CN114176833A

CN114176833A - Artificial heart valve support and artificial heart valve

Info

Publication number: CN114176833A
Application number: CN202010971429.0A
Authority: CN
Inventors: 张庭超; 徐澧; 李阳
Original assignee: Hangzhou Valgen Medtech Co Ltd
Current assignee: Hangzhou Valgen Medtech Co Ltd
Priority date: 2020-09-15
Filing date: 2020-09-15
Publication date: 2022-03-15

Abstract

The invention relates to a heart valve prosthesis bracket and a heart valve prosthesis. The artificial heart valve support comprises an inner support and an outer support. The inner support comprises a first part and a second part from the inflow end to the outflow end in sequence along the axial direction, the radial dimension of the first part is larger than that of the second part, at least one part of the second part is nested in the outer support, at least one part of the first part extends towards the inflow end relative to the outer support, and the part of the first part extending towards the inflow end relative to the outer support covers the flow resistance membrane. The artificial heart valve comprises the artificial heart valve bracket and an artificial valve leaf fixedly connected in the inner bracket. The artificial heart valve support and the artificial heart valve can reduce the risk of paravalvular leakage while being stably positioned in the heart.

Description

Artificial heart valve support and artificial heart valve

Technical Field

The invention relates to the technical field of medical instruments, in particular to a prosthetic heart valve stent and a prosthetic heart valve.

Background

The mitral valve is a one-way "valve" between the Left Atrium (LA) and the Left Ventricle (LV), which ensures blood flow from the Left Atrium to the Left Ventricle. The mitral valve is a complex group of functional and anatomic structures, typically including the annulus, leaflets, chordae tendinae, and papillary muscles.

When the left ventricle is in a relaxed state, the mitral valve opens and blood flows from the left atrium to the left ventricle. When the left ventricle is in a contracted state, the two leaflets of a normal mitral valve can coapt or close tightly, thereby completely blocking the backflow of ventricular blood flow. To achieve this result, the mitral valve is required to have a proper annulus size, complete leaflet structure, support the leaflets by contraction of papillary muscles to pull chordae tendineae, proper closing force by contraction of left ventricular muscle, and normal shape and function of the left ventricle. Abnormalities in any of these factors can cause disease of the heart valve, leading to Mitral Regurgitation (MR).

For patients with severe heart valve disease, the only effective treatment modality is to replace the heart valve. In recent years, interventional artificial heart valve replacement is rapidly developed and applied to clinic, that is, the artificial heart valve is implanted into an in-situ mitral valve of a heart through a minimally invasive interventional operation to replace a damaged native valve, so that a satisfactory treatment effect is achieved.

For the replacement artificial heart valve, on one hand, the replacement artificial heart valve is required to be stably placed in the heart under the flushing of blood and keep the relative position of the replacement artificial heart valve and the valve ring; on the other hand, it is also required that the part of the heart chamber side is not affected by the annulus compression and keeps the fit with the annulus, thereby ensuring the sealing performance of the heart chamber side and reducing the risk of paravalvular leakage. Therefore, how to reduce the risk of paravalvular leakage while ensuring stable positioning of the artificial heart valve is a technical problem to be solved urgently in the field.

Disclosure of Invention

In order to solve the above technical problem or at least partially solve the above technical problem, the present application provides a prosthetic heart valve stent and a prosthetic heart valve.

In a first aspect, the present application provides a prosthetic heart valve stent comprising: an inner stent and an outer stent; the inner support comprises a first part and a second part from an inflow end to an outflow end in sequence along the axial direction, the radial dimension of the first part is larger than that of the second part, at least one part of the second part is nested in the outer support, at least one part of the first part extends towards the inflow end relative to the outer support, and the part of the first part extending towards the inflow end relative to the outer support covers the flow resistance membrane.

In a second aspect, the present application provides a prosthetic heart valve, comprising at least two pieces of prosthetic valve leaflets and the prosthetic heart valve stent; the artificial valve leaf is fixedly connected with the inner support in the inner support of the artificial heart valve support; the edges of the at least two artificial valve leaflets are butted against each other in the circumferential direction.

After the artificial heart valve support and the artificial heart valve are implanted into a heart, a part, extending out towards an inflow end, of the inner support relative to the outer support is tightly attached to an atrium side of an annulus, the artificial heart valve support can be prevented from moving towards the ventricle side due to the fact that the radial size of the part is large, the outer support radially supports the annulus and generates inward radial concave deformation under the extrusion of the annulus, a bulge part on the outer support is formed immediately on an outflow side of the concave deformation, the bulge part can prevent the artificial heart valve support from moving towards the atrium side, and therefore the inner support and the outer support are matched to stably position the artificial heart valve support and the artificial heart valve in the heart, the relative position of the artificial heart valve support and the annulus is kept, and the artificial heart valve support is prevented from falling off from the annulus; more importantly, because the part of the inner support extending out relative to the outer support towards the inflow end is tightly attached to the atrium side of the valve ring, the outer support is radially extruded and deformed by the valve ring and cannot affect the part of the inner support, so that a gap between the part of the inner support and the atrium side of the valve ring due to the deformation of the outer support is avoided, and meanwhile, the part is covered with the flow blocking film, so that the atrium and the ventricle can be effectively isolated, the sealing performance of the atrium side is ensured, and the perivalvular leakage risk is reduced.

Drawings

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

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

In the drawings:

FIG. 1 is a schematic front view of a prosthetic heart valve according to a first embodiment of the present invention;

fig. 2 is a schematic structural view of the inner stent (omitting the flow-blocking membrane) in fig. 1;

FIG. 3 is a schematic view of the inner stent of FIG. 1 covered with a flow-blocking membrane;

fig. 4 and 5 are front and perspective views illustrating the structure of the external bolster of fig. 1;

FIG. 6 is a schematic top view of an outer bolster of the second section having an O-shaped cross-section;

FIG. 7 is a schematic top view of an external bolster having a D-shaped cross section of a second section;

8a-8c are schematic structural views of different embodiments of a stop lever;

fig. 9 is a schematic structural view of an outer holder having a developing mechanism;

FIGS. 10a-10C are enlarged views of various embodiments of the structure of the area C1 in FIG. 9;

FIG. 11 is a schematic perspective view of a prosthetic heart valve according to a first embodiment of the present invention;

fig. 12 is a perspective view of the inner stent and the artificial leaflet of fig. 11;

FIG. 13 is a schematic view of a deformed configuration of the prosthetic heart valve of FIG. 11 when subjected to a radial force F;

FIG. 14 is a schematic view of the prosthetic heart valve of FIG. 11 after implantation into the heart;

FIG. 15 is an enlarged view of the area C2 in FIG. 14;

FIG. 16 is a schematic view of the prosthetic heart valve of FIG. 15 undergoing force and deformation;

FIG. 17 is a schematic structural view of a prosthetic heart valve according to a second embodiment of the present invention;

fig. 18 is a schematic structural view of the inner housing of fig. 17;

fig. 19 is a schematic structural view of the external bolster of fig. 17;

FIG. 20 is a schematic view of the prosthetic heart valve of FIG. 17 after implantation into the heart;

FIG. 21 is an enlarged view of the area C3 in FIG. 20;

FIG. 22 is a further enlarged schematic view of the prosthetic heart valve and valve annulus of FIG. 21;

fig. 23 is a schematic structural view of a prosthetic heart valve (with the flow blocking film and prosthetic leaflet omitted) according to a third embodiment of the present invention;

fig. 24 is a schematic structural view of the external bolster of fig. 23;

fig. 25 is a schematic structural view of a prosthetic heart valve (with the flow blocking film and prosthetic leaflet omitted) according to a fourth embodiment of the present invention;

fig. 26 is a schematic structural view of the external bolster of fig. 25;

FIG. 27 is a schematic view of the prosthetic heart valve of FIG. 25 after implantation in the annulus;

fig. 28 is a schematic structural view of a prosthetic heart valve (with the flow blocking film and prosthetic leaflet omitted) according to a fifth embodiment of the present invention;

fig. 29 is a schematic structural view of the external bolster of fig. 28;

fig. 30 is a schematic view of the prosthetic heart valve stent of fig. 28 after implantation in the annulus.

Detailed Description

For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, it is to be understood that the orientations and positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "longitudinal", "lateral", "vertical", "horizontal", "top", "bottom", "inner", "outer", "leading", "trailing", and the like are configured and operated in specific orientations based on the orientations and positional relationships shown in the drawings, and are only for convenience of describing the present invention, and do not indicate that the device or element referred to must have a specific orientation, and thus, are not to be construed as limiting the present invention.

It is also noted that, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," "disposed," and the like are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. When an element is referred to as being "on" or "under" another element, it can be "directly" or "indirectly" on the other element or intervening elements may also be present. The terms "first", "second", "third", etc. are only for convenience in describing the present technical solution, and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated, whereby the features defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of such features. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, it should be noted that, according to the blood flow direction in the ventricular diastolic state, the inflow end/side and the outflow end/side of the prosthetic heart valve holder and its components, the prosthetic heart valve and its components are defined, the inflow end/side is the end/side near the blood inflow side or the atrium side, and the outflow end/side is the end/side near the blood outflow side or the ventricular side. The axial direction refers to a direction parallel to a central connecting line of the outflow end and the inflow end, the radial direction refers to a direction perpendicular to the axial direction, and the circumferential direction refers to a direction surrounding the circumferential direction. In addition, the radial dimension appears in the text many times, and the radial dimension may be the maximum radial dimension or a radial dimension in a cross section passing through the central axis, and the method for obtaining the radial dimension is not limited, and it is only necessary to ensure that the radial dimension is obtained by the same method as a comparison object. It is to be understood that the above definitions are for convenience only and are not to be construed as limiting the present invention.

As shown in fig. 1 to 16, a prosthetic 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 frame 10 comprises a first portion (also referred to as an inner skirt) 101 and a second portion 102 in order from the inflow end to the outflow end (the arrow R is directed from the inflow end to the outflow end in the axial direction) in the axial direction (i.e. in the direction of the central axis AA), the radial dimension of the first portion 101 is larger than the radial dimension of the second portion 102, at least a part of the second portion 102 is nested in the outer frame 20, at least a part of the first portion 101 protrudes toward the inflow end with respect to the outer frame 20, and a part of the first portion 101 protruding toward the inflow end with respect to the outer frame 20 covers the flow blocking membrane 101 m.

It is noted that the prosthetic heart valve stent 1 of the present invention has a radially compressed delivery state and a radially expanded natural state. In a delivery state, the artificial heart valve stent 1 is radially compressed by external force, so that the artificial heart valve stent can be compressed and loaded into a sheath tube with a smaller radial size, and then is delivered to the heart through the delivery device. In the natural state, the artificial heart valve stent 1 is not affected by external force and is radially and naturally deployed, and the structural features of the artificial heart valve stent 1 in the natural state are described below as no special description exists.

Specifically, in a preferred embodiment of this embodiment, the radial dimension of the first portion 101 with respect to the outer holder 20 towards the inflow end extension (region H in fig. 1) is greater than the radial dimension at the inflow end face of the outer holder 20. Taking as its radial dimension the radial dimension of the first portion 101 at the inflow end of the inflow end extension H with respect to the outer holder 20, as d1 in fig. 2; taking the maximum radial dimension at the end face of the inflow end of the outer stent 20 as its radial dimension, as d0 in fig. 4, there is d1 > d 0. Of course, it is also possible to provide that the radial dimension of the first portion 101 is greater at any point in the axial direction relative to the outer holder 20 in the inflow end extension H than at the inflow end face of the outer holder 20.

Referring to fig. 1 and 14-16, the portion of the inner stent H where the first portion or inner skirt 101 extends towards the inflow end will abut against the native annulus M on the atrial side after the prosthetic heart valve stent 1 is implanted into the heart. By setting the radial dimension of the inner skirt 101 to be larger than the radial dimension at the end face of the inflow end of the outer stent 20, on one hand, the contact area of the inner skirt 101 with the autologous valve ring M in the atrium can be increased by the increased radial dimension, and the artificial heart valve stent 1 is prevented from moving towards the ventricular side; on the other hand, the increased radial dimension also enhances the sealing performance since the portion of the inner stent H that protrudes is not substantially affected by the radial compression of the outer stent 20 by the annulus and does not deform in response to the deformation of the outer stent 20.

In another preferred embodiment of this embodiment, the outflow end of the outer stent 20 is fixedly connected to the second portion 102, the inflow end of the outer stent 20 is freely suspended, and a radial gap is formed between the inflow end of the outer stent 20 and the portion near the inflow end of the outer stent 20 and the second portion 102. Further, the radial clearance L can be between 1 mm and 18 mm. It should be understood that the value of the radial gap is only used as an example and is not a limitation to the present invention, and one skilled in the art can select a suitable dimension according to actual requirements, and other dimensions selected under the teaching of the present invention are within the protection scope of the present invention.

When the outer stent 20 is radially contracted and deformed under the radial compression of the valve annulus, compared with the outflow end fixedly connected with the second part 102, the freely suspended inflow end is less limited, so that the self-deformation margin is larger, and the outer stent can effectively conform to the valve annulus to generate concave deformation; meanwhile, the inflow end of the outer bracket 20 and the vicinity thereof are spaced apart from the second portion 102 of the inner bracket 10 in the radial direction, providing a sufficient deformation space for the deformation of the inflow end of the outer bracket 20 and the vicinity thereof. The effective compliance deformation of the inflow end of the outer support 20 and the part near the inflow end under the radial compression of the valve ring can provide radial supporting force for the valve ring, and the fitting performance of the artificial heart valve support 1 and the valve ring is improved; more importantly, the outflow side of the concave deformation then forms a bulge G on the outer support 20, which bulge G prevents the prosthetic heart valve support 1 from moving towards the atrium side.

After the artificial heart valve support 1 of the present embodiment is implanted into the heart, referring to fig. 16, the first portion or inner skirt 101 of the inner support 10 extending from the outer support 20 toward the inflow end is tightly attached to the atrial side of the valve annulus M, and due to the larger radial dimension of the inner skirt 101, the artificial heart valve support 1 can be prevented from moving toward the ventricular side, the outer stent 20 radially supports the valve annulus M and undergoes a concave deformation radially inward under the compression of the valve annulus M, the outflow side of the concave deformation then forming a bulge G on the outer stent 20, the bulge portion G can prevent the artificial heart valve support 1 from moving towards the atrium side, so that the inner support 10 and the outer support 20 cooperate to stably position the artificial heart valve support 1 in the heart, the relative position of the artificial heart valve support 1 and the valve ring M is kept, and the artificial heart valve support 1 is prevented from falling off from the valve ring; and because the part of the inner support 10 extending out of the inflow end of the outer support 20, namely the inner skirt 101, is tightly attached to the atrium side of the valve ring M, the outer support 20 is radially extruded and deformed by the valve ring M and cannot affect the inner skirt 101 of the inner support 10, so that a gap between the inner skirt 101 and the atrium side of the valve ring M due to the deformation of the outer support 20 is avoided, and meanwhile, the inner skirt 101 is covered with the flow-blocking membrane 101M, so that the atrium and the ventricle can be effectively isolated, the sealing performance of the atrium side is ensured, and the risk of perivalvular leakage is reduced.

In a further preferred embodiment of this embodiment, the inflow end face of the outer holder 20 is axially spaced apart from the first portion 101. Further, the axial separation distance L1 may be between 0.5 and 10 mm. By setting the axial interval, the end of the inflow end of the outer stent 20 can be prevented from being wound around the struts of the first portion 101 of the inner stent 10, so that the artificial heart valve stent 1 can be smoothly and radially unfolded, and the end of the inflow end of the outer stent 20 which is freely suspended can be radially deformed without limitation; at the same time, the sharp part at the end of the inflow end of the outer stent 20 can be prevented from piercing the flow blocking film 101m covering the first portion 101 to prevent leakage.

In an implementation of the present embodiment, referring to fig. 3, the first portion 101 of the inner frame 10 includes a plurality of supporting bars 101a, and the plurality of supporting bars 101a are interconnected to form a plurality of unit patterns 101 b; the second portion 102 of the inner frame 10 includes a plurality of support bars 102a, and the plurality of support bars 102a are interconnected to enclose a plurality of unit patterns 102 b. Any unit pattern may be a diamond, a triangle, or other suitable patterns, the areas of the unit patterns 101b and 102b may be uniform or different, and suitable unit patterns and areas may be selected according to needs, which is not described herein again.

The first part 101 and the second part 102 of the inner stent 10 can be integrally formed; or can be separately prepared and then connected together, for example, by the connecting piece 103 to form an integral structure. In the preparation process, the support rod can be formed by cutting, the cutting mode can be linear cutting or laser cutting, preferably the laser cutting mode, for example, a nickel-titanium tube can be cut into a required shape by a laser cutting machine, and after the nickel-titanium tube is subjected to heat setting treatment, the nickel-titanium tube is formed into a compressed state and an expanded state, the nickel-titanium tube is kept in the compressed state in the conveying device, and the nickel-titanium tube is kept in the expanded state after being released in vivo. Of course, the support rods may also be woven from shape memory material, such as superelastic nitinol, and heat set to the desired shape.

The second portion 102 of the inner housing 10 is generally of a generally cylindrical configuration, and the second portion 102 is connected at an inflow end to the first portion 101 and may be terminated at an outflow end by a connection hole 104 for connection to the outer housing 20.

The first section 101 of the inner stent 10 includes a first flared section 1011 connected to the second section 102, the first flared section 1011 increasing in radial dimension from the connection with the second section 102 toward the inflow end. Further, referring to fig. 2, a radial expansion angle B of the first expansion 1011 is in a range of 45 ° to 90 °, where the radial expansion angle B refers to an opening angle of an outer contour tangent of the first expansion 100 with respect to a central axis AA of the inner stent 10. The first portion 101 may be a first expanded portion 1011 as a whole; the expansion joint also comprises a first expansion part 1011 and a second expansion part 1012 connected with the first expansion part 1011 along the axial direction, the radial dimension of the second expansion part 1012 is gradually increased from the connection part with the first expansion part 1011 to the inflow end, and the radial expansion angle B of the first expansion part 1011 relative to the axial direction is larger than the radial expansion angle B1 of the second expansion part 1012 relative to the axial direction, namely B is more than B1. By properly arranging the first and second expanded

portions

1011 and 1012, the adaptability of the first portion 101 to the valve annulus can be improved, so that the first portion can be more closely attached to the atrial side of the valve annulus, and the possibility of perivalvular leakage is reduced.

The second portion 102 is approximately cylindrical and has substantially the same radial dimensions throughout the axial direction; and the radial dimension of the first expanded portion 1011 of the first portion 101 gradually increases from the junction with the second portion 102 toward the inflow end, so that the radial dimension of the first portion 101 is larger everywhere in the axial direction than the radial dimension of the second portion 102. The radial dimension of the first part 101 may be taken as the radial dimension d1 of the inflow end of the first part 101 in a cross-section through the central axis AA, and the radial dimension d2 of the second part 102 in a cross-section through the central axis AA may be taken as the radial dimension of the second part 102; d1 is larger than d2, for example, d1 preferably has a size range of 40-70 mm, according to clinical application experience, in order to have more excellent performance of the artificial valve, d2 preferably has a size range of 25-30 mm, and the size values of d1 and d2 can be other values, which are not listed.

It should be noted that the first portion 101 may cover the flow blocking film 101m not only on the extending portion H toward the inflow end relative to the outer frame 20, but also on other portions, for example, the whole first portion 101 may be covered with the flow blocking film, and the material of the flow blocking film is preferably PET, PTFE, e-PTFE, etc.; the second part 102 can also be sewed with a flow resisting film, and the material of the flow resisting film is preferably PET, PTFE, e-PTFE and the like; that is, the first and

second portions

101 and 102 of the stent 10 each cover a flow-blocking membrane to further prevent paravalvular leakage. It should be understood that the flow blocking film covered on the second portion 102 may be the same as or different from the flow blocking film on the first portion 101, and is not limited herein.

In an implementation of this embodiment, referring to fig. 5, the external frame 20 includes a plurality of support bars 200a, and the plurality of support bars 200a are interconnected to form a plurality of unit patterns 200 b. The unit patterns 200b may be diamond-shaped, triangular-shaped, or other suitable patterns, the areas of the unit patterns 200b may be uniform or different, and suitable patterns and areas may be selected for the unit patterns 200b according to needs, which is not described herein again.

In the preparation process, the support rod 200a may be formed by cutting the shape memory material, the cutting method may be linear cutting, or laser cutting, preferably laser cutting, for example, a laser cutting machine may be used to cut the nickel-titanium tube into a desired shape, and after heat setting, the support rod is compressed and expanded, and is kept in the delivery device, and is released in vivo to keep the expanded state. Of course, the support rod 200a may be formed by weaving, for example, a superelastic nitinol wire may be woven and heat-set to a desired shape.

In the preferred embodiment, the inner stent 10 has a higher resistance to deformation than the outer stent 20, by which is meant the ability of the stent to deform against external stresses, the higher the resistance to deformation, the smaller the amplitude of the deformation and vice versa, under the same stresses. In other words, the higher the resistance to deformation, the lower the flexibility. By providing the outer stent 20 with a low deformation resistance, the ability of the outer stent to conform to the radial compression of the valve annulus to form a radially inward concave deformation at and near the inflow end of the outer stent 20 and a bulge G on the outer stent 20 at the outflow side of the concave deformation can be improved, thereby ensuring that the prosthetic heart valve stent 1 will not move toward the atrium side and fall off under the scouring of blood flow. The inner stent 10 needs to bear the pulling force of the inner artificial valve leaflet and can keep the first part or the inner skirt 101 thereof attached to the atrium side of the valve annulus, so that the inner stent 10 has high deformation resistance; under the condition that the outer support 20 is radially squeezed by the valve ring to deform, the inner support 10 cannot squeeze and deform the artificial valve leaflets, smooth operation of the valve is ensured, and the inner skirt edge 101 cannot generate a gap with the atrium side of the valve ring under the influence of deformation of the outer support 20, so that paravalvular leakage is reduced.

In order to achieve the higher deformation resistance of the inner stent 10 than the outer stent 20, it may be achieved by one or more of, for example, by setting the area of the unit pattern 200b of the outer stent 20 to be larger than the area of the unit pattern 102b of the inner stent 10; the cross-sectional area of the support bar 200a of the outer bracket 20 may be set smaller than the cross-sectional area of the support bar 102a of the inner bracket 10; it is also possible to form the support rods 102a of the inner stent 10 from a material having a relatively high hardness and to form the support rods 200a of the outer stent 20 from a material having a relatively low hardness. It should be understood that the above method is only used as an example and not a limitation of the present invention, and those skilled in the art can implement the deformation resistance of the inner stent 10 higher than that of the outer stent 20 by other suitable methods under the teaching of the present invention and fall within the protection scope of the present invention.

As shown in fig. 1, 4 and 5, the external frame 20 includes a first section 201 with a generally funnel shape and a second section 202 connected to the first section 201 from the outflow end to the inflow end along the axial direction; the mouth of the first section 201 is fixedly connected to the second portion 102, the open top of the first section 201 is connected to the outflow end of the second section 202, and the inflow end of the second section 202 is free to hang. The first section 201 and the second section 202 can be separately prepared and then connected together; it may be integrally formed, for example, the first segment 201 and the second segment 202 in this embodiment are integrally formed by laser cutting.

The second section 202 of the outer frame 20 may be approximately cylindrical in shape, and the radial cross-sectional shape thereof perpendicular to the axial direction is preferably O-shaped (see fig. 6) or D-shaped (see fig. 7). The outer bracket 20 is easy to manufacture by adopting the O-shaped radial section shape; by adopting the D-shaped radial section shape, the outer support 20 can be more in accordance with the actual physiological anatomical structure of the valve ring, so that the structural appearance of the outer support 20 is matched with the section shape of the valve ring space for accommodating the outer support, and the compression on the ventricular outflow tract is avoided. The radial dimension d0 of the second segment 202 in a cross-section through the central axis AA is close to the natural annulus dimension, preferably in the range of 30-60 mm.

The first section 201 is approximately funnel-shaped, with the smaller open end of the outflow end being the mouth and the larger open end of the inflow end being the top. The first section 201 gradually shrinks from the top opening to the mouth part, the shrinkage angle A is the opening angle of the outer contour tangent line on the same diameter of the mouth part, and the shrinkage angle A is in the range of 90-150 degrees. The mouth may be fixedly connected to the inner frame 10 by crimping, riveting, welding or stitching, for example, a connecting hole 204 may be provided in the mouth, the connecting hole 204 is aligned with the connecting hole 104 provided in the end of the outflow end of the inner frame 10, and a rivet is inserted through the connecting

holes

204 and 104 to fixedly connect the inner frame 10 and the outer frame 20.

Referring to fig. 9, the first segment 201 includes a plurality of support bars 201a, the plurality of support bars 201a being interconnected to define a plurality of unit patterns 201 b; the second segment 202 includes a plurality of support bars 202a, and the plurality of support bars 202a are interconnected to define a plurality of unit patterns 202 b. The unit patterns 201b and 202b may be diamond-shaped, triangular or other suitable patterns, the areas of the unit patterns may be uniform or different, and suitable patterns and areas may be selected for the unit patterns according to needs, which is not described herein again.

Preferably, the radial supporting force of the first section 201 is greater than that of the second section 202, where the radial supporting force refers to a reaction force generated after the stent is subjected to radial compression, and under the same radial compression condition, the larger the reaction force is, the smaller the stress deformation is, the larger the radial supporting force is, and vice versa. In the artificial heart valve stent 1 of the present embodiment, the first section 201 is connected to the inner stent 10, referring to fig. 15 and 16, under the action of the native valve leaflet, the first section 201 can provide a large radial supporting force, and the stress deformation becomes small, so that the inner stent 10 is not squeezed, and thus the artificial valve leaflet in the inner stent 10 is prevented from being squeezed; the radial supporting force of the second section 202 is small, and under the same radial extrusion condition, the radial supporting force is small, and the stress deformation is large, so that the fit valve ring can be more conformed, and the implantation stability is improved.

To achieve a greater radial support force for the first section 201 than for the second section 202, this can be achieved by one or more of the following methods: it is possible to set the area of the unit pattern 201b of the first segment 201 smaller than the area of the unit pattern 202b of the second segment 202; the width of the support bar 201a of the first section 201 may be set larger than the width of the support bar 202a of the second section 202; it is also possible to use a material with a greater hardness for the support rods 201a of the first section 201 and a material with a relatively lesser hardness for the support rods 202a of the second section 202. For example, if support bars with different widths are used, the width dimension of the support bars does not exceed 0.5mm at most, and the dimension is preferably set to 0.3mm, 0.4mm or 0.5 mm. It should be understood that the above manner is only used as an example and not a limitation to the present invention, and those skilled in the art can implement the radial supporting force of the first section 201 larger than the radial supporting force of the second section 202 in other suitable manners under the teaching of the present invention and fall within the protection scope of the present invention.

Referring to fig. 4 and the enlarged areas C shown in fig. 8a-8C, the external frame 20 further comprises at least one limiting rod 203; the stop rod 203 comprises a rod body 2031 connected to the mouth and a floating head 2032 connected to the rod body 2031 in the axial direction, the dimension of the head 2032 in the transverse direction, i.e., the direction LH shown in fig. 8a to 8c, is larger than the dimension of the rod body in the transverse direction, the transverse direction LH being perpendicular to the axial direction. Specifically, the stop rod 203 is generally T-shaped and conveniently placed in a stop slot of the delivery device to connect the prosthetic heart valve stent 1 to the delivery device, for example, referring to fig. 8a, the end may be circular; referring to fig. 8b, the tip may be square; referring to fig. 8c, the tip may be semicircular.

In order to judge the position of the artificial heart valve stent 1 when the artificial heart valve is implanted in the heart, a developing mechanism can be arranged on the outer stent 20 and/or the inner stent 10, and referring to fig. 9, the developing mechanism is arranged in the area C1 in fig. 9. For example, referring to fig. 10a, the developing mechanism may be a developing block fixed to the outer frame 20; referring to fig. 10b, there may be a developing winding wound around the outer frame 20; referring to fig. 10c, there may also be a developer ring surrounding the outer frame 20; or a combination of the above-described developing mechanisms. Similarly, a similar developing mechanism may be provided on the inner frame 10, and will not be described herein. The developing mechanism is made of a developing material, and a commonly used developing material such as tungsten, gold, platinum, tantalum, or the like can be used.

Referring to fig. 11 and 12 and fig. 1 to 5, a prosthetic heart valve 01 according to a first embodiment of the present invention includes a prosthetic leaflet 2 and a prosthetic heart valve stent 1 as described above, the prosthetic leaflet 2 being fixedly coupled to an inner stent 10 of the prosthetic heart valve stent 1 in the inner stent 10. The artificial leaflet 2 may be selected from two pieces, three pieces, or other suitable number, and the edges of any two adjacent artificial leaflets are butted against each other in the circumferential direction. The artificial leaflet 2 is preferably made of biological leaflet material, such as biological tissue material like bovine pericardium and porcine pericardium, and certainly, high molecular material such as ultra-high molecular weight polyethylene can be selected.

Referring to fig. 13-16, when the prosthetic heart valve 01 is implanted at the native annulus M in the heart, the outer stent 20 is compressed by a radial force F, and since the inflow end of the outer 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 each other, so that it is easily deformed by F; the first section 201 near the outflow end of the outer stent 20 is fixedly connected with the inner stent 10, and has strong radial supporting force, and the stress deformation is small under the action of F, so the inflow end of the second section 202 can be inwards sunken and deformed under the action of F, and the outflow end of the first section 201 continues to be in the original state. This deformation causes the outer frame portion near the junction of the first section 201 and the second section 202 or on the outflow side of the concave deformation to bulge outward, forming a bulge G, so that the outer frame 20 as a whole assumes a shape with small ends and large middle, and the bulge G on the outer frame 20 prevents the prosthetic heart valve support 1 from moving toward the atrium side.

As shown in fig. 15 and 16, when the prosthetic heart valve 01 is implanted into the heart, based on the tissue structure morphology, the valve ring M actually presses the prosthetic heart valve 01 from multiple directions and multiple angles, for example, a radial pressing force F2 presses the inflow end of the outer stent 20, which causes the inflow end of the outer stent 20 to be recessed inward, and the outward bulging portion of the outer stent 20 after deformation is subjected to a pressing force F3 of the valve ring M, so that the bulging portion G fits the valve ring M better. At the same time, at least a part of the first portion 101 of the inner stent 10 protrudes towards the inflow end relative to the outer stent 20, abuts against the atrial side of the valve annulus M in the atrium LA, is subject to the supporting force F1 provided by the valve annulus M, and is not affected by the radial deformation of the outer stent 20, so that the prosthetic heart valve 01 can be stably pressed or held in position against the valve annulus M. In addition, the stent portion of the first portion 101 protruding from the inflow end of the outer stent 20 is covered with a flow blocking film, which adheres to the atrial side of the valve annulus M along with the inner stent 10 to isolate the atrium LA from the ventricle LV without being affected by the radial deformation of the outer stent 20, thereby ensuring the sealing property of the atrial side and effectively preventing paravalvular leakage.

Referring to fig. 17-22, the prosthetic heart valve stent according to the second embodiment of the present invention is different from the first embodiment in that the outer stent 20 is covered with a flow-blocking membrane 20b, for example, the flow-blocking membrane 20b is sewn to the supporting rods 20a, so as to further enhance the sealing performance and avoid the occurrence of paravalvular leakage. The flow-blocking membrane 20b may be made of the same material as or different from the flow-blocking membrane on the inner stent.

Specifically, the flow-blocking membrane 101m covering the first portion 101 with respect to the portion of the outer stent 20 protruding toward the inflow end or the flow-blocking membrane covering the entire inner stent 10 may be sealed on the atrial LA side, and the flow-blocking membrane 20b of the outer stent 20 may be sealed on the ventricular LV side, so that the annulus atrial side and the annulus ventricular side both have flow-blocking membranes for sealing, which may further enhance the sealing effect of the artificial heart valve 01, thereby further reducing the occurrence of paravalvular leakage.

It should be understood that the provision of the flow-blocking film on the outer frame is not essential in the present invention, but an alternative arrangement is provided, and the prevention of paravalvular leakage can be effectively achieved by covering the flow-blocking film 101m on the portion of the first portion 101 that protrudes toward the inflow end with respect to the outer frame 20.

Referring to fig. 23 and 24, the prosthetic heart valve stent according to the third embodiment of the invention differs from the first embodiment in that the radial dimension of the second section 202 of the outer stent 20 decreases from the junction with the first section 201 towards the inflow end to further improve the ability of the outer stent 20 to conform to the annulus.

Specifically, the second section 202 is shaped to gradually converge toward the central axis AA toward the inflow end, but the freely suspended inflow end is still spaced apart from the inner frame 10 in the radial direction, and the radial tilt distance L 'is smaller than the gap L between the inner frame 10 and the middle of the outer frame 20, the radial tilt distance L' is the radial distance between the outflow end point of the second section 202 and the inflow end point, the outflow end point is connected to the first section 201, and the inflow end point is freely suspended. Compared with the first embodiment, when the outer stent 20 in this embodiment is squeezed by the valve annulus, the outer stent 20 can adapt to the shape and size of the valve annulus with only small deformation or even without deformation basically, so that the adaptability to the valve annulus is improved, and the position stability of the artificial heart valve after being implanted into the valve annulus is enhanced.

Referring to fig. 25-27, the prosthetic heart valve stent according to the fourth embodiment of the present invention differs from the first embodiment in that the second section 202 of the outer stent 20 has a circumferential recess 202d near the inflow end. This depression 202D is the area between the junction of the second section and the first section and the free, free inflow end of the second section in which the outer bolster is depressed towards the central axis, the area between lines D1 and D2 in fig. 27 representing depression 202D. The recess 202d may be formed by heat setting during the manufacturing process. When the outer stent 20 is pressed by the valve annulus, the concave part 202d is attached to the valve annulus in the natural shape, so that the adaptability of the artificial heart valve stent is enhanced, and the position stability of the artificial heart valve stent is improved.

Referring to fig. 28-30, the prosthetic heart valve stent according to the fifth embodiment of the present invention differs from the first embodiment in that the outer stent 20 further comprises at least one barb 207 provided on the second section 202 or/and near the inflow end of the first section 201, the barb 207 extending outwardly and simultaneously toward the inflow end. The barb 207 extends radially outward and expands toward the inflow end, and an angle between an extending direction AB and a central axis AA is defined as an expansion angle a, and the range of the expansion angle a is preferably 30 ° to 90 °. The barbs 207 may be one or more, and the plurality of barbs 207 may be randomly distributed, or may be distributed circumferentially along the outer cradle 20. For example, one or more layers of barbs 207 may be provided around the circumference of the outer stent 20, with the number of barbs 207 being at least 3. When the outer stent 20 is pressed by the valve annulus M, not only the outer stent 20 is radially deformed, but also the barbs 20 can penetrate the valve annulus tissue, thereby further improving the anchoring force of the outer stent 20.

It will be appreciated that the prosthetic heart valve of the present invention may be radially compressed and housed in a smaller diameter delivery device for delivery to the vicinity of the mitral valve and release to replace the diseased native annulus via transapical, transatrial, or transfemoral-intervalral routes. The delivery device comprises an outer sheath tube and an inner core penetrating the outer sheath tube, the inner core and the outer sheath tube can move relatively along the axial direction, and the artificial heart valve is accommodated in a gap between the distal end part of the inner core and the distal end part of the outer sheath tube after being radially compressed. The inner core is provided with at least one limiting clamping groove for matching with the limiting rod 203 on the artificial heart valve support 1, when the inner core and the outer sheath tube move relatively and the artificial heart valve is gradually released from the outer sheath tube, the limiting clamping groove can limit the instantaneous release of the artificial heart valve, so that an operator can observe through medical images, and the matching between the limiting clamping groove and the limiting rod 203 is released until the releasing position is reasonable, so that the artificial heart valve is completely released.

It will also be appreciated that the prosthetic heart valve of the present invention may also be surgically implanted directly into the heart to replace the diseased native mitral valve, and will not be described in detail herein.

Of course, the prosthetic heart valve of the present invention may also be implanted in the heart by various means to replace the diseased native tricuspid valve, and will not be described in detail herein.

It is to be understood that the foregoing examples, while indicating the preferred embodiments of the invention, are given by way of illustration and description, and are not to be construed as limiting the scope of the invention; it should be noted that, for those skilled in the art, the above technical features can be freely combined, and several changes and modifications can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention; therefore, all equivalent changes and modifications made within the scope of the claims of the present invention should be covered by the claims of the present invention.

Claims

1. A prosthetic heart valve stent, comprising: an inner stent and an outer stent; the inner support comprises a first part and a second part from an inflow end to an outflow end in sequence along the axial direction, the radial dimension of the first part is larger than that of the second part, at least one part of the second part is nested in the outer support, at least one part of the first part extends towards the inflow end relative to the outer support, and the part of the first part extending towards the inflow end relative to the outer support covers the flow resistance membrane.

2. The prosthetic heart valve stent of claim 1, wherein a radial dimension of the first portion relative to the outer stent at the portion protruding toward the inflow end is greater than a radial dimension at an end face of the inflow end of the outer stent.

3. The prosthetic heart valve stent of claim 1, wherein the outflow end of the outer stent is fixedly connected to the second portion, the inflow end of the outer stent is free-floating, and a radial gap is provided between the inflow end of the outer stent and a portion near the inflow end of the outer stent and the second portion.

4. The prosthetic heart valve stent of claim 3, wherein the radial gap is in a range of 1-18 mm.

5. The prosthetic heart valve stent of claim 1, wherein an end surface of the inflow end of the outer stent has an axial gap with the first portion.

6. The prosthetic heart valve stent of claim 1, wherein the inner stent has a higher resistance to deformation than the outer stent.

7. The prosthetic heart valve stent of claim 1, wherein the first portion comprises a first flare connected to the second portion, the first flare having a radial dimension that gradually increases from the connection with the second portion toward an inflow end.

8. The prosthetic heart valve stent of claim 7, wherein the radial deployment angle of the first deployed portion ranges from 45 ° -90 °.

9. The prosthetic heart valve stent of claim 7, wherein the first portion further comprises a second deployment section axially connected to the first deployment section; the radial size of the second expansion part is gradually increased from the connection part of the second expansion part and the first expansion part to the inflow end, and the radial expansion angle of the first expansion part relative to the axial direction is larger than that of the second expansion part relative to the axial direction.

10. The prosthetic heart valve stent of claim 1, wherein the outer stent comprises a generally funnel-shaped first section and a second section connected to the first section from an outflow end to an inflow end in an axial direction; the mouth part of the first section is fixedly connected with the second part, the top opening of the first section is connected with the outflow end of the second section, and the inflow end of the second section is freely suspended.

11. The prosthetic heart valve stent of claim 10,

the second section is approximately cylindrical; or

The radial dimension of the second section decreases from the junction with the first section towards the inflow end; or

The second section has a circumferential recess near the inflow end.

12. The prosthetic heart valve stent of claim 10, wherein the first segment has a contraction angle in a range of 90 ° -150 °.

13. The prosthetic heart valve stent of claim 10, wherein the outer stent further comprises at least one stop bar; the limiting rod comprises a rod body connected with the mouth part and a suspended end head connected with the rod body along the axial direction, and the transverse size of the end head is larger than that of the rod body.

14. The prosthetic heart valve stent of claim 10, wherein the outer stent further comprises at least one barb disposed on the second segment or/and near the inflow end of the first segment, the barb extending outwardly and toward the inflow end.

15. The prosthetic heart valve stent of any one of claims 1-14, further comprising a visualization mechanism disposed on the outer stent and/or on the inner stent.

16. The prosthetic heart valve stent of any of claims 1-14, wherein the first and second portions of the inner stent each cover a flow-blocking membrane.

17. The prosthetic heart valve stent of claim 16, wherein the outer stent covers a flow-blocking membrane.

18. The prosthetic heart valve stent of claim 10, wherein a cross-sectional shape of the second segment perpendicular to the axial direction is O-shaped or D-shaped.

19. A prosthetic heart valve comprising at least two pieces of prosthetic leaflets and the prosthetic heart valve stent of any one of claims 1-18; the artificial valve leaf is fixedly connected with the inner support in the inner support of the artificial heart valve support; the edges of the at least two artificial valve leaflets are butted against each other in the circumferential direction.

20. A prosthetic heart valve replacement system comprising the prosthetic heart valve of claim 19 and a delivery device for delivering the prosthetic heart valve, the prosthetic heart valve having a radially compressed delivery state and a radially expanded natural state, the delivery device comprising an outer sheath and an inner core disposed within the outer sheath, the inner core and the outer sheath being axially movable relative to each other, the prosthetic heart valve being radially compressed and received in a gap between a distal end portion of the inner core and a distal end portion of the outer sheath.