1100 and its various segments in the expanded state described herein are only shown as examples and are not used to limit the present invention.

[0038] It is worth noting that in the present invention, the transition section 1120 adopts a special design. Specifically, the transition section 1120 includes a plurality of transition struts 1121 distributed along the circumferential direction. Each transition strut 1121 includes a first end 1122 connected to the ventricular segment 1110 and a second end 1123 connected to the atrial segment 1130. In the expanded state, each transition strut 1121 extends axially from the first end 1122 and also bends radially outward to extend to the second end 1123. In particular, at least a portion of each transition strut 1121 also bends and extends circumferentially, thereby forming a spatial curved structure. In other words, each transition strut 1121 bends and extends radially and circumferentially while extending axially.

[0039] The transition strut 1121 of the present invention with a spatially curved structure forms a sharp contrast with the transition strut extending axially and radially in the same plane. The transition strut extending axially and radially in the same plane will concentrate the force in the radial direction when it is subjected to the force transmitted from the atrial segment (derived from the squeezing force of the atrial segment by the atrial tissue), and the inflow end of the leaflet is usually close to the transition strut, so this concentrated radial inward squeezing force often squeezes the inflow end of the leaflet, thereby affecting the opening and closing shape of the leaflet. However, when the artificial heart valve 1000 of this embodiment is implanted into the diseased native mitral valve or tricuspid valve, even if the atrial segment 1130 of the artificial heart valve stent 1100 is subjected to squeezing force from the atrial tissue, since the transition strut 1121 of the transition segment 1120 presents a spatially curved structure and has a circumferentially curved section, the force transmitted to the transition segment 1120 by the atrial segment 1130 can be dispersed in the circumferential direction, so that the radial force on the transition segment 1120, that is, the force that affects the opening and closing shape of the leaflets, will be reduced accordingly, and the spatially curved structure of the transition strut 1121 helps to reduce its own stress and strain. Therefore, the squeezing effect of the artificial heart valve stent 1100 on the internal leaflets 1300 will be greatly weakened, thereby effectively reducing the influence on the opening and closing shape of the leaflets 1300.

[0040] Preferably, the multiple transition struts 1121 of the transition section 1120 are evenly spaced and distributed along the circumferential direction. As an example, in this embodiment, the first ends 1122 of the multiple transition struts 1121 of the transition section 1120 are connected to the crests 1112 of the inflow end wave-shaped rods 1111 of the ventricular section 1110. Preferably, each crest 1112 of the inflow end wave-shaped rods 1111 of the ventricular section 1110 is connected to a transition strut 1121 to improve the overall dispersion effect of the transition section 1120.

[0041] It is also preferred that the change rate of the distance between the first end 1122 and the second end 1123 of the same transition strut 1121 in the use state and in the natural state is less than 20%. The distance between the first end 1122 and the second end 1123 of the transition strut 1121 refers to the shortest straight-line distance between the first end 1122 and the second end 1123 of the transition strut 1121. The use state refers to the expansion state of the artificial heart valve 1000 after implantation into the diseased native valve. In this state, the transition strut 1121 is subjected to the force transmitted from the atrial segment 1130 (derived from the squeezing force of the atrial tissue on the atrial segment 1130). The natural state refers to the state in which the artificial heart valve 1000 is naturally expanded without external force. In this state, the transition strut 1121 is not subjected to the force transmitted from the atrial segment 1130.

[0042] The change rate of the distance between the first end 1122 and the second end 1123 of the transition strut 1121 in the use state and in the natural state is less than 20%, indicating that the change range of the distance between the first end 1122 and the second end 1123 of the transition strut 1121 in the use state and in the natural state is limited, and the change is mainly caused by the change of the radial shape of the transition strut 1121. The change rate of less than 20% indicates that thanks to the spatial bending structure of the transition strut 1121, the radial force and radial deformation of the transition strut 1121 are limited, so that the force transmitted from the transition strut 1121 and the transition section 1120 to the artificial heart valve stent 1100 to affect the opening and closing shape of the leaflet 1300 is relatively small.

[0043] Further preferably, the second end 1123 and the first end 1122 of the same transition strut 1121 are circumferentially misaligned in the expanded state. In other words, the second end 1123 and the first end 1122 of the same transition strut 1121 are not aligned in the circumferential direction. Figure 2C From the perspective shown, the second end 1123 of the same transition support rod 1121 is offset by a certain distance in the circumferential direction relative to the first end 1122. This helps to increase the bending amplitude of the transition support rod 1121 in the circumferential direction, thereby improving the effect of the transition support rod 1121 in dispersing the force in the circumferential direction.

[0044] refer to Figures 3A-4BIn this embodiment, each of the transition struts 1121 includes a main curved segment 1124 and an auxiliary curved segment 1125, wherein the main curved segment 1124 is connected between the auxiliary curved segment 1125 and the atrial segment 1130, and the auxiliary curved segment 1125 is connected between the main curved segment 1124 and the ventricular segment 1110. In the expanded state, the main curved segment 1124 extends axially while bending radially outward and circumferentially to present a spatial curved structure, and the axially extending length of the main curved segment 1124 is sufficient to span the valve ring of the native heart valve to be implanted. The auxiliary curved segment 1125 also extends axially while bending radially outward or inward and circumferentially to present a spatial curved structure, however, the circumferential bending direction of the auxiliary curved segment 1125 is opposite to or diverges from the circumferential bending direction of the main curved segment 1124. For example, from Figure 4A From the perspective shown, in this embodiment, the circumferential bending direction of the main bending section 1124 is counterclockwise, while the circumferential bending direction of the auxiliary bending section 1125 is clockwise.

[0045] The transition strut 1121 constructed in this way is advantageous. First, the force transmitted from the atrial segment 1130 (derived from the squeezing force of the atrial tissue on the atrial segment 1130) can be dispersed at least in the radial and circumferential directions through the main curved segment 1124, so as to reduce the radial squeezing force of the artificial heart valve stent 1100 on the internal leaflets 1300, thereby reducing the influence on the opening and closing morphology of the leaflets 1300. Secondly, since the circumferential bending direction of the auxiliary curved segment 1125 is opposite to the circumferential bending direction of the main curved segment 1124, in the same circumferential span, the main curved segment 1124 has a larger bending space, and the bending amplitude or arc length in the circumferential direction is larger, so the effect of dispersing the force in the circumferential direction is better. Furthermore, when the main curved segment 1124 is subjected to the force transmitted from the atrial segment 1130, the auxiliary curved segment 1125 with a spatial bending structure can also provide a buffer for the main curved segment 1124.

[0046] Preferably, in the expanded state, the circumferential bending arc length of the main curved segment 1124 is greater than the circumferential bending arc length of the auxiliary curved segment 1125, so as to improve the circumferential force dispersion effect of the main curved segment 1124. Optionally, for the same transition strut 1121, the ratio of the physical length of the main curved segment 1124 (the sum of the lengths of each part of the main curved segment 1124 along its extension path) to the physical length of the auxiliary curved segment 1125 (the sum of the lengths of each part of the auxiliary curved segment 1125 along its extension path) is in the range of 2 to 10.

[0047] Additionally or alternatively, in the expanded state, the circumferential bending amplitude of the main curved segment 1124 is greater than the circumferential bending amplitude of the auxiliary curved segment 1125, where the circumferential bending amplitude refers to the degree of bending of the arc of the curved segment relative to the straight line between its two end points in the circumferential direction. Additionally or alternatively, the circumferential bending arc of the main curved segment 1124 is at least greater than π / 8, preferably greater than π / 6, which also helps to improve the effect of the main curved segment 1124 in dispersing the force in the circumferential direction.

[0048] Still reference Figures 3A-4B In this embodiment, the atrial segment 1130 includes a plurality of first units 1131 distributed along the circumferential direction. In this embodiment, the atrial segment 1130 includes 12 first units 1131. Each of the first units 1131 includes a first strut 1132 and a second strut 1133, one end of the first strut 1132 and one end of the second strut 1133 are respectively connected to the second ends 1123 of two adjacent transition struts 1121, and the other end of the first strut 1132 and the other end of the second strut 1133 are connected to each other and preferably smoothly transition to reduce damage to the atrial tissue. Preferably, the adjacent first struts 1132 and the second struts 1133 of two adjacent first units 1131 are connected to the second end 1123 of the same transition strut 1121. Optionally, the rod widths of the first strut 1132 and the second strut 1133 may be equal to or different from the rod width of the transition strut 1121.

[0049] It can be understood that in other embodiments, the other end of the first support rod 1132 of each first unit 1131 and the other end of the second support rod 1133 may not be connected; or the other end of the first support rod 1132 of some first units 1131 is connected to the other end of the second support rod 1133, while the other end of the first support rod 1132 of other first units 1131 is not connected to the other end of the second support rod 1133.

[0050] Preferably, in the expanded state, the first strut 1132 and the second strut 1133 are both circumferentially bent, and the bending directions are consistent. This is advantageous. First, this can improve the compliance of the atrial segment 1130, so that the synchronization of the atrial segment 1130 with the movement of the cardiac cycle is improved, thereby reducing the damage of the atrial segment 1130 to the atrial tissue. Secondly, the first strut 1132 and the second strut 1133 that are bent in the circumferential direction also have the ability to disperse the squeezing force from the atrial tissue, and the force transmitted to the transition strut 1121 will also be reduced, which will also help to reduce the impact on the opening and closing shape of the leaflet 1300. Furthermore, the first strut 1132 and the second strut 1133 that are bent in the circumferential direction have a larger physical length to contact the atrial side of the valve ring, and the anti-paravalvular leakage effect is better.

[0051] Also preferably, in the expanded state, the circumferential bending directions of the first support rod 1132 and the second support rod 1133 are opposite to or diverge from the circumferential bending direction of the main curved section 1124. Figure 4A From the perspective shown, the main curved section 1124 is curved in the counterclockwise direction, but the first strut 1132 and the second strut 1133 are curved in the clockwise direction. This helps the circumferential forces on the first strut 1132 and the second strut 1133 offset or balance the circumferential forces on the main curved section 1124, thereby preventing the artificial heart valve stent 1100 from rotating due to the superimposed circumferential forces in the same direction.

[0052] It is worth noting that the fact that the bending directions of the two comparison objects described herein are consistent or opposite does not mean that the bending shapes of the two comparison objects are completely consistent or opposite. Figure 4A and Figure 4B As shown, the same bending direction of the first support rod 1132 and the second support rod 1133 does not mean that the bending shapes of the two are completely the same. The first support rod 1132 has a bending tendency to be concave away from the reference line L in the figure, while the second support rod 1133 has a bending tendency to be convex toward the transition support rod 1121 relative to the reference line L, and the two are asymmetrically distributed relative to the transition support rod 1121. Similarly, the circumferential bending direction of the first support rod 1132 and the second support rod 1133 is opposite to the circumferential bending direction of the main bending section 1124, which does not mean that the bending shapes of the first support rod 1132 and the second support rod 1133 are completely opposite to the bending shapes of the main bending section 1124. For example, the first support rod 1132 and the main bending section 1124 are not 180° rotationally symmetrical, and the bending amplitudes of the second support rod 1133 and the main bending section 1124 are completely different.

[0053] Preferably, in the expanded state, the bending arc length of the first support rod 1132 in the circumferential direction is greater than the bending arc length of the second support rod 1133 in the circumferential direction. This can aggravate the asymmetry of the first support rod 1132 and the second support rod 1133 of the first unit 1131, and further improve the compliance of the first unit 1131.

[0054] Additionally or alternatively, the circumferential bending amplitude of the first support rod 1132 is smaller than the circumferential bending amplitude of the second support rod 1133, which also helps to aggravate the asymmetry of the first support rod 1132 and the second support rod 1133 of the first unit 1131. The circumferential bending amplitude refers to the degree of bending of the arc of each support rod relative to the straight line between its two end points in the circumferential direction. Preferably, the circumferential bending arc of the first support rod 1132 is greater than π / 6, and the circumferential bending arc of the second support rod 1133 is greater than π / 4.

[0055] It is understandable that the artificial heart valve 1000 of the first embodiment is only one preferred embodiment among many embodiments of the present invention, and those skilled in the art may modify, replace, and improve it to obtain other embodiments, such as the other embodiments shown below.

[0056] refer to Figure 5 In the second embodiment, the artificial heart valve stent 2100 of the artificial heart valve is substantially the same as the artificial heart valve stent 1100 of the first embodiment, and the similarities are not repeated here. The main difference between the two is that the peripheral outer contour of the atrial segment 2130 of this embodiment is no longer a regular circle, but is roughly D-shaped, so as to better adapt to the physiological and anatomical structure of the heart.

[0057] refer to Figure 6 In the third embodiment, the artificial heart valve stent of the artificial heart valve is substantially the same as the artificial heart valve stent 1100 of the first embodiment, and the similarities are not repeated here. The main difference between the two is that the atrial segment 3130 of the artificial heart valve stent of this embodiment is no longer composed of 12 first units 1131, but is composed of 15 first units 1131; accordingly, the number of transition struts 1121 of the transition segment 3120 is also changed to 15. Of course, this is only shown as an example. In other embodiments, the atrial segment can also use other numbers of first units, and the transition segment can also use other numbers of transition struts.

[0058] refer to Figure 7 In the fourth embodiment, the artificial heart valve stent of the artificial heart valve is substantially the same as the artificial heart valve stent 1100 of the first embodiment, and the similarities are not repeated here. The main difference between the two is that the atrial segment 4130 of the artificial heart valve stent of this embodiment also includes a plurality of second units 4134 distributed along the circumferential direction. Each second unit 4134 is connected between two adjacent first units 1131. Specifically, each second unit 4134 includes a third support rod 4135 and a fourth support rod 4136. One end of the third support rod 4135 and one end of the fourth support rod 4136 are respectively connected to the first support rod 1132 and the second support rod 1133 connected to the same transition branch rod 1121, and the other end of the third support rod 4135 and the other end of the fourth support rod 4136 are connected to each other and preferably smoothly transition to reduce damage to the atrial tissue. The design of the second unit 4134 can increase the contact area between the atrial segment 4130 and the atrial side of the valve ring, and improve the effect of preventing paravalvular leakage.

[0059] Preferably, in the expanded state, the third strut 4135 and the fourth strut 4136 are both circumferentially bent, and the bending directions are consistent. Also preferably, the circumferential bending directions of the third strut 4135 and the fourth strut 4136 are consistent with the circumferential bending directions of the first strut 1132 and the second strut 1133. This can improve the compliance of the second unit 4134, improve the synchronization of the atrial segment 4130 following the cardiac cycle, and thus reduce the damage of the atrial segment 4130 to the atrial tissue.

[0060] refer to Figure 8 and Fig. 9 In the fifth embodiment, the artificial heart valve stent 5100 of the artificial heart valve is substantially the same as the artificial heart valve stent 1100 of the first embodiment, and the similarities are not repeated here. The main difference between the two is that each transition strut 5121 of the transition segment 5120 of this embodiment no longer includes the auxiliary bending segment 1125, but only includes the main bending segment 5124.

[0061] Specifically, the main curved section 5124 extends axially while bending radially outward and circumferentially to present a spatial curved structure, and the main curved section 5124 extends axially for a length sufficient to span the valve ring of the native heart valve to be implanted. Thus, the force transmitted from the atrial section 1130 (derived from the squeezing force of the atrial tissue on the atrial section 1130) can be dispersed at least in the radial and circumferential directions through the main curved section 5124, so as to reduce the radial squeezing force of the artificial heart valve stent 5100 on the internal leaflets 1300, thereby reducing the influence on the opening and closing morphology of the leaflets 1300.

[0062] Also preferably, if Figures 10A-10B As shown, the circumferential bending direction of the main bending section 5124 is opposite to or diverges from the circumferential bending directions of the first support rod 1132 and the second support rod 1133. Fig. 10A From the perspective shown, the main curved section 5124 is curved in the counterclockwise direction, but the first strut 1132 and the second strut 1133 are curved in the clockwise direction. This helps the circumferential forces on the first strut 1132 and the second strut 1133 offset or balance the circumferential forces on the main curved section 5124, thereby preventing the artificial heart valve stent 5100 from rotating due to the superimposed circumferential forces in the same direction.

[0063] refer to Fig.11In the sixth embodiment, the artificial heart valve stent of the artificial heart valve is substantially the same as the artificial heart valve stent 1100 of the first embodiment, and the similarities are not repeated here. The main difference between the two is that the transition strut 6121 of the transition section of the artificial heart valve stent of this embodiment is twisted on the basis of presenting a spatial bending structure. Specifically, relative twisting occurs between different parts of the transition strut 6121 along its extension direction, and the maximum twisting angle between any two parts (such as the first end 6122 and the second end 6123) is not greater than 180°, wherein the twisting angle refers to the deflection angle of the axis of one part along the rod width direction relative to the axis of another part along the rod width direction.

[0064] For example, while referring to Fig.11 and Figures 12A-12B , the AA-direction cross section of the main curved section 6124 of the transition strut 6121 is twisted compared to the BB-direction cross section of the auxiliary curved section 6125 of the transition strut 6121, and the twisting angle is approximately about 60°. Under the condition of the same rod width b and wall thickness w, the twisting of the transition strut 6121 will cause the change of the sectional inertia moment of different parts of the transition strut 6121, so as to further improve the compliance of the transition strut 6121 and reduce the squeezing effect of the transition strut 6121 on the inflow end of the leaflet 1300.

[0065] refer to Figures 13A-14C In the seventh embodiment, the artificial heart valve 7000 is similar to the artificial heart valve 1000 of the first embodiment in that the artificial heart valve stent 7100 of the artificial heart valve 7000 of this embodiment also includes the atrial segment 1130 and the transition segment 1120. However, the artificial heart valve stent 7100 of this embodiment no longer adopts an integrated artificial heart valve stent 1100, but includes a double-layer valve frame: an outer frame 7200 and an inner frame 7300 of separate design, wherein the inner frame 7300 is connected to the radial inner side of the outer frame 7200. The coating 1200 at least covers the inner surface and / or the outer surface of the outer frame 7200. Optionally, the coating 1200 also covers the inner surface and / or the outer surface of the inner frame 7300. The leaflet 1300 is fixed in the inner frame 7300.

[0066] Specifically, refer to Figures 14A-14C, the outer frame 7200 includes a ventricular segment 7210, the transition segment 1120, the atrial segment 1130 and a first connecting segment 7240. The ventricular segment 7210 has a mesh structure formed by multiple layers (two layers are shown in the figure) of corrugated rods 7211 connected in sequence along the axial direction. The transition segment 1120 is connected between the ventricular segment 7210 and the atrial segment 1130. The first connecting segment 7240 is connected to the ventricular segment 7210 and / or the transition segment 1120 and is located radially inside the transition segment 1120. In this embodiment, the first connecting segment 7240 has a corrugated rod structure, and each of its wave crests 7241 is respectively provided with a plurality of first connecting portions 7242 distributed along the circumferential direction for connecting with the inner frame 7300. In this embodiment, the first connecting portion 7242 is in the shape of a circular hole. Preferably, each trough 7243 of the first connecting segment 7240 is connected to the intersection of the ventricular segment 7210 and the transition segment 1120 (that is, the first end 1122 of each transition strut 1121). In other words, each transition strut 1121 of the transition segment 1120 is connected to a corresponding trough 7243 of the first connecting segment 7240.

[0067] The inner frame 7300 has radial support performance (determined by its own material and shape), and includes a main body 7310, a second connecting section 7320 and a third connecting section 7330. The main body 7310 is generally in the shape of a hollow cylinder, and has a mesh structure formed by multiple layers (four layers are shown in the figure) of corrugated rods 7311 connected in sequence along the axial direction, and the leaflet 1300 is sutured in the main body 7310. The second connecting section 7320 includes a plurality of second connecting parts 7321 distributed along the circumferential direction, and each second connecting part 7321 is connected to a corresponding crest 7312 of the corrugated rod 7311 at the inflow end of the main body 7310. Preferably, each crest 7312 of the corrugated rod 7311 at the inflow end of the main body 7310 is connected to a second connecting part 7321. The second connection portion 7321 is used to be fixedly connected to the first connection portion 7242 (for example, by crimping, riveting, welding, suture suturing, etc.) to connect the inner frame 7300 and the outer frame 7200. Similar to the first connection portion 7242, in this embodiment, the second connection portion 7321 is also in the shape of a circular hole. The third connection segment 7330 includes one or more (three in the figure) connection rods 7331, each connection rod 7331 is connected to a corresponding second connection portion 7321, and the connection rod 7331 is used to connect to a delivery device for delivering the artificial heart valve 7000.

[0068] Compared with the artificial heart valve 1000 of the first embodiment, the artificial heart valve 7000 of this embodiment can not only achieve the technical effects that can be achieved by the transition section 1120 and the atrial section 1130 of the artificial heart valve 1000, but also the leaflets 1300 of the artificial heart valve 7000 of this embodiment are fixed on the inner frame 7300 with radial support performance, and the inner frame 7300 can effectively resist the squeezing of the transition section 1120 and the atrial section 1130 of the outer frame 7200 on the inflow end of the leaflets 1300, so the opening and closing shape of the leaflets 1300 is less affected. In addition, when the inner frame 7300 and the outer frame 7200 of this embodiment are connected to each other, the height of the leaflets 1300 is increased compared with the previous embodiment (such as Fig.13A As shown, the connection portion between the leaflet 1300 and the main body 7310 of the inner frame 7300 corresponds to the first connection segment 7240 and the transition segment 1120 of the outer frame 7200), which helps to reduce the overall axial height of the artificial heart valve stent 7100, shorten the height occupied by the artificial heart valve stent 7100 in the ventricle, and reduce the risk of blocking the left ventricular outflow tract.

[0069] Preferably, in the expanded state, the ventricular segment 7210 at least partially protrudes radially outward relative to the first end 1122 of each transition strut 1121 of the transition segment 1120, so as to define an annular groove 7250 together with the transition segment 1120 for accommodating an anchor ring (not shown). Fig. 14B As shown, the wavy rod 7211 at the inflow end of the ventricular segment 7210 protrudes radially outward from the first end 1122 of each transition strut 1121 to the maximum diameter of the ventricular segment 7210, and then the wavy rod 7211 at the outflow end of the ventricular segment 7210 radially retracts inward from the maximum diameter of the ventricular segment 7210 to the outflow end of the ventricular segment 7210, or the wavy rod 7211 at the outflow end of the ventricular segment 7210 may also extend to the outflow end of the ventricular segment 7210 while maintaining the maximum diameter unchanged.

[0070] Before implanting the artificial heart valve 7000, an anchoring ring can be implanted first, and then the artificial heart valve 7000 can be placed in the anchoring ring so that the anchoring ring is embedded in the annular groove 7250. The anchoring ring and the artificial heart valve 7000 can be used to tighten the leaflets and chordae tendineae between the two to achieve stable positioning of the artificial heart valve 7000.

[0071] refer to Fig.15In the eighth embodiment, the artificial heart valve stent of the artificial heart valve is substantially the same as the artificial heart valve stent 7100 of the seventh embodiment, and the similarities are not repeated here. The main difference between the two is that the first connection portion 8242 of the first connection segment 8240 of the outer frame 8200 of this embodiment no longer adopts a circular hole structure, but adopts a straight hole structure. Correspondingly, the second connection portion (not shown) of the inner frame also adopts a straight hole structure.

[0072] Specifically, the first connection part 8242 includes two horizontal straight rods 8243 and two vertical straight rods 8244, and the two horizontal straight rods 8243 and the two vertical straight rods 8244 together enclose a rectangular frame, wherein "horizontal" refers to the direction perpendicular to the central axis of the outer frame 8200, and "vertical" refers to the direction parallel to or coincident with the central axis of the outer frame 8200. The second connection part of the inner frame also adopts a similar structure, which will not be repeated here. When connecting the outer frame 8200 and the inner frame, a binding wire can be passed through the straight hole of the first connection part 8242 and the straight hole of the second connection part, and then the binding wire can be tied around the horizontal straight rods and / or vertical straight rods of the first connection part 8242 and the second connection part that are close to each other. Compared with the round hole type connection portion in the seventh embodiment, the straight hole type connection portion of this embodiment allows the binding wire to be subjected to concentrated force in the axial and / or radial directions without dispersing the force of the binding wire in other directions. Therefore, only fewer turns of binding wire are needed to firmly connect the outer frame 8200 and the inner frame, which helps to compress the double-layer valve frame to a smaller size for easy delivery.

[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. An artificial heart valve stent having a compressed state and an expanded state, characterized in that: The artificial heart valve stent includes an atrial segment, a ventricular segment and a transition segment located between the atrial segment and the ventricular segment, the transition segment includes a plurality of transition struts distributed along the circumferential direction, each transition strut includes a first end connected to the ventricular segment and a second end connected to the atrial segment, wherein in the expanded state, the transition strut extends axially from the first end while also bending radially outward to extend to the second end, and at least a portion of the transition strut is also bent circumferentially, thereby presenting a spatially curved structure.

2. The artificial heart valve stent according to claim 1, characterized in that: The change rate of the distance between the first end and the second end of the same transition support rod in the use state and the natural state is less than 20%.

3. The artificial heart valve stent according to claim 1, characterized in that: The second end and the first end of the same transition strut are circumferentially offset in the expanded state.

4. The artificial heart valve stent according to claim 1, characterized in that: Each of the transition struts includes at least a main curved segment connected to the atrial segment, wherein in the expanded state, the main curved segment extends axially, bends radially outward and bends circumferentially, and the length of the main curved segment extending axially is sufficient to span the annulus of the native heart valve to be implanted.

5. The artificial heart valve stent according to claim 4, characterized in that: Each of the transition struts also includes an auxiliary curved segment connected between the ventricular segment and the main curved segment, wherein in the expanded state, the auxiliary curved segment also bends circumferentially, but the circumferential bending direction of the main curved segment and the circumferential bending direction of the auxiliary curved segment diverge from each other.

6. The artificial heart valve stent according to claim 5, characterized in that: In the expanded state, the circumferential bending arc length of the main bending segment is greater than the circumferential bending arc length of the auxiliary bending segment, and / or the circumferential bending amplitude of the main bending segment is greater than the circumferential bending amplitude of the auxiliary bending segment, and / or the circumferential bending arc of the main bending segment is at least greater than π / 8.

7. The artificial heart valve stent according to claim 1, characterized in that: Different parts of the same transition support rod are twisted relative to each other, and the maximum twisting angle is no more than 180°.

8. The artificial heart valve stent according to claim 4, characterized in that: In the expanded state, the atrial segment extends radially outward relative to the transition segment; the atrial segment includes a plurality of first units distributed along the circumferential direction, each of the first units includes a first strut and a second strut, one end of the first strut and one end of the second strut are respectively connected to the second ends of two adjacent transition struts, and the other end of the first strut and the other end of the second strut are connected to each other and smoothly transition.

9. The artificial heart valve stent according to claim 8, characterized in that: In the expanded state, the first support rod and the second support rod are both bent along the circumferential direction, and the bending directions are consistent.

10. The artificial heart valve stent according to claim 9, characterized in that: In the expanded state, the circumferential bending directions of the first strut and the second strut are away from the circumferential bending direction of the main bending section.

11. The artificial heart valve stent according to claim 10, characterized in that: In the expanded state, the circumferential bending arc length of the first strut is greater than the circumferential bending arc length of the second strut, and / or the circumferential bending amplitude of the first strut is smaller than the circumferential bending amplitude of the second strut, and / or the circumferential bending arc of the first strut is at least greater than π / 6.

12. The artificial heart valve stent according to any one of claims 1 to 11, characterized in that: The artificial heart valve stent includes an outer frame and an inner frame, the outer frame includes the atrial segment, the ventricular segment, the transition segment and a connecting segment connected to the ventricular segment and / or the transition segment, and the inner frame is connected to the connecting segment and is located radially inward of the outer frame.

13. The artificial heart valve stent according to claim 12, characterized in that: The connecting section comprises a wave-shaped rod having a plurality of wave valleys connected to the ventricular section and a plurality of wave peaks away from the ventricular section, and each transition strut of the transition section is connected to a corresponding wave valley of the wave-shaped rod.

14. The artificial heart valve stent according to claim 12, characterized in that: In the expanded state, at least a portion of the ventricular segment protrudes radially outward relative to the first end of each transition strut to define an annular groove together with the transition segment.

15. An artificial heart valve, characterized in that: It comprises an artificial heart valve stent according to any one of claims 1 to 14, a coating connected to the inner surface and / or outer surface of the artificial heart valve stent, and at least two leaflets fixed in the artificial heart valve stent that can open and close relative to each other.

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