Valve prosthesis

Abstract

The valve prosthesis comprises a stent body and a valve leaflet, the stent body comprises an outflow end and an inflow end, the stent body comprises an inner-layer stent and an outer-layer stent which are connected with each other, the inner-layer stent is arranged in the outer-layer stent, the valve leaflet is arranged in the inner-layer stent, and the outer-layer stent comprises a first stent part; the projection of the first support part on the section in the direction perpendicular to the axis is in a D shape, the D shape comprises a first section and a second section which are connected with each other in the circumferential direction, the arc length of the first section is larger than that of the second section, the part, corresponding to the first section, of the first support part is a first part, and the part, corresponding to the second section, of the second support part is a second part. The part, corresponding to the second section, of the first support part is a second part, an anchor thorn structure is arranged on the periphery of the first support part, and the anchor thorn structure is only arranged on the first part, so that the valve prosthesis has good fixity and safety at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of interventional medical instrument devices, and in particular to a valve prosthesis. BACKGROUND

[0002] With the development of social economy and the aggravation of population aging, senile valvular disease and valvular lesions caused by coronary heart disease and myocardial infarction are also more and more common. Studies have shown that more than 13.3% of people over 75 years old suffer from varying degrees of heart valve disease. Heart valve disease has gradually become one of the important reasons threatening human health, and mitral valve, tricuspid valve, aortic valve disease, etc. are relatively common heart valve diseases in clinic. Taking the mitral valve as an example, the human heart is divided into four heart chambers, i.e. left atrium, left ventricle, right atrium and right ventricle. Two atria are connected with two ventricles respectively, and two ventricles are connected with two large arteries. The mitral valve grows between the left atrium and the left ventricle, which is composed of leaflets, annulus, chordae tendineae and papillary muscles, and plays the role of a one-way valve to ensure that blood flow only moves in a single direction from the left atrium to the left ventricle. Mitral regurgitation is one of the most common mitral valve diseases, which refers to the failure of the mitral valve to properly close during the ventricular contraction phase, causing blood to flow from the left ventricle into the left atrium. Using a mitral valve replacement device is one of the common treatment methods. The mitral valve replacement device is an implantable prosthetic device composed of three parts, i.e. artificial valve leaflets, covering film and stent. The function of the stent is to fix the artificial valve leaflets at the position of the native mitral valve leaflets, so that the artificial valve leaflets can work normally and fix the native mitral valve leaflets, ensuring normal blood flow in the left heart.

[0003] However, the fixation and safety of the valve prosthesis are often unbalanced. SUMMARY

[0004] The present application aims to at least provide a valve prosthesis with good fixation and safety.

[0005] The object is achieved by the following technical solutions:

[0006] According to the technical scheme of the present application, a valve prosthesis is provided, which comprises a stent body and a valve leaflet, the stent body comprises an outflow end and an inflow end, the stent body comprises an inner layer stent and an outer layer stent connected to each other, the inner layer stent is arranged in the outer layer stent, the valve leaflet is arranged in the inner layer stent, the outer layer stent comprises a first stent part, a projection of the first stent part on a cross section in a direction perpendicular to an axis is in a D shape, the D shape comprises a first segment and a second segment connected to each other, an arc length of the first segment is greater than an arc length of the second segment, a part of the first stent part corresponding to the first segment is a first part, a part of the first stent part corresponding to the second segment is a second part, and an outer periphery of the first stent part is provided with an anchor structure, and the anchor structure is arranged only on the first part.

[0007] The valve prosthesis described above, by arranging the inner layer stent in the outer layer stent, arranging the valve leaflet in the inner layer stent, and enabling the outer layer stent to be fixed by being fitted to the tissue, the inner layer stent provided with the valve leaflet is ensured not to be extruded by the tissue, and the working state of the valve leaflet is avoided from being affected. Meanwhile, the outer layer stent comprises a first stent part, a projection of the first stent part on a direction along the axis is in a D shape, wherein the first stent part of the D shape is used to better fit the shape at the valve annulus, thereby improving the sealing performance of the valve and avoiding paravalvular leakage. The D shape comprises a first segment and a second segment connected to each other, an arc length of the first segment is greater than an arc length of the second segment, a part of the first stent part corresponding to the first segment is a first part, a part of the first stent part corresponding to the second segment is a second part, and an outer periphery of the first stent part is provided with an anchor structure, and the anchor structure is arranged only on the first part. In this way, the part where the first part of the first stent part provided with the anchor structure is located is avoided from being directed towards the aortic valve, thereby avoiding the anchor structure from damaging the aortic valve during the beating of the heart, and improving the safety. Meanwhile, the anchor structure is arranged on the part where the first part of the first stent part is located, which can improve the fixation performance of the valve prosthesis.

[0008] In an embodiment, the anchor structure comprises a plurality of anchors, the anchors are arranged on an end part and near the end part of the first part connected to the second part, the anchors arranged on the end part of the first part connected to the second part and near the end part are end anchors,

[0009] a hardness of the end anchors is less than a hardness of the anchors at other positions on the first part;

[0010] Or / and, a number of the end anchors is less than a number of the anchors at other positions on the first part;

[0011] Alternatively or in addition, a plurality of the anchors are circumferentially distributed on the first support portion, and in a projection of the first support portion along the axial direction, all of the anchors have their radially outermost ends located on the periphery of the same circle.

[0012] In an embodiment, the first support portion comprises a plurality of mesh structures, and between any two adjacent mesh structures, there is a node, and the anchor structure comprises a plurality of anchors, one end of each anchor is arranged on the node, and the other end of each anchor is a free end, and the free end extends towards the inflow end and flares outward.

[0013] In an embodiment, the inflow end of the outer layer support is provided with an outwardly turned support skirt, the support skirt is connected to the first support portion, and the anchor structure is arranged at an end of the first support portion away from the support skirt.

[0014] In an embodiment, the side wall of the first support portion where the second portion is located is outwardly convex, or the side wall of the first support portion where the second portion is located is arranged in parallel with the axial direction of the support body.

[0015] In an embodiment, the outflow end comprises a plurality of connection points, and the outer layer support and the inner layer support are connected to the connection points after being connected at or near the outflow end, the plurality of connection points enclose a circle, the circle has a circumference, and the plurality of connection points equally divide the circumference.

[0016] In an embodiment, the outer layer support comprises a second support portion, the first support portion and the second support portion are axially connected, the first support portion is closer to the inflow end than the second support portion, a plane where an end of the first support portion connected to the second support portion is perpendicular to the axial line of the support body, and the second support portion is connected to the outflow end of the inner layer support.

[0017] In an embodiment, the valve prosthesis further comprises a covering, and the covering comprises an inner layer support covering, the inner layer support covering is at least partially arranged on the inner layer support, adjacent valve leaflets have circumferentially spaced openings Q at a position close to the inflow end, the inner layer support covering comprises a plurality of inner layer support covering units connected circumferentially, adjacent inner layer support covering units have circumferentially spaced openings W at a position close to the inflow end, one end of one valve leaflet close to the inflow end and one inner layer support covering unit are both fixed on the inner layer support, so that one end of the inner layer support covering unit close to the inflow end coincides with one end of the valve leaflet close to the inflow end or one end of the inner layer support covering unit close to the inflow end extends further towards the inflow end than one end of the valve leaflet close to the inflow end, and wherein the area of the circumferentially spaced openings W is less than or equal to the area of the circumferentially spaced openings Q.

[0018] In an embodiment, the circumferentially spaced apart openings W are inversely triangular shaped openings, a length of which near one end of the inflow end is longer than a length of which near one end of the outflow end.

[0019] In an embodiment, the outer layer stent covering further comprises a first outer layer covering at least partially disposed outside the outer layer stent and a second outer layer covering at least partially disposed inside the outer layer stent, the second outer layer covering being fixed with the inner layer stent covering at the outflow end or near the outflow end to form a seal between the second outer layer covering and the inner layer stent covering.

[0020] In an embodiment, the first outer layer covering or / and the second outer layer covering wraps around an end of the stent body near the inflow end.

[0021] In an embodiment, the inflow end of the outer layer stent is provided with an outwardly turned stent skirt connected with the first stent portion, the first outer layer covering at least covering the stent skirt, the first outer layer covering being separated from the anchor structure.

[0022] In an embodiment, the first outer layer covering comprises a loose porous structure, and the second outer layer covering comprises a blood sealing material. BRIEF DESCRIPTION OF DRAWINGS

[0023] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a better understanding of the preferred embodiments and are incorporated in and constitute a part of this specification, illustrate embodiments that, together with the description, serve to explain the principles of the application. In the drawings:

[0024] Figure 1 is a structural schematic diagram of a valve prosthesis provided in an embodiment.

[0025] Figure 2 is a structural schematic diagram of a valve prosthesis provided in an embodiment.

[0026] Figure 3 is a structural schematic diagram of a stent body provided in an embodiment.

[0027] Figure 4 is a structural schematic diagram of a stent body provided in an embodiment.

[0028] Figure 5 is a structural schematic diagram of an outer layer stent provided in an embodiment.

[0029] Figure 6 is a structural schematic diagram of an outer layer stent provided in an embodiment.

[0030] Figure 7 FIG. 7 is a structural schematic diagram of a unit structure of a second stent part according to an embodiment.

[0031] Figure 8 FIG. 8 is a partially expanded structural schematic diagram of an outer layer stent according to an embodiment.

[0032] Figure 9 FIG. 9 is a force schematic diagram of a first stent part according to an embodiment.

[0033] Figure 10 FIG. 10 is a structural schematic diagram of a first stent part according to an embodiment.

[0034] Figure 11 FIG. 11 is a structural schematic diagram of an inner layer stent and a transition section according to an embodiment.

[0035] Figure 12 FIG. 12 is a structural schematic diagram of an inner layer stent and a transition section according to an embodiment.

[0036] Figure 13 FIG. 13 is a structural schematic diagram of a leaflet according to an embodiment.

[0037] Figure 14 FIG. 14 is a structural schematic diagram of a leaflet according to an embodiment.

[0038] Figure 15 FIG. 15 is a structural schematic diagram of an inner layer stent covering according to an embodiment.

[0039] Figure 16 FIG. 16 is a structural schematic diagram of an inner layer stent covering according to an embodiment.

[0040] Figure 17 FIG. 17 is a structural schematic diagram of a stent body, a transition section, a connector, and a pulling member provided with a second outer layer covering according to an embodiment.

[0041] Figure 18 FIG. 18 is a structural schematic diagram of a second outer layer covering according to an embodiment.

[0042] Figure 19 FIG. 19 is a structural schematic diagram of a stent body, a transition section, a connector, and a pulling member provided with a first outer layer covering according to an embodiment.

[0043] Figure 20 FIG. 20 is a structural schematic diagram of a first outer layer covering according to an embodiment. DETAILED DESCRIPTION

[0044] Exemplary embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is to be understood that the present disclosure can be embodied in many forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0045] It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order in which they are described, unless specifically identified as an order dependent step. It is also to be understood that additional or alternative steps can be employed.

[0046] Although the terms first, second, third, and the like can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first", "second", and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0047] For the purposes of this description, spatially relative terms such as "inner", "outer", "beneath", "below", "lower", "above", "upper", and the like can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0048] It should be noted that the terms "distal" and "proximal" are used as orientation terms in the field of interventional medical devices, where "distal" refers to the end of the device that is farthest from the heart during a procedure, and "proximal" refers to the end of the device that is closest to the heart during a procedure. Axial refers to a direction parallel to a line connecting a center of the distal end of the medical device to a center of the proximal end of the medical device; radial refers to a direction perpendicular to the axial direction; and circumferential refers to a direction around an outer surface of the medical device.

[0049] Referring to Figure 1 and Figure 2 The present embodiment provides a valve prosthesis 100, comprising a stent body 1 and a leaflet 2, the stent body 1 comprising an inflow end A and an outflow end B, wherein the stent body 1 comprises an inner stent 11 and an outer stent 12, the inner stent 11 being disposed within the outer stent 12, and the leaflet 2 being disposed within the inner stent 11.

[0050] In the present embodiment, the stent body 1 is a self-expandable stent, which is compressed within a delivery sheath and self-expands after being released from the delivery sheath. In other embodiments, the stent body 1 can also be a balloon-expandable stent.

[0051] Referring to Figure 2 and Figure 3The outflow end B comprises a plurality of connection points 13, the outer layer stent 12 is connected with the connection points 13 after being connected with the inner layer stent 11 at or near the outflow end B, the plurality of connection points 13 enclose a circle 101, the circle 101 has a circumference, and the plurality of connection points 13 equally divide the circumference 101. It needs to be particularly pointed out that when at least 80% of all the connection points are on the circumference of the same circle 101, and the distance from less than 20% of the connection points that are not on the circumference of the circle 101 to the center of the circle 101 is not more than ±5% of the radius of the circle 101, it can be called that the plurality of connection points 13 enclose a circle 101; when less than 20% of all the connection points are not on the circumference of the same circle 101, the intersection of the ray that starts from the center of the circle 101 and passes through the connection point and the circle 101, together with other connection points on the circumference of the same circle 101, equally divides the circumference of the circle 101, and it can also be called that the plurality of connection points 13 equally divide the circumference.

[0052] In the embodiment, the inner layer stent 11 is arranged in the outer layer stent 12, the leaflet 2 is arranged in the inner layer stent 11, the outer layer stent 12 can be fixed to the tissue to avoid paravalvular leakage and ensure that the inner layer stent 11 provided with the leaflet 2 is not extruded by the tissue to affect the working state of the leaflet 2. In addition, the outflow end B comprises a plurality of connection points 13, the outer layer stent 12 is connected with the connection points 13 after being connected with the inner layer stent 11 at or near the outflow end B, the plurality of connection points 13 enclose a circle 101, the circle 101 has a circumference, and the plurality of connection points 13 equally divide the circumference, which can ensure that the outflow end B of the stent body 1 has a symmetrical structure, the stent body 1 can be uniformly compressed into a delivery sheath, the compression and subsequent release state of the stent body 1 are ensured, and the stent body 1 can be uniformly stressed when being placed at a lesion position, thereby not being easily detached.

[0053] Referring to Figure 5 The outer layer stent 12 comprises an axially connected first stent part 121 and a second stent part 122, a plane C where one end of the first stent part 121 and the second stent part 122 are connected is perpendicular to the axis O of the stent body 1, and the second stent part 122 is connected with the inner layer stent 11 at or near the outflow end B. In this way, the first stent part 121 can always maintain a uniform stress state, the compression and subsequent release state of the stent body 1 are further ensured, and the stent body 1 can be uniformly stressed when being placed at a lesion position.

[0054] The second stent part 122 is connected with the first stent part 121 at an angle, the second stent part 122 comprises a plurality of stent rods 1220, and the stent rod 1220 comprises at least one of a straight rod and a curved rod.

[0055] Further, in combination with Figure 5 and Figure 6 The second stent part 122 comprises a plurality of unit structures 1221 distributed in the circumferential direction, and each unit structure 1221 comprises a plurality of stent struts 1220, one end of the plurality of stent struts 1220 is connected to the same connection point 13 after converging together, and the other end of at least two stent struts 1220 in the plurality of stent struts 1220 is respectively connected to different positions on the first stent part 121. Since the outer stent 12 is connected to the inner stent 11 through the second stent part 122, the second stent part 122 is thus arranged to avoid being arranged in a grid shape such as a rhombic grid, so that the connection between the outer stent 12 and the inner stent 11 is too rigid, and the extrusion force of the annulus on the outer stent 12 cannot be dispersed, which further affects the shape of the leaflet connected to the inner stent 11 and affects the hemodynamics. Arranging the stent struts 1220 as curved struts makes the outer stent 12 more flexible and easier to deform and adhere to the tissue, and can increase the flexible connection between the outer stent 12 and the inner stent 11, and further disperse the extrusion force of the annulus on the outer stent 12.

[0056] In the embodiment, the first stent part 121 has a D-shaped projection in the cross section perpendicular to the axis direction, and the D-shaped projection comprises a first segment 1210 and a second segment 1211 connected in the circumferential direction, the arc length of the first segment 1210 is greater than that of the second segment 1211, the part of the first stent part 121 corresponding to the first segment 1210 is a first part 12100, and the part of the first stent part 121 corresponding to the second segment 1211 is a second part 12110. It should be noted that the D-shaped projection is not necessarily a very standard D-shaped projection, and the D-shaped projection can be understood as the first segment 1210 and the second segment 1211 having different curvatures, and the curvature of the first segment 1210 is greater than that of the second segment 1211. When the valve prosthesis 100 is placed in the mitral valve in the body, the second part 12110 of the first stent part 121 is placed on the position of the anterior leaflet of the native leaflet, and the first part 12100 of the first stent part 121 is placed on the position of the posterior leaflet of the native leaflet, so as to be more fitted with the anatomical structure at the native leaflet, thereby avoiding the occurrence of paravalvular leakage.

[0057] Further, the second support part 122 comprises unit structures 1221 distributed along the circumference, the unit structures 1221 comprise first unit structures 12211 and second unit structures 12212 which are of the same structure, the first unit structures 12211 are located at the middle positions of the first parts 12100, the second unit structures 12212 are located at the middle positions of the second parts 12110, third unit structures 12213 and fourth unit structures 12214 are arranged on both sides of the first unit structures 12211 respectively, the third unit structures 12213 and the fourth unit structures 12214 are arranged symmetrically with the first unit structures 12211 as the axis of symmetry, fifth unit structures 12215 and sixth unit structures 12216 are arranged on both sides of the second unit structures 12212 respectively, the fifth unit structures 12215 and the sixth unit structures 12216 are arranged symmetrically with the second unit structures 12212 as the axis of symmetry. In this way, the first support part 121 in the shape of D can have a symmetrical structure, so that the stress on the first support part 121 is more uniform, further ensuring the compression and subsequent release state of the support body 1, and ensuring that the stress is uniform when the support body 1 is placed at the lesion position.

[0058] In the embodiment, the unit structure 1221 comprises a first support rod 1222 and a second support rod 1223, one end of the first support rod 1222 and one end of the second support rod 1223 converge together and are connected to the same connection point 13, the other end of the first support rod 1222 and the other end of the second support rod 1223 are connected to different positions of the first support part 121 respectively, the first support rod 1222 comprises a straight rod or a curved rod, and the second support rod 1223 comprises a straight rod or a curved rod.

[0059] In an embodiment, referring to Figure 7 In particular, when at least one of the first support rod 1222 and the second support rod 1223 is a curved rod, the curved rod comprises a plurality of S-shaped curved rods connected in sequence. In this embodiment, after one end of the first support rod 1222 and one end of the second support rod 1223 are connected, a combination rod 1224 is formed by continuing to extend towards the outflow end, and the combination rod 1224 is connected to the inner layer support 11 to form the connection point 13. In other embodiments, one end of the first support rod 1222 and one end of the second support rod 1223 are directly connected to the inner layer support 11 to form the connection point 13.

[0060] In this embodiment, the side wall of the first support part 121 where the second part 12110 is located protrudes outward to increase the overall rigidity of the first support part 121, especially at the middle part of the second part 12110 in the shape of D, if the heart tissue does not fit closely, it is easy to form a paravalvular leakage. In other embodiments, the side wall of the first support part 121 where the second part 12110 is located is arranged in parallel with the axis O of the support body 1.

[0061] Referring to Figure 8 , Figure 8 The schematic diagram shows part of the outer layer stent 12, wherein the preparation process of the outer layer stent 12 includes cutting the nickel-titanium tube to form a hollow tubular structure, and the axial length of each stent rod 1220 of the same unit structure 1221 is the same when the nickel-titanium tube is cut to form the hollow tubular structure. For example, the same unit structure 1221 includes a first stent rod 1222 and a second stent rod 1223, wherein the first stent rod 1222 is a curved rod and the second stent rod 1223 is a straight rod, and the axial length of the first stent rod 1222 and the second stent rod 1223 is H when the cutting is completed. In this way, the cutting operation can be facilitated, and at the same time, it can be ensured that each unit structure 1221 is axially arranged as a whole without being skewed, thereby facilitating subsequent processing.

[0062] When the cutting of the outer layer stent 12 is completed, the hollow tubular structure of the outer layer stent 12 needs to be unfolded and shaped. In combination with Figure 4 , Figure 5 and Figure 7 , in order to keep the first stent part 121 of the outer layer stent 12 upright and not skewed after unfolding, the first stent part 121 can be unfolded in the radial direction and shaped into a D-shaped type by a mold, and at this time, the plane C where the end of the first stent part 121 connected with the second stent part 122 is located is perpendicular to the axis O of the stent body. Further, in order to connect the outer layer stent 12 with the inner layer stent 11 after connection and connect with the connection point 13, the plurality of connection points 13 enclose a circle 101, the circle 101 has a circumference, and the plurality of connection points 13 divide the circumference 101 equally, and at this time, the length or position of the stent rod 1220 of the unit structure 1221 needs to be adjusted, wherein the straight rod can only adjust the position, and the curved rod can adjust the length and position. Therefore, in the present embodiment, the second stent part 122 of the outer layer stent 12 can better assist and ensure the upright and symmetrical shape of the first stent part 121 through its own adjustment, so that the first stent part 121 of the outer layer stent 12 can better fit the tissue and is not prone to paravalvular leakage.

[0063] Referring again to Figure 5 and Figure 6 , the inflow end A of the outer layer stent 12 is provided with an outwardly turned stent skirt 123, the stent skirt 123 is connected with the first stent part 121, the stent skirt 123 includes a circumferentially connected first stent skirt 1231 and a second stent skirt 1232, the first stent skirt 1231 is connected with the first part 12100, the second stent skirt 1232 is connected with the second part 12110, and the outward turning degree of the first stent skirt 1231 is greater than that of the second stent skirt 1232. Due to the anatomical structure of the target tissue position, the above outward turning arrangement better fits the target tissue, reduces the gap between the outer layer stent 12 and the target tissue, and thereby reduces the formation of thrombus.

[0064] In an embodiment, the skirt 123 comprises skirt connecting pieces 1233 and skirt extension pieces 1234 connected to each other, one end of the skirt connecting pieces 1233 is connected to the first stent part 121, and the other end of the skirt connecting pieces 1233 is connected to the skirt extension pieces 1234. The skirt extension pieces 1234 comprise elastic structures, which can be curved rod structures or other elastic structures, so as to better adapt to the structure of the tissue and have higher flexibility. Specifically, the skirt extension pieces 1234 have a V-shaped structure, and the skirt extension pieces 1234 are connected circumferentially.

[0065] In an embodiment, referring to Figure 5 and Figure 6 , the outer periphery of the first stent part 121 is provided with anchor structures 14, and the anchor structures 14 are arranged only on the first part 12100 corresponding to the first section 1210 of the first stent part 121. In this way, the first part 12100 corresponding to the first section 1210 of the first stent part 121 provided with the anchor structures 14 is prevented from facing the aortic valve, so as to prevent the anchor structures 14 from damaging the aortic valve during the beating of the heart, thereby improving the safety, and the anchor structures 14 arranged on the first part 12100 corresponding to the first section 1210 of the first stent part 121 can improve the fixation performance of the valve prosthesis.

[0066] The anchor structures 14 comprise a plurality of anchors 140, and the plurality of anchors 140 are arranged in one or more layers on the first part 12100, and the anchors 140 in each layer are arranged circumferentially.

[0067] In an embodiment, the anchors 140 arranged on the end portion and the vicinity of the end portion of the first part 12100 connected to the second part 12110 are end anchors 140a, the hardness of the end anchors 140a is less than that of the anchors 140 arranged on other positions of the first part 12100, or / and the number of the end anchors 140a is less than that of the anchors 140 arranged on other positions of the first part 12100. In this embodiment, when the valve prosthesis 100 is placed in the mitral valve in the body, the regions M and N of the end portion and the vicinity of the end portion of the first part 12100 connected to the second part 12110 are located at the anterior commissure of the mitral valve and the posterior commissure of the mitral valve, respectively. Figure 9, the valve prosthesis 100 is gradually squeezed by the delivery sheath 200, because the cross section of the delivery sheath 200 is circular and the first stent part 121 of the outer stent 12 is D-shaped, the stress on the outer periphery of the first stent part 121 of the outer stent 12 is uneven, and the regions M and N on the first stent part 121 of the outer stent 12 are the first to contact the delivery sheath 200, and the two regions are squeezed more than other regions as the delivery sheath 200 is gradually squeezed radially, and when the limit of the overall structure is reached, the outer stent 12 is unstable, the first stent part 121 of the outer stent 12 is folded inward, and the first stent part 121 of the outer stent 12 is squeezed inward after being folded to the valve leaflet 2, which can cause damage to the surface of the valve leaflet 2, and can cause calcification, perforation and rupture of the valve leaflet 2, and can reduce the service life of the artificial valve. Therefore, by reducing the number of anchor spikes in the regions M and N or reducing the hardness of the anchor spikes, the uneven stress on the first stent part 121 of the D-shaped outer stent 12 caused by the interaction between the first stent part 121 of the outer stent 12 and the circular cross section of the delivery sheath 200 can be effectively alleviated.

[0068] In another embodiment, referring to Figure 10 , the plurality of anchor spikes 140 are circumferentially distributed on the first stent part 121, and in the projection of the first stent part 121 on the cross section perpendicular to the axis direction, the radially outermost end of all the anchor spikes 140 is located on the outer periphery of the same circle P. Such arrangement is also to effectively alleviate the uneven stress on the first stent part 121 of the D-shaped outer stent 12 caused by the interaction between the first stent part 121 of the outer stent 12 and the circular cross section of the delivery sheath 200, and when the valve prosthesis 100 is received in the delivery sheath 200, the delivery sheath 200 is more uniformly squeezed radially on the first stent part 121 of the outer stent 12, thereby avoiding the inward folding of the first stent part 121 of the outer stent 12.

[0069] In an embodiment, referring again to Figure 5 , the first stent part 121 includes a plurality of mesh structures 1212, and adjacent two mesh structures 1212 have a node 1213, one end of the anchor spike 140 / 140a is arranged on the node 1213, and the other end of the anchor spike 140 / 140a is a free end extending toward the inflow end and opening outward.

[0070] In an embodiment, the anchor structure 14 is arranged at the end of the first stent portion 121 away from the stent skirt 123. It can be appreciated that the stent skirt 123 is configured to conform to the target tissue, and the anchor structure 14 is arranged at the end of the first stent portion 121 away from the stent skirt 123 to avoid the anchor structure 14 affecting the conformation of the stent skirt 123 to the target tissue, so as to avoid paravalvular leakage.

[0071] Referring again to Figure 1 and Figure 2 , the valve prosthesis 100 further comprises a covering 3, the covering 3 comprising an outer stent covering 31 arranged on the outer stent 12 and an inner stent covering 32 arranged on the inner stent 11, the outer stent covering 31 and the inner stent covering 32 being fixed at or near the outflow end B to form a seal between the outer stent covering 31 and the inner stent covering 32, so as to avoid paravalvular leakage.

[0072] In the present embodiment, referring to Figures 11 to 16 , the valve prosthesis 100 comprises a plurality of leaflets 2 connected circumferentially, adjacent leaflets 2 having a circumferentially spaced opening Q at a position near the inflow end A, the inner stent covering 32 comprises a plurality of inner stent covering units 320 connected circumferentially, adjacent inner stent covering units 320 having a circumferentially spaced opening W at a position near the inflow end A. Wherein, one end of one leaflet 2 near the inflow end A and one inner stent covering unit 320 are both fixed on the inner stent 11, so that the end of the inner stent covering unit 320 near the inflow end A coincides with the end of the leaflet 2 near the inflow end A or the end of the inner stent covering unit 320 near the inflow end A extends further to the inflow end A than the end of the leaflet 2 near the inflow end A, so that the area of W is less than or equal to the area of Q. It should be noted that the end of the leaflet 2 near the inflow end A herein refers to the boundary of the end of the leaflet 2 near the inflow end A (for example, the arc boundary 23 of the leaflet 2 in Figure 13 ), not an end point; the end of the inner stent covering unit 320 near the inflow end A also refers to the boundary of the end of the inner stent covering unit 320 near the inflow end A (for example, the arc boundary 321 of the inner stent covering unit 320 in Figure 15 ), not an end point. In this way, unnecessary covering at the inflow end A of the inner stent 11 can be removed, and the area of the covering at the inflow end of the inner stent 11 is minimized, so as to increase the blood passing space at the inflow end of the inner stent 11, increase the blood passing amount and the blood passing rate, prevent blood stasis, and avoid thrombosis; at the same time, the boundary of the end of the leaflet 2 near the inflow end A can be arranged within the boundary of the end of the inner stent covering unit 320 near the inflow end A, so as to avoid blood leakage and paravalvular leakage.

[0073] In an embodiment, the circumferentially spaced apart openings W are all inverted-triangle shaped openings, in which the length of one end close to the inflow end is longer than the length of one end close to the outflow end. The inverted-triangle shaped opening can be understood as a standard inverted triangle, or a simple deformation of the standard inverted triangle (e.g. the three sides of the inverted triangle are curved, zigzagged, etc.). The circumferentially spaced apart openings Q can also be inverted-triangle shaped openings.

[0074] In the present embodiment, referring to Figure 13 and 15 , one end of the leaflet 2 close to the inflow end A is provided with a first suture hole 21, and one end of the inner layer stent graft unit 320 close to the inflow end A is provided with a second suture hole 3201, and the leaflet 2, the inner layer stent graft unit 320 and the inner layer stent 11 are fixed by suturing through the first suture hole 21 and the second suture hole 3201. In other embodiments, the leaflet 2, the inner layer stent graft unit 320 and the inner layer stent 11 can also be fixed by gluing.

[0075] In the present embodiment, on the inner layer stent graft 32, windows 3202 are provided between adjacent inner layer stent graft units 320 for the leaflet horn 22 to pass through and be fixed with the inner layer stent graft unit 320 and the inner layer stent 11.

[0076] Referring to Figures 17 to 20 , in an embodiment, the outer layer stent graft 31 includes a first outer layer graft 311 and a second outer layer graft 312, the first outer layer graft 311 is at least partially disposed outside the outer layer stent 12, and the second outer layer graft 312 is at least partially disposed inside the outer layer stent 12. The second outer layer graft 311 is fixed with the inner layer stent graft 32 at the outflow end B or close to the outflow end B to form a seal between the second outer layer graft 311 and the inner layer stent graft 32.

[0077] The first outer layer graft 311 or / and the second outer layer graft 312 wraps the inflow end A of the outer layer stent 12 to avoid the inflow end A of the outer layer stent 12 being exposed and thus injuring the tissue. In an embodiment, after the second outer layer graft 312 covers the inner surface of the outer layer stent 12, it continues to extend outward after reaching the inflow end A of the outer layer stent 12, so that there is a gap between the inflow end A of the outer layer stent 12 and the end of the second outer layer graft 312 close to the inflow end, to provide a space for the outer layer stent 12 to be compressed or expanded, thereby avoiding the outer layer stent graft 31 being pierced.

[0078] In an embodiment, referring to Figure 17 , 18The second outer covering 312 has a body portion 3121 and an everted portion 3122, wherein the body portion 3121 is located in the outer stent 12, and the everted portion 3122 is everted outside the outer stent 12 around the inflow end A of the outer stent 12, and the first outer covering 311 at least partially covers the everted portion 3122. Similarly, in other embodiments, the first outer covering 311 can be provided with an inverted portion (not shown in the figure), which is inverted into the outer stent 12 around the inflow end A of the outer stent 12, and the second outer covering 312 at least partially covers the inverted portion.

[0079] In an embodiment, the end of the first outer covering 311 near the inflow end coincides with and is fixed to the end of the second outer covering 312 near the inflow end. This embodiment can be understood as that the first outer covering 311 or the second outer covering 312 is not provided with an everted or inverted portion.

[0080] In the present embodiment, the first outer covering 311 comprises a loose porous structure, has good ductility, is suitable for cell growth, and achieves a rapid endothelialization effect; the second outer covering 312 comprises a blood sealing material, which plays a role in isolating blood and preventing liquid leakage.

[0081] In an embodiment, the first outer covering 311 at least covers the stent skirt 123 of the outer stent 12, and the first outer covering 311 is separated from and does not coincide with the anchor structure 14, so as to reduce the outer diameter of the valve prosthesis 100 after radial compression, and facilitate the entry into a smaller sheath.

[0082] In the present embodiment, referring to Figure 11 and Figure 12 , the inner stent 11 has a mesh structure, which comprises a plurality of diamond-shaped meshes 110, the diamond-shaped meshes 110 are circumferentially connected to form a layer of meshes, and the plurality of diamond-shaped meshes 110 comprise multiple layers of meshes. The mesh structure has good supportability, can better support the valve leaflets 2, and makes the valve leaflets not easy to deform during operation, thereby avoiding paravalvular leakage and affecting the blood passing rate.

[0083] Again referring to Figure 1 and Figure 12In the embodiment, the valve prosthesis 100 further comprises a transition section 5, a connecting head 6 and a pull member 7. The transition section 5 is connected to the stent body 1 at one end and connected to the connecting head 6 at the other end, and the connecting head 6 is connected to the pull member 7. In the initial period after the valve prosthesis 100 is implanted, the pull member 7 is mainly connected to the apex tissue to fix the valve prosthesis 100. After a period of time, with the disappearance of the mitral regurgitation and the deformation of the left ventricle, the pull member 7 will be relaxed, and at this time the valve prosthesis 100 has been well endothelialized, and the fixation of the valve prosthesis 100 is mainly realized through the anchor structure 140. The anchor structure 140 ensures that the valve prosthesis 100 does not shift, and provides a good basis for complete endothelialization of the artificial valve. After that, the valve prosthesis 100 is completely endothelialized and basically will not fall off.

[0084] In the embodiment, one end of the transition section 5 is connected to the inner stent 11 of the stent body 1, so as to avoid the influence of the force of the pull member 7 on the outer stent 12, so as to avoid the deformation of the outer stent 12, and thus affect the fixation performance and sealing performance of the valve prosthesis 100 as a whole. The transition section 5 comprises a plurality of connection units 51 distributed in the circumferential direction, and the adjacent connection units 51 have a passage 52 capable of providing an operation space for a secondary surgery. The connection unit 51 itself can also have a space, and can also be capable of providing an operation space for a secondary surgery.

[0085] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A valve prosthesis, comprising a stent body and valve leaflets, the stent body including an outflow end and an inflow end, characterized in that, The main body of the support includes an inner support and an outer support that are connected to each other. The inner support is disposed inside the outer support, and the leaflets are disposed inside the inner support. The outer support includes a first support portion. The projection of the first support portion on a cross section perpendicular to the axis is D-shaped. The D-shape includes a first segment and a second segment that are circumferentially connected. The arc length of the first segment is greater than the arc length of the second segment. The portion of the first support portion corresponding to the first segment is a first part, and the portion of the first support portion corresponding to the second segment is a second part. An anchor structure is provided on the outer periphery of the first support portion. The anchor structure is only provided on the first part.

2. The valve prosthesis as described in claim 1, characterized in that, The anchor structure includes multiple anchors, with the anchors located at the end of the first part that connects to the second part and near that end. These anchors are end anchors. The hardness of the end anchor is less than the hardness of the anchors at other locations on the first part; Or / and, the number of the end anchors is less than the number of the anchors at other locations on the first site; Alternatively / and, a plurality of the anchors are circumferentially distributed on the first support portion, and in the projection of the first support portion along the axial direction, the radially outermost ends of all the anchors are located on the outer periphery of the same circle.

3. The valve prosthesis as described in claim 1, characterized in that, The first support portion includes multiple grid structures, with nodes between two adjacent grid structures. The anchor structure includes multiple anchors, with one end of each anchor disposed at the node and the other end of each anchor being a free end that extends toward the inflow end and opens outward.

4. The valve prosthesis as described in claim 1, characterized in that, The inflow end of the outer support is provided with an outwardly turned support skirt, which is connected to the first support portion. The anchor structure is provided at the end of the first support portion away from the support skirt.

5. The valve prosthesis as described in claim 1, characterized in that, The side wall of the first support portion where the second part is located protrudes outward, or the side wall of the first support portion where the second part is located is arranged parallel to the axial direction of the support body.

6. The valve prosthesis as described in claim 1, characterized in that, The outflow end includes multiple connection points. The outer support and the inner support are connected at or near the outflow end and then connected to the connection points. The multiple connection points form a circle with a circumference, and the multiple connection points equally divide the circumference.

7. The valve prosthesis as described in claim 1, characterized in that, The outer support includes a second support portion, the first support portion and the second support portion are axially connected, the first support portion is closer to the inflow end than the second support portion, the plane at the end where the first support portion and the second support portion are connected is perpendicular to the axis of the support body, and the second support portion is connected to the outflow end of the inner support.

8. The valve prosthesis as described in claim 1, characterized in that, The valve prosthesis further includes a covering, which includes an inner stent covering. The inner stent covering is at least partially disposed on the inner stent. Adjacent leaflets have circumferentially spaced openings Q near the inflow end. The inner stent covering includes a plurality of circumferentially connected inner stent covering units. Adjacent inner stent covering units have circumferentially spaced openings W near the inflow end. One end of a leaflet near the inflow end and one inner stent covering unit are both fixed to the inner stent, such that the end of the inner stent covering unit near the inflow end coincides with the end of the leaflet near the inflow end, or the end of the inner stent covering unit near the inflow end extends further towards the inflow end than the end of the leaflet near the inflow end. The area of ​​the circumferentially spaced openings W is less than or equal to the area of ​​the circumferentially spaced openings Q.

9. The valve prosthesis as described in claim 8, characterized in that, The circumferentially spaced opening W is an inverted triangular shape, and the length of the end of the opening closer to the inflow end is longer than the length of the end closer to the outflow end.

10. The valve prosthesis as described in claim 8, characterized in that, The coating also includes an outer support coating, which includes a first outer coating and a second outer coating. The first outer coating is at least partially disposed outside the outer support, and the second outer coating is at least partially disposed inside the outer support. The second outer coating and the inner support coating are fixed at or near the outlet end to form a seal between the second outer coating and the inner support coating.

11. The valve prosthesis as described in claim 10, characterized in that, The first outer film and / or the second outer film cover the end of the support body near the inflow end.

12. The valve prosthesis as described in claim 10, characterized in that, The inflow end of the outer support is provided with an outwardly turned support skirt, which is connected to the first support portion. The first outer film covers at least the support skirt and is separate from the anchor structure.

13. The valve prosthesis as described in claim 10, characterized in that, The first outer coating has a loose, porous structure, and the second outer coating has a blood-sealing material.

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