Artificial valve stent and artificial valve

Abstract

The invention relates to an artificial valve stent and an artificial valve. The artificial valve stent comprises an inner stent and an outer stent; the inner bracket is nested in the outer bracket; the inner support is sequentially provided with a valve leaflet loading section and an inner transition section in the axial direction. The valve leaflet loading section is used for supporting and connecting an artificial valve leaflet; the diameter of the inner transition section is greater than that of the valve leaflet loading section; the outer support is sequentially provided with a flange section, a main body section and an outer transition section in the axial direction. The diameter of the flange section is greater than that of the main body section; the diameter of the outer transition section is smaller than that of the main body section; and the inner transition section is fixedly connected with the outer transition section. The transition angle of the outer stent can be increased while the height of the short stent is maintained, reduction of the rigidity of the transition position of the outer stent is facilitated, stent shaping and stent loading are facilitated, stress of the transition position of the implanted outer stent is reduced, fatigue resistance of the stent is improved, and the stent is particularly suitable for a large valve ring or an ultra-large valve ring.

Description

Technical Field

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

[0002] The heart contains four chambers. The left atrium and left ventricle are located on the left side of the heart, and the right atrium and right ventricle are located on the right side of the heart. The ventricular inflow tract is formed between the atrium and the ventricle, the left ventricular outflow tract is formed by the left ventricle and the aorta, and the right ventricle and the pulmonary artery form the right ventricular outflow tract. There are valves with "one-way valve" functions at the ventricular inflow tract and ventricular outflow tract to ensure the normal flow of blood in the heart chamber. When there is a problem with the valve, the heart's hemodynamics changes and the heart function is abnormal, which is called valvular heart disease.

[0003] Tricuspid regurgitation can lead to myocardial remodeling, progressive ventricular enlargement, and eventually heart failure. Transcatheter tricuspid valve replacement (TTVR) uses a catheter intervention method to compress the artificial valve into a delivery system outside the body, deliver it to the human tricuspid valve ring, and release and fix the artificial valve to the tricuspid valve ring to replace the native valve. Compared with surgical operations, TTVR does not require an extracorporeal circulation assist device, has less trauma, and allows patients to recover quickly. The hemodynamic indicators of patients can be significantly improved after surgery. Although tricuspid valve replacement technology has developed rapidly, there are still some recognized difficulties in valve design, including: ① Compared with the aortic valve, the native annulus diameter of the tricuspid valve is larger. Correspondingly, the leaflet area of ​​the artificial valve must also be large. The larger the leaflet area, the worse the fatigue resistance and the larger the diameter after compression and gripping; ② The diameter of the delivery catheter of the existing tricuspid valve prosthesis is very large, which increases the difficulty of delivery and the risk of vascular damage; ③ The right ventricle is crescent-shaped, and its shape is more complex than that of the left ventricle. If the subvalvular height of the prosthetic valve is too high, it will affect the native heart structure and heart function, touch the abnormal heart tissue such as the papillary muscle, and induce adverse postoperative effects.

[0004] Specifically, most of the existing tricuspid valve prostheses adopt a double-layer stent design, with the outer stent used as anchoring and the inner stent used to sew the artificial valve leaflets. Usually, the inner stent is smaller, the outer stent is larger, and the inner stent is mostly designed as a cylindrical stent with equal diameter. In view of the fact that the tricuspid valve ring of patients with tricuspid regurgitation is usually larger, an outer stent with a larger diameter is required for anchoring. Since the inner and outer stents need to be connected together, the outer stent needs to transition from a large diameter to a small diameter to form a transition section connected to the inner stent of equal diameter. Due to the difficulty of stent shaping and the characteristics of the material itself, the transition from the outer stent to the inner stent is usually not a straight line, and there will be rounded corners. And the angle of transition from the outer stent to the inner stent cannot be too small. For example, when the transition angle is 90°, the rigidity at the corner of the stent will be too large, which is not conducive to loading and stent shaping. Secondly, when the inner stent moves due to the impact of blood flow, the stress at the corner of the outer stent with variable diameter will also be too large (cantilever beam), thereby shortening the life of the stent. Therefore, in order to ensure the processing of the stent and the fatigue performance of the stent, a larger transition angle is usually retained, but the axial height of the outer stent needs to be increased. The increase in the axial height of the stent will cause a greater risk of damage to the subvalvular structure of the tricuspid valve. Therefore, for those skilled in the art, how to increase the transition angle of the outer stent without increasing the axial height of the stent is a technical problem that needs to be solved urgently.

[0005] It should be noted that the information disclosed in the background technology section of this application is intended to deepen the understanding of the general background technology of this application, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0006] The object of the present invention is to provide an artificial valve stent and an artificial valve, which can increase the transition angle of the external stent while maintaining a relatively short stent height, thereby reducing the stiffness of the transition point of the external stent and the stress at the transition point after implantation, and can also adapt to the extremely large valve ring of the mitral valve or tricuspid valve, while improving the fatigue resistance of the stent.

[0007] To achieve the above-mentioned purpose, the present invention provides an artificial valve stent, which includes an inner stent and an outer stent; the inner stent is nested in the outer stent; the inner stent is provided with a leaflet loading section and an inner transition section in sequence along the axial direction; the leaflet loading section is used to support and connect the artificial leaflet; the diameter of the inner transition section is larger than the diameter of the leaflet loading section; the outer stent is provided with a flange section, a main body section and an outer transition section in sequence along the axial direction; the diameter of the flange section is larger than the diameter of the main body section; the diameter of the outer transition section is smaller than the diameter of the main body section; the inner transition section is connected and fixed to the outer transition section.

[0008] Optionally, the inner support is further provided with a curved grab ear, which extends from the inner support to the outside of the outer support and is positioned at the periphery of the main section and the outer transition section, and the grab ear and the main section and the outer transition section can accommodate the native leaflet.

[0009] Optionally, there are multiple gripping ears, and the multiple gripping ears are arranged along the circumference of the inner bracket.

[0010] Optionally, the diameter of a certain position on the grab ear is smaller than the diameter of the main body segment.

[0011] Optionally, the grab ear has a fixed end and a free end relative to each other, the fixed end is connected to the leaflet loading section, the free end is arranged on the outside of the outer support, and the free end includes a terminal head, and the angle α between the terminal head and the preset direction of the axis of the inner support is an acute angle, and the preset direction is the direction from the outflow end to the inflow end.

[0012] Optionally, the angle α is 20° to 60°, and / or the length of the distal head is 3 mm to 10 mm.

[0013] Optionally, the grab ear further comprises a rod portion extending between the fixed end and the free end, wherein a surface of at least one of the rod portion and the distal head portion is coated with a polymer material or a biological material.

[0014] Optionally, the diameter of the inner transition section is 1.0 to 1.4 times the diameter of the leaflet loading section.

[0015] Optionally, a transition angle between the outer transition section and the main body section is β2, and the transition angle β2 is 100° to 140°.

[0016] To achieve the above objectives, the present invention also provides an artificial valve, which includes an artificial valve leaflet; and an artificial valve stent as described in any one of the above; the artificial valve leaflet is arranged inside the inner stent of the artificial valve stent and is connected to the valve leaflet loading section.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] In order to adapt to the problem of large tricuspid or mitral valve orifice area, the present invention provides an artificial valve stent and an artificial valve, wherein an inner transition section is formed by expanding the inner stent outward, so as to be connected and fixed with the outer transition section of the outer stent that is contracted inward, thereby reducing the diameter change of the outer stent, and increasing the transition angle of the outer stent while maintaining a shorter stent height, which is not only conducive to reducing the rigidity of the transition of the outer stent, facilitating stent shaping and stent loading, but also reducing the stress of the transition of the outer stent after implantation, which is conducive to improving the fatigue resistance of the stent. Moreover, the advantages of this structural design are particularly prominent under large valve ring or super large valve ring diameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0020] Figure 1 This is a front view of an inner bracket according to a preferred embodiment of the present invention.

[0021] Figure 2 for Figure 1 Top view of the inner bracket.

[0022] Figure 3 This is a front view of an external support according to a preferred embodiment of the present invention.

[0023] Figure 4 for Figure 3 Top view of the middle and outer brackets.

[0024] Figure 5 This is an axonometric view of an artificial valve stent according to a preferred embodiment of the present invention.

[0025] Figure 6 for Figure 5 Top view of the artificial valve stent.

[0026] Figure 7 This is a front view of an artificial valve stent according to a preferred embodiment of the present invention.

[0027] Figure 8 This is a schematic diagram of loading and delivering an artificial valve through a delivery catheter according to a preferred embodiment of the present invention.

[0028] Fig. 9 for Figure 8 Schematic diagram of the artificial valve being deployed after it is partially released to free the lug from the delivery catheter.

[0029] Fig.10 This is a diagram showing the use status of an artificial valve positioned at a native valve according to a preferred embodiment of the present invention. Both the artificial valve and the native valve shown in the diagram are cross-sectional views.

[0030] Fig.11It is a simplified schematic diagram of an external support according to a preferred embodiment of the present invention.

[0031] [The accompanying drawings are described as follows]:

[0032] 1-catheter, 10-artificial valve stent, 100-inner stent, 110-leaflet loading section, 101-suture frame, 102-grid frame, 120-inner transition section, 130-grab ear, 131-distal head, 132-polymer material or biomaterial, 200-outer stent, 210-flange section, 220-main body section, 230-outer transition section, 20-native leaflet, 30-artificial leaflet, 40-native valve ring. DETAILED DESCRIPTION

[0033] To make the content of the present invention more clear and understandable, the present invention is further described below in conjunction with the accompanying drawings. Of course, the present invention is not limited to the specific embodiments provided below, and general replacements known to those skilled in the art are also included in the protection scope of the present invention.

[0034] The terms used in this application document are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms of "a", "said" and "the" used in this application are also intended to include plural forms, unless the context clearly indicates other meanings. It should be understood that similar words such as "one" or "one" do not indicate a quantitative limitation, but rather indicate the presence of at least one; "multiple" means two or more. Similar words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" cover the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Secondly, the present invention is described in detail using schematic diagrams, but these schematic diagrams are only for the convenience of detailing examples of the present invention and should not be used as limitations of the present invention.

[0035] The "circumferential" mentioned in this application document generally refers to the direction corresponding to the axis around the artificial valve; "lateral" generally refers to the direction perpendicular to the axis of the artificial valve; "axial" generally corresponds to the direction of the central axis of the artificial valve; the terms "inflow end" and "outflow end" are defined by the position of the artificial valve relative to the native valve after implantation in the body. According to the normal flow direction of blood, the "inflow end" is the end where blood flows into the artificial valve, the "outflow end" is the end where blood flows out of the artificial valve, the "proximal end" is the end close to the operator during delivery, and the "distal end" is the end away from the operator during delivery.

[0036] One of the purposes of the present invention is to provide an artificial valve stent to solve the problem that the double-layer stent used in existing artificial valves to adapt to the large area of ​​the native valve orifice is difficult to balance the axial height of the outer stent and the transition angle at the corner.

[0037] A second object of the present invention is to provide an artificial valve using the artificial valve stent.

[0038] It should also be noted here that although the innovation of the present invention comes from the field of tricuspid valve technology proposed in the background technology, those skilled in the art can understand that the present invention can also be applied to the mitral valve to solve problems similar to or basically the same as those of the tricuspid valve.

[0039] like Figures 1 to 11 As shown, this embodiment provides an artificial valve that can be implanted into the heart by transcatheter intervention, reach the native valve, and release and fix it at the native valve to replace the native valve. The artificial valve includes an artificial valve stent 10 and an artificial valve leaflet 30 (see Fig.10 The artificial valve leaflet 30 is arranged inside the artificial valve stent 10. The artificial valve may further include a skirt, which is attached to the artificial valve stent 10.

[0040] The artificial valve leaflets 30 are at least two pieces, which can be dynamically switched between an open state and a closed state. In the closed state, all the artificial valve leaflets 30 are tightly closed or joined in a sealed abutment manner; in the open state, a blood flow channel is formed between the artificial valve leaflets 30 to achieve unidirectional blood flow. The artificial valve leaflet 30 can be formed by any suitable material or combination of materials. In detail, the artificial valve leaflet 30 can be selected from biological tissue or animal pericardial tissue, for example: chemically stable tissue from the heart valve of an animal (such as a pig), a cow (bovine pericardium) or a sheep (sheep pericardium) or a pig (pig pericardium) or a horse (equine pericardium), preferably bovine pericardial tissue; it can also be made of small intestinal submucosal tissue or synthetic materials, for example, expanded polytetrafluoroethylene or polyester, specifically for example: thermoplastic polycarbonate polyurethane, polyether polyurethane, segmented polyether polyurethane, silicone polyether polyurethane, silicone-polycarbonate polyurethane, and ultra-high molecular weight polyethylene, etc.; biocompatible polymers can also be selected, for example: polyolefins, elastomers, polyethylene glycol, polyether sulfone, polysulfone, polyvinyl pyrrolidone, polyvinyl chloride, other fluorine-containing polymers, silicone polyesters, siloxane polymers and / or oligomers, and / or polylactones, and block copolymers thereof. Optionally, the surface of the artificial valve leaflet 30 also has an anticoagulant film layer, and the anticoagulant includes but is not limited to a heparinized polymer.

[0041] Regarding the artificial valve stent 10, due to the large valve opening of the tricuspid valve or mitral valve in anatomy, a double-layer stent is usually made to reduce the area of ​​the artificial valve. The double-layer stent can distribute the functions of carrying the artificial valve leaflet 30 and anchoring, sealing, etc. to different single-layer stents, so as to achieve the purpose of not affecting the normal operation of other structures of the heart and better exerting the implantation treatment function. Therefore, the artificial valve stent 10 adopts a double-layer stent.

[0042] For details, please refer to Figures 1 to 7 The artificial valve stent 10 comprises an inner stent 100 and an outer stent 200; the inner stent 100 is nested in the outer stent 200, and the two are arranged coaxially. The inner stent 100 mainly carries the artificial valve leaflet 30. The artificial valve leaflet 30 is arranged inside the inner stent 100, and the skirt is attached to the outer stent 200 and / or the inner stent 100. The inner stent 100 and the outer stent 200 are both mesh cylindrical.

[0043] Figure 1 and Figure 2 The schematic diagram of the structure of the inner stent 100 is shown separately. The inner stent 100 can be made of biocompatible materials with shape memory properties such as nickel titanium, or biocompatible materials such as cobalt chromium alloy and stainless steel. In view of the small diameter of the inner stent 100 and the large diameter of the outer stent 200, the diameter of the inner stent 100 needs to transition outward until it is consistent with the diameter of the outer stent 200. Figure 1 As described, the inner support 100 is provided with a leaflet loading section 110 and an inner transition section 120 in sequence along the axial direction from the inflow end to the outflow end; the leaflet loading section 110 is used to support and connect the artificial leaflet 30; the inner transition section 120 extends axially toward the side away from the leaflet loading section 110, and the diameter (d2, outer diameter) of the inner transition section 120 is greater than the diameter (d1, outer diameter) of the leaflet loading section 110.

[0044] The leaflet loading section 110 can be designed with equal diameter, and the cross section of the leaflet loading section 110 is circular when viewed from a top view. Generally, the joints of the artificial leaflets 30 are sutured at the lowest position of the leaflet loading section 110, and a plurality of suture frames 101 are provided circumferentially at the lowest position of the leaflet loading section 110, and the joints of the artificial leaflets 30 are sutured through the suture frames 101, and the fixed edges of the artificial leaflets 30 are sutured and fixed along the grid frame 102 at the leaflet loading section 110.

[0045] The diameter of the leaflet loading section 110 gradually increases to the diameter of the inner transition section 120, and the two are smoothly transitioned and connected. The inner transition section 120 can be a cylinder of equal diameter, but is not limited to the equal diameter design. Figure 2 From the top view shown, the outer edge profile of the inner transition section 120 is substantially circular. To prevent the inner transition section 120 from having an excessively large diameter and affecting the strength of the inner stent 100, the diameter d2 of the inner transition section 120 is preferably 1.0-1.4 times the diameter d1 of the leaflet suture section 110, so as to prevent the inner stent 100 from deforming and ensure its strength.

[0046] Figure 3 and Figure 4A schematic diagram of the structure of the outer support 200 is also shown separately. The outer support 200 mainly plays an anchoring role. Preferably, the outer support 200 is made of a shape memory alloy; the outer support 200 can also be made of a material that can be elastically or plastically deformed, such as a balloon expandable, or can be a shape memory alloy that responds to temperature changes to transform between a contracted delivery state and an expanded deployment state; the outer support 200 can also be constructed of braided wire or other suitable materials. For example, the outer support 200 can be made of a biocompatible metal frame or a laser-cut solid metal tube made of, for example, nitinol, titanium alloy, cobalt-chromium alloy, MP35n, 316 stainless steel, L605, Phynox / Elgiloy, platinum-chromium, or other biocompatible metals.

[0047] The diameter of the outer support 200 needs to transition inward until it is consistent with the diameter of the inner support 100. Figure 3 As described, the outer support 200 is provided with a flange section 210, a main section 220 and an outer transition section 230 in sequence along the axial direction from the inflow end to the outflow end. The flange section 210, the main section 220 and the outer transition section 230 can be integrally formed, or can be a split structure and fixedly connected. The skirt is mainly attached to the flange section 210 and the main section 220. The skirt can also be attached to the outer transition section 230 and connected to the inner support 100 to form a closed skirt to prevent blood from flowing between the inner and outer supports.

[0048] The shape defined by the flange section 210 is a trumpet shape, which extends axially away from the main body section 220. The diameter of the flange section 210 is greater than the diameter of the main body section 220. Specifically, the diameter of the flange section 210 gradually increases in the direction away from the main body section 220 in the axial direction, which can match the size change of the anatomical structure from the atrium to the native valve ring 40.

[0049] The main body section 220 is used to be arranged on the native valve ring 40 (see Fig.10 ), and the main body segment 220 is set with an interference fit (oversize) with the native valve ring 40. Normally, the diameter of the main body segment 220 is slightly larger than the diameter of the native valve ring 40, so as to provide a certain radial squeezing force on the native valve ring 40, but not provide a large radial squeezing force, so as not to damage the native valve ring 40 and compress the conduction tissue. Of course, in other examples, the diameter of the main body segment 220 can also be smaller than the diameter of the native valve ring 40. The main body segment 220 can be cylindrical or conical. If it is conical, the diameter gradually decreases from the atrium to the ventricle, which is conducive to stable anchoring.

[0050] The diameter of the outer transition section 230 is smaller than the diameter of the main section 220, that is, the outer support 200 is retracted at the outflow end. Specifically, the diameter of the main section 220 gradually decreases to the diameter of the outer transition section 230, and finally the diameter (D1, inner diameter) of the outer transition section 230 matches the diameter (d2, outer diameter) of the inner transition section 120, that is, D1=d2.

[0051] Figures 5 to 7 As described, the inner transition section 120 of the inner support 100 is connected and fixed with the outer transition section 230 of the outer support 200, and the connection between the two can be suturing, riveting or other fixing methods. For the convenience of connection and fixing, the inner transition section 120 and the outer transition section 230 can be provided with an extension rod at the wave crest of the outflow end, and the extension rod of the inner transition section 120 is connected and fixed with the extension rod of the outer transition section 230, and the number of connection and fixing points can be consistent or inconsistent with the number of wave heads at the outflow end. It should also be known that in other examples, the inner transition section 120 may not be provided with an extension rod, and only the outer transition section 230 is provided with an extension rod. Moreover, a through hole can be provided at the connection between the inner transition section 120 and the outer transition section 230 for suturing or riveting.

[0052] The present invention reduces the diameter reduction of the outer stent 200 by utilizing the outer expansion diameter change of the inner stent 100, and can increase the transition angle (β2, see Fig.11 ), which is not only conducive to reducing the rigidity of the transition of the external stent 200, facilitating stent shaping and stent loading, but also reduces the stress at the transition of the external stent 200 after implantation, which is conducive to improving the fatigue resistance of the external stent 200. The advantages of this structural design are particularly prominent in large valve rings or ultra-large valve ring diameters.

[0053] More detailed, such as Fig.11 As shown, when the diameter difference between the inner stent 100 and the outer stent 200 is too large (such as an oversized valve ring), while ensuring the same valve ring size and the same inner and outer frame sizes, the inner stent 100 changes diameter outward, reducing the diameter change of the outer stent 200, and while maintaining the overall height of the stent shorter, the transition angle of the outer stent 200 can be increased from β1 to β2, and β2 is the final transition angle. Because of this, when the outer stent 200 can be maintained at a shorter height, the impact on the native heart structure and heart function can be reduced, and abnormal cardiac tissues such as the papillary muscles can be avoided, and adverse postoperative effects can be avoided. Moreover, by adopting a combination of inner and outer stents, the area of ​​the artificial valve leaflet 30 can be reduced. Since the area of ​​the artificial valve leaflet 30 is reduced, the fatigue performance is improved, and the diameter after compression and gripping is also reduced, thereby reducing the diameter of the delivery catheter, reducing the difficulty of delivery and the risk of vascular damage.

[0054] Therefore, the transition angle between the outer transition section 230 and the main section 220 of the outer support 200 is β2, and the transition angle β2 is preferably 100° to 140°. For example, optionally, the transition angle β2 is 100°, 110°, 120°, 130° or 140°. The transition angle β2 can ensure that the axial height of the outer support 200 is appropriate, and the stiffness and stress at the transition are in a better state.

[0055] Regarding the flange section 210, Fig.10 As shown, after implantation, the flange segment 210 can cover the atrioventricular orifice (i.e., cover the native valve ring 40 and the atrial tissue near the native valve ring 40), or in other words, the flange segment 210 is the extension of the main segment 220 from the ventricle to the atrium. Figure 3 As shown, there is an angle θ between the flange section 210 and the transverse section of the external stent 200, and the angle θ is preferably -10° to 30°. More suitably, the angle θ between the flange section 210 and the transverse section is a negative angle, that is, less than 0°, which is more conducive to the flange section 210 fitting the atrial tissue. In addition, the end of the flange section 210 facing away from the main section 220 can be configured to abut against the atrial tissue at the native valve ring 40 to strengthen the anchoring. In addition, as described in the figure, the flange section 210 is mainly composed of a plurality of stent rods, which can be the curved structure or spiral structure shown in the figure, or any other suitable structure, which is not limited by the present invention.

[0056] Return to reference Figure 1 and Figure 2 The inner bracket 100 may also be provided with a curved gripping ear 130, which extends from the inner bracket 100 to the outside of the outer bracket 200 and is positioned at the periphery of the main section 220 and the outer transition section 230. Fig.10 As shown, when in use, the gripping ears 130 and the main body section 220 can accommodate the native leaflets 20, and the gripping ears 130 and the outer transition section 230 can also accommodate the native leaflets 20. Therefore, the native leaflets 20 can be grasped by using the gripping ears 130, so that the native leaflets 20 are clamped between the outer support 200 and the gripping ears 130. In particular, the gripping ears 130 can cooperate with the flange section 210 to clamp the native leaflets 20 in the axial direction, so that the artificial valve support 10 is stably anchored in the axial direction.

[0057] Specifically, the flange section 210 is arranged close to the native valve ring 40, so that the flange section 210 is pressed against the native valve ring 40, and the grab ears 130 clamp the artificial valve leaflet 30 between the flange section 210 and the grab ears 130 along the axial direction. The grab ears 130 and the flange section 210 cooperate together to stably anchor the entire artificial valve stent 100 in the axial direction. At the same time, the use of the grab ears 130 prevents the outer stent 200 from rotating in the circumferential direction. At this time, the main body section 220 does not need a large radial support force to stably anchor the stent between the atrium and the ventricle.

[0058] The leaflet loading section 110, the inner transition section 120 and the grab ears 130 can be integrally formed or can be separate structures and fixedly connected. The inner transition section 120 and the grab ears 130 can also be connected by welding, suturing, gluing, etc.

[0059] It should also be understood that the grab ear 130 includes an arc-shaped bending area and a main extension area located on one side of the arc-shaped bending area, and the main extension area extends toward the inflow end to grab the native leaflet 20. The arc-shaped bending area of ​​the grab ear 130 should be an arc or a quasi-arc to avoid excessive stress and rigidity. For example, the arc-shaped bending area is generally U-shaped or C-shaped or other similar or similar shapes.

[0060] Another advantage of setting the grab ear 130 on the inner support 100 is that the grab ear 130 needs to cross the outer support 200 from the inner support 100. Compared with being set on the outer support 200, the transition radius (arc-shaped bending area) of the grab ear 130 on the inner support 100 is increased, which is beneficial for loading and releasing the grab ear 130, that is, the transition radius is large, and the stiffness of the transition section of the grab ear 130 is small. When the grab ear 130 is loaded and released, the rebound force is small, making the loading and releasing process more stable. In addition, the capture radius of the grab ear 130 during release is increased, which is more conducive to capturing the native leaflet 20 and facilitating positioning and fixation.

[0061] For a more secure anchoring, the diameter of a certain position on the gripping ear 130 (d3, see Figure 1 ) is smaller than the diameter (D2, see Figure 3 ), so that the gripping ears 130 can still be close to the external stent 200 after the stent is implanted, firmly clamp the native valve leaflets 20, and improve the stability of valve fixation. The diameter of a certain position on the gripping ears 130 can be the size defined by the stem of the gripping ears 130 close to the everted distal head 131, or it can be the maximum diameter of the gripping ears 130.

[0062] The number of the grab ears 130 is preferably multiple. Figure 2It is shown that a plurality of gripping ears 130 are arranged along the circumference of the inner bracket 100, and the number of the gripping ears 130 is consistent with the wave head (wave crest or wave trough) of the inner bracket 100, and a gripping ear 130 is arranged between every two adjacent wave heads. Of course, it is not limited to this. The lengths of the gripping ears 130 can be the same or different.

[0063] Each gripping ear 130 should have a fixed end and a free end opposite to each other, wherein the fixed end is connected to the leaflet loading section 110, and the free end is arranged outside the outer support 200, and the free end includes a distal head 131, which is the free end away from the inner support 100. The distal head 131 can be a head structure with a smooth surface, such as a spherical or rounded cone or other shapes, so as to protect the tissue at the native valve from being punctured.

[0064] like Fig.10 As shown, from an anatomical point of view, the thickness of the native valve leaflet 20 is generally thicker at the base (close to the native valve ring 40) and gradually becomes thinner toward the free edge (away from the native valve ring 40). This thickness distribution helps the native valve leaflet 20 maintain flexibility and functionality during the heart cycle.

[0065] Further, such as Figure 7 As shown, the angle α between the distal head 131 and the preset direction of the axis of the inner stent 100 is an acute angle, and the preset direction is the direction from the outflow end to the inflow end. In other words, the distal head 131 is preferably bent (or everted) in a direction away from the axis of the stent. By everting the distal head 131 of the grab ear 130, it helps the free end of the grab ear 130 to adapt to the anatomical structure of the native leaflet 20 and prevent the native leaflet 20 from being stabbed. The eversion angle of the distal head 131 should be appropriate, for example, the angle α of the distal head 131 is 20° to 60°, optionally, 20°, 30°, 40°, 50° or 60°. The length of the distal head 131 is preferably 3mm to 10mm.

[0066] In order to prevent the ear grabber 130 from damaging the native tissue, the surface of the distal head 131 is coated with a polymer material or a biological material 132 (see Fig.10 ), the polymer material or biomaterial 132 can also promote the endothelialization of the grab ear 130. The polymer material 132 is mainly made of flexible materials, including but not limited to ePTFE (expanded polytetrafluoroethylene), PU (polyurethane), PET (polyethylene terephthalate) and other materials or combinations of materials. The biomaterial 132 can be selected from the pericardium or other biological tissues. As can be understood by those skilled in the art, polymer materials can be obtained by chemical synthesis or natural extraction, while biomaterials are mainly derived from organisms. The polymer material or biomaterial 132 can be set on the surface of the distal head 131 in any suitable manner, such as a coating, a film sleeve, etc.

[0067] In addition, the surface of the stem of the gripping ear 130 may also be coated with a polymer material or a biological material 132. The stem of the gripping ear 130 extends between a fixed end and a free end.

[0068] To facilitate understanding, the usage of the artificial valve of this embodiment is further described below.

[0069] Figure 8 The diagram shows the state of the artificial valve of this embodiment being transported via the catheter 1. During the transport process, the entire artificial valve is crimped and loaded into the catheter 1. The overall diameter after crimping is small. It can also be seen that the flange section 210 at the proximal end is compressed and in an axially extended state, while the grab ear 130 at the distal end is straightened and in an axially extended state.

[0070] Fig. 9 It also shows the state where the catheter 1 is withdrawn after reaching the designated position, and the grab ears 130 are released first. At this time, the grab ears 130 are released from the constraints of the catheter 1 and then autonomously unfold and recover to their original shapes.

[0071] Then, if Fig.10 As shown, after the artificial valve is delivered to the native valve ring 40, the artificial valve is released and fixed at the native valve ring 40 to replace the native valve.

[0072] In summary, the present invention provides an artificial valve and an artificial valve stent thereof, which reduces the diameter reduction of the outer stent 200 by designing the inner stent 100 to change diameter outward, increases the transition angle of the outer stent 200 while maintaining a shorter stent height, and is beneficial to reducing the rigidity of the transition of the outer stent 200, facilitating stent shaping and stent loading; at the same time, it also reduces the stress at the transition of the outer stent 200 after implantation, which is beneficial to improving stent fatigue. The artificial valve and the artificial valve stent thereof provided by the present invention are particularly suitable for large valve rings or extra-large valve rings, and the effect is more prominent.

[0073] It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the disclosed content of the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession can make some changes, modifications and evolutions of the technical content disclosed above without departing from the spirit and scope of the present invention, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An artificial valve stent, characterized in that: It comprises an inner support and an outer support; the inner support is nested in the outer support; the inner support is provided with a leaflet loading section and an inner transition section in sequence along the axial direction; the leaflet loading section is used to support and connect an artificial leaflet; the diameter of the inner transition section is larger than the diameter of the leaflet loading section; the outer support is provided with a flange section, a main body section and an outer transition section in sequence along the axial direction; the diameter of the flange section is larger than the diameter of the main body section; the diameter of the outer transition section is smaller than the diameter of the main body section; the inner transition section is connected and fixed to the outer transition section.

2. The artificial valve stent according to claim 1, characterized in that: The inner support is also provided with a curved grab ear, which extends from the inner support to the outside of the outer support and is positioned at the periphery of the main section and the outer transition section. The grab ear and the main section and the outer transition section can accommodate the native leaflet.

3. The artificial valve stent according to claim 2, characterized in that: There are a plurality of gripping ears, and the plurality of gripping ears are arranged along the circumference of the inner bracket.

4. The artificial valve stent according to claim 2, characterized in that: The diameter of a certain position on the grab ear is smaller than the diameter of the main body section.

5. The artificial valve stent according to claim 2, characterized in that: The grab ear has a fixed end and a free end relative to each other, the fixed end is connected to the leaflet loading section, the free end is arranged on the outside of the outer support, and the free end includes a terminal head, and the angle α between the terminal head and the preset direction of the axis of the inner support is an acute angle, and the preset direction is the direction from the outflow end to the inflow end.

6. The artificial valve stent according to claim 5, characterized in that: The angle α is 20° to 60°, and / or the length of the distal head is 3 mm to 10 mm.

7. The artificial valve stent according to claim 5, characterized in that: The grab ear further comprises a stem portion extending between the fixed end and the free end, wherein a surface of at least one of the stem portion and the distal head portion is coated with a polymer material or a biological material.

8. The artificial valve stent according to claim 1, characterized in that: The diameter of the inner transition section is 1.0 to 1.4 times the diameter of the leaflet loading section.

9. The artificial valve stent according to claim 1, characterized in that: A transition angle between the outer transition section and the main section is β2, and the transition angle β2 is 100° to 140°.

10. An artificial valve, characterized in that: It comprises an artificial valve leaflet; and an artificial valve stent as described in any one of claims 1 to 9; the artificial valve leaflet is arranged inside the inner stent of the artificial valve stent and is connected to the valve leaflet loading section.

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