CN111110398A

CN111110398A - Split type heart valve support and prosthesis thereof

Info

Publication number: CN111110398A
Application number: CN201811279766.2A
Authority: CN
Inventors: 赵春霞; 石若璘; 阳明; 陈国明; 赵婧; 李�雨
Original assignee: Shanghai Microport Cardioflow Medtech Co Ltd
Current assignee: Shanghai Microport Cardioflow Medtech Co Ltd
Priority date: 2018-10-30
Filing date: 2018-10-30
Publication date: 2020-05-08

Abstract

The invention discloses a split type heart valve stent and a prosthesis thereof, wherein the split type heart valve stent comprises an outer layer stent and an inner layer stent; the outer layer support is provided with an outer layer inflow channel and an outer layer outflow channel which are axially connected, and an outer layer anchoring structure is arranged on the outer side of the outer layer outflow channel; the inner layer bracket is provided with an inner layer inflow channel and an inner layer outflow channel which are axially connected and is positioned at the inner side of the outer layer bracket in the radial direction; the outer-layer support and the inner-layer support are of split structures, and a first matching piece and a second matching piece are arranged on the outer-layer support and the inner-layer support respectively, so that the outer-layer support and the inner-layer support are operated step by step during loading and releasing. The split type heart valve prosthesis provided by the invention can avoid or reduce the phenomena of left ventricular outflow tract blockage and paravalvular leakage; the diameter of the valve leaf is small, and the fatigue resistance of the valve is good; the diameter of the catheter of the delivery system matched with the stent is smaller, so that the delivery difficulty and the risk of blood vessel injury are reduced.

Description

Split type heart valve support and prosthesis thereof

Technical Field

The invention relates to a heart valve stent and a prosthesis thereof, in particular to a split type heart valve stent and a prosthesis thereof used in transcatheter mitral valve or tricuspid valve replacement surgery.

Background

With the development of socioeconomic and the aging of population, the incidence rate of valvular heart disease is obviously increased, and researches show that the incidence rate of valvular heart disease of the old people over 75 years old is up to 13.3%. At present, the traditional surgical treatment is still the first treatment method for patients with severe valvular diseases, but for the patients with advanced age, complicated multiple organ diseases, chest-open operation history and poor cardiac function, the traditional surgical treatment has high risk and high death rate, and some patients even have no operation chance. Transcatheter mitral valve replacement/repair has the advantages of no need of thoracotomy, small trauma, quick recovery of patients and the like, and is widely concerned by experts and scholars.

The mitral valve, also known as the mitral valve, is located in the left ventricular inflow tract and has a primary structure of the mitral valve complex, including the mitral annulus, leaflets, chordae tendinae, and papillary muscles, and also includes ventricular walls in some literature. The mitral annulus is dense connective tissue around the ostium of the left atria ventricle, the anterior annulus of which is composed of a partially noncancerous annulus of the aortic valve located in the left ventricular outflow tract, a partially left coronary annulus, and left and right fibrous trigones, and the posterior annulus of which is the posterior leaflet attachment. The anterior mitral leaflet is a fibrous extension of the aortic valve and forms a left ventricular inflow tract with the posterior leaflet and a left ventricular outflow tract corresponding to the cardiac septum. The chordae tendineae of the mitral valve are distributed between the leaflets and the myocardium as a support device connecting the leaflets and the myocardium of the mitral valve, and the subvalvular structure of the mitral valve plays an important role in maintaining the structure and function of the left heart.

The tricuspid valve, which is the atrioventricular valve of the right heart, is similar in structure to the mitral valve, and also includes leaflets, annulus, chordae tendinae, papillary muscles, and myocardium. The heart valve prosthesis structure replacing the native mitral valve can therefore also be applied to replace the native tricuspid valve, with the prosthesis valve size varying according to the native valve size.

While the field of mitral valve replacement is rapidly evolving, there are several recognized challenges in the design of valve prostheses:

1. the native annulus of the mitral valve is larger in diameter compared to the aortic valve, and accordingly, the leaflet area of the prosthetic valve is also large. The larger the leaflet area, the worse the fatigue resistance performance of the valve prosthesis. Meanwhile, the valve leaflet has a large area, the size of the needed stent is correspondingly large, the diameter of a catheter for conveying the valve prosthesis is also large, and the conveying difficulty and the risk of blood vessel injury are increased.

2. The atrioventricular valve assembly structure is complicated, and if highly too high can influence primary heart structure and cardiac function under the prosthetic valve lamella, take place the chordae tendineae fracture, touch heart tissue such as papillary muscle unusual, easily cause left ventricle outflow tract to block simultaneously, induce bad postoperative influence.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a split type heart valve stent and a prosthesis thereof, which can reduce the height under the valve of a prosthetic valve, avoid or reduce the blockage of a left ventricular outflow tract, avoid the leakage phenomenon around the valve, improve the fatigue resistance of the valve, and reduce the conveying difficulty and the risk of blood vessel damage.

The technical scheme adopted by the invention for solving the technical problems is to provide a split type heart valve stent, which comprises an outer-layer stent and an inner-layer stent; the outer layer support is provided with an outer layer inflow channel and an outer layer outflow channel which are axially connected, and an outer layer anchoring structure is arranged on the outer side of the outer layer outflow channel; the inner-layer support is provided with an inner-layer inflow channel and an inner-layer outflow channel which are axially connected and is positioned on the inner side of the outer-layer support in the radial direction, the outer-layer support and the inner-layer support are of split structures, and a first fitting piece and a second fitting piece are respectively arranged on the outer-layer support and the inner-layer support, so that the outer-layer support and the inner-layer support can be operated step by step during loading and releasing.

Further, the first fitting piece is arranged at the tail end of the outer layer inflow channel or/and the outer layer outflow channel, the second fitting piece is arranged at the tail end of the inner layer inflow channel or/and the inner layer outflow channel, and the first fitting piece and the second fitting piece are hangers.

Further, the inner stent has an inner diameter in the expanded state that is greater than the smallest inner diameter of the outer outflow tract in the expanded state.

Further, the rigidity of the inner layer support is greater than that of the outer layer support.

Further, the outer layer stent or/and the inner layer stent is composed of at least one row of grid-like structural units connected with each other in the circumferential direction in the axial direction.

Further, the outer layer inflow channel is horn-shaped and extends in the direction away from the inner layer support.

Further, the main body of the outer outflow tract is cylindrical, conical, elliptic cylindrical or a cylinder with a D-shaped cross section.

Further, outer layer anchor structure distributes two at least along the circumferencial direction of outer outflow tract, the one end of outer layer anchor structure is the stiff end, and the other end is the free end.

Further, the outer layer anchoring structure is a cantilever structure.

Furthermore, the cantilever structure is a rod-shaped structure, the fixed end of each rod-shaped structure is fixedly connected to the outer side of the outer-layer outflow channel, and the free end of each rod-shaped structure is spherical or ellipsoidal.

Further, the cantilever structure is provided with barbs on the side facing the outer layer bracket or is provided with saw-toothed shapes.

Further, the inner outflow tract and the inner inflow tract have the same inner diameter in the expanded state.

The present invention provides a split-type heart valve prosthesis, which comprises the split-type heart valve stent and valve leaflets, wherein the valve leaflets are arranged on the inner side of the inner-layer stent.

Further, the split heart valve prosthesis further comprises a skirt, and the skirt is arranged on the inner surface or/and the outer surface of the outer layer support or/and the inner layer support.

Compared with the prior art, the invention has the following beneficial effects: 1. the heart valve stent and the prosthesis provided by the invention have double-layer structures, wherein the outer layer stent is a large stent, and the inner layer stent is a small stent. The outer layer big bracket plays the role of fixing and supporting and is placed at the native valve ring; the valve with valve leaf is sewed on the inner layer small support to replace the native valve leaf. Because the size of the inner layer support is small, the diameter size of the valve leaflet can be reduced by the design of the double-layer support, and the fatigue resistance of the valve can be obviously improved. The double-layer support can effectively reduce the height of the implanted prosthetic valve under the native valve annulus, and reduce the risk of obstruction of the left ventricular outflow tract. 2. Because outer support and inlayer support are split type structure, in actual operation, outer support and inlayer support can load and release step by step, compare in traditional individual layer support, load required sheath pipe diameter less, have reduced the risk of the support transport degree of difficulty and vascular damage. 3. The rigidity of the outer layer bracket is low, particularly the part of the outer layer inflow channel of the outer layer bracket is well jointed with the atrioventricular orifice, so that paravalvular leakage can be effectively prevented; the rigidity of the inner layer support is high, the radial supporting force is good, and the normal work of the valve leaflet can be guaranteed. 4. The outer-layer support is provided with an outer-layer anchoring device, the native valve leaflet is located between the outer-layer support main body and the outer-layer anchoring structure in the expansion state, and the support is prevented from shifting under the impact of blood when the heart contracts. 5. The inner layer outflow channel of the inner layer support is matched with the outer layer outflow channel of the outer layer support in shape, the inner layer support is designed to be Oversize, the outer layer support and the inner layer support are fixed through friction force, and the inner layer support can be prevented from shifting under the left ventricle pressure.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a heart valve prosthesis according to an embodiment of the present invention;

FIG. 2 is a schematic illustration of a heart valve prosthesis in an embodiment of the invention in position in a heart;

FIG. 3 is a schematic structural view of an outer layer stent in an embodiment of the present invention;

fig. 4 is a schematic structural diagram of an inner-layer valve stent assembly in an embodiment of the invention.

In the figure:

1 heart valve prosthesis 11 outer layer stent 12 inner layer valve stent combination

13 skirt 111 outer layer inflow channel 112 outer layer outflow channel

113 outer anchor structure 113A fixed end 113B free end

114 outer layer hangers 121 inner layer inflow channel 122 inner layer outflow channel

123 suture rod for inner layer hangers 125 of valve 124

126 inner stent 111A outer inflow channel proximal end 111B outer inflow channel distal end

112A outer outflow tract proximal end 112B outer outflow tract distal end 121A inner outflow tract proximal end

121B distal end of inner layer inflow channel 122A proximal end of inner layer outflow channel 122B distal end of inner layer outflow channel

2 heart

Detailed Description

The invention is further described below with reference to the figures and examples.

To more clearly describe the structural features of the present invention, the terms "proximal" and "distal" are used as terms of orientation, wherein "proximal" refers to the end that is closer to the operator during the procedure; "distal" means the end away from the operator. The term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

FIG. 1 is a schematic diagram of the overall structure of a heart valve prosthesis according to an embodiment of the present invention; fig. 2 is a schematic view of the position of a heart valve prosthesis 1 in a heart 2 according to an embodiment of the invention.

Referring to fig. 1 and 2, the heart valve prosthesis 1 provided in the present embodiment includes an outer stent 11, an inner valve stent assembly 12, and a skirt 13. The inner-layer valve support assembly 12 comprises an inner-layer support 126 and a valve 123 fixed on the inner surface of the inner-layer support 126, the inner-layer support 126 is radially positioned on the inner side of the outer-layer support 11, and the inner-layer support 126 is strong in rigidity and can bear the blood acting force of the valvular prosthesis 1 in the movement process of valve leaflets; the outer layer stent 11 has weaker rigidity relative to the inner layer stent 126, is well attached to native tissues, and mainly realizes the perivalvular leakage prevention function of the valvular prosthesis 1. The outer layer stent 11 and the inner layer valve stent assembly 12 have two forms of a pressing state and an expansion state. In the present invention, unless otherwise specified, all features of the stent in the expanded state are described.

FIG. 3 is a schematic structural diagram of an outer layer stent in an embodiment of the invention.

As shown in FIG. 3, the outer stent 11 includes an outer inflow channel 111, an outer outflow channel 112, an outer anchoring structure 113, and an outer suspension loop 114. According to the direction of blood flow, the outer layer outflow channel 112 is located at the downstream of the outer layer inflow channel 111, the outer layer inflow channel 111 corresponds to the part of blood flowing into the prosthesis during valve operation, the outer layer outflow channel 112 corresponds to the part of blood flowing into the prosthesis during valve operation, the outer side of the outer layer outflow channel 112 is provided with an outer layer anchoring structure 113, and the outer layer hanging lug 114 is located at the tail end of the outer layer inflow channel 111 or/and the outer layer outflow channel 112, except the tail end of the outer layer outflow channel occupied by the outer layer anchoring structure 113.

The outer layer support 11 is composed of structural units with changeable axial forms, such as grid structural units or wave structural units, and the like, and is composed of at least one row of structural units which are mutually connected in the circumferential direction in the axial direction, and a plurality of rows of units in the axial direction can be mutually and directly connected or indirectly connected. Preferably, the grid-shaped structural units can be rhombic, pentagonal, hexagonal and the like, which can form a closed-shaped structural unit.

The outer stent 11 has two forms, a crimped state in which the axial dimension of the structural unit is increased and the circumferential diameter is decreased, and an expanded state in which the axial dimension of the structural unit is decreased and the circumferential diameter is increased.

The outer layer inflow channel 111 extends in a trumpet shape to a side away from the inner layer support 126, covering the atrioventricular orifice. The distal end 111B of the outer layer inflow channel 111 has a diameter greater than the native valve diameter, and preferably the proximal end 111A of the outer layer inflow channel in the expanded state has a diameter of 35-75 mm.

In one embodiment, the outer outflow tract 112 has a cylindrical or conical body that effectively conforms to the native leaflets without circumferential alignment. In another embodiment, the outer outflow tract 112 has a D-shaped cross-section or an elliptical cross-section, more conforming to the native valve configuration.

An outer layer anchoring structure 113 is disposed about the outer layer outflow channel 112 and has a fixed end 113A and a free end 113B. The fixed end 113A can be fixed at any position outside the outer outflow tract 112. Preferably, the fixed end 113A is fixed to the outer outflow tract distal end 112B. The outer-layer anchoring structures 113 are distributed at least two times along the circumference of the outer-layer outflow tract 112, and respectively anchor the outer-layer stent 11 and two valve leaflets of the native valve. In the expanded state of the valvular prosthesis stent, the native valve leaflets of the valve are clamped between the outer layer anchoring structure 113 and the outer layer stent 11, and the valvular prosthesis 1 is prevented from obviously displacing towards the stent outflow tract by blood pressure. The outer anchoring structure 113 and the outer outflow channel 112 may be integrally formed, or they may be connected by riveting, welding, or fastening.

Preferably, the outer layer anchoring structure 113 is a cantilever structure. In one embodiment, the cantilever structures are rod-like structures, each of which has a fixed end fixedly connected to the outer side of the outer outflow channel 112 and a free end 113B with a shape without sharp corners, such as a sphere or an ellipsoid. Preferably, the cantilever structure is barbed towards the side of the outer stent 11, the barbs penetrating the leaflets in the expanded state, further increasing the anchoring force. In another embodiment, the side of the cantilever structure where the cantilever structure is attached to the native valve leaflet, i.e. the side of the cantilever structure facing the outer stent 11, is zigzag, so as to increase the friction between the cantilever structure and the valve leaflet and improve the anchoring stability.

The outer support 11 and the inner support 126 are of a split structure, and the outer support 11 and the inner support 126 are respectively provided with a matching piece matched with a conveying system of the conveying support, so that the outer support 11 and the inner support 126 are operated step by step when being loaded and released. Preferably, the outer support 11 and the inner support 126 are respectively provided with a first fitting piece and a second fitting piece, the first fitting piece is arranged at the tail end of the outer inflow channel 111 or/and the outer outflow channel 112, the second fitting piece is arranged at the tail end of the inner inflow channel 121 or/and the inner outflow channel 122, the first fitting piece and the second fitting piece are hangers, the outer hangers 114 are arranged on the outer support 11, and the inner hangers 124 are arranged on the inner support 126.

The outer hanging lug 114 is used for matching the outer stent 11 with a conveying system for conveying the outer stent 11, and the outer hanging lug 114 is connected with the conveying system to ensure that the outer stent 11 is loaded into the conveying system, released and separated from the conveying system, and the relative position of the outer stent 11 and the conveying system is unchanged during in-vivo conveying in the conveying system. The outer lugs 114 are the structures of the outer stent 11 that eventually break away from the delivery system so that the outer lugs 114 are located at the distal ends of the outer inflow channel 111 or/and the outer outflow channel 112 (except for the distal end of the outflow channel occupied by the outer anchoring structure 113). Specifically, according to the difference between the implantation mode of the outer stent 11 and the function of the delivery system, the outer hangers 114 can be distributed at the tail end of the outer outflow channel 111, and the outer outflow channel 112 is released first in the release process; the outer layer hangers 114 are distributed at the tail end of the outer layer outflow channel 112, and the outer layer inflow channel 111 is released firstly in the releasing process; the outer layer hangers 114 are distributed at the tail end of the outer layer outflow channel 112 and the tail end of the outer layer inflow channel 111, the release process is bidirectional release, and the outer layer hangers 114 on one side can be released firstly or the outer layer hangers 114 on two sides can be released simultaneously finally.

The material of the outer stent 11 is nickel titanium or other biocompatible material with shape memory properties. The stent can be manufactured by adopting silk weaving, or cutting process, or the silk weaving, the cutting process, or the cutting process and the heat treatment, sand blasting, polishing and other processes, and also can be manufactured by adopting other processes for manufacturing the stent, such as 3D printing and the like. In one embodiment, the filament weaving process may employ one or more filaments for weaving. In another embodiment, the outer stent 11 is manufactured by a combination of cutting and braiding processes. For example, the outer-layer inflow conduit 111 is formed using a braided wire, while the outer-layer outflow conduit 112 and the outer-layer anchoring structure 113 are formed using a cutting process. The outer flow inlet 111 is directly or indirectly connected to the outer flow outlet 112, and the outer anchoring structure 113 is also directly or indirectly connected to the outer flow outlet 112. Direct connection means that the structural units at different positions have intersection points, and the intersection points are formed by welding or integrally forming. The indirect connection is that the structural unit of the outer layer inflow channel 111 and the structural unit of the outer layer outflow channel 112 have no intersection point, for example, a third-party component such as a rivet is used for connection.

Referring to fig. 1 and 4, the inner-layer valve stent assembly 12 includes an inner-layer stent 126, a valve 123, an inner-layer suspension loop 124 and a suture rod 125. The inner stent 126 comprises an inner inflow channel 121 and an inner outflow channel 122, the inner inflow channel 121 and the inner outflow channel 122 are according to the direction of blood flow, the inner outflow channel 122 is located downstream of the inner inflow channel 121, i.e. the inner inflow channel 121 corresponds to the portion of the inner stent of the prosthesis from which blood flows in the valve operation, and the inner outflow channel 122 corresponds to the portion of the inner stent of the prosthesis from which blood flows out in the valve operation; the inner layer lugs 124 are located at the distal end of the inner layer inflow channel 121 and/or the inner layer outflow channel 122, i.e., the inner layer lugs 124 are located at the inner layer inflow channel proximal end 121A and/or the inner layer outflow channel distal end 122B.

The inner stent 126 is tubular, has significant radial and axial stiffness, and can withstand leaflet pull. The inner layer support 126 is composed of structural units such as a lattice structural unit or a wave structural unit, which can be changed in axial form. The axial direction of the structure unit is composed of at least one row of structure units which are mutually connected in the circumferential direction, and the units in the axial direction can be directly connected or indirectly connected with each other. The inner stent 126 is made of biocompatible materials with shape memory characteristics, such as nickel titanium, or biocompatible materials, such as cobalt-chromium alloy and stainless steel, by cutting, heat treatment, sand blasting, polishing or other processes capable of processing stents. When the inner stent 126 is made of nickel titanium material, the fatigue performance of the valve leaflet can be ensured by enhancing the rigidity of the inner stent 126 in a mode of increasing the wall thickness, the rod width, adjusting the phase transition temperature point and the like. The balloon is expanded to a designated shape to play a role in the process of being implanted into a human body.

The inner fluid inlet channel 121 is cylindrical with an outside diameter no greater than the diameter of the native valve it replaces, and the inner fluid outlet channel 122 is cylindrical with the same diameter as the inner fluid inlet channel 121. Preferably, the tubular diameter of the inner stent 126 in the expanded state is 20-35mm, which is larger than the smallest tubular diameter of the outer outflow tract 112 in the expanded state (oversize design). In another embodiment, the inner outflow channel 122 has a tubular structure, the portion of the inner outflow channel 122 connected to the inner inflow channel 121 has the same size, and optionally, the portion of the inner outflow channel 122 radially away from the inner inflow channel 121 has a trumpet shape. The inner outflow tract 122 is provided with a suture rod 125 for connecting the valve leaflets, and the inner stent 126 is stably connected with the valve 123 on the inner side. Optionally, the suture shaft 125 is provided with suture holes for suturing the valve leaflets. The valve 123 comprises at least two valve leaflets, the valve leaflets are made of animal pericardium or other biocompatible polymer materials, one ends of the valve leaflets are directly or indirectly stably connected with the inner-layer support 126, and the other ends of the valve leaflets are free ends. The leaflets of valve 123 are attached to the inner outflow tract 122, and in the operating state, the prosthetic leaflets function to open and close the blood passage in place of the native leaflets.

The inner-layer hanging lugs 124 are used for matching the inner-layer valve support assembly 12 with a conveying system for conveying the inner-layer valve support assembly 12, and the inner-layer hanging lugs 124 are connected with the conveying system to ensure that the inner-layer valve support assembly 12 is loaded into the conveying system, released to be separated from the conveying system and the relative position of the inner-layer valve support assembly 12 and the conveying system is unchanged during in-vivo conveying in the conveying system. Like the outer layer hanger 114 described above, the inner layer hanger 124 is the structure of the inner layer stent 126 that is eventually released from the delivery system, so that the inner layer hanger 124 is positioned at the distal end of the inner layer inflow channel 121 or/and the inner layer outflow channel 122, i.e., the inner layer hanger 124 is positioned at the proximal end 121A of the inner layer inflow channel or/and the distal end 122B of the inner layer outflow channel. Specifically, the inner hangers 124 may be distributed at the end of the inner outflow tract 121 according to the different implantation methods and functions of the delivery system of the inner stent 126, and the inner outflow tract 122 is released first in the releasing process; the inner layer hangers 124 are distributed at the tail end of the inner layer outflow channel 122, and the inner layer inflow channel 121 is released firstly in the releasing process; the inner layer hangers 124 are distributed at the tail end of the inner layer outflow channel 122 and the tail end of the inner layer inflow channel 121, the release process is bidirectional release, and the inner layer hangers 124 on one side can be released firstly or the inner layer hangers 124 on two sides can be released simultaneously finally.

In use, the outer stent 11 and the inner valve stent assembly 12 are loaded into the same delivery system. Wherein, the outer layer stent 11 and the inner layer valve stent assembly 12 are assembled in the conveying system along the axial direction without overlapping each other, so that the loaded sheath tube has a smaller diameter, which is beneficial to the approach of blood vessels and avoids tissue damage. The delivery system accesses the outer stent 11 and the inner valve stent assembly 12 to the left atrium, the outer stent 11 is released to complete the valve leaflet grabbing and self-anchoring, and the inner valve stent assembly 12 is released after the valve leaflet grabbing and self-anchoring. Alternatively, the delivery system delivers the outer stent 11 into the body and then releases the outer anchoring structure 113 to hook the valve leaflets for anchoring, and then delivers the inner valvular-stent combination 12 to the position where the inner outflow tract 122 matches the outer outflow tract 112. Optionally, the inner stent 126 is of an Oversize design, and the inner valve-stent assembly 12 is frictionally secured to the outer stent 11 to prevent displacement of the inner valve-stent assembly 12 under left ventricular pressure. Alternatively, the inner-layer valve stent assembly 12 and the outer-layer stent 11 may be fixedly connected by other connection means such as a snap fit.

The skirt 13 is a thin film attached to the inner or outer surface of the stent and having the function of preventing the leakage around the valve, and can be made of high polymer material PET (polyethylene terephthalate), PTFE (polytetrafluoroethylene), or biological tissue material. The outer layer bracket 11 and the inner layer bracket 126 are both provided with skirt edges 13, and can be single-layer or double-layer. The double-layer skirt edge means that the skirt edges 13 are sewn on the inner layer and the outer layer of the stent, and the single-layer skirt edge means that the skirt edges 13 are sewn on the inner layer of the stent. Preferably, for the inner stent 126, an inner skirt is provided which is secured to the inside of the inner inflow channel 121 and is fixedly attached to the leaflets. Preferably, for the outer stent 11, a skirt 13 is provided between the flanges from the annulus to the outer inflow channel.

The tricuspid valve, which is the atrioventricular valve of the right heart, is similar in structure to the mitral valve, and also includes leaflets, annulus, chordae tendinae, papillary muscles, and myocardium. The method for replacing the native mitral valve can also be applied to replace the native tricuspid valve, which differs in size, with the prosthetic valve for interventional replacement differing in size.

In summary, the heart valve prosthesis provided by the invention has the following advantages:

1. has a double-layer structure, the outer layer bracket 11 is a large bracket, and the inner layer bracket 126 is a small bracket. The outer layer big bracket plays the role of fixing and supporting and is placed at the native valve ring; the small inner layer rack is sewed with valve leaf to replace original valve leaf. The design of the bi-layer stent allows for a reduction in the diameter size of the leaflets, and the fatigue resistance of the valve 123 is significantly improved due to the small size of the inner layer stent 126. The double-layer support can effectively reduce the height of the implanted prosthetic valve under the native valve annulus, and reduce the risk of obstruction of the left ventricular outflow tract.

2. In actual operation, because inlayer support and outer support set up the hangers respectively, double-deck support can load and release step by step, compares in traditional individual layer support, and it is less to load required sheath pipe diameter, has reduced the risk of carrying the degree of difficulty and vascular damage.

3. The rigidity of the outer layer bracket 11 is low, particularly the part of the outer layer inflow channel 111 of the outer layer bracket 11 is well jointed with the atrioventricular orifice, so that paravalvular leakage can be effectively prevented; the inner layer support 126 has higher rigidity and better radial supporting force, and can ensure the normal work of the valve leaflet.

4. The outer stent 11 has an outer anchoring structure 113, and the native valve leaflets are located between the main body of the outer stent 11 and the outer anchoring structure 113 in the expanded state to prevent the stent from shifting under the impact of blood during systole.

5. The inner outflow channel 122 of the inner stent 126 matches the outer outflow channel 112 of the outer stent 11, the inner stent 126 has an Oversize design, and the inner stent 126 and the outer stent 11 are fixed by friction to prevent the inner stent 126 from being displaced under left ventricular pressure.

Although the present invention has been described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A split type heart valve support is characterized by comprising an outer support and an inner support;

the outer layer support is provided with an outer layer inflow channel and an outer layer outflow channel which are axially connected, and an outer layer anchoring structure is arranged on the outer side of the outer layer outflow channel;

the inner layer bracket is provided with an inner layer inflow channel and an inner layer outflow channel which are axially connected and is positioned at the inner side of the outer layer bracket in the radial direction,

the outer-layer support and the inner-layer support are of split structures, and a first matching piece and a second matching piece are arranged on the outer-layer support and the inner-layer support respectively, so that the outer-layer support and the inner-layer support are operated step by step during loading and releasing.

2. The split-type heart valve stent of claim 1, wherein the first fitting piece is arranged at the end of the outer layer inflow channel or/and the outer layer outflow channel, the second fitting piece is arranged at the end of the inner layer inflow channel or/and the inner layer outflow channel, and the first fitting piece and the second fitting piece are lugs.

3. The split-heart valve stent of claim 1, wherein the inner diameter of the inner stent in the expanded state is greater than the smallest inner diameter of the outer outflow tract in the expanded state.

4. The split-type heart valve stent of claim 1, wherein the stiffness of the inner stent is greater than the stiffness of the outer stent.

5. The split-type heart valve stent of claim 1, wherein the outer stent or/and the inner stent is/are composed of at least one row of grid-like structural units connected to each other in the circumferential direction in the axial direction.

6. The split-type heart valve stent of claim 1, wherein the outer inflow channel is flared and extends away from the inner stent.

7. The split-type heart valve stent of claim 1, wherein the main body of the outer outflow tract is cylindrical, conical, elliptical cylindrical, or cylindrical with a D-shaped cross-section.

8. The split-type heart valve stent of claim 1, wherein at least two outer anchoring structures are distributed along the circumferential direction of the outer outflow tract, and one end of each outer anchoring structure is a fixed end while the other end is a free end.

9. The split-body heart valve stent of claim 8, wherein the outer layer anchoring structure is a cantilever structure.

10. The split-type heart valve stent of claim 9, wherein the cantilever structures are rod-shaped structures, a fixed end of each rod-shaped structure is fixedly connected to the outer side of the outer outflow tract, and a free end of each rod-shaped structure is spherical or ellipsoidal.

11. The split-type heart valve stent of claim 9, wherein the cantilever structure is provided with barbs on the side facing the outer stent or is provided with a saw-tooth shape.

12. The split-body heart valve stent of claim 1, wherein the inner outflow tract and the inner inflow tract have the same inner diameter in the expanded state.

13. A split heart valve prosthesis comprising the split heart valve stent of any one of claims 1-12 and leaflets disposed inside the inner stent.

14. The split-type heart valve prosthesis of claim 13, further comprising a skirt provided on an inner surface or/and an outer surface of the outer stent or/and the inner stent.