Exterior supported self-expanding stent-graft

• US 20020156523A1
• Filed: 06/07/2002
• Published: 10/24/2002
• Est. Priority Date: 08/31/1994
• Status: Abandoned Application

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Inventors: Lau, Lilip, Maroney, Charles
• Application Number:
  US10/163,568
• Publication Number:
  US 20020156523A1
• Time in Patent Office: Days
• US Class Current: 623/1.13
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2/92 Stents in the form of a rolled-up sheet expanding after insertion into the vessel , e.g. with a spiral shape in cross-section
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2002/061 provided with means for allowing access to secondary lumens
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/91508 the meander having a difference in amplitude along the band
• CPC Class Codes: A61F 2002/91516 the meander having a change in frequency along the band
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2310/00017 Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00137 : Tungsten or W-based alloys
• CPC Class Codes: A61F 2310/00149 : Platinum or Pt-based alloys

Abstract

This is a medical device and a method of using it. The device is a foldable stent-graft which may be percutaneously delivered with (or on) an endovascular catheter or via surgical techniques or using other suitable techniques and then expanded. The stent-graft uses a kink-resistant stent structure and an interior graft which is attached to the stent in such a way that the graft does not kink and yet the stent is able to conform to curves in the blood vessel lumen.

The expandable stent structure preferably has a helically deployed torsional member with an undulating shape which is wound to form the generally cylindrical shape deployed as the stent. The helical winding desirably is aligned to allow the undulations in adjacent turns of the helix to be in phase. The adjacent undulating shapes are held in that phased relationship using a flexible linkage, typically made of a polymeric material. The stent may also be of a ring configuration. The stent may be flared to promote smooth blood flow and to assure that the stent will remain in its chosen position.

The graft component cooperating with the stent is tubular and mounted on the interior of the stent. Although it may be made of any of a variety of materials, it preferably is an expanded polyfluorocarbon. The graft component may be bound to the flexible linkage which holds the stent windings in phase (or to the stent structure itself) at a number of sliding attachment points. This manner of attachment allows the stent to slide locally with respect to the graft structure or, in the case of the helically wound stent structure, allows the adjacent undulating shapes in adjacent helical turns to slide longitudinally with respect to each other as the stent is bent and still support the shape of the graft.

Claims

1. A self-expanding stent-graft suitable for introduction into a body lumen, said stent-graft having a generally cylindrical form with two ends, a passageway with a radius extending between those ends, and an axis extending along said passageway, said stent-graft comprising:

a stent component of at least one helically aligned torsion member defining said cylinder, said helically aligned torsion member having undulating elements with unconfining apexes, said apexes being arranged in an intercooperating phased relationship between adjacent helical turns, and

a tubular graft member substantially coaxial with the passageway and interior to the cylinder and distributively and slidably connected to said stent component.

2. The stent-graft of claim 1 additionally comprising at least one flexible link passing through said undulating elements on adjacent helical turns to maintain said undulating elements in phased relationship and wherein the tubular graft member is connected to the flexible link.

3. The stent-graft of claim 1 additionally comprising at least one polymeric loop passing around said undulating elements and wherein the at least one polymeric loop is connected to the tubular graft member.

4. The stent-graft of claim 1 where the torsion member has a torsional component paralleling the axis and wherein said torsional component of said torsion member restorably twists when said cylindrical form is distorted.

5. The stent-graft of claim 1 where the stent is formed of wire and the shape of the undulating elements is selected from sinusoidal, U-shaped, V-shaped, and ovaloid shapes.

6. The stent-graft of claim 1 where the torsion member comprises a material selected from stainless steels, cobalt chromium alloys, platinum/tungsten alloys, titanium alloys, and nickel-titanium alloys.

7. The stent-graft of claim 1 where the torsion member comprises nitinol.

8. The stent-graft of claim 1 where the torsion member is produced from a sheet material or tubing.

9. The stent-graft of claim 1 where the tubular member comprises one or more materials selected from polyethylene, polypropylene, polyglycolic acid, polyesters, polyamides, their mixtures, blends, copolymers, mixtures, blends and copolymers;

polyesters, polyaramids, polyfluorocarbons, and porous or nonporous polyurethanes; and

collagenous materials.

10. The stent-graft of claim 1 where the tubular member comprises polyethylene terephthalate.

11. The stent-graft of claim 1 where the tubular member comprises porous or non-porous polytetrafluoroethylene.

12. The stent-graft of claim 11 where the porous or non-porous polytetrafluoroethylene is expanded.

13. The stent-graft of claim 11 where the porous or non-porous polytetrafluoroethylene is copolymerized with hexafluoropropylene.

14. The stent-graft of claim 11 where the porous or non-porous polytetrafluoroethylene is copolymerized with hexafluoropropylene.

15. The stent-graft of claim 9 additionally comprising radiopaque fibers within said tubular member.

16. The stent-graft of claim 1 where at least one end of the stent is flared.

17. The stent-graft of claim 2 where the linkage is of a material selected from polyethylene, polypropylene, polyglycolic acid, polyesters, polyamides, their mixtures, blends, copolymers, mixtures, blends and copolymers;

polyesters, polyaramids, polyfluorocarbons, and porous or nonporous polyurethanes; and

metals.

18. The stent-graft of claim 17 where the linkage is of the same material as the tubular member.

19. The stent-graft of claim 3 where the at least one loop is of a material selected from polyethylene, polypropylene, polyglycolic acid, polyesters, polyamides, their mixtures, blends, copolymers, mixtures, blends and copolymers;

polyesters, polyaramids, polyfluorocarbons, and porous or nonporous polyurethanes.

20. The stent-graft of claim 19 where the at least one loop is of the same material as the tubular member.

21. A self-expanding stent-graft suitable for introduction into a body lumen having a generally cylindrical form, said stent-graft having two ends, a passageway with a radius extending between those ends, and an axis extending along said passageway, said stent-graft comprising:

a stent component of at least one ring assembly extending circumferentially about said passageway, said ring assembly containing at least one torsion member approximately parallel to said axis, said torsion member being situated so that when said ring assembly is distorted, said torsion member is twisted, and

a tubular graft member substantially coaxial with the passageway and interior to the cylinder and distributively and slidably connected to said stent component.

22. The stent-graft of claim 21 wherein the stent component comprises more than one ring assembly.

23. The stent-graft of claim 22 wherein the ring assemblies are joined by tie members which are generally parallel to said axis.

24. The stent-graft of claim 21 where the stent has multiple torsion members.

25. The stent-graft of claim 21 where the ring assemblies comprise a material selected from stainless steels, cobalt chromium alloys, platinum/tungsten alloys, titanium alloys, and nickel-titanium alloys.

26. The stent-graft of claim 21 where the ring assemblies comprise nitinol.

27. The stent-graft of claim 21 where the ring assemblies are produced from a sheet material or tubing.

28. The stent-graft of claim 21 where the tubular member comprises a material selected from polyethylene, polypropylene, polyglycolic acid, polyesters, polyamides, their mixtures, blends, copolymers, mixtures, blends and copolymers;

polyesters, polyaramids, polyfluorocarbons, and porous or nonporous polyurethanes; and

collagenous materials.

29. The stent-graft of claim 21 where the tubular member comprises polyethylene terephthalate.

30. The stent-graft of claim 21 where the tubular member comprises porous or non-porous polytetrafluoroethylene.

31. The stent-graft of claim 30 where the porous or non-porous polytetrafluoroethylene is expanded.

32. The stent-graft of claim 31 where the porous or non-porous polytetrafluoroethylene is copolymerized with hexafluoropropylene.

33. The stent-graft of claim 31 where the porous or non-porous polytetrafluoroethylene is copolymerized with hexafluoropropylene.

34. The stent-graft of claim 21 additionally comprising radiopaque fibers within said tubular member.

35. The stent-graft of claim 21 additionally comprising at least one polymeric loop passing around said torsion members and wherein the at least one polymeric loop is connected to the tubular graft member.

36. The stent-graft of claim 35 where the at least one loop is of a material selected from polyethylene, polypropylene, polyglycolic acid, polyesters, polyamides, their mixtures, blends, copolymers, mixtures, blends and copolymers;

polyesters, polyaramids, polyfluorocarbons, and porous or nonporous polyurethanes.

37. The stent-graft of claim 36 where the at least one loop is of the same material as the tubular member.