Product and process for manufacturing a wire stent coated with a biocompatible fluoropolymer

• US 6,652,574 B1
• Filed: 09/28/2000
• Issued: 11/25/2003
• Est. Priority Date: 09/28/2000
• Status: Expired due to Fees

• Current Assignee: Vascular Concepts Holdings Limited
• Original Assignee: Vascular Concepts Holdings Limited
• Inventors: Jayaraman, Swaminathan
• Primary Examiner(s): VANATTA, AMY B
• Application Number:
  US09/672,422
• Time in Patent Office: 1,153 Days
• Field of Search: 623/1.46, 623/1.15, 623/1.16, 623/1.17, 623/1.18, 623/1.19, 623/1.2, 623/1.22, 623/1.11, 623/900, 623/1.39, 623/1.49, 623/1.13, 606/198, 606/194, 606/195, 606/191, 606/192, 427/2.24, 427/2.28, 427/2.3, 427/2.31
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/885 comprising a coil including a plurality of spiral or helical sections with alternate directions around a central axis
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: D04B 21/16 incorporating synthetic threads
• CPC Class Codes: D10B 2509/06 Vascular grafts; stents
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling
• CPC Class Codes: Y10T 29/4998 Combined manufacture including applying or shaping of fluent material
• CPC Class Codes: Y10T 29/49982 Coating

Abstract

A stent is made from multiple wire strands coated with a biocompatible fluoropolymer. A knitting or braiding machine receives a plurality of the coated wire strands from spools and interlaces them into a tubular stent. The coated wire strand is made of materials such as stainless steel, tungsten, titanium, nickel titanium alloy (NITINOL®) gold or silver. The wire can be heat set prior to coating with the fluoropolymer. The resulting stent is tubular in shape and has a uniform porosity around each interlaced coated wire component.

Claims

1. A compressible stent having a tubular shape in a relaxed state, the stent comprising a plurality of wire strands interlaced together, at least one wire strand having a substantially uniform biocompatible porous fluoropolymer coating.

2. The compressible stent according to claim 1 wherein the fluoropolymer coating on each wire is porous expanded polytetrafluoroethylene.

3. The compressible stent according to claim 1 wherein the wire strand is selected from the group consisting of nickel-titanium alloy, stainless steel, tungsten, titanium, gold and silver.

4. The compressible stent according to claim 1 wherein the fluoropolymer coating is 1 to 8 μ

m thick around the wire strand to form a substantially uniform jacket.

5. The compressible stent according to claim 1 wherein the porous fluoropolymer coating on the wire strand has a uniform porosity throughout an annular wall formed by the coating.

6. The compressible stent according to claim 2 wherein the expanded polytetrafluoroethylene coating on each wire has a uniform porosity throughout an annular wall formed by the coating.

7. The compressible stent according to claim 1 wherein the multiple coated wire strands have been interlaced together in a knitting machine.

8. The compressible stent according to claim 1 wherein the multiple coated wire strands have been interlaced together in a braiding machine.

9. The compressible stent according to claim 7 wherein the stent has about four coated wire strands interlaced together.

10. The compressible stent according to claim 8 wherein the stent has about four coated wire strands interlaced together.

11. A compressible stent according to claim 1 wherein at least one wire strand is made of shape memory material.

12. A compressible stent according to claim 11 wherein at least one wire strand has a predetermined shape.

13. A compressible stent according to claim 11 wherein at least one wire strand is heat treated to a predetermined shape.

14. A compressible stent comprising:

a plurality of wire strands interlaced together forming a tubular shape in a relaxed state, each wire strand having a first and second end; and

,

a biocompatible porous fluoropolymer coating disposed on the wire strands, each wire strand being covered with the coating from the first end to the second end of each wire strand.

15. A compressible stent according to claim 14 wherein the fluoropolymer is selected from the group consisting of PTFE, ePTFE and FEP.

16. A compressible stent according to claim 14 wherein at least one wire strand is made of shape memory material.

17. A compressible stent according to claim 16 wherein at least one wire strand has a predetermined shape.

18. A compressible stent according to claim 16 wherein at least one wire strand is heat treated to a predetermined shape.

19. A compressible stent according to claim 14 wherein fabric material is interlaced between the wire strands, the fabric material is selected from the group consisting of polyester, polypropylene, polyethylene, polyurethane and polytetrafluoroethylene.

20. A compressible stent according to claim 14 wherein the wire strands are two-dimensional braided.

21. A compressible stent according to claim 14 wherein the wire strands are three-dimensional braided.

22. A compressible stent according to claim 14 wherein the stent includes twenty-four wire strands.

23. A compressible stent according to claim 14 wherein the ends of the wire strands include biocompatible glue.

24. A compressible stent according to claim 14 wherein the ends of the wire strands are ultrasonically welded.

25. A compressible stent according to claim 14 wherein the ends of the wire strands are looped.