CN115702841A - Valve stent and valve prosthesis - Google Patents

Abstract

The invention provides a valve stent and a valve prosthesis, wherein the valve stent comprises an outer layer stent, an inner layer stent and at least one buffer part; the outer layer support is sleeved outside the inner layer support and is connected with the inner layer support through the buffer portion. The setting of buffer can effectively reduce the deformation of outer support and open and the influence of closing to valve leaf on the inlayer support, and then makes buffer can show and weaken or completely cut off outer support with the condition of the mutual atress between the inlayer support. In addition, the valve stent adopts the design of a double-layer stent, so that the fatigue resistance of the valve prosthesis can be effectively improved, the valve prosthesis can be more attached to native tissues, the influence of the valve stent on the ventricular contractility is reduced, and the stability of the valve stent closure is ensured.

Description

Valve stent and valve prosthesis

Technical Field

The invention relates to the technical field of medical equipment, in particular to a valve stent and a valve prosthesis.

Background

With the development of socioeconomic and the increase of aging population, senile valvular diseases, coronary heart disease and valvular diseases caused by myocardial infarction are more and more common. Studies have shown that over 13.3% of elderly people over the age of 75 years suffer from different degrees of valvular heart disease. Heart valve disease has become one of the leading causes of health threats to humans. Mitral valve and tricuspid valve diseases are relatively common heart valve diseases in clinic. The heart of a human body is divided into four heart chambers, namely a left atrium, a left ventricle, a right atrium and a right ventricle, the two atria are respectively connected with the two ventricles, and the two ventricles are connected with the two main arteries. The mitral valve grows between the left atrium and the left ventricle, is composed of valve leaflets, valve rings, chordae tendinae, and papillary muscles, plays the role of a one-way valve, and ensures that the blood flows in a single direction. The right atrioventricular orifice, the fibrous scaffolding ring of dense connective tissue, is attached with 3 triangular valves, called tricuspid valve or right atrioventricular valve. The tricuspid valve acts like a "one-way valve" and ensures that blood circulation must flow from the right atrium to the right ventricle and through a certain amount of flow.

Mitral valve prosthesis replacement is one of effective treatment methods for mitral valve diseases, and a common mitral valve prosthesis in the prior art is a single-layer mitral valve prosthesis, after the single-layer mitral valve prosthesis is implanted in a body, when a left ventricle relaxes, when blood passes through an inflow channel, valve leaflets open, and a single-layer mitral valve stent only can be subjected to extrusion force of an annulus. When the left ventricle contracts, the valve leaflets close, and due to the action of the blood pressure, the valve leaflets can receive pressure based on the area size, and the pressure can be borne by the single-layer mitral valve support. The area of the valve leaflets needing to be sewn on the single-layer mitral valve support is equal to the sectional area of the support, if the single-layer mitral valve support is designed into a double-layer structure, the skirt and the valve leaflets are sewn on the inner-layer support of the double-layer structure, the area of the valve leaflets can be reduced, the force which the inner-layer support needs to bear when the valve leaflets are closed is reduced, and the anti-fatigue capability of the inner-layer support is improved. In addition, the saddle-shaped annulus of the mitral native valve has a folding motion when the ventricle relaxes and contracts, and when a single-layer mitral valve prosthesis is implanted, the native valve annulus needs to be expanded into the shape of a single-layer mitral valve stent in order to ensure that the leaflets can be normally closed, which results in loss of native annulus motion and reduced ventricular contractility. If the single-layer mitral valve stent is designed into a double-layer stent, the outer layer stent in the double-layer stent can move along with the native valve annulus, and the valve leaflets on the inner layer stent in the double-layer stent can still be normally opened and closed, so that the motion of the native valve annulus can be maintained, the influence of the valve stent on the ventricular contraction capacity can be reduced, and the valve closure stability can be ensured. The design of the double-layer mitral valve stent structure can also isolate the mutual influence between the outer stent and the inner stent to a certain extent. Of course, the principles of replacement of a tricuspid valve prosthesis are similar to those of a mitral valve prosthesis and will not be described in detail here.

However, in the current double-layer mitral valve stent structure, the inner and outer layer stents are generally connected by direct welding, and the deformation of the outer layer stent and the inner layer stent is severe in the opening and closing process of the valve leaflets, which affects the fatigue resistance of the double-layer mitral valve stent. Therefore, the outer stent has a greater impact on the opening and closing of the leaflets on the inner stent as it moves with the native annulus. Therefore, the weakening degree of the force between the native valve annulus and the valve leaflets by the outer-layer stent and the inner-layer stent of the double-layer mitral valve stent is still not obvious enough, and the ventricular contractility is further influenced.

Therefore, it is a problem to be solved to develop a method for significantly reducing or isolating the mutual stress between the outer stent and the inner stent, reducing the influence of the valve stent on the ventricular contractility, and improving the stability of the valve stent closure.

Disclosure of Invention

The invention aims to provide a valve stent and a valve prosthesis, which aim to solve the problems that an outer-layer stent and an inner-layer stent of the conventional valve stent are stressed to deform, the valve stent has large influence on ventricular contractility and the closing stability of the valve stent is low.

In order to solve the above technical problems, the present invention provides a valve stent, comprising: the outer layer bracket, the inner layer bracket and at least one buffer part; the outer layer support is sleeved outside the inner layer support and is connected with the inner layer support through the buffering portion.

Optionally, the buffer part comprises at least one buffer structure, and the buffer structure comprises at least one of a straight rod type structure, an S-shaped bent structure, a Z-shaped bent structure, a square bent structure or a trapezoid bent structure.

Optionally, the buffer part further comprises a connecting rod, and the buffer structure is connected with one or more of the outer bracket, the inner bracket and other buffer structures through the connecting rod; the distance from the wave crest to the wave trough of the outer contour of the buffer structure is a second width, and the second width is not larger than the width of the connecting rod along the circumferential direction of the valve support.

Optionally, an axis of the S-shaped bending structure extends in a wave shape, the buffer structure has a first width in a direction perpendicular to the axis of the buffer structure, a distance from a peak to a trough of an outer contour of the buffer structure is a second width, and the first width is between one quarter and one half of the second width.

Optionally, the S-shaped curved structure includes a first straight line segment, a first curved segment, a second straight line segment, a second curved segment and a third straight line segment, which are connected in sequence, the first straight line segment, the second straight line segment and the third straight line segment are linear, the first curved segment and the second curved segment are curved, and the curvatures of the first curved segment and the second curved segment are the same.

Optionally, the first straight-line segment, the second straight-line segment and the third straight-line segment are arranged in parallel, and the first straight-line segment, the second straight-line segment and the third straight-line segment are perpendicular to the axial direction of the valve holder.

Optionally, the first bending section and the second bending section are semi-circular structures, the direction of the buffer structure perpendicular to the axis of the buffer structure has a first width, and the diameter of the inner circle of the semi-circular structure is between one fourth and one half of the first width.

Optionally, the buffer part is arranged on the outer bracket.

Optionally, the inner stent has a valve connecting portion, the buffer structure of the buffer portion connected to the valve connecting portion has a first length along the extending direction of the buffer portion, and the remaining buffer structures of the buffer portion have a second length along the extending direction of the buffer portion, and the first length is longer than the second length.

Optionally, the extending direction of the buffer part is arranged at an angle to the axial direction of the valve support.

Optionally, the valve stent has a valve stent length along the axial direction of the valve stent, and the length of the projection of the buffer part in the axial direction of the valve stent accounts for 20% -30% of the length of the valve stent.

Optionally, the valve stent further comprises a stent suspension loop, and the buffer part is connected with the inner-layer stent through the stent suspension loop.

Optionally, the outer stent and the inner stent are connected by the buffer part along the outflow end of the valve stent.

Optionally, outer support includes flange, outer support main part and barb, the flange with the axial one end of support main part is connected, the barb is located the net node of outer support main part to extend towards the flange end and set up.

In order to solve the above technical problem, the present invention further provides a valve prosthesis, including: valve stents, leaflets and skirts as described above; the valve leaf and the skirt are respectively arranged on the valve support.

In the valve stent and the valve prosthesis provided by the invention, the valve stent comprises an outer layer stent, an inner layer stent and at least one buffer part; the outer layer support is sleeved outside the inner layer support and is connected with the inner layer support through the buffer portion. The setting of buffer can effectively reduce the deformation of outer support and open and the influence of closing to valve leaf on the inlayer support, and then makes buffer can show and weaken or completely cut off outer support with the condition of the mutual atress between the inlayer support. In addition, the valve support adopts the design of double-layer support, can effectively promote the antifatigue ability of valve prosthesis, can make valve prosthesis and native tissue laminate more, reduces valve support to the influence of ventricular contractility, guarantees the stability of valve closure.

Drawings

It will be appreciated by those skilled in the art that the drawings are provided for a better understanding of the invention and do not constitute any limitation to the scope of the invention. Wherein:

FIG. 1 is a schematic view of a valve stent according to an embodiment of the present invention.

Fig. 2 is a schematic view of an outer stent of the valve stent of fig. 1.

Fig. 3 is a schematic view of an S-bend structure according to an embodiment of the invention.

Fig. 4 is a schematic view of a Z-bend configuration according to an embodiment of the invention.

FIG. 5 is a schematic diagram of a square-shaped curved structure according to an embodiment of the invention.

Fig. 6 is a schematic view of a trapezoidal bending structure according to an embodiment of the present invention.

Fig. 7 is a schematic view of a stent lattice of an outer stent body according to an embodiment of the present invention.

Fig. 8 is a schematic view of another stent lattice of an outer stent body according to an embodiment of the present invention.

Fig. 9 is a schematic view of an outer stent hanger in accordance with an embodiment of the present invention.

Fig. 10 is a schematic view of an inner stent of a valve stent according to an embodiment of the present invention.

In the drawings:

h 1-first width, h 2-second width;

a-the extending direction of the buffer part, B-the axial direction of the valve support, and alpha-the angle between the extending direction of the buffer part and the axial direction of the valve support;

100-outer stent, 110-flange, 120-outer stent body, 130-barb;

200-inner stent, 210-inner stent body;

300-buffer, 300 a-buffer, 300 b-connecting rod;

310-S-shaped bent structure, 311-first straight line segment, 312-first bent segment, 313-second straight line segment, 314-second bent segment, 315-third straight line segment,

320-Z-shaped bending structure, 330-square bending structure and 340-trapezoid bending structure;

400-bracket hangers, 410-inner layer outer layer bracket hangers and 420-outer layer bracket hangers.

Detailed Description

To further clarify the objects, advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is to be noted that the drawings are in simplified form and are not to scale, but are provided for the purpose of facilitating and clearly illustrating embodiments of the present invention. Further, the structures illustrated in the drawings are often part of actual structures. In particular, the drawings may have different emphasis points and may sometimes be scaled differently.

As used in this specification, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise. The terms "a number of" are generally used in a sense that includes "at least one," the term "at least two" is generally used in a sense that includes "two or more," and further, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate a number of the indicated technical features. Thus, features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of the features and the terms "mounted", "connected" and "connected" are to be construed broadly and may be, for example, a fixed connection, a detachable connection or an integral part; either directly or indirectly through intervening media, either internally or in any other relationship. The "distal end" means the end distal from the healthcare worker's operation and the "proximal end" means the end proximal to the healthcare worker's operation. Furthermore, as used in the present invention, the disposition of an element with another element generally only means that there is a connection, coupling, fit or driving relationship between the two elements, and the connection, coupling, fit or driving relationship between the two elements may be direct or indirect through intermediate elements, and cannot be understood as indicating or implying any spatial positional relationship between the two elements, i.e., an element may be in any orientation inside, outside, above, below or to one side of another element, unless the content clearly indicates otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations. Furthermore, in the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the present invention.

The embodiment of the invention provides a valve stent and a valve prosthesis, wherein the valve stent comprises an outer layer stent, an inner layer stent and at least one buffer part; the outer layer support is sleeved outside the inner layer support and is connected with the inner layer support through the buffer portion. The setting of buffer can effectively reduce the deformation of outer support and open and the influence of closing to valve leaf on the inlayer support, and then makes buffer can show and weaken or completely cut off outer support with the condition of the mutual atress between the inlayer support. In addition, the valve support adopts the design of double-layer support, can effectively promote the antifatigue ability of valve prosthesis, can make valve prosthesis and native tissue laminate more, reduces valve support to the influence of ventricular contractility, guarantees the stability of valve closure.

The following description refers to the accompanying drawings.

FIG. 1 is a schematic view of a valve stent according to an embodiment of the present invention; FIG. 2 is a schematic view of an outer stent of the valve stent of FIG. 1; FIG. 3 is a schematic view of an S-bend configuration according to an embodiment of the present invention; FIG. 4 is a schematic view of a Z-bend configuration according to an embodiment of the present invention; FIG. 5 is a schematic view of a square bend configuration according to an embodiment of the present invention; FIG. 6 is a schematic view of a trapezoidal shaped curved structure according to an embodiment of the present invention; FIG. 7 is a schematic view of a stent lattice of an outer stent body according to an embodiment of the present invention; FIG. 8 is a schematic view of an alternative stent lattice of an outer stent body according to an embodiment of the present invention; FIG. 9 is a schematic view of an outer stent hanger of an embodiment of the present invention;

fig. 10 is a schematic view of an inner stent of a valve stent according to an embodiment of the present invention.

Referring to fig. 1 to 7, the valve prosthesis provided in the present embodiment can be used for replacing a mitral valve, a tricuspid valve, an aortic valve, or a pulmonary valve, and is particularly suitable for use in a mitral valve and a tricuspid valve. The valve prosthesis includes a valve stent and a valve. The valve stent is a double-layer stent and comprises an outer-layer stent 100, an inner-layer stent 200 and at least one buffer part 300. In the present exemplary embodiment, the valve stent is suitable for mitral valve prosthesis, and the outer stent 100 and the inner stent 200 of the double-layer stent have a gap therebetween, and the size of the gap changes with the movement of the inner and outer stents. Preferably, the valve stent provided by the present embodiment is a self-expandable mitral valve stent. In this embodiment, the connection between each strut of the outer stent 100 and the inner stent 200 is connected by a buffer 300. In other embodiments, at least one strut in the outer stent 100 and the inner stent 200 is connected by at least one buffer 300, and the rest can be directly connected.

As shown in fig. 1, the outer stent 100 is, for example, a stent on the outside of a double-layered stent, and serves as an anchoring and skirt-bearing function when implanted. The outer stent 100 preferably comprises a flange 110, an outer stent body 120, and barbs 130. The flange 110 is connected to one axial end of the stent body 120, and the barbs 130 are located on the mesh nodes of the outer stent body 120 and extend toward the flange end. The inner stent 200, for example, preferably comprises an inner stent body 210. The outer stent body 120 and the inner stent body 210 are preferably, for example, annular net-shaped. The outer stent 100 and the inner stent 200 are made of shape memory alloy, preferably nitinol, and the material of the outer stent 100 is not limited in this embodiment. For the specific structure of the outer stent 100 and the inner stent 200, please refer to the following description. As shown in fig. 1 to 3, the outer bracket 100 is sleeved outside the inner bracket 200 and connected to the inner bracket 200 through the buffer portion 300. The buffer part 300 is disposed between the outer bracket 100 and the inner bracket 200, and is used for reducing the mutual stress of the outer bracket 100 and the inner bracket 200, so as to realize the buffer function. Preferably, the outer stent 100 and the inner stent 200 are connected by a buffer 300 along the outflow end of the valve stent. In this embodiment, it is more preferable that the buffer part 300 is disposed on the outer layer bracket 100, for example, one end of the buffer part 300 is integrally formed with the outer layer bracket 100, and the other end of the buffer part 300 is connected to the inner layer bracket 200 by a hanger. Further, the buffer portion 300 is disposed at the outflow end of the outer stent 100, so that the inner stent 200 can be maximally influenced while achieving better mechanical properties. Of course, in other embodiments, the buffering portion 300 may also be disposed on the inner bracket 200, for example, one end of the buffering portion 300 is integrally formed with the inner bracket 200, and the other end of the buffering portion 300 is connected to the outer bracket 100 by a hanging loop. Alternatively, the buffering part 300 may be a separate member, one end of the buffering part 300 is connected to the outer bracket 100 by a hanging loop, and the other end of the buffering part 300 is connected to the inner bracket 200 by a hanging loop. More preferably, the extending direction a of the buffer part 300 is disposed at an angle with the axial direction B of the valve stent, so that the force of the outer stent 100 moving in the radial direction can be dispersed and absorbed by the buffer part 300. More preferably, the angle α between the extending direction a of the buffer part 300 and the axial direction B of the valve stent is 0 to 45 °, and it can be known from mechanical analysis that the buffer part 300 can better disperse and absorb the force of the outer stent 100 moving in the radial direction. Of course, the angle α between the extending direction a of the buffer part 300 and the axial direction B of the valve holder may be set at 45 °, and those skilled in the art can set the angle according to actual requirements. In other embodiments, the extending direction a of the buffer part 300 and the axial direction B of the valve support may be set at an angle greater than 45 °, and the buffer function of the buffer part 300 may also be realized. It is understood that the extending direction a of the cushioning portion 300 may be a length direction of the entire structure of the cushioning portion 300. The inner stent 200 is, for example, a stent inside a double-layered stent for carrying leaflets and a skirt constituting a mitral valve prosthesis. The valve support adopts the design of a double-layer support, the valve leaflets are sewn on the inner-layer support 200, and the area of the closed valve leaflets is smaller than that of the single-layer valve support, so that the pulling force applied to the valve support is smaller, and the anti-fatigue capability of the valve prosthesis can be effectively improved. In the double-layered stent of the valve stent of the present embodiment, since the outer-layered stent 100 does not directly carry the valve, the strength requirement for the outer-layered stent 100 is weaker than that for the single-layered valve stent. Therefore, when the left ventricle contracts and relaxes, under the same contractile force, the outer stent 100 of the double-layered stent can generate a larger deformation amount, so that the matching of the valve stent and the native tissue is facilitated, the influence of the valve stent on the ventricular contractile ability is reduced, and meanwhile, the stability of valve closure is also ensured.

Preferably, the valve stent has a valve stent axial length along the axial direction of the valve stent, and the projection of the buffer part 300 in the axial direction B of the valve stent occupies 20% to 30% of the valve stent length. For example, the projection of the buffer portion 300 in the axial direction B of the valve stent occupies 20%, 25%, or 30% of the length of the valve stent. Specifically, for example, the length of the valve stent is 100mm, and the projected length of the buffer part 300 may be 20mm, 25mm or 30mm. For example, if the buffer part 300 is disposed at 45 ° to the axial direction of the valve holder and the projected length of the buffer part 300 is defined as 30mm, the length of the buffer part 300 may be 42.3mm. By such arrangement, the buffering portion 300 has better mechanical properties in the valve stent, so that the buffering performance of the buffering portion 300 is better, and the mutual influence between the inner stent 200 and the outer stent 100 is reduced. Of course, the projected length of the valve stent can be set by those skilled in the art according to actual needs. It should be understood that the numerical value of 45 °,20% to 30% is not limited to a specific numerical value, and may be a numerical value slightly deviated within an error range, for example, a numerical value of about 45 °, about 20%, or about 30%.

Referring to fig. 3 to 6, the buffering portion 300 preferably includes at least one buffering structure 300a, the buffering structure 300a may preferably be at least one of a straight rod type structure, an S-shaped bent structure, a Z-shaped bent structure, a square bent structure, or a trapezoidal bent structure, for example, the buffering portion 300 can weaken a force from the outer stent 100, so that the inner stent 200 is subjected to less force, and thus the force between the outer stent 100 and the inner stent 200 is weakened or isolated from the interaction force, and thus the buffering portion 300 can significantly weaken or isolate the interaction force between the outer stent 100 and the inner stent 200, and thus the buffering portion 300 can be used to reduce or isolate the influence of the movement of the outer stent 100 on the inner stent 200, and can effectively reduce the influence of the movement of the outer stent 100 on the opening and closing of the leaflets on the inner stent 200. Thus, when the outer stent 100 moves with the native annulus, the opening and closing of the leaflets of the inner stent 200 is not affected, or is affected little, by the movement of the outer stent 100. In other embodiments, the buffer portion 300 is not limited to a bending structure, but may be other structures capable of attenuating the force from the outer stent 100, such as a spiral structure, a conical structure, and the spiral structure or the conical structure is also used for absorbing and dispersing the force between the inner stent 200 and the outer stent 100.

Preferably, the buffer portion 300 includes a buffer structure 300a, an axis of the S-shaped bent structure of the buffer structure 300a extends in a wave shape, the buffer structure 300a has a first width h1 in a direction perpendicular to the axis, a distance between a peak and a trough of an outer contour of the buffer structure 300a is a second width h2, and the first width h1 is between one fourth and one half of the second width h 2. In the present exemplary embodiment, the buffer portion 300 has, for example, an S-shaped bent structure 310, and the first width h1 of the S-shaped bent structure 310 is one fourth of the second width h2, so as to ensure that the S-shaped bent structure 310 can absorb the force from the outer bracket 200. Of course, in other embodiments, the first width h1 of the buffering part 300 may be one third or one half of the second width h 2. It can be understood that the first width h1 may represent a self width of the buffer part 300.

As shown in fig. 3, the cushioning portion 300 further includes a connection rod 300b, and the cushioning structure 300a is connected to one or more of the outer support 100, the inner support 200, and the other cushioning structures 300a through the connection rod 300 b; the distance from the wave crest to the wave trough of the outer contour of the buffer structure 300a is a second width h2, and the second width h2 is not more than the width of the connecting rod 300b along the circumferential direction of the valve stent. In the present exemplary embodiment, the connecting rod 300B may extend along the axial direction B of the valve stent, so as to connect the outer stent 100 and the buffer structure 300a, and connect the inner stent 200 and the buffer structure 300a. Of course, the connecting rod 300b may also extend along the extending direction a of the buffer portion, and those skilled in the art may set the connecting rod according to actual requirements. In fact, when the number of the buffer structures 300a is two or more, the connecting rod 300b can also be disposed between two buffer structures 300a for connecting two buffer structures 300a. The connecting rod 300b has a width in the circumferential direction of the valve stent, which is the width of the connecting rod 300b itself. The second width h2 is not greater than the width of the connecting rod 300b itself. With this arrangement, the structural stability of the cushioning portion 300 disposed between the outer bracket 100 and the inner bracket 200 is ensured, so that the second width h2 of the cushioning portion 300 is not too wide or too thin to provide a cushioning effect.

Further, the cushioning portion 300 includes an S-shaped bent structure 310. It will be appreciated that the S-shaped curved structure 310 has an infinite number of wave numbers, and that a plurality of discrete wave shapes or a plurality of continuous wave shapes may be provided. Preferably, the S-shaped curved structure 310 includes a first straight line segment 311, a first curved segment 312, a second straight line segment 313, a second curved segment 314, and a third straight line segment 315, which are sequentially connected, where the first straight line segment 311, the second straight line segment 313, and the third straight line segment 315 are straight lines, the first curved segment 312 and the second curved segment 314 are curved, and curvatures of the first curved segment 312 and the second curved segment 314 are the same, so as to ensure that a single S-shaped curved structure 310 can uniformly absorb an acting force. Further, the lengths of the first straight line segment 311, the second straight line segment 313 and the third straight line segment 315 in the circumferential direction of the valve support of the buffer 300 are the same, so that the structural stability of the buffer 300 is ensured, and the uniform absorption of acting force is further ensured.

Preferably, as shown in fig. 3, the first straight line segment 311, the second straight line segment 313 and the third straight line segment 315 are parallel to each other, which is beneficial for better dispersing strain of the buffer 300 when the outer layer bracket 100 is deformed. And the first straight line segment 311, the second straight line segment 313 and the third straight line segment 315 are perpendicular to the axial direction B of the valve stent, so as to ensure the setting position and direction of the S-shaped bending structure on the outer stent 100, ensure better strain dispersion of the buffer part 300, and absorb stress. In fact, the first straight line segment 311, the second straight line segment 313 and the third straight line segment 315 may also be perpendicular to the extending direction a of the buffer portion.

Preferably, as shown in fig. 3, the first curved section 312 and the second curved section 314 are semi-circular ring structures. It can be understood that, when the first bending section 312 is bent, since the first bending section 312 has a width itself, two semicircular structures are formed, of which a semicircle near the inner portion forms an inner circle having an inner circle diameter size and a semicircle near the outer portion forms an outer circle having an outer circle diameter size. The inner circle and the outer circle of the second bending portion 314 are similar to the first bending portion 312, and are not described herein again. The inner circle diameter dimension of the semi-circular ring-shaped structure represents the diameter dimension of the inner circle near the inner portion, and the inner circle diameter dimension of the semi-circular ring-shaped structure is between one quarter and one half of the width of the first bending section 312 or the second bending section 314. In the present embodiment, the first width h1 of the first curved section 312 is the same as the second width h1 of the second curved section 314. The inner diameter of the semicircular structure of the first curved section 312 is preferably half of the first width h1 of the first curved section 312, and the distance between the first straight line section 311 and the second straight line section 313 is controlled, so that the magnitude of the force of the buffer part 300 on the outer stent 100 can be controlled. Of course, in other embodiments, the inner circle diameter of the semi-circular configuration of the first curved segment 312 may be one-third, or one-fourth, or other dimension of the first width h1 of the first curved segment. The smaller the inner circle diameter of the semicircular structure is, the larger the force of the buffer part 300 dispersing the outer stent 100 is, the larger the inner circle diameter of the semicircular structure is, the smaller the force of the buffer part 300 dispersing the outer stent 100 is, and those skilled in the art can set the values according to actual conditions.

Preferably, the inner stent 200 has a valve connecting portion, for example, the position where the inner stent 200 is connected to the valve leaflet is the valve connecting portion. When the outer stent 100 and the inner stent 200 are connected by the buffer part 300, the valve connecting part of the inner stent 200 may be directly connected to the buffer part 300, for example, or may be indirectly connected to the buffer part 300, for example, the valve connecting part is connected to the buffer part 300 by a connecting rod; or one or several rows of grids are spaced between the valve connecting portion and the buffer portion 300. The cushioning structure 300a of the cushioning portion 300 connected to the valve-connecting portion has a first length in the extending direction a of the cushioning portion, and the remaining cushioning structures 300a of the cushioning portion 300 have a second length in the extending direction a of the cushioning portion, the first length being longer than the second length. This is because the valve connecting portion is connected to the valve leaflet, which affects the stress of the valve connecting portion when the valve leaflet is opened and closed, and the acting force that the valve connecting portion needs to bear is larger, and in order to alleviate the transmission of the acting force of the valve connecting portion of the inner stent 200, the buffer portion 300 needs to absorb and disperse more acting force, and therefore, the buffer structure 300a connected to the valve connecting portion needs to be longer, so that the inner stent 200 and the outer stent 100 are independent of each other as much as possible and are not affected by the acting force.

As shown in fig. 3 to 6, preferably, the valve stent includes at least one buffer portion 300, the buffer portion 300 has at least one buffer structure 300a, and the buffer structure 300a includes at least one of an S-shaped curved structure, a Z-shaped curved structure, a square-shaped curved structure or a trapezoidal-shaped curved structure. In this embodiment, as shown in fig. 2 and 3, the valve stent includes a plurality of buffer portions 300, the buffer portions 300 have one, two or more buffer structures 300a, and two adjacent buffer structures 300a are connected by the connecting rod 300 b. The buffer structure 300a is preferably an S-shaped bent structure 310, for example, and the S-shaped bent structure 310 can better disperse the stress. The length of the buffer structure 300a along the extending direction a of the buffer part can be set according to actual needs, for example, as shown in the two rightmost and middle buffer structures 300a in fig. 3, the lengths of the two buffer structures 300a can be different. In an exemplary embodiment, the length of the buffer structure 300a in each buffer portion 300 is the same, so as to ensure that the buffer structure 300a at the connection between the outer stent 100 and the inner stent 200 can uniformly buffer the acting force during the movement of the outer stent 100. Further, the cushioning structures 300a of all the cushioning portions 300 of the outer stent 100 have the same curved structure, for example, all the cushioning portions have the S-shaped curved structure 310. Preferably, the number of the S-shaped curved structures 310 is the same, so that the cushioning structure 300a can uniformly cushion the acting force. In other embodiments, the cushioning structure 300a may also be a combination of different bending structures, for example, on one cushioning portion 300, the cushioning structure 300a may be provided with a combination of an S-bending structure 310 and a Z-bending structure 320, and may also be provided with a Z-bending structure 320, a square bending structure 330, or the like. Alternatively, different cushioning structures 300a may be disposed on each of the cushioning portions 300, for example, an S-shaped curved structure 310 is disposed on one of the cushioning portions 300, and a square curved structure 330 is disposed on the other cushioning portion; alternatively, one of the cushioning portions 300 may be provided with a Z-shaped curved structure 320, and the other may be provided with a trapezoidal curved structure 340.

Preferably, the valve stent further comprises a stent hanging lug 400, and the buffer part 300 is connected with the inner-layer stent through the stent hanging lug 400. The stent hangers 400 are used for matching the valve prosthesis with a delivery system for delivering the valve prosthesis, and the shape of the stent hangers 400 matches with that of the groove of the delivery system to form connection, so that the relative positions of the valve prosthesis and the delivery system are not changed when the valve prosthesis is loaded into the delivery system, released from the delivery system and delivered in vivo in the delivery system. The number and position of the bracket hangers 400 can be determined according to actual needs. In this embodiment, the stent hanger 400 is configured to fit into a groove of a delivery system and is connected to the buffer portion and the inner stent. The bracket hangers 400 include, for example, an inner bracket hanger 410 and an outer bracket hanger 420, the outer bracket hanger 420 is connected to the buffer portion 300, the inner bracket hanger 410 is connected to the inner bracket 200, and the outer bracket hanger 420 is connected to the inner bracket hanger 410, so that the buffer portion 300 is connected to the inner bracket 200. Of course, in other embodiments, the buffer portion 300 may be directly connected to the inner layer bracket.

In the present exemplary embodiment, as shown in fig. 1 and 3, the outflow end of the outer stent 100 has a lattice structure disposed around the circumference of the outer stent 100, and the lattice structure is preferably a diamond-shaped lattice structure. One of the connection bars of each of the cushioning parts 300 is preferably connected to the vertices of the diamond-shaped lattice structure in a one-to-one correspondence, and one end of one of the cushioning structures of the cushioning part 300 is connected to the one of the connection bars, and the one of the cushioning structures is preferably an S-shaped curved structure as described above. One of them buffer structure's the other end and another the one end of connecting rod is connected, the other end and an outer support hangers 420 of another connecting rod are connected, outer support hangers 420 and inlayer support hangers 410 interconnect, and inlayer support hangers 410 is connected inlayer support 200, so sets up for outer support 100 is connected through buffering portion 300 with inlayer support 200, and the buffer structure 300a of buffering portion 300 has the effect of absorption or cushioning effect, and then can play the cushioning effect of the effort between outer support 100 and inlayer support 200. Of course, the mesh structure of the outer bracket 100 may also be a triangular or other polygonal structure, and the number of the buffer portions 300, the number of the connecting rods 300b in the buffer portions 300 or the buffer structures 300a of the buffer portions 300, and the specific structures of the inner bracket lugs 410 and the outer bracket lugs 420 may be set according to actual situations, for details, refer to the description herein, and are not repeated herein.

The specific structures of the outer stent 100, the outer stent hangers 420, the inner stent 200, and the inner stent hangers 410 of the present embodiment mentioned above will be described in detail below.

The outer shell stent 100 further comprises a flange 110, an outer shell stent body 120, and barbs 130.

As shown in fig. 2, the flange 110 has a diameter slightly larger than the diameter of the outer stent body 120. The maximum diameter at the edge of the flange 110 ranges from 30 to 100mm. In the axial direction of the outer stent 100, the end where the flange 110 is located is a proximal end, and the end away from the flange 110 is a distal end. As shown in FIG. 2, the flange 110 may be a V-shaped structure or a diamond grid, and the diamond grid may be designed with reference to the outer stent body 120. The flange 110 can be made in a number of different ways. For example, the flange 110 may be integrally formed with the outer stent body 120 using a cutting technique: the contours of the flange 110 and the outer layer support main body 120 are cut from the metal pipe by cutting means such as laser, and the mitral valve support is expanded and shaped into a design structure through a heat treatment shaping process. For another example, the flange 110 and the outer stent body 120 may be formed separately using a cutting technique: the contour of the flange 110 is cut from the metal pipe by cutting means such as laser, the flange 110 is expanded and shaped into a designed structure by a heat treatment shaping process, and finally the flange 110 is connected with the outer layer stent body 120 by welding, riveting or connecting by using skirt, suture or pericardial material and other means. Of course, the flange 110 may also be formed in other manners, and the embodiment is not limited herein.

Referring to fig. 2, 7 and 8, the diameter of the outer layer bracket body 120 is slightly smaller than that of the flange 110, the diameter of the end of the outer layer bracket body 120 connected to the flange 110 is 20-90mm, the diameter of the far end is 20-90mm, the diameters of the two ends are independent, and there is no absolute size relationship. As shown in fig. 7 and 8, the outer stent body 120 may have a diamond-shaped lattice structure, and may be designed to have a lattice structure similar to a diamond shape or a hexagonal structure. As shown in fig. 7, in the approximately diamond structure, the length of the upper bar and the length of the side stem are independent of each other, and the upper bar may be longer than the lower bar and may be shorter than the lower bar. The outer stent body 120 can be made in a number of different ways. For example, the contour of the outer stent body 120 is cut from a metal tube by a cutting means such as laser, and the outer stent body 120 is expanded and shaped into a designed structure by a heat treatment shaping process. For another example, the design structure of the outer stent body 120 is directly woven by using metal wire. For another example, the design structure of the outer stent body 120 is printed by using metal as a material using a 3D printing technology. Of course, the outer bracket body 120 may also be formed in other manners, and the embodiment is not limited herein.

Preferably, the buffer part 300 may be integrally formed with the outer stent 100 using a cutting technique: the outlines of the flange 110 and the outer layer support main body 120 are cut from the metal pipe by cutting means such as laser, and the mitral valve support is expanded and shaped into a designed structure by a heat treatment shaping process.

As shown in fig. 2 and 7, the barbs 130 are located on the lattice nodes of the outer stent body 120 and are uniformly distributed in the circumferential direction. The barb 130 and the outer stent body 120 may have a certain included angle, which is: 0 to 90 degrees. The barbs 130 may be formed in a number of different ways. For example, the barbs 130 may be integrally formed with the outer stent body 120 using a cutting technique.

As shown in fig. 1 to 3 and 9, the outer layer bracket hanger 420 is located at the lower end of the cushioning portion 300. The outer bracket hangers 420 may be circular, T-shaped, square, elliptical, hook-shaped, or the like, and those skilled in the art may set the structure of the outer bracket hangers 420 according to actual needs, which is not limited in this embodiment. The outer stent hangers 420 are circumferentially distributed, and one or more hangers may be present in the same row. The outer stent hanger 420 may be integrally formed with the outer stent body 120 and the cushioning portion 300 by using a cutting technique.

As shown in fig. 10, the inner stent 200 includes an inner stent body 210, and the inner stent hangers 410 are attached to the inner stent body 210.

As shown in fig. 10, the maximum diameter of the inner stent body 210 is smaller than the minimum diameter of the outer stent 100. The proximal end of the inner stent body 210 is the inflow end of the membrane stent, and the distal end of the inner stent body 210 is the outflow end of the valve stent. Similar to the outer stent body 120, the proximal end of the inner stent body 210 may have a diamond-shaped lattice structure, and may be designed to have an approximately diamond-shaped lattice structure or a hexagonal structure. The upper bar is independent of the lower bar, and the upper bar may be longer than the lower bar and shorter than the lower bar. The distal structure of the inner stent body 210 is a straight rod and wave rod combination. The inner stent body 210 may be made in a number of different ways. For example, the inner stent body 210 is formed by cutting the contour of the inner stent body 210 from a metal tube by a cutting means such as laser, and then expanding and shaping the inner stent body 210 into a designed structure by a heat treatment shaping process. For example, the design structure of the inner stent body 210 is directly braided using metal wire. For another example, the design structure of the inner stent body 210 is printed by using metal as a material using a 3D printing technology. Of course, the inner layer bracket main body 210 may also be formed in other manners, and the embodiment is not limited herein.

The inner bracket lugs 410 correspond to the outer bracket lugs 420 one to one and are then connected together. The connection mode can be welding, riveting, adding other connecting pieces, such as adding a circular ring. The connection mode may also be in other forms, and this embodiment is not limited herein. The connection can be that the inner layer bracket hanging lug 410 and the outer layer bracket hanging lug 420 are tightly attached together, or a certain gap is left to allow relative movement of 0-1 mm. The inner layer bracket ears 410 are the same as the outer layer bracket ears 420 in size, number, shape, position and manufacturing manner.

The present embodiments also provide a valve prosthesis, comprising: the valve support, the valve leaflet and the skirt are arranged on the valve support respectively. The valve prosthesis has the beneficial effects brought by the valve stent, and the details are not repeated herein. The structure and principle of the valve leaf and the skirt can be referred to the prior art, and the embodiment is not described again. The structure and principle of other components of the valve prosthesis can be referred to the prior art, and the embodiment is not explained again.

In summary, in the valve stent and the valve prosthesis provided by the embodiments of the present invention, the valve stent includes an outer layer stent, an inner layer stent, and at least one buffer portion; the outer layer support is sleeved outside the inner layer support and is connected with the inner layer support through the buffering portion. The setting of buffering portion can effectively reduce the influence that the deformation of outer support opened and closed to leaflet on the inlayer support, and then makes the buffering portion can show and weaken or completely cut off outer support with the condition of the mutual atress between the inlayer support. In addition, the valve support adopts the design of double-layer support, can effectively promote the antifatigue ability of valve prosthesis, can make valve prosthesis and native tissue laminate more, reduces valve support to the influence of ventricular contractility, guarantees the stability of valve closure.

It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the invention without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention will still fall within the protection scope of the technical solution of the present invention.

Claims (15)

1. A valve stent, comprising: the outer layer bracket, the inner layer bracket and at least one buffer part;

the outer layer support is sleeved outside the inner layer support and is connected with the inner layer support through the buffer portion.

2. The valve stent of claim 1, wherein the cushioning portion comprises at least one cushioning structure comprising at least one of a straight rod-type structure, an S-bend structure, a Z-bend structure, a square bend structure, or a trapezoidal bend structure.

3. The valve stent of claim 2, wherein the cushioning portion further comprises an attachment strut by which the cushioning structure is attached to one or more of the outer stent, the inner stent, and the other cushioning structures; the distance from the wave crest to the wave trough of the outer contour of the buffer structure is a second width, and the second width is not larger than the width of the connecting rod along the circumferential direction of the valve support.

4. The valve stent of claim 2, wherein the axis of the S-shaped curved structure extends in a wave shape, the cushioning structure has a first width in a direction perpendicular to the axis of the cushioning structure, the outer profile of the cushioning structure has a peak-to-trough spacing of a second width, and the first width is between one quarter and one half of the second width.

5. The valve stent of claim 2, wherein the S-bend structure comprises a first straight segment, a first bend segment, a second straight segment, a second bend segment, and a third straight segment connected in series, wherein the first straight segment, the second straight segment, and the third straight segment are straight, the first bend segment and the second bend segment are bend, and the first bend segment and the second bend segment have the same curvature.

6. The valve holder of claim 5, wherein the first, second, and third linear segments are disposed parallel to one another and are perpendicular to an axial direction of the valve holder.

7. The valve stent of claim 6, wherein the first and second curved segments are semi-circular structures, the cushioning structure having a first width in a direction perpendicular to its axis, the semi-circular structures having an inner circle diameter dimension between one quarter and one half of the first width.

8. The valve stent of claim 1, wherein the bumper is disposed on the outer stent.

9. The valve stent according to claim 1, wherein the inner stent has a valve connecting portion, the cushioning structure of the cushioning portion connected to the valve connecting portion has a first length in an extending direction of the cushioning portion, and the cushioning structures of the remaining cushioning portions have a second length in the extending direction of the cushioning portion, the first length being longer than the second length.

10. The valve holder according to claim 1, wherein the buffer portion extends at an angle to the axial direction of the valve holder.

11. The valve support according to claim 10, wherein the valve support has a valve support length along the axial direction of the valve support, and the length of the projection of the buffer part in the axial direction of the valve support is 20-30% of the valve support length.

12. The valve stent of claim 1, further comprising stent hangers, wherein the buffer portion is connected to the inner stent by the stent hangers.

13. The valve stent of claim 1, wherein the outer stent is connected to the inner stent by the bumper along an outflow end of the valve stent.

14. The valve stent of claim 1, wherein the outer stent comprises a flange, an outer stent body and barbs, the flange is connected with one axial end of the stent body, and the barbs are located on the grid nodes of the outer stent body and extend towards the flange end.

15. A valve prosthesis, comprising: the valve stent, leaflets, and skirt of any one of claims 1-14; the valve leaf and the skirt are respectively arranged on the valve support.

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