CN113040988A

CN113040988A - Blood vessel support

Info

Publication number: CN113040988A
Application number: CN201911371170.XA
Authority: CN
Inventors: 肖本好; 李�真
Original assignee: Shenzhen Xianjian Changtong Medical Co ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2021-06-29
Anticipated expiration: 2039-12-26
Also published as: CN113040988B

Abstract

The invention relates to a vascular stent which comprises a supporting layer and a flexible layer, wherein the supporting layer comprises a plurality of repeating units which are arranged along the axial direction, hollow parts are formed among the repeating units, the flexible layer at least covers part of the hollow parts, the flexible layer comprises a plurality of fiber yarns, and an included angle between the length extending direction of the fiber yarns and the length extending direction of the vascular stent is larger than 0 degree and smaller than 90 degrees. The supporting layer is used for carrying out effectual support to stenosis department pathological change blood vessel to avoid its further stenosis to block up, the flexible layer is attached to on the supporting layer, because the flexible layer has the flexibility, thus can conform to the laminating plaque surface, thereby avoid the plaque to drop. Further, because supporting layer and flexible layer are foraminiferous structure, the crisscross whole hole of overlapping adjustable blood vessel support of mesh after the two stack to further avoid droing of little plaque. In addition, when the lesion area has a branch blood vessel, the blood flow can flow out through the pore, thereby ensuring that the branch blood vessel is not blocked.

Description

Blood vessel support

Technical Field

The invention belongs to the field of medical instruments, and particularly relates to a vascular stent.

Background

At present, the main interventional therapy means for the stenosis of the vascular plaque is to implant a vascular stent. There are two kinds of common blood vessel stents, one is a covered stent, and the other is a metal bare stent. When the stent graft is selected, the problem of occlusion or restenosis may occur due to the fact that the stent graft has a problem that the wall thickness is large and the inner cavity of the stent is small, and in addition, the stent graft is not suitable for the area with the branch blood vessel (the branch blood vessel is blocked due to the existence of the stent graft). When the metal bare stent is selected, the metal bare stent is subjected to continuous artery diastolic extrusion of blood vessels, and the stent metal wires can cause the plaque to fall off from the gap of the metal bare stent due to continuous stimulation of the plaque, so that the problem of thrombus is caused, and particularly when the metal bare stent is used in a carotid artery position, the risk of cerebral apoplexy can be caused.

In conclusion, the existing covered stents and metal bare stents can not obtain satisfactory effect when treating the vascular plaque stenosis.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a stent for treating plaque stenosis in a blood vessel, which is free from problems such as occlusion or restenosis and plaque detachment caused by implantation of the stent. The purpose is realized by the following technical scheme:

the embodiment of the invention provides a vascular stent, which comprises a supporting layer and a flexible layer, wherein the supporting layer comprises a plurality of repeating units which are distributed along the axial direction, hollow parts are formed among the repeating units, the flexible layer at least covers part of the hollow parts, the flexible layer comprises a plurality of fiber yarns, and an included angle between the length extending direction of the fiber yarns and the length extending direction of the vascular stent is larger than 0 degree and smaller than 90 degrees.

In an embodiment, the axial elongation of the flexible layer is not greater than the axial elongation of the support layer.

In one embodiment, the repeating unit comprises peaks having an included angle, and the included angle between the length direction of the fiber filaments and the length direction of the blood vessel stent is not more than half of the included angle of the peaks.

In one embodiment, the flexible layer is a grid structure, and a plurality of the fiber filaments are interlaced with each other to form a grid-shaped flexible layer.

In one embodiment, the repeating unit comprises W-shaped wave rings, each two adjacent W-shaped wave rings form a group of wave rings, and wave troughs of one W-shaped wave ring in the group of wave rings are correspondingly connected with wave crests of the other W-shaped wave ring so as to form a plurality of quadrilateral grids in the group of wave rings; the filament forms two nodes when passing through two opposite screw rods of the quadrilateral mesh, wherein at one node, the filament passes through the inner side of the screw rod, and at the other node, the filament passes through the outer side of the screw rod.

In one embodiment, the flexible layer comprises a plurality of fibrous tapes helically wound around the outer surface of the support layer.

In one embodiment, the fiber band comprises two parallel edges, the plurality of fiber filaments are connected between the two edges, and the plurality of fiber filaments are arranged in parallel.

In one embodiment, the included angle between the fiber filaments on two adjacent fiber belts is larger than 0 degree.

In one embodiment, the fiber filaments of the two adjacent fiber bands respectively extend towards two sides of the axis of the blood vessel support.

In one embodiment, the flexible layer comprises a plurality of fiber belts connected in series along the axial direction, fiber distribution areas and hollow-out areas are formed on the fiber belts and distributed alternately, and the plurality of fiber filaments are arranged in the fiber distribution areas in parallel.

In one embodiment, the repeating unit comprises wave circles which comprise a plurality of wave crests and wave troughs, and in every two adjacent wave circles, the wave trough of one wave circle passes through the wave crest of the other wave circle to form an overlapping region between the wave trough and the wave crest, and simultaneously, the wave crest of the one wave circle and the wave trough of the other wave circle form a quadrilateral grid.

In an embodiment, the fiber distribution area is arranged corresponding to and covering the quadrilateral mesh, and the hollow-out area is arranged corresponding to the overlapping area.

The invention has the advantages that:

the blood vessel support comprises a support layer and a flexible layer, wherein the support layer is used for effectively supporting a lesion blood vessel at a stenosis so as to avoid further stenosis blockage, and the flexible layer is attached to the support layer. Because the flexible layer has the flexibility, therefore can follow the laminating plaque surface to the flexible layer can also play the effect of buffering, reduces stress concentration, and the holding power that the supporting layer was applyed can not all directly be used the plaque on, has reduced the pressure that receives on the plaque unit area, thereby avoids the plaque to drop. And the flexible layer comprises a plurality of fiber filaments, and the included angle between the length extending direction of the fiber filaments and the length extending direction of the intravascular stent is larger than 0 degree and smaller than 90 degrees, so that the flexible layer can better conform to the change of the supporting layer structure.

Drawings

The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings.

In the drawings:

FIG. 1 is a schematic structural diagram of a vascular stent according to one embodiment of the present invention;

FIG. 2 is a schematic partial structure diagram of a supporting layer according to an embodiment of the invention;

FIG. 3 is a schematic view of a partial structure of a flexible layer according to one embodiment of the present invention;

FIG. 4 is a schematic structural view of a blood vessel stent implanted in a blood vessel according to one embodiment of the present invention (arrows in the figure represent the flow direction of blood);

FIG. 5 is a schematic view of a blood vessel stent implanted in a blood vessel according to one embodiment of the present invention (the lesion region has a branch blood vessel, and the arrows in the figure represent the flow direction of blood);

FIG. 6 is a schematic view of a stent in accordance with one embodiment of the present invention from an expanded state to a compressed state (FIG. a is the expanded state, FIG. b is the compressed state);

FIG. 7 is a prior art stent graft shown in the expanded state and compressed state (shown in FIG. a and compressed state in FIG. b);

FIG. 8 is a schematic representation of a comparison of gap size and patch size for filaments according to one embodiment of the present invention;

FIG. 9 is a schematic diagram showing the position relationship between the fiber filaments and the quadrilateral meshes when the stent is in the expanded state according to one embodiment of the present invention;

FIG. 10 is a schematic diagram showing the position relationship between the fiber filaments and the quadrilateral meshes when the stent is in a compressed state according to one embodiment of the present invention;

FIG. 11 is a schematic diagram showing the position relationship between the fiber filaments and the lead screws at the end of the support layer when the stent is in a deployed state according to one embodiment of the present invention;

FIG. 12 is a schematic diagram showing the position relationship between the fiber filaments and the lead screws at the ends of the support layer when the stent is in a compressed state according to one embodiment of the present invention;

FIG. 13 is a schematic structural view of a second embodiment of the intravascular stent of the present invention;

FIG. 14 is a schematic view of the connection relationship between the flexible layer and the supporting layer according to a second embodiment of the present invention;

FIG. 15 is a partial schematic view of a flexible layer according to a second embodiment of the invention;

FIG. 16 is an enlarged partial view of a flexible layer according to a second embodiment of the present invention;

FIG. 17 is a schematic view of a vascular stent according to a third embodiment of the present invention;

FIG. 18 is a partial schematic view of a vascular stent in accordance with a third embodiment of the present invention;

FIG. 19 is a schematic structural view of a fourth embodiment of the intravascular stent of the present invention;

fig. 20 is a schematic view of a stent in a curved configuration to accommodate a curved vessel.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless specifically identified as an order of performance. It should also be understood that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For convenience of description, spatially relative terms, such as "inner", "outer", "lower", "below", "upper", "above", and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" can include both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

One embodiment of the present invention provides a blood vessel stent 100, and the structure of the blood vessel stent 100 can refer to fig. 1 and fig. 2. Specifically, the vascular stent 100 comprises a support layer 10, wherein the support layer 10 comprises a plurality of repeating units arranged along the axial direction, and hollow parts 12 are formed between the repeating units. The blood vessel stent 100 further comprises a flexible layer 20 with pores, the flexible layer 20 is connected with the support layer 10, and the flexible layer 20 at least covers part of the hollow part 12.

The blood vessel support 100 comprises a support layer 10 and a flexible layer 20, wherein the support layer 10 is used for effectively supporting a lesion blood vessel at a stenosis part to avoid further stenosis blockage, and the flexible layer 20 is connected with the support layer 10 and can be conformed to the surface of a plaque due to the flexibility of the flexible layer 20, so that the plaque is prevented from falling off. Further, because the support layer 10 and the flexible layer 20 are both of a porous structure, the mesh holes are overlapped in a staggered manner after the support layer and the flexible layer are overlapped, so that the whole pores of the intravascular stent 100 can be adjusted, and the small plaques are further prevented from falling off. In addition, when the lesion area has a branch blood vessel, the blood flow can flow out through the pore, thereby ensuring the branch blood vessel to supply blood.

Further, the repeating unit may be a W-shaped wave ring 11 made of a braided wire, the W-shaped wave ring 11 has a plurality of wave crests and wave troughs alternately arranged, and the W-shaped wave ring 11 is used as the repeating unit, so that the supporting layer 10 has very good elasticity, so that the supporting layer 10 can be sufficiently expanded in a free state and has a relatively small volume in a compressed state. It is understood that the wave crests or the wave troughs of the plurality of W-shaped wave rings 11 may be aligned with each other or may be staggered with each other along the axial direction of the stent 100, which is not limited by the present invention. In other embodiments, the repeating units may also take on other configurations that facilitate compression and expansion, such as circular arc type wave rings, etc.

Further, as shown in fig. 3, the flexible layer 20 includes a plurality of fiber filaments 21. The fiber yarns 21 are of flexible yarn structures, the fiber yarns 21 are mutually staggered to form a latticed flexible layer (the staggered points among the fiber yarns 21 are marked as nodes A), and the formed latticed flexible layer is relatively soft (at least softer than the supporting layer), so that the latticed flexible layer can be well attached to the surface of a plaque, and the plaque is prevented from falling off. Specifically, the fiber filaments 21 shuttle between the hollow parts of the support layer, and an included angle is formed between the length direction of the single fiber filament 21 and the length direction of the blood vessel stent, and the included angle is greater than 0 degree and smaller than 90 degrees. The theory of high parallelogram flexibility shows that the included angle is larger than 0 degree and smaller than 90 degrees, so that the flexible layer can better conform to the change of the supporting layer structure. In practice, in order to provide good support, the natural expanded diameter of the stent is generally larger than the diameter of the blood vessel, and the stent is slightly compressed after being implanted into the blood vessel. In order to avoid the flexible layer from being folded or piled up when the vascular stent is compressed, the axial elongation of the flexible layer is not more than that of the support layer, and the radial piling is more serious when the axial elongation is larger. In this embodiment, the included angle between the length direction of the fiber filament and the length direction of the blood vessel stent is not more than half of the included angle of the wave crest of the wave ring 11. The lattice-shaped flexible layer forms a plurality of nodes a at the hollow-out portions 12 of the support layer 10, thereby ensuring that the flexible layer 20 assumes a completely curved state to conform to the plaque area at the stenosis of the blood vessel. As shown in fig. 4, in a branched blood vessel 200, one side of the blood vessel is a stenotic lesion with a plaque 210, the flexible layer 20 can conform to cover the plaque 210, on one hand, the plaque 210 can be prevented from falling off, and on the other hand, the stenotic lesion can be expanded by the radial force of the support layer 10.

It will be appreciated that in other embodiments, the axial elongation of the flexible layer may be made no greater than the axial elongation of the support layer by material selection or wire diameter selection.

On the other hand, as shown in fig. 5, the lattice-shaped flexible layer formed by interlacing the fiber filaments 21 is filled with pores, and when the blood vessel stent 100 is used in an area with a branch blood vessel 200, the lattice-shaped flexible layer can allow blood flow in the branch blood vessel to pass through, thereby ensuring that the branch blood vessel 200 is not blocked.

Furthermore, the grid-shaped flexible layer and the lead screw of the support layer 10 are positioned on the same circumference, and the fiber filaments 21 can move, so that when the blood vessel stent 100 is compressed, the overall outer diameter is smaller than that of the covered stent 300 with the same size, namely D0 is larger than D2 is larger than D1, as shown in fig. 6 and 7, thereby the blood vessel stent 100 can be loaded into a conveyor with lower Profile.

Further, the gaps between the filaments 21 may be set according to the size of the plaque area. Generally, the pores of the mesh-like flexible layer are smaller than the size of the plaque surface area, as shown in FIG. 8, i.e., S1 < S2, where S1 is the pore area and S2 is the plaque surface area.

In some specific embodiments, every two W-shaped wave rings 11 are a set of wave rings (as shown in fig. 2) along the axial direction of the blood vessel stent 100. In each group of wave coils, the wave troughs of one W-shaped wave coil 11 are correspondingly connected with the wave crests of another W-shaped wave coil 11 to form a plurality of quadrilateral grids 111 in the group of wave coils. As shown in fig. 9, for one fiber filament 21, when passing through two opposing lead screws of the quadrilateral mesh 111, two nodes B and C are formed, wherein at one node B, the fiber filament 21 passes through the inner side (the side close to the axis of the vascular stent 100) of the lead screw, and at the other node C, the fiber filament 21 passes through the outer side (the side away from the axis of the vascular stent 100) of the lead screw, so that the fiber filament 21 is alternately inserted into each quadrilateral mesh 111 of the support layer 10 to ensure that the flexible layer 20 is always connected with the support layer 10. Meanwhile, the node where the adjacent fiber yarn intersects with the screw rod on the same screw rod is in an opposite form, for example, at the point B where the first fiber yarn intersects with the screw rod, the fiber yarn is positioned on the inner side of the screw rod, and the intersection point of the adjacent fiber yarn and the screw rod is positioned on the outer side of the screw rod.

Specifically, as shown in fig. 9 and 10, when the supporting layer 10 is compressed, the nodes slide along the lead screws, i.e., a → a ', B → B ', C → C ', and at the same time, the size and position of the pores on the lattice-shaped flexible layer are changed to conform to the change of the supporting layer 10. In addition, as shown in fig. 11 and 12, in the quadrilateral meshes 111 at the two ends of the blood vessel stent 100, one end of the fiber 21 is movably fixed on the lead screw at the most end, the movable node is marked as D, and when the supporting layer 10 is compressed, the node can slide along the axial direction of the lead screw, i.e., D → D', to conform to the change of the supporting layer 10. Therefore, during the expansion and compression of the blood vessel stent 100, the flexible layer 20 and the support layer 10 can be changed in coordination, and wrinkles are not easily formed.

In other embodiments, different sets of wave rings can be connected by connectors 13, so that the sets of wave rings are connected to each other to form the support layer 10. As shown in fig. 2, adjacent wave coils or wave coil groups are connected by a connecting member 13.

As shown in fig. 13, the second embodiment of the present invention provides a blood vessel stent 100, which has substantially the same structure as the first embodiment, except for the structure of the flexible layer 20.

Specifically, the flexible layer 20 includes a plurality (e.g., 2, 3, etc.) of fiber bands 22 helically wound around the outer surface of the stent body 10, with adjacent fiber bands 22 forming adjacent edges 23 therebetween. Further, adjacent strips of fabric may be joined together by stitching or the like at adjacent edges 23. In the present embodiment, a plurality of fiber bands 22 are spirally wound on the outer surface of the stent body 10, and the flexible layer 20 can satisfy the use requirements of deformation compliance of the support layer 10 and blood flow passing.

As shown in fig. 14, the flexible layer 20 may be further connected to the support layer 10 by a movable wire or membrane grommet 30 or the like.

Further, as shown in fig. 15, the fiber tape 22 includes two parallel sides and a plurality of parallel arranged fiber filaments 221 connected between the two sides, and an angle between the fiber filaments 221 and the sides is less than 90 °. In the embodiment, the fiber filaments 221 on the fiber belt 22 are arranged in parallel, gaps among the fiber filaments 221 can form pores, and nodes piled up with each other are not easy to occur among the fiber filaments 221, so that the probability of forming wrinkles is lower, and a better antithrombotic effect is achieved. Similarly, in order to make the flexible layer have good compliance when the stent is deformed, the extending length of the fiber band and the included angle between the extending length of the fiber filaments on the fiber band and the length direction of the stent are both greater than 0 degree and less than 90 degrees. In order to avoid the flexible layer from being folded or piled up when the blood vessel stent is compressed, the axial elongation of the flexible layer is not more than that of the support layer. In this embodiment, the included angle between the length direction of the fiber filament and the length direction of the blood vessel stent is not more than half of the included angle of the wave crest of the wave ring 11.

As shown in fig. 16, the angles formed by the fibers 221 on two adjacent fiber belts 22 and the edges are different, that is, the included angle θ between the fibers 221 on two adjacent fiber belts 22 is greater than 0 °, so that the arrangement directions of the fibers 221 on two adjacent fiber belts 22 are different, and the flexible layer 20 has better deformation compliance in all directions. Preferably, the filaments of two adjacent fiber bands extend towards two sides of the axis of the stent respectively, that is, when the fiber bands are unfolded, the filaments of two adjacent fiber bands extend from the same starting point towards the proximal end of the stent respectively towards two sides of the axis of the stent.

The fiber filaments 221 on different fiber bands 22 may have different distances D1 therebetween, and the distance D1 between the fiber filaments 221 on each fiber band 22 may be designed according to the size of the plaque 210 at the stenosis of the blood vessel.

It will be appreciated that the plurality of fibrous strips 22 may be separate structures that are then joined by stitching or the like at adjacent edges 23, or may be a unitary structure.

As shown in fig. 17 and 18, a stent 100 according to a third embodiment of the present invention has a structure substantially the same as that of the first embodiment, except that the supporting layer 10 and the flexible layer have different structures.

Specifically, in the present embodiment, in each adjacent two W-shaped wave rings 11, the wave trough of one W-shaped wave ring 11 passes through the wave crest of the other W-shaped wave ring 11 to form an overlapping region between the wave trough and the wave crest, and at the same time, a quadrilateral mesh is formed between the wave crest of the one W-shaped wave ring 11 and the wave trough of the other W-shaped wave ring 11. In the embodiment, an overlapping region is formed between each independent W-shaped wave ring 11 of the supporting layer 10, so that the gap on the supporting layer 10 is small, and the vascular stent 100 has a better bending effect, is more easily adapted to the shape of a blood vessel, and is not easy to form wrinkles.

Further, when the supporting layer 10 is specifically designed, the area of the overlapping area should be smaller than that of the quadrilateral mesh area.

Further, the flexible layer 20 includes a plurality of fiber bands 24 connected in series along the axial direction of the blood vessel stent 100, the fiber bands 24 are formed with fiber distribution regions 241 and hollow-out regions 242 alternately distributed, the fiber distribution regions 241 are arranged corresponding to the quadrilateral meshes and cover a portion of the quadrilateral meshes, and the hollow-out regions 242 are arranged corresponding to the overlapping regions between adjacent wave circles. The fiber distribution region 241 includes a plurality of parallel fiber filaments, an included angle is formed between the length extending direction of the fiber filaments and the length direction of the blood vessel stent, and the included angle is greater than 0 degree and smaller than 90 degrees. In order to avoid the flexible layer from being folded or piled up when the blood vessel stent is compressed, the axial elongation of the flexible layer is not more than that of the support layer. In this embodiment, the included angle between the length direction of the fiber filament and the length direction of the blood vessel stent is not more than half of the included angle of the wave crest of the wave ring 11. The flexible layer 20 of multiple fiber bands 24 can be compressed in the circumferential direction and extended in the axial direction to avoid excessive elongation and contraction of the stent 100.

Further, the height of the overlapping region between two adjacent W-shaped wave coils 11 is H2, and the overlapping manner may be inter-hanging, node wire fastening, or the like. The fiber tape 24 has a width H1, and the fiber tape 24 is formed by connecting a plurality of fiber distribution regions 241 by a boundary line 243, and the fiber distribution regions 241 of adjacent fiber tapes 24 are axially offset from each other. To ensure that the flexible layer will block the falling plaque from entering the blood circulation, the area covered by the fibrous tape should be larger than the area not covered by the fibrous tape, and H1 is set to be larger than H2. Meanwhile, although the overlapping region between the adjacent wave rings corresponds to the hollow-out region 242 of the fiber band, the patch can be prevented from falling to some extent because the region includes the peaks and the troughs of the two adjacent wave rings.

Further, the sizes of the hollow-out area 242 and the fiber distribution area 241 may be designed according to the size of the plaque 210 at the stenosis portion of the blood vessel, specifically, the sizes of the hollow-out area 242 and the fiber distribution area 241 are smaller than the size of the plaque 210. The fiber distribution regions 241 are also angularly and angularly adjusted as the support layer 10 is radially compressed.

As shown in fig. 19 and 20, the fourth embodiment of the present invention provides a blood vessel stent 100, which has substantially the same structure as the first embodiment except that the specific structure of the flexible layer 20 is different.

In particular, in the present embodiment, the flexible layer 20 is composed of regions (251, 252, 253) with different densities, and the density of the three regions satisfies 251 > 253 > 252, as shown in fig. 19. In practical use, since the stent is used for bending a blood vessel, the elongation rates of the large curve side D, the small curve side D and the middle region C are generally inconsistent, as shown in fig. 20, the elongation rates of the three portions of the stent satisfy ∈ D > ∈ C > ∈ D. When the complete intravascular stent is bent, the folds are easy to form due to axial stacking, the generation of the bent folds of the stent is avoided, 252 with lower density can be selected at the small bent side of the stent where the folds are easy to form, 251 with lower density is selected at the large bent side D with high elongation, 253 with medium density is selected at the middle region C, the middle region C is adapted to the trend of the bent blood vessel, the formation of the bent folds of the stent in the axial direction can be avoided, in addition, two adjacent fiber wires are used, the distance is smaller and a certain included angle is formed, the angle range is 0-90 degrees, the angle between the fiber wires and the length direction of the stent is smaller than a half of the included angle of a metal wave ring, and the folds can be formed when the stent.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. The intravascular stent is characterized by comprising a supporting layer and a flexible layer, wherein the supporting layer comprises a plurality of repeating units which are arranged along the axial direction, hollow parts are formed among the repeating units, the flexible layer at least covers part of the hollow parts, the flexible layer comprises a plurality of fiber yarns, and the included angle between the length extending direction of the fiber yarns and the length extending direction of the intravascular stent is larger than 0 degree and smaller than 90 degrees.

2. The vascular stent of claim 1, wherein the flexible layer has an axial elongation that is no greater than an axial elongation of the support layer.

3. The vascular stent of claim 2, wherein the repeating unit comprises peaks having an included angle, and the included angle of the length direction of the fiber filaments with the length direction of the vascular stent is not more than half of the included angle of the peaks.

4. The vascular stent of claim 1, wherein the flexible layer is a grid structure, and a plurality of the fiber filaments are interlaced with each other to form a grid-shaped flexible layer.

5. The blood vessel support according to claim 4, wherein the repeating unit comprises W-shaped wave rings, each two adjacent W-shaped wave rings form a group of wave rings, and wave troughs of one W-shaped wave ring in the group of wave rings are correspondingly connected with wave crests of the other W-shaped wave ring so as to form a plurality of quadrilateral meshes in the group of wave rings;

the filament forms two nodes when passing through two opposite screw rods of the quadrilateral mesh, wherein at one node, the filament passes through the inner side of the screw rod, and at the other node, the filament passes through the outer side of the screw rod.

6. The vascular stent of claim 1, wherein the flexible layer comprises a plurality of fibrous tapes helically wound on the outer surface of the support layer.

7. The vascular stent of claim 6, wherein the fiber band comprises two parallel edges, the plurality of fiber filaments are connected between the two edges, and the plurality of fiber filaments are arranged in parallel.

8. The vascular stent of claim 7, wherein the included angle between the fiber filaments on two adjacent fiber bands is greater than 0 degree.

9. The stent according to claim 8, wherein the fiber filaments of the two adjacent fiber bands extend towards two sides of the axis of the stent respectively.

10. The blood vessel support as claimed in claim 1, wherein the flexible layer comprises a plurality of fiber bands connected in series along an axial direction, the fiber bands are formed with fiber distribution areas and hollow-out areas alternately distributed, and the plurality of fiber filaments are arranged in parallel in the fiber distribution areas.

11. The vascular stent of claim 10, wherein the repeating unit comprises wave rings comprising a plurality of wave crests and wave troughs, and in every two adjacent wave rings, the wave troughs of one wave ring pass through the wave crests of the other wave ring to form an overlapping region between the wave troughs and the wave crests, and simultaneously, the wave crests of the one wave ring and the wave troughs of the other wave ring form a quadrilateral grid.

12. The vascular stent of claim 11, wherein the fiber distribution area is arranged corresponding to and covering the quadrilateral mesh, and the hollow area is arranged corresponding to the overlapping area.