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CN-122005162-A - Implantable stent and method of making the same

CN122005162ACN 122005162 ACN122005162 ACN 122005162ACN-122005162-A

Abstract

The application provides an implantable stent and a method for manufacturing the same. The implantable stent is formed by braiding a plurality of wires, each wire of the implantable stent having its own final configuration, the manufacturing method comprising providing a plurality of wires including at least one first wire formed of a first material selected from materials having a shape memory function and at least one second wire formed of a second material selected from materials having a degradable property, pre-deforming and heat treating each wire of the plurality of wires to have a predetermined configuration, and mixedly braiding all wires to form the implantable stent, wherein the manufacturing method does not perform a heat treatment operation for heat setting the braided implantable stent.

Inventors

  • ZHOU SHENGJUN
  • FU SHI
  • ZHANG MIAO
  • LIU CHENYANG

Assignees

  • 上海励楷科技有限公司

Dates

Publication Date
20260512
Application Date
20260324

Claims (19)

  1. 1. A method of manufacturing an implantable stent formed by braiding a plurality of wires and each wire in the implantable stent having its respective final configuration, the method comprising: Providing a plurality of wires comprising at least one first wire formed from a first material selected from materials having shape memory functions and at least one second wire formed from a second material selected from materials having degradable characteristics; Pre-deforming and heat treating each of the plurality of wires to have a predetermined configuration, and All wires are mixed woven to form the implantable stent, Wherein the manufacturing method does not perform a heat treatment operation for heat setting purposes on the woven implantable stent.
  2. 2. The manufacturing method according to claim 1, wherein pre-deforming and heat-treating each wire to have a preset configuration comprises: Pre-deforming and heat-treating each first wire to have a predetermined configuration, the shape of the predetermined configuration of the first wire being the same as the shape of its final configuration and at least one dimension of the predetermined configuration of the first wire being different from the corresponding dimension of its final configuration, and Each second wire is pre-deformed and heat treated to have a pre-set configuration that is the same shape and size as its final configuration.
  3. 3. The method of manufacturing of claim 2, wherein the pre-set and final configuration of each wire is helical, the dimensions including an outer diameter and a pitch of the helix.
  4. 4. A method of manufacturing according to claim 3, wherein for the first wire, one of the outer diameter and pitch of the preset configuration is the same as the final configuration, the other being greater than the final configuration.
  5. 5. The method of manufacturing of claim 4, wherein pre-deforming and heat treating each first wire includes sizing the preset configuration based on a size of a final configuration of the first wire prior to performing the pre-deforming operation.
  6. 6. The method of manufacturing of any of claims 1-5, wherein the plurality of wires further comprises at least one third wire formed from a third material that is a third material different from the first material and the second material, the method of manufacturing further comprising: Each third wire is pre-deformed and heat treated to have a predetermined configuration prior to the hybrid braiding, the predetermined configuration of the third wire being the same as or different from the final configuration.
  7. 7. A method of manufacturing an implantable stent formed by braiding a plurality of wires and each wire in the implantable stent having its respective final configuration, the method comprising, in order: Providing a plurality of wires comprising at least one first wire formed from a first material selected from materials having shape memory functions and at least one second wire formed from a second material selected from materials having degradable characteristics; Pre-deforming each first wire and heat treating it to set it to the final configuration, the heat treatment being carried out at a first heat treatment temperature specific to the first material, and Weaving all wires in a mixed manner to form the implantable stent; The implantable stent is heat treated to set at a second heat treatment temperature specific to the second material, the second heat treatment temperature being lower than the first heat treatment temperature.
  8. 8. The method of manufacturing of claim 7, wherein the plurality of wires further comprises at least one third wire formed from a third material that is a third material different from the first material and the second material, the third heat treatment temperature specific to the third material being higher than the second heat treatment temperature specific to the second material, the method of manufacturing further comprising, prior to the hybrid braiding: Each third wire is pre-deformed and heat-treated to its final configuration at a heat-treatment temperature specific to the third material prior to hybrid braiding.
  9. 9. The manufacturing method according to any one of claims 1 to 8, wherein an end portion of each wire is rewound and/or expanded.
  10. 10. The method of any of claims 1-9, wherein the hybrid braiding includes winding some filaments clockwise and some filaments counterclockwise.
  11. 11. The manufacturing method according to any one of claims 1 to 10, wherein the heat treatment is performed after the wire is pre-deformed to be wound around the mandrel with a braiding machine, and the mandrel is removed.
  12. 12. The method of manufacturing according to any one of claims 1 to 11, wherein each of the plurality of wires is in the form of a single wire or in the form of a strand member formed of at least two wires, Wherein, in case the plurality of wires comprises strand parts, the step of providing a plurality of wires comprises, for each strand part, an operation of forming the strand parts from at least two wires by means of twisting and/or braiding.
  13. 13. An implantable stent manufactured by the manufacturing method according to any one of claims 1 to 12.
  14. 14. The implantable stent of claim 13, wherein each of the plurality of wires is in the form of a single wire or a strand of material formed from at least two wires, Wherein the single wire has a circular cross section or a non-circular cross section; wherein the strand is formed from at least two filaments by twisting and/or braiding.
  15. 15. An implantable stent according to claim 13 or 14, wherein the stent comprises dense segments of less porosity and sparse segments of greater porosity.
  16. 16. The implantable stent of any one of claims 13-15, wherein the implantable stent is a single layer stent.
  17. 17. The method of manufacturing of any of claims 13-16, wherein the first wire is a single wire, at least one of the second wires is a single wire, and at least another of the second wires is a strand member.
  18. 18. The method of manufacturing of claim 17, wherein a ratio of the number of first wires, the number of individual wires in the second wires, and the number of strand members in the second wires is 1:8:3 or 1:3:2.
  19. 19. An implantable stent according to any one of claims 13 to 18, wherein the material with shape memory function comprises nickel titanium alloy and cobalt chromium alloy, and/or the material with degradable properties comprises magnesium-based or zinc-based or iron-based or molybdenum-based degradable material, polylactic acid, polyglycolic acid, polylactide and polyglycolide.

Description

Implantable stent and method of making the same Technical Field The present application relates to an implantable stent, in particular a self-expanding stent, and a method for manufacturing the same. Background Vascular stents used as blood flow guides (flow diverter, FD) are typically formed from a braided wire. When the vascular stent is formed by weaving only the wires of the shape memory alloy material, the stent can cause chronic vascular inflammation, influence the recovery of the vasoconstriction function and the like because the stent exists in a patient for a long time. When a vascular stent is formed only from a braiding of filaments of degradable material, the stiffness and radial opening capability of the stent may be insufficient. To this end, both filaments of shape memory alloy material and filaments of degradable material may be mixed braided to form a stent in the art. However, when the heat treatment for the purpose of shaping is performed after the formation of the stent is completed, the filaments of the memory alloy material and the degradable material cannot simultaneously obtain the optimal shaping effect and the respective optimal mechanical properties due to different heat treatment conditions, for example, a large difference in heat treatment temperature, and thus cannot exert the respective maximum properties. Disclosure of Invention The object of the present application is to solve at least one of the above technical problems. The first aspect of the application provides a method of manufacturing a new implantable stent comprising an initial step of providing a plurality of wires comprising at least one first wire formed from a first material selected from materials having a shape memory function and at least one second wire formed from a second material selected from materials having a degradable property, a sizing step of pre-deforming and sizing each wire of the plurality of wires to a predetermined configuration, and a braiding step of mixedly braiding all wires to form the implantable stent. In one embodiment, pre-deforming and heat treating each wire to have a predetermined configuration comprises: Pre-deforming and heat-treating each first wire to have a predetermined configuration, the shape of the predetermined configuration of the first wire being the same as the shape of its final configuration and at least one dimension of the predetermined configuration of the first wire being different from the corresponding dimension of its final configuration, and Each second wire is pre-deformed and heat treated to have a pre-set configuration that is the same shape and size as its final configuration. In one embodiment, the predetermined and final configuration of each wire is helical, and the dimensions include the outside diameter and pitch of the helix. In one embodiment, for the first wire, one of the outside diameter and pitch of the preset configuration is the same as the final configuration, the other is greater than the final configuration. In an embodiment, pre-deforming and heat treating each first wire includes determining a size of the preset configuration based on a size of a final configuration of the first wire prior to performing the pre-deforming operation. In an embodiment, the plurality of wires further comprises at least one third wire formed from a third material that is a third material different from the first material and the second material, the method of manufacturing further comprising: Each third wire is pre-deformed and heat treated to have a predetermined configuration prior to the hybrid braiding, the predetermined configuration of the third wire being the same as or different from the final configuration. A second aspect of the present application provides a method of manufacturing an implantable stent formed by braiding a plurality of wires and each of the wires in the implantable stent having its respective final configuration, the method comprising in sequence: Providing a plurality of wires comprising at least one first wire formed from a first material selected from materials having shape memory functions and at least one second wire formed from a second material selected from materials having degradable characteristics; Pre-deforming each first wire and heat treating it to set it to the final configuration, the heat treatment being carried out at a first heat treatment temperature specific to the first material, and Weaving all wires in a mixed manner to form the implantable stent; The implantable stent is heat treated to set at a second heat treatment temperature specific to the second material, the second heat treatment temperature being lower than the first heat treatment temperature. In an embodiment, the plurality of wires further comprises at least one third wire formed from a third material, the third material being a third material different from the first material and the second material, a third heat treatment temperature specific