Prosthetic heart valve stent and prosthetic heart valve

Abstract

The present application relates to a kind of artificial heart valve stents and artificial heart valve.The artificial heart valve stent includes inner support and outer support.Inclination from inflow end to outflow end, first portion and second portion are included in sequence in inner support, the radial dimension of first portion is greater than the radial dimension of second portion, at least a portion of second portion is nested in outer support, and at least a portion of first portion extends to inflow end relative to outer support, and the portion of first portion extending to inflow end relative to outer support covers flow blocking film.The artificial heart valve includes the artificial heart valve stent and artificial valve leaflet fixedly connected in inner support.The artificial heart valve stent and artificial heart valve can reduce the risk of paravalvular leakage while being stably positioned in heart.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to an artificial heart valve stent and an artificial heart valve. Background Technology

[0002] The mitral valve is a one-way valve between the left atrium (LA) and the left ventricle (LV), ensuring that blood flows from the left atrium to the left ventricle. The mitral valve is a complex system of functions and anatomical structures, typically including the annulus, leaflets, chordae tendineae, and papillary muscles.

[0003] When the left ventricle is in diastole, the mitral valve opens, allowing blood to flow from the left atrium to the left ventricle. When the left ventricle is in systole, the two leaflets of a normal mitral valve close tightly, completely preventing backflow of blood from the ventricle. For this to be effective, the mitral valve annulus must be of appropriate size, the leaflets must be structurally intact, the papillary muscles must contract to pull the chordae tendineae to support the leaflets, the closing force from left ventricular muscle contraction must be appropriate, and the left ventricle must have normal morphology and function. Any abnormality in these factors can lead to valvular heart disease, resulting in mitral regurgitation (MR).

[0004] For patients with severe valvular heart disease, the only effective treatment is heart valve replacement. In recent years, interventional artificial heart valve replacement surgery has developed rapidly and been applied clinically. This involves implanting an artificial heart valve into the original mitral valve of the heart through minimally invasive interventional surgery to replace the damaged natural valve, achieving relatively satisfactory treatment results.

[0005] For replaced artificial heart valves, on the one hand, they must be able to stably position themselves in the heart under the flushing of blood, maintaining their relative position with the valve annulus; on the other hand, the portion located on the atrial side must not be affected by the compression of the valve annulus and must maintain close contact with it, thereby ensuring the atrial side seal and reducing the risk of paravalvular leakage. Therefore, how to reduce the risk of paravalvular leakage while ensuring the stable positioning of the artificial heart valve is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this application provides an artificial heart valve stent and an artificial heart valve.

[0007] In a first aspect, this application provides an artificial heart valve stent, comprising: an inner stent and an outer stent; wherein, the inner stent comprises, along the axial direction from the inflow end to the outflow end, a first part and a second part, the radial dimension of the first part being greater than the radial dimension of the second part, at least a portion of the second part being nested in the outer stent, at least a portion of the first part extending toward the inflow end relative to the outer stent, and the portion of the first part extending toward the inflow end relative to the outer stent being covered by a flow-blocking membrane.

[0008] Secondly, this application provides an artificial heart valve, including at least two artificial leaflets and the artificial heart valve stent; the artificial leaflets are fixedly connected to the inner stent within the artificial heart valve stent; the edges of the at least two artificial leaflets are abutted against each other in the circumferential direction.

[0009] After the artificial heart valve stent and artificial heart valve provided in this application are implanted into the heart, the portion of the inner stent extending towards the inflow end relative to the outer stent is closely attached to the atrial side of the valve annulus. Because this portion has a larger radial dimension, it can prevent the artificial heart valve stent from moving towards the ventricle. The outer stent radially supports the valve annulus and undergoes radial inward concave deformation under the compression of the valve annulus. The outflow side of this concave deformation then forms a bulge on the outer stent. This bulge can prevent the artificial heart valve stent from moving towards the atrial side. Thus, the inner and outer stents work together to secure the artificial heart valve stent and artificial heart valve. The heart valve is stably positioned within the heart, maintaining the relative position of the artificial heart valve stent and the valve annulus, preventing the artificial heart valve stent from dislodging from the valve annulus. More importantly, because the portion of the inner stent extending towards the inflow end relative to the outer stent is tightly fitted to the atrial side of the valve annulus, the radial compression deformation of the outer stent by the valve annulus will not affect this portion of the inner stent. This avoids the gap between this portion of the inner stent and the atrial side of the valve annulus caused by the deformation of the outer stent. At the same time, this portion is also covered with a flow-blocking membrane, which can effectively isolate the atrium and ventricle, ensuring the atrial side seal and reducing the risk of paravalvular leakage. Attached Figure Description

[0010] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] In the attached image:

[0013] Figure 1 This is a front view schematic diagram of the artificial heart valve according to the first embodiment of the present invention;

[0014] Figure 2 yes Figure 1 A schematic diagram of the internal support structure (excluding the flow-blocking membrane);

[0015] Figure 3 yes Figure 1 A schematic diagram of a structure in which the inner support is covered with a flow-blocking membrane;

[0016] Figure 4 and Figure 5 yes Figure 1 Front view and three-dimensional schematic diagram of the external support structure;

[0017] Figure 6 This is a top view of the O-shaped cross-section of the second section of the external support;

[0018] Figure 7 This is a top view of the outer support frame with a D-shaped cross-section for the second section;

[0019] Figures 8a-8c These are structural diagrams illustrating different implementations of the limiting rod;

[0020] Figure 9 This is a schematic diagram of the structure of the outer support with the developing mechanism;

[0021] Figures 10a-10c yes Figure 9 Enlarged structural diagrams of different implementation methods in region C1;

[0022] Figure 11 This is a three-dimensional structural schematic diagram of the artificial heart valve according to the first embodiment of the present invention;

[0023] Figure 12 yes Figure 11 A three-dimensional structural diagram of the internal support and artificial leaflet;

[0024] Figure 13 yes Figure 11 A schematic diagram of the deformation structure of an artificial heart valve under radial force F;

[0025] Figure 14 yes Figure 11 A schematic diagram of an artificial heart valve after it has been implanted into the heart;

[0026] Figure 15 yes Figure 14 Enlarged view of region C2 in the middle;

[0027] Figure 16 yes Figure 15 A schematic diagram of the stress and deformation of an artificial heart valve in a photograph;

[0028] Figure 17 This is a schematic diagram of the structure of the artificial heart valve according to the second embodiment of the present invention;

[0029] Figure 18 yes Figure 17 A schematic diagram of the internal support structure;

[0030] Figure 19 yes Figure 17 A schematic diagram of the external support structure;

[0031] Figure 20 yes Figure 17 A schematic diagram of an artificial heart valve after it has been implanted into the heart;

[0032] Figure 21 yes Figure 20 Enlarged view of region C3 in the middle;

[0033] Figure 22 yes Figure 21 A further enlarged schematic diagram of the artificial heart valve and valve annulus;

[0034] Figure 23 This is a schematic diagram of the structure of the artificial heart valve (excluding the choke membrane and artificial leaflets) according to the third embodiment of the present invention;

[0035] Figure 24 yes Figure 23 A schematic diagram of the external support structure;

[0036] Figure 25 This is a schematic diagram of the structure of the artificial heart valve (excluding the choke membrane and artificial leaflets) according to the fourth embodiment of the present invention;

[0037] Figure 26 yes Figure 25 A schematic diagram of the external support structure;

[0038] Figure 27 yes Figure 25 A schematic diagram of an artificial heart valve after it has been implanted into the valve annulus;

[0039] Figure 28 This is a schematic diagram of the structure of the artificial heart valve (excluding the choke membrane and artificial leaflets) according to the fifth embodiment of the present invention;

[0040] Figure 29 yes Figure 28 A schematic diagram of the external support structure;

[0041] Figure 30 yes Figure 28 A schematic diagram of an artificial heart valve stent implanted into the valve annulus. Detailed Implementation

[0042] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0043] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0044] In the description of this invention, it should be noted that, based on the blood flow direction during ventricular diastole, the inflow end / side and outflow end / side of the artificial heart valve stent and its components, and the artificial heart valve and its components, are defined. The inflow end / side is the end / side closer to the blood inflow side or closer to the atrium, and the outflow end / side is the end / side closer to the blood outflow side or closer to the ventricle. Axial direction refers to the direction parallel to the line connecting the centers of the outflow end and the inflow end, radial direction refers to the direction perpendicular to the axial direction, and circumferential direction refers to the direction around the circumference. Furthermore, the radial dimension appears multiple times in the text. This radial dimension can be the maximum radial dimension or the radial dimension within a cross-section passing through the central axis. The method for obtaining the radial dimension is not limited, as long as the same method is used to obtain the radial dimension for the objects being compared. It should be understood that the above definitions are for convenience of expression only and should not be construed as limiting the invention.

[0045] like Figure 1-16As shown, an artificial heart valve stent 1 according to a first embodiment of the present invention includes: an inner stent 10 and an outer stent 20; wherein, the inner stent 10 includes a first part (also called an inner skirt) 101 and a second part 102 in sequence along the axial direction (i.e., the direction of the central axis AA) from the inflow end to the outflow end (arrow R points from the inflow end to the outflow end along the axial direction), the radial dimension of the first part 101 is larger than the radial dimension of the second part 102, at least a part of the second part 102 is nested in the outer stent 20, at least a part of the first part 101 extends toward the inflow end relative to the outer stent 20, and the portion of the first part 101 extending toward the inflow end relative to the outer stent 20 covers the flow-blocking membrane 101m.

[0046] It should be noted that the artificial heart valve stent 1 of the present invention has a radially compressed delivery state and a radially expanded natural state. In the delivery state, the artificial heart valve stent 1 is radially compressed by external force, allowing it to be compressed and inserted into a sheath with a smaller radial dimension, thereby being delivered to the heart via a delivery device. In the natural state, the artificial heart valve stent 1 is not subjected to external force and naturally expands radially. Unless otherwise specified, the following description refers to the structural features of the artificial heart valve stent 1 in its natural state.

[0047] Specifically, in a preferred embodiment of this example, the first portion 101 extends towards the inflow end relative to the outer support 20 ( Figure 1 The radial dimension of the region (shown in region H) is greater than the radial dimension at the inflow end face of the outer support 20. The radial dimension of the first part 101 relative to the inflow end end of the portion H extending towards the inflow end of the outer support 20 is taken as its radial dimension, as shown below. Figure 2 In the figure, d1; take the maximum radial dimension at the inflow end face of the outer support 20 as its radial dimension, such as Figure 4 If d0 is greater than d1, then d0 is greater than d1. Alternatively, the radial dimension of the first part 101 extending towards the inflow end relative to the outer support 20 at any point along the axial direction can be set to be greater than the radial dimension at the inflow end face of the outer support 20.

[0048] See Figure 1 and Figures 14 to 16The inner stent H, which extends towards the inlet end of the first part, or inner skirt 101, will lap against the autologous valve annulus M on the atrial side after the artificial heart valve stent 1 is implanted in the heart. By setting the radial dimension of the inner skirt 101 to be larger than the radial dimension at the inlet end face of the outer stent 20, on the one hand, the increased radial dimension can increase the contact area between the inner skirt 101 and the autologous valve annulus M in the atrium, preventing the artificial heart valve stent 1 from moving towards the ventricle; on the other hand, since this extended part of the inner stent H is basically unaffected by the radial compression of the valve annulus on the outer stent 20, it will not deform with the deformation of the outer stent 20, so the increased radial dimension can also enhance the sealing performance.

[0049] In another preferred embodiment of this invention, the outflow end of the outer support 20 is fixedly connected to the second part 102, the inflow end of the outer support 20 is freely suspended, and there is a radial gap between the inflow end of the outer support 20 and the portion near the inflow end of the outer support 20 and the second part 102. Further, the aforementioned radial gap L can be between 1 and 18 mm. It should be understood that this radial gap value is merely an example and is not a limitation of the present invention. Those skilled in the art can choose a suitable size according to actual needs, and other sizes selected under the teachings of this invention are all within the protection scope of this invention.

[0050] When the external stent 20 contracts and deforms radially under the radial compression of the valve annulus, the freely suspended inflow end is less restricted compared to the outflow end fixedly connected to the second part 102, thus having greater room for deformation and effectively conforming to the valve annulus to produce a concave deformation. Simultaneously, the inflow end and its surrounding portion of the external stent 20 are radially spaced from the second part 102 of the inner stent 10, providing sufficient deformation space for the deformation of the inflow end and its surrounding portion. The effective conforming deformation of the inflow end and its surrounding portion of the external stent 20 under the radial compression of the valve annulus can provide radial support force to the valve annulus, improving the fit between the artificial heart valve stent 1 and the valve annulus. More importantly, the concave deformation of the outflow side then forms a bulge G on the external stent 20, which can prevent the artificial heart valve stent 1 from moving towards the atrium.

[0051] After the artificial heart valve stent 1 in this embodiment is implanted into the heart, see [link to relevant documentation]. Figure 16As shown, the first part of the inner stent 10 extending towards the inflow end relative to the outer stent 20, or the inner skirt 101, is closely attached to the atrial side of the valve annulus M. Because the radial dimension of the inner skirt 101 is relatively large, it can prevent the artificial heart valve stent 1 from moving towards the ventricle. The outer stent 20 radially supports the valve annulus M and undergoes radially inward concave deformation under the compression of the valve annulus M. The outflow side of the concave deformation then forms a bulge G on the outer stent 20. This bulge G can prevent the artificial heart valve stent 1 from moving towards the atrial side. Thus, the inner stent 10 and the outer stent 20 work together to stably position the artificial heart valve stent 1 in the heart. Maintaining the relative position of the artificial heart valve stent 1 and the valve annulus M prevents the artificial heart valve stent 1 from falling off the valve annulus. Since the inner skirt 101 of the inner stent 10, which extends towards the inflow end relative to the outer stent 20, is in close contact with the atrial side of the valve annulus M, the radial compression deformation of the outer stent 20 by the valve annulus M will not affect the inner skirt 101 of the inner stent 10. This avoids the inner skirt 101 from having a gap with the atrial side of the valve annulus M due to the deformation of the outer stent 20. At the same time, the inner skirt 101 is also covered with a flow-blocking membrane 101m, which can effectively isolate the atrium and ventricle, ensure the sealing of the atrial side, and reduce the risk of paravalvular leakage.

[0052] In another preferred embodiment of this invention, the inflow end face of the outer stent 20 is axially separated from the first portion 101. Further, the axial separation distance L1 can be between 0.5 and 10 mm. By setting the axial separation, the inflow end face of the outer stent 20 can be prevented from entangled with the support rod of the first portion 101 of the inner stent 10, ensuring that the artificial heart valve stent 1 can smoothly expand radially, and that the freely suspended inflow end face of the outer stent 20 can undergo unrestricted radial deformation; simultaneously, it also prevents the sharp portion of the inflow end face of the outer stent 20 from piercing the flow-blocking membrane 101m covering the first portion 101, thus preventing leakage.

[0053] In the specific implementation of this embodiment, please refer to... Figure 3 The first part 101 of the inner support 10 includes a plurality of support rods 101a, which are interconnected to form a plurality of unit patterns 101b; the second part 102 of the inner support 10 includes a plurality of support rods 102a, which are interconnected to form a plurality of unit patterns 102b. Any unit pattern can be a rhombus, a triangle, or other suitable pattern. The areas of unit patterns 101b and 102b can be uniform or different. Suitable unit patterns and areas can be selected as needed, which will not be elaborated here.

[0054] The first part 101 and the second part 102 of the inner support 10 can be integrally formed; alternatively, they can be manufactured separately and then connected together, for example, by connecting them into an integral structure via connector 103. During the manufacturing process, the support rod can be formed by cutting, either by wire cutting or laser cutting, preferably laser cutting. For example, a laser cutting machine can be used to cut a nickel-titanium tube into the required shape, and after heat setting, it forms a compressed state and an expanded state. It remains in the compressed state in the conveying device and remains in the expanded state after being released inside the body. Alternatively, the support rod can be woven from shape memory material, for example, using highly elastic nickel-titanium alloy wire for weaving and heat setting into the required shape.

[0055] The second part 102 of the inner support 10 is usually an approximately cylindrical structure. The inflow end of the second part 102 is connected to the first part 101, and the outflow end can be provided with a connection hole 104 for connection with the outer support 20.

[0056] The first portion 101 of the inner support 10 includes a first extension 1011 connected to the second portion 102, the radial dimension of which gradually increases from the connection point with the second portion 102 toward the inflow end. Further, see [reference needed]. Figure 2 The radial expansion angle B of the first expansion portion 1011 is within the range of 45° to 90°. Here, the radial expansion angle B refers to the angle between the tangent of the outer contour of the first expansion portion 100 and the central axis AA of the inner stent 10. The first part 101 can be the entire first expansion portion 1011; or it can include the first expansion portion 1011 and a second expansion portion 1012 connected to the first expansion portion 1011 along the axial direction. The radial dimension of the second expansion portion 1012 gradually increases from the connection point with the first expansion portion 1011 towards the inflow end, and the radial expansion angle B of the first expansion portion 1011 relative to the axial direction is greater than the radial expansion angle B1 of the second expansion portion 1012 relative to the axial direction, i.e., B > B1. By reasonably setting the first expansion portion 1011 and the second expansion portion 1012, the adaptability of the first part 101 to the valve annulus can be improved, so as to fit more tightly to the atrial side of the valve annulus and reduce the possibility of paravalvular leakage.

[0057] The second part 102 is approximately cylindrical, with its radial dimensions being essentially the same at all points along the axial direction. The radial dimension of the first extended portion 1011 of the first part 101 gradually increases from its connection point with the second part 102 towards the inflow end. Therefore, the radial dimension of the first part 101 at all points along the axial direction is greater than that of the second part 102. The radial dimension d1 of the inflow end of the first part 101 within the cross-section passing through the central axis AA can be taken as the radial dimension of the first part 101, and the radial dimension d2 of the second part 102 within the cross-section passing through the central axis AA can be taken as the radial dimension of the second part 102. d1 is greater than d2. For example, d1 is preferably in the range of 40–70 mm. Based on clinical experience, to achieve better artificial valve performance, d2 is preferably in the range of 25 mm–30 mm. Of course, the values ​​of d1 and d2 can also be other values, which will not be listed here.

[0058] It is worth noting that the first part 101 can be covered not only with a flow-blocking membrane 101m on the portion H extending towards the inflow end relative to the outer stent 20, but also with other parts. For example, the entire first part 101 can be covered with a flow-blocking membrane, preferably made of PET, PTFE, e-PTFE, etc. A flow-blocking membrane can also be sewn onto the second part 102, preferably made of PET, PTFE, e-PTFE, etc. That is, both the first part 101 and the second part 102 of the inner stent 10 are covered with flow-blocking membranes to further prevent paravalvular leakage. It should be understood that the flow-blocking membrane covering the second part 102 can be the same as or different from the flow-blocking membrane on the first part 101; this is not limited here.

[0059] In the specific implementation of this embodiment, please refer to... Figure 5 The outer support 20 includes a plurality of support rods 200a, which are interconnected to form a plurality of unit patterns 200b. The unit pattern 200b can be a rhombus, a triangle or other suitable pattern. The area of ​​the unit pattern 200b can be uniform or different. Suitable patterns and areas can be selected for the unit pattern 200b as needed, which will not be elaborated here.

[0060] During the manufacturing process, the support rod 200a can be formed from shape memory material by cutting. The cutting method can be wire cutting or laser cutting, with laser cutting being preferred. For example, a laser cutting machine can be used to cut a nickel-titanium tube into the required shape. After heat setting, it forms a compressed state and an unfolded state. It remains in the compressed state in the conveying device and remains in the unfolded state after being released within the body. Alternatively, the support rod 200a can also be woven, for example, using highly elastic nickel-titanium alloy wire for weaving and heat setting to the required shape.

[0061] In a preferred embodiment, the inner stent 10 has a higher resistance to deformation than the outer stent 20. Resistance to deformation refers to the stent's ability to resist deformation under external stress. Under the same stress, a higher resistance to deformation results in a smaller deformation amplitude, and vice versa. In other words, higher resistance to deformation means lower flexibility. By setting the outer stent 20 to have a lower resistance to deformation, its ability to conform to radial compression of the valve annulus and form a radially inward concave deformation at its inflow end and nearby areas can be improved. Furthermore, a bulge G is formed on the outflow side of the concave deformation on the outer stent 20, ensuring that the artificial heart valve stent 1 does not move towards the atrium and dislodge under the flushing of blood flow. The inner stent 10 needs to withstand the traction force of its inner artificial leaflet and maintain the fit of its first part, or inner skirt 101, with the atrial side of the valve annulus. Therefore, the inner stent 10 has a high resistance to deformation. When the outer stent 20 is deformed by radial compression of the valve annulus, the inner stent 10 will not compress or deform the artificial leaflet, ensuring the smooth operation of the "valve". Furthermore, the inner skirt 101 will not be affected by the deformation of the outer stent 20 and will not create a gap with the atrial side of the valve annulus, reducing paravalvular leakage.

[0062] To achieve a higher deformation resistance for the inner support 10 than for the outer support 20, one or more of the following methods can be used: For example, the area of ​​the unit pattern 200b of the outer support 20 can be larger than the area of ​​the unit pattern 102b of the inner support 10; the cross-sectional area of ​​the support rod 200a of the outer support 20 can be smaller than that of the support rod 102a of the inner support 10; or the support rod 102a of the inner support 10 can be made of a material with higher hardness, while the support rod 200a of the outer support 20 can be made of a material with relatively lower hardness. It should be understood that the above methods are merely examples and are not intended to limit the invention. Those skilled in the art, under the guidance of this invention, can use other suitable methods to achieve a higher deformation resistance for the inner support 10 than for the outer support 20, all of which are within the scope of protection of this invention.

[0063] like Figure 1 , Figure 4 and Figure 5 As shown, the outer support 20, along the axial direction from the outflow end to the inflow end, includes a first segment 201 that is approximately funnel-shaped and a second segment 202 connected to the first segment 201; the nozzle of the first segment 201 is fixedly connected to the second part 102, the top opening of the first segment 201 is connected to the outflow end of the second segment 202, and the inflow end of the second segment 202 is freely suspended. The first segment 201 and the second segment 202 can be manufactured independently and then connected together; or they can be manufactured as a single piece. For example, in this embodiment, the first segment 201 and the second segment 202 are integrally formed by laser cutting.

[0064] The second segment 202 of the outer support 20 can be approximated as a cylinder, and its radial cross-section perpendicular to the axial direction is preferably O-shaped (see [reference]). Figure 6 ) or D-shaped (see Figure 7 The use of an O-shaped radial cross-section makes the external stent 20 easier to manufacture; the use of a D-shaped radial cross-section allows the external stent 20 to better fit the actual physiological and anatomical structure of the valve annulus. This ensures that the structural morphology of the external stent 20 matches the cross-sectional shape of the valve annulus space in which it is housed, thus avoiding compression of the ventricular outflow tract. The radial dimension d0 of the second segment 202 within the cross-section passing through the central axis AA is close to the size of the natural valve annulus, preferably ranging from 30 to 60 mm.

[0065] The first segment 201 is approximately funnel-shaped, with the smaller opening at the outlet being the nozzle and the larger opening at the inlet being the top opening. The first segment 201 gradually tapers from the top opening towards the nozzle, with the taper angle A being the angle between the tangent lines of the outer contour of the nozzle on the same diameter. This taper angle A ranges from 90° to 150°. The nozzle can be fixedly connected to the inner support 10 by means of crimping, riveting, welding, or sewing. For example, a connecting hole 204 can be provided in the nozzle, aligned with a connecting hole 104 at the outlet end of the inner support 10. Rivets pass through connecting holes 204 and 104 to fix the inner support 10 and the outer support 20 together.

[0066] See Figure 9 The first segment 201 includes multiple support rods 201a, which are interconnected to form multiple unit patterns 201b; the second segment 202 includes multiple support rods 202a, which are interconnected to form multiple unit patterns 202b. The unit patterns 201b and 202b can be rhombuses, triangles, or other suitable patterns. The area of ​​the unit patterns can be uniform or different; suitable patterns and areas can be selected according to needs, which will not be elaborated further here.

[0067] Preferably, the radial support force of the first segment 201 is greater than that of the second segment 202. Here, the radial support force refers to the reaction force generated after the stent is subjected to radial compression. Under the same radial compression conditions, the greater the reaction force, the smaller the stress deformation, and the greater the radial support force, and vice versa. In the artificial heart valve stent 1 of this embodiment, the first segment 201 is connected to the inner stent 10, see [reference needed]. Figure 15 and Figure 16Under the action of the original leaflet, the first segment 201 can provide a large radial support force and small stress deformation, so as not to squeeze the stent 10, and thus avoid squeezing the artificial leaflet in the stent 10; the second segment 202 has a smaller radial support force. Under the same radial compression conditions, the radial support force is smaller and the stress deformation is larger, so it can better conform to the valve annulus and improve implantation stability.

[0068] To achieve a greater radial support force in the first segment 201 than in the second segment 202, one or more of the following methods can be used: The area of ​​the unit pattern 201b in the first segment 201 can be smaller than the area of ​​the unit pattern 202b in the second segment 202; the width of the support rod 201a in the first segment 201 can be greater than the width of the support rod 202a in the second segment 202; or the support rod 201a in the first segment 201 can be made of a material with higher hardness, while the support rod 202a in the second segment 202 can be made of a material with relatively lower hardness. For example, if support rods of different widths are used, their width dimension should not exceed 0.5 mm, and preferably be 0.3 mm, 0.4 mm, or 0.5 mm. It should be understood that the above methods are merely examples and are not intended to limit the invention. Those skilled in the art, under the guidance of this invention, can use other suitable methods to achieve a greater radial support force in the first segment 201 than in the second segment 202, all of which are within the scope of protection of this invention.

[0069] See Figure 4 and Figures 8a-8c The enlarged area C shown includes the outer support 20, which also includes at least one limiting rod 203. The limiting rod 203 axially comprises a rod body 2031 connected to the nozzle and a suspended end 2032 connected to the rod body 2031. The lateral direction of the end 2032 is... Figures 8a-8c The dimension in the LH direction shown is larger than the dimension in the transverse direction of the rod, where the transverse LH is perpendicular to the axial direction. Specifically, the limiting rod 203 is generally T-shaped, facilitating placement within the delivery device limiting slot to connect the artificial heart valve stent 1 to the delivery device, for example, see [reference missing]. Figure 8a The end can be round; see reference. Figure 8b The end can be square; see 8c, the end can be semi-circular.

[0070] To facilitate the determination of the position of the artificial heart valve stent 1 during implantation in the heart, a contrast-enhancing mechanism can also be provided on the outer stent 20 and / or the inner stent 10. (See [reference needed]) Figure 9 , Figure 9 The developing unit is located in area C1. For example, see... Figure 10a The developing mechanism can be a developing block fixed on the outer support 20; see reference Figure 10b Alternatively, it can be a developing wire wound around the outer support 20; see [reference]. Figure 10c Alternatively, it can be a developing ring surrounding the outer support 20; or a combination of the developing mechanisms described above. Similarly, a similar developing mechanism can be provided on the inner support 10, which will not be described in detail here. The developing mechanism is made of developing material, such as commonly used developing materials like tungsten, gold, platinum, and tantalum.

[0071] See Figure 11 and 12 and Figures 1 to 5 According to the first embodiment of the present invention, the artificial heart valve 01 includes an artificial leaflet 2 and an artificial heart valve stent 1 as described above. The artificial leaflet 2 is fixedly connected to the inner stent 10 within the inner stent 10 of the artificial heart valve stent 1. Two, three, or other suitable numbers of artificial leaflets 2 can be selected, with the edges of any two adjacent artificial leaflets abutting each other circumferentially. The artificial leaflet 2 is preferably made of a biological leaflet material, such as bovine pericardium, porcine pericardium, or other biological tissue materials; however, polymer materials, such as ultra-high molecular weight polyethylene, can also be used.

[0072] See Figure 13-16 When the artificial heart valve 01 is implanted into the autologous valve annulus M in the heart, the external stent 20 is compressed by a radial force F. Since the inflow end of the external stent 20 is freely suspended, the second segment 202 near the inflow end is not connected to the inner stent 10 and is radially spaced from it, so it is prone to deformation under the action of F. The first segment 201 near the outflow end of the external stent 20 is fixedly connected to the inner stent 10 and has a strong radial support force. Under the action of F, the stress deformation is small. Therefore, under the action of F, the inflow end of the second segment 202 will be concave and deformed inward, while the outflow end of the first segment 201 continues to maintain its original state. This deformation will cause the external stent portion near the connection between the first segment 201 and the second segment 202, or the concave and deformed outflow side, to bulge outward, forming a bulge portion G. This makes the external stent 20 generally present a shape that is small at both ends and large in the middle. The bulge portion G on the external stent 20 can prevent the artificial heart valve stent 1 from moving towards the atrium.

[0073] like Figure 15 , Figure 16As shown, when the artificial heart valve 01 is implanted into the heart, based on the tissue structure morphology, the valve annulus M will actually compress the artificial heart valve 01 from multiple directions and angles. For example, the radial compression force F2 compresses the inflow end of the external stent 20, causing the inflow end of the external stent 20 to be concave inward. The outward bulging part of the external stent 20 after deformation is subjected to the compression force F3 of the valve annulus M, making the bulging part G fit the valve annulus M more closely. At the same time, at least a portion of the first part 101 of the inner stent 10 extends towards the inflow end relative to the outer stent 20, and is attached to the atrial side of the valve annulus M in the atrium LA. It is supported by the support force F1 provided by the valve annulus M and is not affected by the radial deformation of the outer stent 20. In this way, the artificial heart valve 01 can be stably compressed or held in the position of the valve annulus M. In addition, the portion of the stent extending toward the inflow end relative to the outer stent 20 in the first part 101 is also covered with a flow-blocking membrane. This flow-blocking membrane is attached to the atrial side of the valve annulus M together with the inner stent 10, isolating the atrium LA from the ventricle LV, and is not affected by the radial deformation of the outer stent 20, thereby ensuring the sealing of the atrial side and effectively preventing paravalvular leakage.

[0074] See Figure 17-22 Compared to the first embodiment, the artificial heart valve stent according to the second embodiment of the present invention differs in that the outer stent 20 is also covered with a choke membrane 20b, for example, the choke membrane 20b is sewn onto the support rod 20a, thereby further enhancing the sealing performance and preventing paravalvular leakage. The choke membrane 20b can be made of the same material as the choke membrane on the inner stent or a different material.

[0075] Specifically, the choke membrane 101m covering the portion of the first part 101 extending towards the inflow end relative to the outer stent 20, or the choke membrane covering the entire inner stent 10, can be sealed on the atrial LA side, and the choke membrane 20b on the outer stent 20 can be sealed on the ventricular LV side. In this way, both the atrial and ventricular sides of the valve annulus have choke membranes for sealing, which can further enhance the sealing effect of the artificial heart valve 01, thereby further reducing the probability of paravalvular leakage.

[0076] It should be understood that the flow-blocking membrane on the outer support in this invention is not necessary, but an optional feature. By covering the portion of the first part 101 that extends toward the inflow end relative to the outer support 20 with the flow-blocking membrane 101m, perivalvular leakage can be effectively prevented.

[0077] See Figure 23 and 24 Compared with the first embodiment, the artificial heart valve stent according to the third embodiment of the present invention differs in that the radial dimension of the second segment 202 of the external stent 20 gradually decreases from the connection with the first segment 201 toward the inflow end, so as to further improve the ability of the external stent 20 to adapt to the valve annulus.

[0078] Specifically, the second segment 202 is shaped towards the inflow end into a structure that gradually tilts and converges towards the central axis AA. However, its freely suspended inflow end remains radially separated from the inner stent 10. Its radial tilting distance L' is less than the gap L between the inner stent 10 and the middle of the outer stent 20. The radial tilting distance L' refers to the radial distance between the outflow end and the inflow end of the second segment 202. The outflow end is connected to the first segment 201, while the inflow end is freely suspended. Compared to the first embodiment, in this embodiment, when the outer stent 20 is compressed by the valve annulus, the outer stent 20 only deforms slightly or even almost without deformation to adapt to the shape and size of the valve annulus, thereby improving its adaptability to the valve annulus and enhancing the positional stability of the artificial heart valve after implantation into the valve annulus.

[0079] See Figure 25-27 Compared to the first embodiment, the artificial heart valve stent according to the fourth embodiment of the present invention differs in that the inflow end of the second segment 202 of the external stent 20 has a circumferential recess 202d. This recess 202d is located between the connection point of the second and first segments and the free-suspension inflow end of the second segment, in a region formed by the external stent recessing towards the central axis. Figure 27 The area between straight lines D1 and D2 in the diagram represents the recess 202d. This recess 202d can be formed during the fabrication process through heat setting. When the external stent 20 is compressed by the valve annulus, the recess 202d conforms to the natural shape of the valve annulus, enhancing the adaptability of the artificial heart valve stent and thus improving its positional stability.

[0080] See Figures 28-30 Compared with the first embodiment, the artificial heart valve stent according to the fifth embodiment of the present invention differs in that the external stent 20 further includes at least one barb 207 disposed on the second segment 202 and / or near the inflow end of the first segment 201. The barb 207 extends outward and simultaneously toward the inflow end. The barb 207 extends radially outward and unfolds toward the inflow end, and the angle between its extension direction AB and the central axis AA is defined as the unfolding angle α, which preferably ranges from 30° to 90°. There can be one or more barbs 207, which can be randomly distributed or distributed circumferentially around the external stent 20. For example, one or more layers of barbs 207 can be arranged around the circumference of the external stent 20, and the number of barbs 207 is at least three. When the external stent 20 is compressed by the valve annulus M, it not only undergoes radial deformation, but the barbs 20 can also penetrate the valve annulus tissue, thereby further improving the anchoring force of the external stent 20.

[0081] It is understood that the artificial heart valve of the present invention can be radially compressed and housed in a delivery device with a small diameter, and delivered to the vicinity of the mitral valve and released via a transapical, transatlantic, or transfemoral vein-atrial septal route to replace the diseased natural valve annulus. The delivery device includes an outer sheath and an inner core inserted within the outer sheath. The inner core and the outer sheath can move relative to each other axially. After radial compression, the artificial heart valve is housed in the gap between the distal portion of the inner core and the distal portion of the outer sheath. The inner core is provided with at least one limiting groove for cooperating with a limiting rod 203 on the artificial heart valve stent 1. When the inner core and the outer sheath move relative to each other and the artificial heart valve is gradually released from the outer sheath, the limiting groove can restrict the instantaneous release of the artificial heart valve, thereby facilitating the operator's observation through medical imaging until the release position is appropriate before releasing the limiting groove and the limiting rod 203 to completely release the artificial heart valve.

[0082] It is also understood that the artificial heart valve of the present invention can also be directly implanted into the heart through surgery to replace the diseased natural mitral valve, which will not be elaborated here.

[0083] Of course, the artificial heart valve of the present invention can also be implanted into the heart through various means to replace the diseased natural tricuspid valve, which will not be elaborated here.

[0084] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. An artificial heart valve stent, characterized in that, include: An inner support and an outer support; wherein the inner support comprises a first part and a second part in sequence along the axial direction from the inflow end to the outflow end, the radial dimension of the first part is greater than the radial dimension of the second part, at least a portion of the second part is nested in the outer support, at least a portion of the first part extends toward the inflow end relative to the outer support, and the portion of the first part extending toward the inflow end relative to the outer support is covered with a flow-blocking membrane. The external support includes multiple support rods, which are interconnected to form multiple unit patterns. The outflow end of the outer bracket is fixedly connected to the second part, the inflow end of the outer bracket is freely suspended, and there is a radial gap between the inflow end of the outer bracket and the part near the inflow end of the outer bracket and the second part. The outer support radially supports the valve annulus and can undergo radially inward concave deformation under the compression of the valve annulus.

2. The artificial heart valve stent according to claim 1, characterized in that, The radial dimension of the first portion extending toward the inflow end relative to the outer support is greater than the radial dimension at the end face of the inflow end of the outer support.

3. The artificial heart valve stent according to claim 1, characterized in that, The radial clearance ranges from 1 to 18 mm.

4. The artificial heart valve stent according to claim 1, characterized in that, There is an axial gap between the end face of the inflow end of the outer support and the first part.

5. The artificial heart valve stent according to claim 1, characterized in that, The inner support has a higher resistance to deformation than the outer support.

6. The artificial heart valve stent according to claim 1, characterized in that, The first part includes a first expansion portion connected to the second part, the radial dimension of the first expansion portion gradually increasing from the connection point with the second part toward the inflow end.

7. The artificial heart valve stent according to claim 6, characterized in that, The radial expansion angle of the first expansion portion ranges from 45° to 90°.

8. The artificial heart valve stent according to claim 6, characterized in that, The first part further includes a second expansion part axially connected to the first expansion part; the radial dimension of the second expansion part gradually increases from the connection point with the first expansion part toward the inflow end, and the radial expansion angle of the first expansion part relative to the axial direction is greater than the radial expansion angle of the second expansion part relative to the axial direction.

9. The artificial heart valve stent according to claim 1, characterized in that, The outer support includes a first section that is approximately funnel-shaped and a second section connected to the first section along the axial direction from the outflow end to the inflow end; the nozzle of the first section is fixedly connected to the second section, the top opening of the first section is connected to the outflow end of the second section, and the inflow end of the second section is freely suspended.

10. The artificial heart valve stent according to claim 9, characterized in that, The second segment is approximately cylindrical; or the radial dimension of the second segment gradually decreases from the connection point with the first segment toward the inflow end; or the inflow end of the second segment has a circumferential recess.

11. The artificial heart valve stent according to claim 9, characterized in that, The contraction angle of the first segment ranges from 90° to 150°.

12. The artificial heart valve stent according to claim 9, characterized in that, The outer support also includes at least one limiting rod; the limiting rod includes a rod body connected to the nozzle and a suspended end connected to the rod body along the axial direction, and the lateral dimension of the end is larger than the lateral dimension of the rod body.

13. The artificial heart valve stent according to claim 9, characterized in that, The outer support also includes at least one barb disposed on the second segment and / or near the inflow end of the first segment, the barb extending outward and simultaneously toward the inflow end.

14. The artificial heart valve stent according to any one of claims 1-13, characterized in that, The artificial heart valve stent also includes a contrast-enhancing mechanism disposed on the external stent and / or the internal stent.

15. The artificial heart valve stent according to any one of claims 1-13, characterized in that, Both the first and second parts of the inner support are covered with a flow-blocking membrane.

16. The artificial heart valve stent according to claim 15, characterized in that, The outer support is covered with a flow-blocking membrane.

17. The artificial heart valve stent according to claim 9, characterized in that, The cross-sectional shape of the second segment perpendicular to the axial direction is O-shaped or D-shaped.

18. An artificial heart valve, characterized in that, It includes at least two artificial leaflets and an artificial heart valve stent as described in any one of claims 1-17; the artificial leaflets are fixedly connected to the inner stent within the artificial heart valve stent; the edges of the at least two artificial leaflets are abutted against each other in the circumferential direction.

19. An artificial heart valve replacement system, characterized in that, The invention includes the artificial heart valve as described in claim 18 and a delivery device for delivering the artificial heart valve, wherein the artificial heart valve has a radially compressed delivery state and a radially expanded natural state, the delivery device includes an outer sheath and an inner core inserted through the outer sheath, the inner core and the outer sheath being axially movable relative to each other, and the artificial heart valve, after radial compression, is housed in the gap between the distal portion of the inner core and the distal portion of the outer sheath.

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