CN113662708A - Support and heart valve prosthesis - Google Patents

Abstract

The invention provides a stent and a heart valve prosthesis, wherein the stent comprises a plurality of first wave bars and a plurality of second wave bars; the plurality of first wave bars extend along the axial direction of the support and are sequentially arranged around the axis of the support along the circumferential direction; a grid area is formed between two adjacent first wave bars; each grid area comprises more than two second wave bars, two ends of each second wave bar are respectively connected with two adjacent first wave bars, and the arrangement directions of the second wave bars in the same grid area are the same; two adjacent first wave bars are configured to move in opposite directions along the axial direction of the stent, so as to drive the second wave bars to incline relative to the first wave bars, and the inclination directions of the second wave bars in two adjacent grid areas are opposite, so that the stent expands or contracts in the radial direction.

Description

Support and heart valve prosthesis

Technical Field

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

Background

There are four valves in the human heart, including the aortic, pulmonary, mitral, and tricuspid valves. They all function as one-way valves, and the heart valves open and close rhythmically along with the rhythmic contraction and relaxation of the heart in the blood circulation, so that the blood smoothly passes through the valve orifices and prevents the reflux, and the blood circularly flows in a certain direction in the body to maintain the normal function of the circulatory system. When the heart valve is inflamed, the structure is damaged, fibrosis, adhesion and shortening are caused, myxoma is deformed like, ischemic necrosis and calcium precipitation are caused, and congenital developmental deformity and the like can also cause the valve to be diseased to influence normal blood circulation, so the heart valve disease is medically known. In older adults 65 years old, the incidence of aortic valve stenosis (AS) due to aortic valve degeneration is up to 10%, with the most common type being calcific-aortosis (CAS).

The heart valve intervention operation is a medical technology which is rapidly developed in recent years, and the principle is that a valve prosthesis is implanted into a native valve position through an apex or a blood vessel in a micro-trauma mode and is replaced, so that the aim of treating a patient is finally achieved. The operation has the characteristics of small wound, quick recovery, low risk and the like, and is particularly suitable for patients with advanced heart valves. Transcatheter Aortic Valve Implantation (TAVI) is a type of interventional treatment method for aortic valvular diseases, and is mainly used for treating aortic stenosis and aortic insufficiency.

At present, two main types of aortic valve stent systems are put into clinical application, one is a ball-expanding valve stent which forms a stent main body structure by non-memory alloy and needs to be released by a balloon expansion mode; the other type is a self-expanding valve stent which is formed by a main stent structure made of a memory metal material, utilizes the self-expansion characteristic of the metal material to carry out in vivo release and stably anchor in a lesion area. For self-expanding valve stents, the traditional transcatheter release is: the delivery system restrains the outflow tracts of the stent in a mechanical connection mode, and the outflow tracts are released one by one from the inflow tracts to the outflow tracts in the releasing process. The release process forms a conical opening at the inflow passage end, when the calcification degree of a lesion part is light and the fibrosis degree of valve leaflets is heavy, the support is not easy to form anchoring immediately after contacting with the valve annulus, so that the support can slip in the release process, and the positioning effect is poor. In addition, whether the valve stent is a ball-expanding valve stent or a traditional self-expanding valve stent, a stage of completely blocking blood flow necessarily exists in the release process of the stent, so that the heart needs to be rapidly paced to reduce the ventricular pressure and facilitate valve positioning. For example, in a balloon-expandable valve stent, when inflated with a balloon, the balloon is now completely occluding the blood flow; in conventional released self-expanding valve stents, the outflow tract is completely blocked from blood flow when it contacts the annulus and the prosthetic valve is not yet open. Clinical studies show that rapid pacing of the heart can affect the cardiac electricity generation and conduction of the heart to some extent, thereby causing complications.

Aiming at transcatheter aortic valve implantation, in the release process of the existing self-expandable valve stent, a connecting structure is generally arranged at one end of the stent, when a conveying system carries and conveys the stent to a target position, a sheath tube and an inner tube move relatively to release the stent gradually, in the process, one end of the stent is released firstly (the inflow channel or the outflow channel is released firstly), the other end of the stent is released later, the released stent section is in a horn mouth shape, the anchoring is unstable and easy to generate the slippage of the stent, the slippage of the stent can cause the stent to move towards the left ventricle direction, and the conduction bundle can be stabbed or pressed to cause the function damage of the conduction bundle and the generation of conduction block; it may also cause contusion of other native tissues; in addition, there is a possibility that the unopened prosthetic valve blocks the blood flow path during the release process, which may affect the normal heart function and lead to serious complications.

In conclusion, how to improve the positioning performance of the valve stent and avoid the blockage of blood in the release process of the valve stent is a difficult problem which needs to be solved urgently in clinic, and has important significance for reducing the occurrence of complications.

Disclosure of Invention

The invention aims to provide a stent and a heart valve prosthesis, which aim to solve the problems that the existing valve stent has poor positioning performance when being released, is easy to block blood flow and the like.

In order to solve the above technical problem, the present invention provides a stent for interventional therapy, comprising: a plurality of first wave bars and a plurality of second wave bars;

the plurality of first wave bars extend along the axial direction of the support and are sequentially arranged around the axis of the support along the circumferential direction; a grid area is formed between two adjacent first wave bars;

each grid area comprises more than two second wave bars, two ends of each second wave bar are respectively connected with two adjacent first wave bars, and the arrangement directions of the second wave bars in the same grid area are the same;

two adjacent first wave bars are configured to move in opposite directions along the axial direction of the stent, the second wave bars are configured to tilt relative to the first wave bars, and the tilting directions of the second wave bars in two adjacent grid areas are opposite, so that the stent is converted between a contracted state and an expanded state in the radial direction.

Optionally, the stent has a reference surface perpendicular to the first wave bar and passing through a connection point of the first wave bar and the second wave bar, and the tilt of the second wave bar relative to the first wave bar does not cross the reference surface during the transition of the stent from the contracted state to the expanded state in the radial direction.

Optionally, the support is in during the expansion state, the second ripples pole with first ripples pole out of plumb, first ripples pole with the contained angle of second ripples pole is greater than one side of 90 and is the obtuse angle side, first ripples pole with one side that the contained angle of second ripples pole is less than 90 is the acute angle side.

Optionally, the bracket further comprises a hanging lug, and the hanging lug is arranged at the end part of the first wave rod, which is located on the side of the obtuse angle.

Optionally, the support further comprises a wire-pulling hole, and the wire-pulling hole is formed in the end portion of the obtuse angle side of the first wave rod at intervals.

Optionally, when the stent is in the expanded state, an included angle between the first wave bar and the second wave bar on the acute angle side is between 10 ° and 80 °.

Optionally, the number of the first wave bars is a multiple of 3.

Optionally, a radially outer dimension of the first wave bar is greater than a radially outer dimension of the second wave bar.

Optionally, each grid region includes a plurality of second wave bars, and the plurality of second wave bars are uniformly arranged.

Optionally, the angle between the first wave bar and the axis of the support is not more than 5 °.

In order to solve the above technical problem, the present invention also provides a heart valve prosthesis, which includes: more than two pieces of valves and a stent as described above, the valves being openably and closably disposed within the stent.

In summary, in the stent and the heart valve prosthesis provided by the present invention, the stent includes a plurality of first wave bars and a plurality of second wave bars; the plurality of first wave bars extend along the axial direction of the support and are sequentially arranged around the axis of the support along the circumferential direction; a grid area is formed between two adjacent first wave bars; each grid area comprises more than two second wave bars, two ends of each second wave bar are respectively connected with two adjacent first wave bars, and the arrangement directions of the second wave bars in the same grid area are the same; two adjacent first wave bars are configured to move in opposite directions along the axial direction of the stent, so as to drive the second wave bars to incline relative to the first wave bars, and the inclination directions of the second wave bars in two adjacent grid areas are opposite, so that the stent expands or contracts in the radial direction.

With the configuration, the adjacent first wave bars can move in opposite directions by applying forces in opposite directions to the adjacent first wave bars, so that the support is driven to radially expand and contract. Therefore, when the stent is released, the stent can be released in an equal-diameter mode, so that the main structure of the stent is expanded in a mode close to the equal diameter after being released, a transition mode of a bell mouth shape is avoided, a positioning reference effect is avoided for anchoring the stent in the body (at the release stage, the end of the stent which is released first is provided, and in the conventional situation, the end of the stent which is released in the body slides, and in the TAVI, the end of the stent which is usually an inflow channel end is provided, so that the anchoring stability is improved, and the accuracy of the anchoring position is improved; stress concentration areas of the stent are also dispersed, and the probability of damaging the native tissues of the heart is reduced; the equal diameter deployment of the stent also avoids blockage of the blood flow passageway by an incompletely opened valve. Based on the characteristics, the occurrence probability of conduction block can be reduced. Furthermore, the equal-diameter release of the bracket is also beneficial to observing the release form of the bracket, so that an operator can conveniently adjust the form in time. Furthermore, when the support is recovered, the force in the opposite direction is applied to the first wave rod of the support, the radial size of the support can be rapidly reduced, the support is rapidly pressed and held in the body, the circumferential extrusion force of the support to the sheath tube of the conveying system is reduced, the pressure of the support to the sheath tube is reduced, the operation safety is improved, and the recyclability of the support after release is improved.

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 simplified schematic illustration of a representative portion of a stent;

FIG. 2 is a simplified schematic illustration of an exemplary portion of a stent according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a force analysis of a diamond-shaped mesh;

FIG. 4 is a force analysis diagram of a parallelogram grid;

FIG. 5 is a schematic view of an exemplary portion of a stent according to an embodiment of the present invention;

FIG. 6 is a schematic illustration of a finite element analysis of a stent according to an embodiment of the present invention;

fig. 7 is a schematic diagram illustrating an included angle between a first wave bar and a second wave bar according to an embodiment of the invention.

In the drawings:

01-a scaffold; 05-a scaffold;

10-a first wave bar; 11-a point of attachment; 12-obtuse angle side; 13-acute side; 20-a second wave bar; 30-a grid area; 40-hanging a lug; 41-special-shaped structure; 42-a pull wire hole; 50-valve mounting hole.

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 greatly simplified form and are not to scale, but are merely intended to facilitate and clarify the explanation of the 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, and the term "or" is generally used in its sense including "and/or", the term "proximal" generally being the end near the operator, the term "distal" generally being the end near the lesion in the patient, and "one end" and "the other end" and "proximal" and "distal" generally referring to the corresponding two parts, including not only the end points, unless the content clearly dictates otherwise.

The core idea of the invention is to provide a stent and a heart valve prosthesis, so as to solve the problems that the existing valve stent has poor positioning performance when being released, is easy to block blood flow and the like.

The following description refers to the accompanying drawings.

Referring to fig. 1 to 7, fig. 1 is a simplified diagram of a typical portion of a stent, fig. 2 is a simplified diagram of a typical portion of a stent according to an embodiment of the present invention, fig. 3 is a force analysis diagram of a diamond-shaped mesh, fig. 4 is a force analysis diagram of a parallelogram-shaped mesh, fig. 5 is a diagram of a typical portion of a stent according to an embodiment of the present invention, fig. 6 is a diagram of a finite element analysis of a stent according to an embodiment of the present invention, and fig. 7 is a diagram of an included angle between a first wave rod and a second wave rod according to an embodiment of the present invention.

As shown in fig. 1, a typical section of aconventional stent 01 for interventional therapy is shown (mainly, a partial view of thestent 01 in the axial direction). The grid formed by thebracket 01 is in a quadrilateral (rhombus) or hexagonal shape and the like, a connecting structure is arranged at one end of thebracket 01, and thebracket 01 is pressed and held under the combined action of axial tension provided by the conveyor and circumferential extrusion force of the conveying conduit. In order to realize the synchronous retraction of the two ends (the upper end and the lower end in fig. 1) of the inflow channel and the outflow channel of thestent 01, axial acting force can be simultaneously applied to the two ends of thestent 01, so that the grids of thestent 01 are folded inwards under the action of the axial force to realize loading. The inventor finds that when the upper end and the lower end of theconventional support 01 are provided with applied tension, the upper end point and the lower end point of each rhombic grid displace in the opposite direction of the applied tension, the left end point and the right end point are folded inwards, and the requirement on the performance of a conveying system is high due to the fact that the applied tension is large, and equal-diameter release of a main structure of the support is not easy to achieve. The inventors analyzed that this is related to the way theconventional stent 01 is stressed.

Based on the above analysis, referring to fig. 2 and 5, an embodiment of the present invention provides astent 05 for interventional therapy, which includes: a plurality of first wave bars 10 and a plurality of second wave bars 20; the plurality of first wave bars 10 extend along the axial direction of thestent 05 and are sequentially arranged along the circumferential direction around the axis of thestent 05; agrid area 30 is formed between two adjacent first wave bars 10; eachgrid area 30 includes more than two second wave bars 20, two ends of eachsecond wave bar 20 are respectively connected with two adjacent first wave bars 10, and the arrangement directions of the second wave bars 20 in thesame grid area 30 are the same; two adjacent first wave bars 10 are configured to move in opposite directions along the axial direction of thestent 05, so as to drive the second wave bars 20 to tilt relative to the first wave bars 10, and the tilt directions of the second wave bars 20 in twoadjacent grid areas 30 are opposite, so that thestent 05 is radially switched between a contracted state and an expanded state. Specifically, as shown in fig. 2, taking a typical part of thebracket 05 as an example for illustration, three first wave bars 10 are sequentially arranged along the vertical direction of fig. 2, and twogrid areas 30 at two sides of the middlefirst wave bar 10 respectively include 5 second wave bars 20. When the middlefirst wave bar 10 is forced upward in fig. 2 and the two first wave bars 10 on both sides are forced downward in fig. 2, thesecond wave bar 20 in theleft grid area 30 is inclined to the left and downward, and thesecond wave bar 20 in theright grid area 30 is inclined to the right and downward, that is, the inclination directions of the second wave bars 20 in the twoadjacent grid areas 30 are opposite. It should be understood that the opposite directions of inclination described herein do not mean the opposite directions, but mean the different directions of inclination. With this arrangement, eachgrid section 30 of thestent 05 comprises a plurality of grids similar to a parallelogram, and by applying forces in opposite directions to the adjacent first wave bars 10, the adjacent first wave bars 10 can move in opposite directions, and the second wave bars 20 are pulled to incline, so as to drive thestent 05 to expand or contract in a radial direction in a substantially equal-diameter manner. Here, the contracted state refers to a state in which the angle between thesecond wave bar 20 and thefirst wave bar 10 is minimum, the distance between the first wave bars 10 is minimum, the radial outer dimension of theentire stent 05 is also minimum, and thestent 05 in the contracted state can be stored in a delivery system (e.g., a sheath) for delivery. The expanded state refers to a state in which the angle between thesecond wave bar 20 and thefirst wave bar 10 is the largest, at which the distance between the first wave bars 10 is the largest and the radial outer dimension of theentire stent 05 is also the largest, i.e., an expanded state, i.e., a working state after thestent 05 is placed in a human body. Preferably, thestent 05 has self-expanding properties, i.e. it is a self-expanding stent. Of course, in other embodiments, thestent 05 may be a ball-expanding stent. It should be noted that, the arrangement directions of the second wave bars 20 in thesame grid region 30 are the same, which means that the second wave bars 20 are arranged in the substantially same trend. If the second wave bars 20 are linear, the second wave bars 20 are preferably arranged in parallel with each other, but the second wave bars 20 may not be parallel to each other or have a slight angle therebetween, and when a force is applied to thefirst wave bar 10, thesecond wave bar 20 may be inclined within a certain range. Specifically, in some embodiments, the second wave bars 20 in the same grid area may be different, for example, a portion of the second wave bars 20 is linear, a portion of the second wave bars 20 is curved or zigzag, and the like, and the second wave bars 20 with different shapes are arranged in the same arrangement direction, and the same-direction inclination can also be realized under the driving of thefirst wave bar 10. Those skilled in the art can arrange the second wave bars 20 differently according to the actual shape, arrangement, number, etc.

The inventors have found that the parallelogram-meshedstent 05, which achieves radial expansion and contraction, has a smaller axial force than the diamond-meshedstent 01. Please refer to fig. 3 and fig. 4, which are force analysis diagrams of the diamond-shaped mesh and the parallelogram-shaped mesh, respectively. The included angles of the upper and lower ends of the two grids are alpha, and equal tension F is applied to the opposite angles of the two grids₀. The tensile force F₀Will be transmitted along the wave rod of the support, forming an inwardly directed force component, where the force component in fig. 3 is F₁The component force is F in FIG. 4₂. From mechanical geometry analysis it can be known that: f₁＝2F₀*tan(α/2)，F₂＝F_0*tan (α), derived by continuing: f₁/F₂＝1-tan²(α/2). Thus having F₁<F₂. From the above-mentioned results, it can be understood that the same magnitude of the acting force F is applied₀Acting on the support, the horizontal component force of the traditional rhombic grid is smaller than that of the parallelogram grid. The horizontal component is the force which actually acts on the radial expansion of the support (namely, thesupport 05 radially expands and contracts under the action of the horizontal component), so that thesupport 05 adopting the parallelogram grid can realize the radial expansion and contraction, and compared with thesupport 01 of the traditional rhombic grid, the axial force which needs to be applied is smaller, the load of a conveying system can be reduced, and the requirement on the conveying system is reduced.

Further, please refer to fig. 6, which is a schematic diagram of a finite element analysis of the rhombus mesh and the parallelogram mesh, wherein the software simulation conditions of the finite element analysis are as follows: the axial stretching speed of the grid is the same, the displacement of the grid in the axial direction is the same under the same time, namely the deformation degree is basically consistent, and a relation graph of time and axial force, namely a tension curve graph, is obtained through testing. In fig. 6, the abscissa is time (in seconds/s) and the ordinate is axial force (in newtons/N), a force is applied to a single diamond-shaped mesh, the direction of the force is located on the diagonal of the diamond-shaped mesh, and the curve of the applied force is shown as curve Q1 in fig. 6; applying a force to the single parallelogram grid, wherein the direction of the force is located on two opposite parallel sides of the parallelogram grid, and the curve of the tensile force after applying the force is shown as a curve Q2 in FIG. 6; as can be seen from fig. 6, under the same conditions of time and stretching rate, when the same displacement is generated in the axial direction, the axial force of the parallelogram grids is significantly smaller than that of the rhomboid grids, that is, the force required for pressing and holding thebracket 05 of the parallelogram grids is significantly smaller than that of thebracket 01 of the rhomboid grids, so that thebracket 05 of the parallelogram grids is stressed in a manner significantly better than thebracket 01 of the rhomboid grids (the diagonal stress). While in general, large loading forces (including the force required to squeeze the stent) can place significant stress on the delivery system; the force required by thestent 05 to be crimped is significantly smaller than that of thestent 01 with the rhombic grids, so that the load of a conveying system is effectively reduced, and the constant-diameter release of thestent 05 is realized under the condition of limited axial tension.

Preferably, thefirst wave bar 10 and thesecond wave bar 20 are made of a memory metal material. In an exemplary embodiment, thefirst wave bar 10 and thesecond wave bar 20 may be integrally formed by cutting.

The memory metal material has deformation recovery capability, namely, under low temperature (such as ice water bath), the memory metal material is changed into a martensite phase, shows soft characteristic, can be subjected to proper operations of twisting, bending, compressing and the like, and can be recovered to an austenite phase after the temperature is increased. At normal body temperature, thestent 05 made of memory metal material exhibits strong radial support force. In an in vitro implantation procedure, thestent 05 is typically first rendered soft in the martensite phase for loading at low temperature (ice-water bath), and after loading is completed, the delivery catheter follows the vascular access into the desired region, and then thestent 05 is released, during which thestent 05 gradually reverts from the martensite phase to the austenite phase, becoming progressively stiffer. Before thestent 05 is removed from the sheath to be released, tension in opposite directions can be applied to the adjacent first wave bars 10 to maintain the radial contraction state of the stent, and then the tension applied to the first wave bars 10 is gradually removed, so that thestent 05 radially expands in an equal diameter manner.

Preferably, thestent 05 has a reference plane perpendicular to thefirst wave bar 10 and passing through aconnection point 11 of thefirst wave bar 10 and thesecond wave bar 20, and during transition of thestent 05 from the contracted state to the expanded state in the radial direction, thesecond wave bar 20 adjacent to theconnection point 11 is inclined relative to thefirst wave bar 10 without crossing the reference plane. Generally, since thesecond wave bar 20 and thefirst wave bar 10 have a certain width, the connection between the two wave bars has a certain geometric size. Theconnection point 11 of thefirst wave lever 10 and thesecond wave lever 20 is understood here to be the intersection of the axis of thefirst wave lever 10 and the axis of thesecond wave lever 20. It will be appreciated that in the collapsed condition of thesupport 05, the angle between thesecond wave bar 20 and the reference plane is greatest and closer to the axial direction of thefirst wave bar 10. During the transition from the contracted state to the expanded state, thesecond wave lever 20 gradually inclines and approaches the reference plane with theconnection point 11 as a rotation axis, but should be limited not to cross the reference plane (may coincide with the reference plane). During the transition of thestent 05 from the contracted state to the expanded state, when the second wave bars 20 are overlapped on the reference surface, that is, when the second wave bars 20 are perpendicular to the first wave bars 10, the distance between the first wave bars 10 can obtain the maximum value, and when the second wave bars 20 cross the reference surface, the distance between the first wave bars 10 is decreased instead. If the second wave bars 20 cross the reference plane during the transition of thestent 05 from the contracted state to the expanded state, the radial outer dimension of theentire stent 05 will exhibit: thestent 05, which increases-to a maximum-decreasing state in which the radially outer dimension decreases after expansion, may undesirably over-expand the human tissue or lose stable positioning when decreasing after expansion. It is therefore desirable to limit the tilt of thesecond wave bar 20 from crossing the reference plane. In some embodiments, when thestent 05 is in the expanded state, with thesecond wave bar 20 coinciding with the reference plane, i.e. perpendicular to thefirst wave bar 10, thestent 05 can take its largest radial outer dimension. Alternatively, thefirst wave bar 10 is substantially straight and thesecond wave bar 20 is S-shaped and bent, and the axis of thesecond wave bar 20 can be understood as the central axis of the S-shape. Of course, the shape of thesecond wave lever 20 is not limited to the S shape, and those skilled in the art can configure the shape of thesecond wave lever 20 differently according to the actual application.

Preferably, referring to fig. 7, when thestent 05 is in the expanded state, thesecond wave bar 20 is not perpendicular to thefirst wave bar 10, a side of thefirst wave bar 10, which has an included angle greater than 90 °, with thesecond wave bar 20 is anobtuse angle side 12, and a side of thefirst wave bar 10, which has an included angle less than 90 °, with thesecond wave bar 20 is anacute angle side 13. It should be noted that theobtuse angle side 12 and the acute angle side refer to two opposite end sides of thefirst wave lever 10, taking theobtuse angle side 12 as an example, when thesecond wave lever 20 is not perpendicular to thefirst wave lever 10, the samesecond wave lever 20 and the axial direction of thefirst wave lever 10 form a complementary obtuse angle and an acute angle, and the side of thefirst wave lever 10 facing the obtuse angle is the obtuse angle side. In contrast, the side of thefirst wave lever 10 facing the acute angle is the acute angle side. For a particularfirst wave bar 10, thefirst wave bar 10 has only oneobtuse angle side 12 and only oneacute angle side 13, because the second wave bars 20 in thesame grid region 30 are arranged in the same direction. It will be appreciated that for the part of thebracket 05 shown in figure 7, the obtuseangled side 12 of thefirst wave bar 10 is the upper side and the acuteangled side 13 is the lower side.

Further, when thestent 05 is in the expanded state, an included angle between thefirst wave bar 10 and thesecond wave bar 20 on the acute angle side is between 10 ° and 80 °. Eachsecond wave bar 20 forms a complementary obtuse angle and an acute angle with the axial direction of thefirst wave bar 10, and the two angles are respectively located on two sides of the intersection point of thesecond wave bar 20 and thefirst wave bar 10. The included angle between thefirst wave bar 10 and thesecond wave bar 20 on the acute angle side is an acute angle formed by thesecond wave bar 20 and the axial direction of thefirst wave bar 10. Such as the angle on the underside of eachsecond wave bar 20 in figure 7. With such an arrangement, the inclination change angle of thesecond wave rod 20 is small, so that the strain at the joint of thesecond wave rod 20 and thefirst wave rod 10 can be ensured within the elastic range, and the second wave rod is not permanently deformed after being loaded into the sheath.

Further, as shown in fig. 5, thebracket 05 further includes a hanginglug 40, and the hanginglug 40 is disposed at an end of thefirst wave lever 10 on the obtuse angle side. It should be understood that the end of the obtuse angle side is not limited to the end of thefirst wave bar 10, but is understood to be a section of thefirst wave bar 10 near the end portion. The form of implementation of the hanginglug 40 is not limited, and can be a special-shapedstructure 41, for example, which is matched with a fixing piece arranged on the conveying system through shape matching. In a preferred embodiment, thesupport 05 is controlled to be pressed and released by a pulling wire, and specifically, the support further comprises a pullingwire hole 42, the pullingwire hole 42 is arranged at the end of the obtuse angle side of thefirst wave rod 10 at intervals, that is, the pullingwire hole 42 is arranged at intervals at the end of thefirst wave rod 10 in the same direction. Preferably, thewire hole 42 is provided in one direction of thestent 05, and as shown in fig. 5, thewire hole 42 is provided at one end above thestent 05. In this manner, during release of thestent 05, thestent 05 expands in a nearly constant diameter after release under the control of the pull wire. Optionally, the outer contour of the hanginglug 40 is smooth, so as to avoid scratching human tissues. Preferably, one hanginglug 40 is provided at an end of eachfirst wave lever 10, or the hanging lugs 40 are provided at intervals from the end of thefirst wave lever 10 in the same direction. For example, the upper end of thefirst wave bar 10 is provided with a hanginglug 40, the upper end of thethird wave bar 10 is provided with a hanginglug 40, the upper end of thefifth wave bar 10 is provided with a hanginglug 40, and so on. The even number of thehangers 40 of thefirst wave lever 10 are arranged in the direction different from the direction in which thehangers 40 of the first, third and fifth first wave levers 10 are arranged, and thehangers 40 may be arranged at intervals or all of the even number of the first wave levers 10. The shape of the hanginglug 40 positioned in different directions of thefirst wave lever 10 may be the same or different. Optionally, the end of thefirst wave bar 10 is further provided with avalve mounting hole 50 for connection with a valve.

Preferably, the number of the first wave bars 10 is a multiple of 3, so that the valve can be sutured more conveniently. In some embodiments of the present invention, the number of the first wave bars 10 is preferably 6 to 12, so as to increase the force uniformity of each grid, and as the number of the first wave bars 10 is increased, the axial force of thewhole stent 05 can be uniformly distributed on each pulling device (such as the connecting wires), so that the acting force on the pulling devices (connecting wires) is further reduced, and the performance requirement on the conveying device is reduced.

Preferably, the radially outer dimension of thefirst wave bar 10 is larger than the radially outer dimension of thesecond wave bar 20. The arrangement ensures the tensile and compressive properties of thefirst wave rod 10, and improves the overall rigidity and stability of thebracket 05. In some embodiments of the present invention, the length of thefirst wave bar 10 is determined by the required height of thestent 05, and is optionally 10mm to 60mm, preferably 20mm to 45mm, and more preferably 20mm to 30mm, so that thestent 05 has a shorter axial dimension, on one hand, the coaxiality of thestent 05 with respect to the valve annulus is improved, on the other hand, theshorter stent 05 provides sufficient space for the coronary artery to intervene, and furthermore, the implantation depth of thestent 05 can be controlled at a higher position, so as to prevent the inflow channel from contacting the conduction bundle, and further reduce or avoid the occurrence of conduction block.

Optionally, eachgrid region 30 includes a plurality of second wave bars 20, and the plurality of second wave bars 20 are uniformly arranged. The second wave bars 20 are uniformly arranged, that is, the second wave bars 20 in eachgrid region 30 are arranged at equal intervals. It is understood that the spacing of the second wave bars 20 indifferent grid areas 30 may be the same or different. The second wave bars 20 arranged uniformly can make thesupport 05 more uniform when being extended or retracted. Of course, the second wave bars 20 may be arranged at different intervals, or may be differently arranged according to the shape of the main body of theholder 05.

Optionally, the angle between thefirst wave bar 10 and the axis of thesupport 05 is not more than 5 °. Thefirst wave bar 10 extends along the axial direction of thesupport 05, and is not limited to thefirst wave bar 10 being parallel to the axis of thesupport 05, but may be at an angle. Here, the included angle between thefirst wave rod 10 and the axis of thesupport 05 is limited to be not more than 5 °, so that the axial force applied to the end of thefirst wave rod 10 can more efficiently form a radial component force, and is converted into a force for pushing thesupport 05 to expand and contract in the radial direction. Of course, the plurality of first wave bars 10 may be parallel to each other, and maintain the same included angle with the axis of thebracket 05, or the plurality of first wave bars 10 may also be non-parallel, for example, the arrangement order of 5 °, 0 °, and 5 ° is formed, and the invention is not limited thereto.

Based on the above-mentioned stent, the present embodiment also provides a heart valve prosthesis, which includes: two or more pieces of a valve (not shown) and thestent 05 described above, the valve being openably and closably disposed in thestent 05. Preferably, the heart valve prosthesis comprises a 3-piece valve, the ends of which are connected to the first wave bars 10, such as to the valve mounting holes 50. The heart valve prosthesis may be suitably configured by those skilled in the art in light of the prior art. Since the heart valve prosthesis provided by the present embodiment includes the stent as described above, and has the beneficial effects brought by the stent, further description of other structures and principles of the heart valve prosthesis is omitted here. The following exemplarily illustrates an application of the heart valve prosthesis provided in the present embodiment:

the model and the access route of the TAVI heart valve prosthesis are selected according to the condition of a patient, the heart valve prosthesis is selected and is pressed in vitro, and the heart valve prosthesis is loaded into a sheath of a delivery system. The conveying system loaded with the heart valve prosthesis is implanted into a diseased position through an approach, then the heart valve prosthesis is released in a pull line control mode, thestent 05 of the heart valve prosthesis is gradually restored to an austenite phase from a martensite phase under the body temperature environment, native valve leaflets at the diseased position are propped open, and the valves in the heart valve prosthesis replace the native valve leaflets to play the function of the heart valve.

In summary, in the stent and the heart valve prosthesis provided by the invention, the adjacent first wave bars can move in opposite directions by applying forces in opposite directions to the adjacent first wave bars, so as to drive the stent to radially expand and contract. Therefore, when the support is released, the support can be released in an equal-diameter mode, so that the main body structure of the support is unfolded in a mode close to the equal diameter after being released, and a transition mode of a bell mouth shape is avoided, the end part of the anchoring end is prevented from sliding, the anchoring stability is improved, and the accuracy of the anchoring position is improved; stress concentration areas of the stent are also dispersed, and the probability of damaging the native tissues of the heart is reduced; the equal diameter deployment of the stent also avoids blockage of the blood flow passageway by an incompletely opened valve. Based on the characteristics, the occurrence probability of conduction block can be reduced. Furthermore, the equal-diameter release of the bracket is also beneficial to observing the release form of the bracket, so that an operator can conveniently adjust the form in time. Furthermore, when the support is recovered, the force in the opposite direction is applied to the first wave rod of the support, the radial size of the support can be rapidly reduced, the support is rapidly pressed and held in the body, the circumferential extrusion force of the support to the sheath tube of the conveying system is reduced, the pressure of the support to the sheath tube is reduced, the operation safety is improved, and the recyclability of the support after release is improved.

It should be noted that the above description is only for describing the preferred embodiments of the present invention, and not for limiting the scope of the present invention, and that any changes and modifications made by those skilled in the art in light of the above disclosure are all within the scope of the appended claims.

Claims (10)

1. A stent for interventional therapy, comprising: a plurality of first wave bars and a plurality of second wave bars;

the plurality of first wave bars extend along the axial direction of the support and are sequentially arranged around the axis of the support along the circumferential direction; a grid area is formed between two adjacent first wave bars;

each grid area comprises more than two second wave bars, two ends of each second wave bar are respectively connected with two adjacent first wave bars, and the arrangement directions of the second wave bars in the same grid area are the same;

two adjacent first wave bars are configured to move in opposite directions along the axial direction of the stent, the second wave bars are configured to tilt relative to the first wave bars, and the tilting directions of the second wave bars in two adjacent grid areas are opposite, so that the stent is converted between a contracted state and an expanded state in the radial direction.

2. The stent of claim 1, wherein the stent has a reference surface perpendicular to the first wave bar and passing through a point of connection of the first wave bar with the second wave bar, wherein tilting of the second wave bar relative to the first wave bar does not cross the reference surface during transition of the stent in a radial direction from the contracted state to the expanded state.

3. The stent according to claim 2, wherein when the stent is in the expanded state, the second wave bar is not perpendicular to the first wave bar, a side of the first wave bar that includes an angle larger than 90 ° with the second wave bar is an obtuse angle side, and a side of the first wave bar that includes an angle smaller than 90 ° with the second wave bar is an acute angle side.

4. The stent of claim 3, further comprising a hanger provided at an end of the first wave bar on the obtuse angle side.

5. The stent according to claim 4, further comprising a wire hole provided at an end of the obtuse-angle side of the first spaced wave bar.

6. The stent of claim 3, wherein the first wave bar and the second wave bar form an angle between 10 ° and 80 ° on the acute side when the stent is in the expanded state.

7. The stent of claim 1, wherein the number of first wave bars is a multiple of 3.

8. The stent of claim 1, wherein a radially outer dimension of the first wave bar is greater than a radially outer dimension of the second wave bar.

9. The stent of claim 1 wherein the first wave bar is at an angle of no more than 5 ° to the axis of the stent.

10. A heart valve prosthesis, comprising: two or more pieces of a valve and a stent according to any one of claims 1 to 9, the valve being openably and closably disposed within the stent.

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