Net covering support

Abstract

The invention provides a net covering support which comprises a flexible net and a support body, and the support body is fixed to the flexible net and used for supporting the flexible net. The flexible net is of a tubular structure formed by weaving flexible wires. The stent is provided with a plurality of supporting layers, each supporting layer extends on at least part of the circumference of the flexible net and is connected end to end, and all the supporting layers are arranged at intervals in the axial direction of the flexible net. The stent has small-size elongation in the pressing and holding process, so that the pushing resistance of the stent in the operation process can be reduced, pushing is facilitated, and the stent has good pushing hand feeling. Meanwhile, the stent has small-size shrinkage in the expansion process, so that positioning and releasing of the stent are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a mesh-covered stent. Background Art

[0002] At present, the most advanced treatment for cerebral vascular aneurysm disease is the use of blood flow diversion devices. Blood flow diversion devices are mostly realized by braided stents, which have a dense mesh structure and can achieve a 20% coverage rate on the blood vessel wall after expansion, thereby achieving the purpose of changing the hemodynamics in the aneurysm.

[0003] However, since the braided stent has an expanded state and a compressed state, while achieving the blood flow guidance function, the braided stent will stretch about 50% longer in the compressed state than in the expanded state. The excessive axial length of the braided stent will make the pushing resistance very large, making the pushing process of the braided stent very difficult. At the same time, since the axial length of the braided stent is easy to change, the compression and stretching of the braided stent during the operation can easily cause the stent to shift in the blood vessel after the operation, which places high requirements on the implantation operation of the stent. In addition, since the supporting force of the braided stent is weak, it depends on the operator's surgical experience to keep the braided stent close to the blood vessel wall during the operation, which increases the uncertainty of the operation.

[0004] Therefore, for those skilled in the art, how to design a mesh-covered stent whose length is not easily changed significantly during compression or expansion is a technical problem that urgently needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a mesh-covered stent, which has a smaller extension in a compressed state, thereby reducing the pushing resistance of the stent during surgery. At the same time, the stent has a smaller shortening during expansion, so as to facilitate the positioning and release of the stent.

[0006] To achieve the above-mentioned purpose, the present invention provides a mesh-covered stent, comprising a flexible mesh and a stent, wherein the stent is fixed on the flexible mesh and is used to support the flexible mesh; the flexible mesh is a tubular structure woven from flexible wires; the stent has a plurality of support layers, each of which extends over at least a portion of the circumference of the flexible mesh and is connected end to end, and all of the support layers are arranged at intervals along the axial direction of the flexible mesh.

[0007] Optionally, at least a portion of each support layer in contact with the flexible mesh is provided with a groove, and the groove is used to accommodate at least a portion of the flexible wire material to reduce the total thickness of the flexible mesh and the stent in the radial direction of the flexible mesh.

[0008] Optionally, the mesh-covered support further includes a connecting rod, and adjacent support layers are connected by the connecting rod.

[0009] Optionally, each of the support layers is wavy in shape in its own extension direction and has a plurality of waveforms, and the waveforms of adjacent support layers are aligned in the axial direction;

[0010] At least part of the waveforms on each of the supporting layers is connected to the corresponding waveforms on the adjacent supporting layer through the connecting rods.

[0011] Optionally, a portion of the position on each support layer that contacts the flexible net is provided with grooves, and 1 to 9 flexible wires are arranged between adjacent grooves in the extending direction of the waveform.

[0012] Optionally, each of the supporting layers has 4 to 12 waveforms in the circumferential direction of the flexible net; each of the waveforms has 1 to 10 grooves; and the number of the connecting rods between adjacent supporting layers is 0 to 6.

[0013] Optionally, the depth of the groove in the radial direction of the flexible net is greater than the radius of the flexible wire; and the width of the groove in the circumferential direction of the flexible net is greater than the radius of the flexible wire.

[0014] Optionally, the depth of the groove in the radial direction of the flexible net is 5um to 100um, the width of the groove in the circumferential direction of the flexible net is 5um to 100um, and the diameter of the flexible wire is 10um to 100um.

[0015] Optionally, the flexible wire material at least partially accommodated in the groove forms a fixed point with the groove; and the number of the fixed points on the entire flexible net is 2 to 500.

[0016] Optionally, the width of the support layer in the circumferential direction of the flexible net is 20 um to 150 um, and the height of the support layer in the radial direction of the flexible net is 20 um to 150 um.

[0017] Optionally, the flexible net has a plurality of mesh holes, and the inner diameter of the mesh holes is 1 um to 500 um.

[0018] The present invention provides a mesh-covered stent, which comprises a flexible mesh and a stent, wherein the stent is fixed on the flexible mesh and is used to support the flexible mesh; the flexible mesh is a tubular structure woven from flexible filaments; the stent has a plurality of support layers, each of which extends over at least part of the circumference of the flexible mesh and is connected end to end, and all of the support layers are arranged at intervals along the axial direction of the flexible mesh.

[0019] The mesh-covered stent is woven from flexible wires and has support layers arranged at intervals along the axial direction. Since the support layers are connected by a flexible mesh, the flexible mesh can play a role in blood flow guidance, and has a smaller elongation when compressed from an expanded state, which can reduce the pushing resistance of the stent during surgery, facilitate pushing, and bring a better pushing feel, thus solving the problem of large pushing force when the current blood flow guiding device is implanted. In addition, the stent can also have a smaller shortening when expanded from a compressed state, so as to facilitate the positioning and release of the stent, thus also solving the problem of large shortening of the current blood flow guiding device after expansion. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the axially expanded structure of the flexible net and the bracket in a preferred embodiment of the present invention;

[0021] Figure 2 It is a schematic top view of the local structure of the flexible wire material and the support layer in a preferred embodiment of the present invention;

[0022] Figure 3 It is a schematic front view of the local structure of the flexible wire material and the support layer in a preferred embodiment of the present invention.

[0023] In the figure: flexible net 1; flexible wire material 11; mesh 12; bracket 2; support layer 21; groove 211; waveform 212. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the accompanying drawings are in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0025] The terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. The term "proximal end" generally refers to the end close to the operator; the "distal end" is the end opposite to the "proximal end", and generally refers to the end away from the operator.

[0026] like Figure 1As shown, a preferred embodiment of the present invention provides a mesh-covered stent, comprising a flexible mesh 1 and a stent 2, wherein the stent 2 is fixed on the flexible mesh 1 and used to support the flexible mesh 1. The flexible mesh 1 is a tubular structure woven from flexible wires 11, and the stent 2 has a plurality of support layers 21, and the support layers 21 are preferably prepared by cutting. Each support layer 21 extends over at least part of the circumference of the flexible mesh 1 and is connected end to end, and all support layers 21 are arranged at intervals along the axial direction of the flexible mesh 1.

[0027] The mesh-covered stent provided by the present invention is woven from a flexible mesh and has support layers 21 arranged at intervals along the axial direction. Since the support layers 21 are connected by a flexible mesh, the flexible mesh 1 can play a role in blood flow guidance, and has a smaller elongation when compressed from an expanded state, so that the pushing resistance of the stent 2 during surgery can be reduced, so as to facilitate pushing and bring a better pushing feel, solving the problem of large pushing force when the current blood flow guiding device is implanted. In addition, the stent 2 can also have a smaller shortening when expanded from a compressed state, so as to facilitate the positioning and release of the stent 2, thereby solving the problem of large shortening of the current blood flow guiding device after expansion.

[0028] In a preferred embodiment, each support layer 21 extends over the entire circumference of the flexible net 1 and is connected end to end to enhance the radial support force of the support layer 21 on the flexible net 1 and to avoid deformation of the stent 2 during expansion and compression as much as possible. Of course, in other implementations, each support layer 21 may also extend over part of the circumference of the flexible net 1, that is, the length of the support layer 21 in the circumferential direction of the flexible net 1 is less than the circumference of the flexible net 1, so that the two ends of the support layer 21 are not connected.

[0029] Reference Figure 2 and Figure 3 As shown, in a preferred embodiment, a groove 211 is provided on at least a portion of each support layer 21 that contacts the flexible net 1, and the groove 211 is used to accommodate at least a portion of the flexible wire 11 to reduce the total thickness of the flexible net 1 and the bracket 2 in the radial direction of the flexible net 1, thereby enabling the flexible net 1 and the bracket 2 to match a smaller size of the conveying device.

[0030] As a specific embodiment, the groove 211 may be configured to accommodate a portion of the flexible wire 11 , that is, a portion of the cross section of the flexible wire 11 is located inside the groove 211 , and another portion of the cross section of the flexible wire 11 is located outside the groove 211 .

[0031] As another specific embodiment, the groove 211 can also be configured to accommodate all the flexible wires 11, that is, all the flexible wires 11 are located in the groove 211 without protruding from the surface of the groove 211, so as to minimize the total thickness of the flexible net 1 and the bracket 2 in the radial direction of the flexible net 1.

[0032] In some embodiments, grooves 211 are provided at all positions on each support layer 21 that contact the flexible mesh 1 , and all flexible wires 11 can be located in the grooves 211 to further reduce the total thickness of the flexible mesh 1 and the stent 2 in the radial direction of the flexible mesh 1 .

[0033] In other embodiments, a groove 211 is provided at a portion of each cut 21 that contacts the flexible net 1 , and a portion of the flexible wire 11 that contacts the bracket 2 can be located in the groove 211 , while another portion of the flexible wire 11 that contacts the bracket 2 is located on the surface of the bracket 2 .

[0034] To ensure that the total thickness of the flexible net 1 and the support 2 in the radial direction of the flexible net 1 is within a predetermined range, the width of the support layer 21 in the circumferential direction of the flexible net 1 is preferably 20um to 150um, and the height of the support layer 21 in the radial direction of the flexible net 1 is preferably 20um to 150um.

[0035] In addition, the flexible net 1 has a plurality of meshes 12, and the inner diameter of the meshes 12 is 1 um to 500 um, wherein the smaller the inner diameter of the meshes 12, the more significant the blood flow guiding effect of the flexible net 1. Preferably, the inner diameter of the meshes 12 is 100 um to 300 um.

[0036] Further, the depth of the groove 211 in the radial direction of the flexible net 1 is preferably greater than the radius of the flexible wire 11, and the width of the groove 211 in the circumferential direction of the flexible net 1 is preferably also greater than the radius of the flexible wire 11, so that most of the cross-section of the flexible wire 11 is located in the groove 211, thereby preventing the flexible net 1 from being separated from the bracket 2. In more detail, the depth of the groove 211 in the radial direction of the flexible net 1 is preferably 5um to 100um, and the width of the groove 211 in the circumferential direction of the flexible net 1 is preferably 5um to 100um.

[0037] Preferably, the diameter of the flexible wire 11 can be set to 10 um to 100 um, and the cross section of the flexible wire 11 can be circular, square or elliptical.

[0038] The flexible material 11 is preferably made of a polymer material with good biocompatibility. For example, the material for making the flexible material 11 can be a combination of one or more of polyethylene terephthalate plastics (PET), thermoplastic polyurethane elastomer rubber (TPU), polytetrafluoroethylene (PTFE), and polylactic acid (PLA). The stent 2 is preferably made of a metal material with good biocompatibility, for example, the stent 2 can be made of materials such as nickel-titanium alloy.

[0039] To assist in the treatment, the surface of the flexible material 11 may be coated with phosphorylcholine, polypeptide, heparin, or drugs such as rapamycin and paclitaxel.

[0040] The present application does not limit the weaving method of the flexible wire material 11. The flexible wire material 11 can be woven by weft knitting or warp knitting, and can be woven by 1-on-1, 2-on-1 or 2-on-2.

[0041] In the prior art, since both ends of the stent are free ends of flexible metal wires, and the free ends of the thinner diameter flexible metal wires are very sharp, the stent is prone to stimulate the vascular endothelium during implantation and cause complications such as vascular stenosis.

[0042] To solve the above problems, refer to Figure 1 In one embodiment, each support layer 21 is wavy in shape in its own extension direction and has a plurality of waveforms 212. With such a structure, on the one hand, since the two ends of the wavy support layer 21 are wavy and there are no sharp free ends, the stent 2 is not easy to pierce the vascular endothelium during implantation and position adjustment, thereby ensuring the safety of the stent 2 during implantation; on the other hand, at this time, each waveform 212 of the support layer 21 can change its own shape during expansion or compression, and can have a smaller elongation and shortening in the process of expansion or compression, so it has a smaller push resistance, which is convenient for pushing. At the same time, since the flexible wire 11 preferably adopts a polymer material with good biocompatibility, the material is softer than the flexible metal wire and is not easy to irritate the blood vessels. In some embodiments, the two ends of the flexible wire 11 can be woven into a closed mesh structure, or fixed to the two ends of the stent 2 respectively, so that the flexible wire 11 has no single fiber free end.

[0043] In other embodiments, the shape of each supporting layer 21 may also be a sawtooth waveform, a pulse waveform or other shapes. The present application does not limit the shape of the supporting layer 21 .

[0044] Preferably, the support 2 further comprises a connecting rod (not shown), and adjacent support layers 21 are connected by the connecting rod. In this embodiment, the waveforms 212 of adjacent support layers 21 are preferably aligned in the axial direction, and at least part of the waveforms 212 on each support layer 21 is connected to the corresponding waveforms 212 on the adjacent support layer 21 through the connecting rod.

[0045] As a preferred example, one or more waveforms 212 on each supporting layer 21 are connected to corresponding waveforms 212 on adjacent supporting layers 21 through connecting rods, so as to achieve connection of adjacent supporting layers 21. As another preferred example, all waveforms 212 on each supporting layer 21 are connected to corresponding waveforms 212 on adjacent supporting layers 21 through connecting rods, so that adjacent supporting layers 21 are firmly connected through the connecting rods.

[0046] It should be noted that connecting rods may not be provided between adjacent supporting layers 21 , and in this case, adjacent supporting layers 21 are connected only by the flexible net 1 .

[0047] The present application does not limit the position of the connecting rods on adjacent waveforms 212 , and the connecting rods may be disposed at the crest position, the trough position, or any position between the crests or troughs of the waveform 212 .

[0048] In a preferred example, each support layer 21 preferably has 4 to 12 waveforms 212 in the circumferential direction of the flexible net 1. Each waveform 212 has 1 to 10 grooves 211, and the number of grooves 211 on each waveform 212 can be determined according to the inner diameter of the mesh 12 of the flexible net 1. The number of connecting rods between adjacent support layers 21 is preferably 0 to 6.

[0049] Preferably, a groove 211 is provided in a portion of the position on each supporting layer 21 that contacts the flexible net 1, and 1 to 9 flexible wires 11 are arranged between adjacent grooves 211 in the extension direction of the waveform 212. That is, 1 to 9 flexible wires 11 without accommodating grooves 211 are spaced between the flexible wires 11 located in adjacent grooves 211 in the extension direction of the waveform 212.

[0050] The present application does not limit the connection method between the flexible net 1 and the bracket 2. For example, the flexible net 1 and the flexible wire material 11 embedded in the groove 211 can be fixedly connected by hot melting, gluing, laser welding or ultrasonic welding.

[0051] In this embodiment, the flexible wire 11 at least partially accommodated in the groove 211 forms a fixed point (not shown) with the groove 211, and the number of the fixed points is less than or equal to the number of the grooves 211. The number of fixed points on the entire flexible net 1 is preferably 2 to 500, and the multiple fixed points can be evenly distributed along the circumference and axial direction of the flexible net 1, or can be randomly distributed on the flexible net 1.

[0052] In a specific example, the flexible net 1 is made of a polyethylene terephthalate plastic with a diameter of 20um and is woven by weft knitting. The head and tail ends of the support layer 21 can be bonded by hot melt. The support layer 21 of the bracket 2 has a radial depth and a circumferential width of 70um in the flexible net 1. The support layer 21 has a plurality of grooves 211, and the grooves 211 on the support layer 21 have a radial depth and a circumferential width of 25um in the flexible net 1. Each groove 211 is used to accommodate the flexible wire 11 at the corresponding position, and the flexible wire 11 is fixedly connected to the groove wall of the groove 211 by hot melt.

[0053] In summary, the mesh-covered stent provided by the present invention is woven from a flexible mesh and has support layers 21 arranged at intervals along the axial direction. Since the support layers 21 are connected by a flexible mesh, the flexible mesh 1 can play a role in blood flow guidance, and has a smaller elongation when compressed from an expanded state, so that the pushing resistance of the stent 2 during surgery can be reduced, so as to facilitate pushing and bring a good pushing feel, thus solving the problem of large pushing force when the current blood flow guiding device is implanted. In addition, the stent 2 can also have a smaller shortening when expanded from a compressed state, so as to facilitate the positioning and release of the stent 2, thus solving the problem of large shortening of the current blood flow guiding device after expansion.

[0054] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the protection scope of the present invention.

Claims

1. A mesh-covered support, characterized in that: It comprises a flexible net and a bracket, wherein the bracket is fixed on the flexible net and used to support the flexible net; the flexible net is a tubular structure woven from flexible filaments; the bracket has a plurality of support layers, each of which extends over at least part of the circumference of the flexible net and is connected end to end, and all the support layers are arranged at intervals along the axial direction of the flexible net.

2. The mesh-covered support according to claim 1, characterized in that: At least a portion of each support layer in contact with the flexible net is provided with a groove, and the groove is used to accommodate at least a portion of the flexible wire material to reduce the total thickness of the flexible net and the stent in the radial direction of the flexible net.

3. The mesh-covered support according to claim 1, characterized in that: It also includes a connecting rod, through which adjacent supporting layers are connected.

4. The mesh-covered support according to claim 3, characterized in that: Each of the support layers is wavy in shape in its own extension direction and has a plurality of waveforms, and the waveforms of adjacent support layers are aligned in the axial direction; At least part of the waveforms on each of the supporting layers is connected to the corresponding waveforms on the adjacent supporting layer through the connecting rods.

5. The mesh-covered support according to claim 4, characterized in that: A portion of the position on each support layer that contacts the flexible net is provided with grooves, and 1 to 9 flexible wires are arranged between adjacent grooves in the extending direction of the waveform.

6. The mesh-covered support according to claim 4, characterized in that: Each of the supporting layers has 4 to 12 waveforms in the circumferential direction of the flexible net; each of the waveforms has 1 to 10 grooves; and the number of the connecting rods between adjacent supporting layers is 0 to 6.

7. The mesh-covered support according to claim 2, characterized in that: The depth of the groove in the radial direction of the flexible net is greater than the radius of the flexible wire; the width of the groove in the circumferential direction of the flexible net is greater than the radius of the flexible wire.

8. The mesh-covered support according to claim 2, characterized in that: The depth of the groove in the radial direction of the flexible net is 5um to 100um, the width of the groove in the circumferential direction of the flexible net is 5um to 100um, and the diameter of the flexible wire is 10um to 100um.

9. The mesh-covered support according to claim 2, characterized in that: The flexible wire material at least partially contained in the groove forms a fixed point with the groove; the number of the fixed points on the entire flexible net is 2 to 500.

10. The mesh-covered support according to any one of claims 1 to 8, characterized in that: The width of the support layer in the circumferential direction of the flexible net is 20um to 150um, and the height of the support layer in the radial direction of the flexible net is 20um to 150um.

11. The mesh-covered support according to any one of claims 1 to 8, characterized in that: The flexible net has a plurality of meshes, and the inner diameter of the meshes is 1 um to 500 um.

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