阅读说明：本技术 一种心脏瓣膜假体及其支架和置换系统 (Heart valve prosthesis and stent and replacement system thereof ) 是由 张磊 冀丽军 陈国明 李�雨 于 2020-05-19 设计创作，主要内容包括：本发明公开了一种心脏瓣膜假体及其支架和置换系统,所述支架在轴向上包括多层网格,所述多层网格包括位于近端的顶层网格和位于远端的底层网格,所述底层网格上的网格沿圆周方向连续分布,从所述底层网格到所述顶层网格每层网格的网格数量依次减少,且所述每层网格减少的网格数量为所述顶层网格的网格数量。本发明提供的心脏瓣膜支架在每层网格的网格数量依次减少后形成缺口,缺口的存在能够为冠脉再介入提供足够的空间,同时实现了除了底层网格之外,不形成其他网格尖端,以实现支架在体内完全释放后也可回收,从而实现了支架的完全可回收。(The invention discloses a heart valve prosthesis, a stent and a replacement system thereof, wherein the stent comprises a plurality of layers of grids in the axial direction, the plurality of layers of grids comprise a top layer grid positioned at a near end and a bottom layer grid positioned at a far end, the grids on the bottom layer grid are continuously distributed along the circumferential direction, the number of grids of each layer of grids from the bottom layer grid to the top layer grid is sequentially reduced, and the number of the grids reduced by each layer of grids is the number of the grids of the top layer grid. The heart valve stent provided by the invention has the advantages that the gaps are formed after the number of the grids of each layer of grid is reduced in sequence, the existence of the gaps can provide enough space for coronary artery re-intervention, and meanwhile, except for the bottom layer of grid, other grid tips are not formed, so that the stent can be recycled after being completely released in a body, and the complete recycling of the stent is realized.)

1. A heart valve stent is characterized by comprising a plurality of layers of meshes in the axial direction, wherein the plurality of layers of meshes comprise a top layer mesh at the near end and a bottom layer mesh at the far end, the meshes on the bottom layer mesh are continuously distributed in the circumferential direction, the number of meshes of each layer of mesh from the bottom layer mesh to the top layer mesh is sequentially reduced, and the number of meshes of each layer of mesh which is gradually reduced is the number of meshes of the top layer mesh.

2. The heart valve stent of claim 1, wherein the number of layers of the mesh of the stent is 2-9 layers.

3. The heart valve stent of claim 1, wherein a tab is attached to a proximal end of the top mesh.

4. The heart valve stent of claim 3, wherein the number of hangers and the number of meshes of the top mesh are the same, both being a multiple of 3.

5. The heart valve stent of claim 1, wherein the number of meshes per layer of mesh is sequentially reduced to form a V-shaped notch at a proximal end of the heart valve stent.

6. The heart valve stent of claim 5, wherein a support structure is disposed in the V-shaped notch, the support structure is a connecting rod, and comprises a first rod, a connecting rod end and a second rod which are connected with each other in sequence, the connecting rod end is arc-shaped, and the first rod and the second rod are axially symmetrically distributed.

7. The heart valve stent of claim 6, wherein an angle α formed by the first and second rods and a tangent line at a junction of the ends of the connecting rods ranges from 30 ° to 180 ° when the stent is in the deployed state.

8. The heart valve stent of claim 6, wherein the ends of the connecting rods are recessed 0 ° -30 ° relative to the multi-layer lattice toward a central axis of the stent in the expanded state of the stent.

9. The heart valve stent of claim 6, wherein the connecting rods are integrally formed with the multi-layer mesh and the hanging lugs, and two ends of the connecting rods are connected with the adjacent mesh or the adjacent hanging lugs on the top layer mesh.

10. A heart valve prosthesis comprising a heart valve stent according to any one of claims 1 to 9 and a valve, the valve being secured inside the heart valve stent.

11. A valve replacement system comprising the heart valve prosthesis of claim 10 and a delivery system, the top mesh having a hanger disposed on an end thereof, the delivery system comprising a fixation head configured to couple with the hanger.

Technical Field

The invention relates to the field of medical instruments, in particular to a heart valve prosthesis, a stent and a replacement system thereof.

Background

The principle of the intervention aortic valve implantation is that a heart valve prosthesis is loaded into a delivery system and delivered to the root of an aorta in a transcatheter mode, and a stent is released to ensure that the heart valve prosthesis is fixed at the aortic valve annulus to replace a native valve with degraded function, so that the heart function of a patient is improved. The technique can treat aortic valve diseases under the conditions of no thoracotomy and no heartbeat, and avoids huge trauma to patients caused by the conventional surgical thoracotomy and heartbeat arrest.

With the aging of the population structure of China, the attack population of aortic valvular diseases gradually changes from high-age high-risk to low-age low-risk. Unlike elderly, low risk patients, the lower risk patients more require a stent to meet the function of full recovery to avoid a flap-in-flap, which can greatly increase the risk of blocking the coronary ostia. The recyclability of the aortic valve stent is only aimed at the recyclability of the valve in the positioning process clinically, namely, the delivery system releases the valve stent to 2/3 stent, and a part of the stent is still left unreleased, in the state, the position and the shape abnormality of the stent can be generated, and the stent can be loaded into the sheath again to be positioned and released so as to achieve the expected release shape. This form of recyclability, however, does not address the problem of recyclability (implant failure or stent life expiration) after the valve stent is fully opened.

In addition, in the clinical positioning stage, the existing valve system performs positioning evaluation under the condition of partial release and partial restraint, so that the force of the delivery system on the heart valve stent is always applied, and the position and/or the shape of the completely released stent cannot be accurately judged, thereby affecting the operation quality.

Therefore, there is a need for a stent that can be retrieved after complete release, allowing the stent to achieve a consistent positioning configuration and final release configuration.

Disclosure of Invention

It is an object of the present invention to provide a heart valve prosthesis and a stent and replacement system therefor, the stent being recoverable again after complete release.

In order to solve the technical problem, the invention provides a heart valve stent, which comprises a plurality of layers of grids in the axial direction, wherein the plurality of layers of grids comprise a top layer grid positioned at the near end and a bottom layer grid positioned at the far end, the grids on the bottom layer grid are continuously distributed along the circumferential direction, the number of grids in each layer of grids from the bottom layer grid to the top layer grid is sequentially reduced, and the number of grids in each layer of grids which is decreased progressively is the number of grids in the top layer grid.

Preferably, the number of the grid layers of the bracket is 2-9.

Preferably, the near end of the top grid is connected with a hanger.

Preferably, the number of the hangers is the same as the number of the grids of the top grid, and the hangers and the grids are multiples of 3.

Preferably, the number of meshes of each layer of meshes is reduced in turn to form a V-shaped notch at the proximal end of the heart valve stent.

Preferably, a supporting structure is arranged in the V-shaped notch, the supporting structure is a connecting rod and sequentially comprises a first rod, a connecting rod end part and a second rod which are connected with each other, the connecting rod end part is in an arc shape, and the first rod and the second rod are in axial symmetry distribution.

Preferably, when the stent is in the unfolded state, an included angle α formed by tangents at the connection positions of the first rod and the second rod with the end portions of the connecting rods ranges from 30 ° to 180 °.

Preferably, when the bracket is in the unfolding state, the end part of the connecting rod is inwards concave 0-30 degrees relative to the multilayer grid towards the direction close to the central axis of the bracket.

Preferably, the connecting rod with multilayer net, hangers integrated into one piece, just the both ends of connecting rod with adjacent net or adjacent on the top layer net the hangers are connected.

In order to solve the technical problem, the invention further provides a heart valve prosthesis, which comprises the heart valve stent and a valve, wherein the valve is fixed inside the heart valve stent.

In order to solve the technical problem, the invention further provides a valve replacement system, which comprises the heart valve prosthesis and a delivery system, wherein the end part of the top layer grid is provided with a lug, and the delivery system comprises a fixing head configured to be connected with the lug.

Compared with the prior art, the invention has the following beneficial effects: according to the heart valve prosthesis, the stent and the replacement system thereof, the number of the grid layers of the stent and the number of the grids of each layer are limited, the number of the grids of each layer is reduced in sequence to form the gap, the gap can provide enough space for coronary artery to intervene again, and other grid tips are not formed except the grids at the bottom layer, so that the stent can be recovered after being completely released in a body, and the stent can be completely recycled; when the number of the support grid layers is 2-5, the maximum diameter of the support after being pressed and held is favorably reduced, the sheathing diameter of the support is further controlled, the support can be conveniently recycled into the sheath, meanwhile, the height of the support is lower, the risk of blocking a coronary artery is reduced, meanwhile, an operable space is provided for future PCI (percutaneous coronary intervention) operations, and the safety in and after the operation is improved; particularly, the number of the hanging lugs is preferably 3 times, so that when the support is conveniently recycled into the sheath, the hanging lugs are pressed and held synchronously, and recycling is facilitated. In addition, the supporting structure is arranged at the notch, so that the radial supporting force of the support is improved.

Drawings

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

FIG. 2 is a schematic view of the overall structure of a heart valve stent according to another embodiment of the present invention;

FIG. 3 is a schematic structural view of a V-shaped connecting rod in an embodiment of the present invention;

FIG. 4 is a schematic top view of a heart valve stent according to an embodiment of the invention;

FIG. 5 is a schematic top view of a heart valve stent according to another embodiment of the invention;

FIG. 6 is a schematic top view of a heart valve stent according to another embodiment of the invention;

FIG. 7 is a schematic view of the angle formed by the concave connection rod of FIG. 6;

FIG. 8 is a schematic representation of the construction of a valve replacement system in an embodiment of the present invention;

FIG. 9 is a schematic view of the engagement between the hanger on the heart valve stent and the fixation head on the delivery system in an embodiment of the present invention;

FIG. 10 is a schematic view of the engagement between a hanger on a heart valve stent and a fixation head on a delivery system according to another embodiment of the present invention.

In the figure:

1-bracket 11-connecting rod 12-hanging lug 13-bottom grid

14-gap 15-junction 16-transition layer grid 17-top layer grid

2-filament 3-anchor 31 first groove 32 second groove

33-first via 34-second via

4-inner tube 5-outer tube 111-first rod 112-second rod

113-connecting rod end 121-head end 122-connecting part 123-hole groove

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. "axial" refers to the direction in which the central axis of the stent is located; the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

The invention provides a heart valve prosthesis, which comprises a heart valve support and a valve, wherein the heart valve support can be made of a memory alloy material, the valve can be a biological material film, and the valve is fixed in the heart valve support in a sewing, bonding and other modes. The heart valve support and the heart valve prosthesis formed by the heart valve support can be kept in a compressed state in a sheath of a delivery system, and are released from the delivery system after being delivered to a lesion in a patient body, so that the compressed state is converted into a deployed state.

Referring to fig. 1, the heart valve stent provided in this embodiment includes a plurality of layers of meshes and hangers 12 in an axial direction, the plurality of layers of meshes include at least a bottom layer of meshes 13, a transition layer of meshes 16 and a top layer of meshes 17 in sequence from a distal end to a proximal end, and the hangers 12 are disposed at the proximal end of the top layer of meshes 17; the present invention does not particularly limit the main body profile of the stent 1, and is preferably cylindrical or hourglass shaped; the stent is more preferably cylindrical, and the cylindrical shape is more favorable for ensuring the coaxiality of the released stent; the shape of each grid on the support is not limited, and the grid can be a rhombic grid or a regular hexagonal grid.

In the axial distribution, the number of the grids of each layer is reduced from the bottom grid 13 to the top grid 17 through the middle transition layer grid 16, and the number of the grids of the top grid 17 in the circumferential direction is equal to the number of the hangers 12. In order to realize the support with shorter length in the axial direction, the support is arranged in a mode that the number of grid layers is less and the number of grids in each layer is reduced in sequence. Preferably, the total length of the stent 1 in the axial direction is not more than 28mm, more preferably not more than 25 mm. Shortening the axial length of the stent 1 can reduce the risk of blocking the coronary ostia and improve the operation safety.

The grid number gradient is realized by the following forms:

assuming that the number of the grids distributed in the circumferential direction of the top grid 17 and the number of the hangers 12 are both n, the total number of the grid layers is m, where m and n are positive integers, the number of the grids distributed in the circumferential direction of the bottom grid 13 is the product of m and n. From the bottom grid 13, the number of the grids is decreased by n grids layer by layer until the number of the grids of the top grid 17 is n. The grids on the bottom grid 13 are circumferentially and continuously distributed, and the grids on the other layers are circumferentially and discontinuously distributed.

The number m of grid layers is preferably more than or equal to 2 and less than or equal to 9; more preferably, m is more than or equal to 2 and less than or equal to 5, and the smaller value of m is more favorable for controlling the sheathing-entering outer diameter of the bracket in a smaller range and improving the recoverability of the bracket. The larger the number m of the mesh layers, the larger the number of the mesh layers of the bottom mesh 13, which increases the maximum outer diameter of the stent after being crimped. Further, the number m of mesh layers is preferably 3.

The number of the hangers 12 is the same as that of the top grid 17, preferably a multiple of 3, so that when the sheaths are recovered, the hangers 12 are pressed and held synchronously and gathered in a geometric center; besides, the suture of the valve is also convenient, because the suture site of the valve is positioned on the generatrix of the main structure of the bracket of the hangers 12, the valve is provided with 3 valve leaflets conventionally; therefore, it is more preferable to provide 3 hangers to facilitate control and fixation of the leaflets.

With continued reference to fig. 1, as the number of the grids of each layer of grids decreases in sequence, the proximal end of the stent 1 forms a notch 14, and the shape of the notch 14 is preferably V-shaped. The structure has the advantages that other grid tips are not formed except the far-end grid tips of the bottom grid 13, so that the problems existing when the grid tips exist are avoided, for example, the conveying system cannot directly apply force to the grid tips, and on one hand, the bracket cannot be synchronously pressed and held during recovery, and even cannot enter a sheath; on the other hand, the whole stress of the bracket is unbalanced, and the bracket or the sheath tube is easy to damage during recovery, so that the recovery fails. The stent of this construction allows the stent 1 to be uniformly stressed at the beginning of retrieval, the proximal end to be more easily crimped, and then gradually retrieved into the sheath, as shown in fig. 8-10.

Referring to fig. 2, in order to increase the radial supporting force of the stent 1, in a preferred embodiment, a supporting structure is disposed in the middle of the notch 14 of the stent 1; in order to facilitate processing, pressing and conveying, the supporting structure can be arranged into a V-shaped and U-shaped connecting rod 11, the connecting rod 11 can be integrally formed with the bracket 1 and can also be connected to the bracket 1 through a connecting piece, and further, the V-shaped connecting rod 11 can be used for preventing film clamping when being concaved inwards. The connecting rod 11 is not limited to a V shape or a U shape as long as the connecting rod can be folded along with the compression of the bracket 1 and is sunken towards the inside of the bracket 1; or may be W-shaped, and the shape of the connecting rod 11 is not particularly limited in the present invention. Specifically, as shown in fig. 3, the V-shaped or U-shaped connecting rod 11 sequentially includes a first rod 111, a connecting rod end 113 and a second rod 112 connected to each other, preferably, in order to avoid forming a tip, the connecting rod end 113 is arc-shaped, the first rod 111 and the second rod 112 are distributed in axial symmetry, in a preferred embodiment, the connecting rod 11 is integrally formed with the grid and the hanging lug 12 of the bracket 1, and both ends of the connecting rod 11 are connected with the adjacent grid or the adjacent hanging lug 12 on the top grid 17 to form a connecting part 15.

In a specific embodiment, the number of the meshes of the top layer mesh 17 and the number of the hangers n are 3, the total number m of the meshes is 3, and the number of the meshes of the bottom layer mesh 13 distributed in the circumferential direction is the product of 3 and 3, that is, 9 meshes. In order to realize the transition from the bottom grid 13 to the top grid 17, the transition grid 16 is distributed with 1 layer in the axial direction, i.e. the transition from 9 grids on the bottom grid 13 to 6 grids on the transition grid 16 is carried out, and then the transition is carried out to 3 grids on the top grid 17. Gaps 14 are formed at the gaps of the transition layer grids 16 and the top layer grids 17, and the V-shaped connecting rods 11 are arranged in the gaps 14.

Referring to fig. 3, when the bracket 1 is in the unfolded state, an included angle α formed by tangents of the joints of the first rod 111 and the second rod 112 and the end portion 113 of the connecting rod ranges from 30 ° to 180 °, and when the positions of the first rod 111 and the second rod 112 near the end portion 113 of the connecting rod are straight rods, the included angle α is an included angle formed by the first rod 111 and the second rod 112 after extending and intersecting; when the first and second bars 111 and 112 are curved bars near the end 113, the included angle α is an included angle formed by a tangent line at the junction of the first and second bars 111 and 112 and the end 113. One skilled in the art can design the appropriate included angle α according to specific mechanical property requirements.

Referring to fig. 4, 5 and 6, when the stent 1 is in the expanded state, in one embodiment, the connecting rod ends 113 are convex with respect to the multi-layer lattice in a direction away from the central axis of the stent 1, as shown in fig. 4; in another embodiment, the tie bar ends 113 are flush with the profile of the stent multi-layer lattice in the circumferential direction, as shown in fig. 5; in yet another embodiment, the connecting rod end 113 is recessed relative to the multi-layer lattice toward the central axis of the stent 1, as shown in FIG. 6. When the end part 113 of the connecting rod is flush with the outline of the multi-layer grid in the circumferential direction or the end part 113 of the connecting rod is concave towards the direction close to the central axis of the stent 1 relative to the multi-layer grid of the stent, the stent rod can be prevented from clamping the valve when the stent 1 is compressed; referring to fig. 7, preferably, the concave angle β is 0 ° to 30 °, and when the first rod 111 and the second rod 112 near the end 113 of the connecting rod are straight rods, the concave angle β is an included angle formed between an extension line of the first rod 111 or the second rod 112 near the end 113 of the connecting rod and a central axis of the bracket 1; when the first rod 111 and the second rod 112 near the end 113 are curved rods, the concave angle β is an included angle formed between a tangent of the first rod 111 or the second rod 112 near the end 113 of the connecting rod and a central axis of the bracket 1.

Referring to fig. 8, the present invention further provides a valve replacement system, which includes a stent 1 and a delivery system, wherein a hanging lug 12 is disposed on an end portion of a top grid 17, the delivery system includes an inner tube 4 and an outer tube 5, the inner tube 4 is sleeved in the outer tube 5, a fixing head 3 is disposed on the inner tube 4, and the hanging lug 12 is fixed on the fixing head 3. The hangers 12 are preferably of a centrosymmetric or axisymmetric configuration. Referring to fig. 9, in an embodiment, the hanging lug 12 includes a head end portion 121 and a connecting portion 122 which are integrally formed, the connecting portion 122 is connected with a proximal end portion of the top layer mesh 17, a circumferential dimension of the head end portion 121 is larger than a circumferential dimension of the connecting portion 122, correspondingly, a first groove 31 matching with a shape of the hanging lug 12 is provided on the conveying system end fixing head 3, the hanging lug 12 is clamped in the first groove 31 for fixing, a first through hole 33 is provided in the first groove 31, the wire 2 is sleeved on the connecting portion 122 and connected with a control member (not shown) in a handle after passing through the first through hole 33, and the bracket 1 is controlled to be recoverable after being completely released by sheathing the pulling of the wire 2, so that the releasing and recovering of the bracket 1 can be controlled by the wire 2. In this embodiment, the hanging lug 12 and the fixing head 3 are fixed by shape fitting, and the specific shape of the hanging lug 12 is not particularly limited in the present invention. Referring to fig. 10, in another embodiment, a hole groove 123 or a concave structure is further disposed on the head end 121 of the hanging lug 12, correspondingly, a second groove 32 matching with the shape of the hanging lug 12 is disposed on the fixing head 3, and the hanging lug 12 is clamped in the second groove 32 for fixing. The silk thread 2 passes through the hole groove 123 and the second through hole 34 and then is connected with a control piece (not shown) in the handle; the stent 1 is controlled to be sheathed by drawing the silk thread 2, so that the stent 1 can be recovered after being completely released, and the stent 1 can be controlled to be released and recovered by the silk thread 2. One skilled in the art can also choose one or a combination of the two according to the requirement.

Therefore, the heart valve prosthesis and the stent and replacement system thereof provided by the invention have at least the following advantages:

(1) in the invention, the number of the grid layers of the stent and the number of the grids of each layer of the grid are limited (namely m and n are limited), so that the purpose that other grid tips are not formed except the far-end grid tip of the bottom layer grid is realized, the stent can be completely recycled, and meanwhile, a gap is formed, and the existence of the gap can provide enough space for coronary artery re-intervention.

(2) In the invention, when m is more than or equal to 2 and less than or equal to 5, the maximum diameter of the bracket after being pressed and held is more favorably reduced, the diameter of the sheath is further controlled, and the sheath is more favorably recycled.

(3) The number of the hangers is preferably 3 times, so that when the hangers are conveniently recycled into the sheath, the hangers are pressed and held synchronously, and the recycling is more facilitated.

(4) According to the invention, the support structure is arranged at the notch, so that the integral support force of the support can be improved.

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.