Pressure lamination method for forming composite ePTFE/textile and ePTFE/stent/textile prostheses

• US 20040182511A1
• Filed: 12/19/2003
• Published: 09/23/2004
• Est. Priority Date: 06/11/2001
• Status: Active Grant

• Current Assignee: Lifeshield Sciences LLC (Acacia Research Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Sowinski, Krzysztof, Rakos, Ronald
• Granted Patent: US 7,560,006 B2
• Time in Patent Office: Days
• US Class Current: 156/287
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61L 27/16 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/48 with macromolecular fillers
• CPC Class Codes: A61L 27/507 for artificial blood vessels apparatus for applying cells on a blood vessel prosthesis A61F2/062
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61L 31/129 containing macromolecular fillers
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene

Abstract

A method of forming a composite textile and ePTFE implantable device includes the steps of (a) providing an ePTFE layer having opposed surfaces comprising a microporous structure of nodes interconnected by fibrils; (b) providing a textile layer having opposed surfaces; (c) applying a coating of an elastomeric bonding agent to one of the opposed surfaces of the ePTFE layer or the textile layer; (d) providing a hollow member having an open end and an opposed closed end defining a fluid passageway therebetween and having a wall portion with at least one hole extending therethrough, the hole being in fluid communication with the fluid passageway; (e) concentrically placing the ePTFE layer and the textile layer onto the hollow member and over the at least one hole of the hollow member to provide an interior composite layer and an exterior composite layer, thereby defining a composite assembly, wherein the interior composite layer is one of the ePTFE layer or the textile layer and the exterior composite layer is the other of the ePTFE layer or the textile layer; (f) placing the hollow member with the composite assembly within a pressure chamber; (g) applying a pressure differential so that the pressure within the chamber is greater than a pressure within the fluid passageway of the hollow member; and (h) applying heat to the bonding agent to adhesively bond the textile layer and the ePTFE layer to provide a laminated composite assembly.

Claims

1. A method of forming a composite textile and ePTFE implantable device comprising the steps of:

(a) providing an ePTFE layer having opposed surfaces comprising a microporous structure of nodes interconnected by fibrils;

(b) providing a textile layer having opposed surfaces;

(c) applying a coating of an elastomeric bonding agent to one of said opposed surfaces of said ePTFE layer or said textile layer;

(d) providing a hollow member having an open end and an opposed closed end defining a fluid passageway therebetween and having a wall portion with at least one hole extending therethrough, the hole being in fluid communication with said fluid passageway;

(e) concentrically placing said ePTFE layer and said textile layer onto said hollow member and over said at least one hole of said hollow member to provide an interior composite layer and an exterior composite layer, thereby defining a composite assembly, wherein said interior composite layer is one of said ePTFE layer or said textile layer and said exterior composite layer is the other of said ePTFE layer or said textile layer;

(f) placing said hollow member with said composite assembly within a pressure chamber;

(g) applying a pressure differential so that the pressure within said chamber is greater than a pressure within said fluid passageway of said hollow member; and

(h) applying heat to said bonding agent to adhesively bond said textile layer and said ePTFE layer to provide a laminated composite assembly.

2. The method of claim 1, wherein said applying step includes:

applying a solution of said bonding agent.

3. The method of claim 2, wherein said applying step further includes:

spray coating said surface of said ePTFE layer with said solution.

4. The method of claim 1, wherein said textile layer is a hollow tubular textile layer having an inner and outer textile surface and said ePTFE layer is applied to said inner textile surface.

5. The method of claim 4, wherein said ePTFE layer is a hollow tubular structure.

6. The method of claim 4, wherein said implantable device is a vascular prosthesis.

7. The method of claim 1, wherein said textile layer is a hollow tubular textile layer having an inner and outer textile surface and said ePTFE layer is applied to said outer textile surface.

8. The method of claim 7, wherein said implantable device is a vascular prosthesis.

9. The method of claim 1, further including the step of applying an elastic barrier member over an exterior surface of said exterior composite layer.

10. The method of claim 9, wherein said elastic barrier is adjacently disposed over said exterior surface of said exterior composite layer.

11. The method of claim 9, wherein said elastic barrier is adjacently disposed over said exterior surface of said exterior composite layer without applying a flowable mass particulate therebetween.

12. The method of claim 1, where said applied pressure differential is from about 1 psia to about 50 psia.

13. The method of claim 1, wherein the step of applying heat to said bonding agent includes heating said bonding agent from about 325°

F. to about 450°

F.

14. The method of claim 1, wherein the step of applying said coating of said elastomeric bonding agent includes applying said coating to one of said opposed surfaces of said ePTFE layer with said bonding agent being disposed within said microporous structure.

15. The method of claim 4, further including the steps of:

providing a distensible stent; and

placing said distensible stent between said textile layer and said ePTFE layer.

16. The method of claim 15, further including the step of providing a second layer of EPTFE between said stent and said textile layer.

17. The method of claim 4, further including the steps of:

providing a distensible stent; and

placing said distensible stent onto said hollow member prior to the step of placing said ePTFE layer and said textile layer onto said hollow member.

18. The method of claim 1, wherein said bonding agent is selected from the group consisting of urethanes, styrene/isobutylene/styrene block copolymers, silicones, and combinations thereof.

19. The method of claim 1, wherein said bonding agent is a polycarbonate urethane.

20. The method of claim 1, wherein said textile layer is knitted textile layer, a woven textile layer, a stretch-knit textile layer, a braided textile layer, and combinations thereof.

21. The method of claim 1, wherein said textile layer and said ePTFE layer are substantially planar.

22. The method of claim 21, wherein said composite device is a vascular patch.

27. A composite vascular prosthesis formed by the method of claim 1, wherein said prosthesis has a bond peel strength of at of at least 32 g/mm and a variation of said bond peel strength of less than about 4.

28. A composite vascular prosthesis formed by the method of claim 15, wherein said prosthesis has a bond shear strength of at least 4.5 g/mm² and a variation of said bond shear strength of less than about 2.

23. A composite vascular prosthesis comprising:

a tubular ePTFE structure having a microporous structure of nodes interconnected by fibrils;

a tubular textile structure; and

a cured elastomeric bonding agent adhesively securing said ePTFE structure and said textile structure;

wherein said textile structure and said ePTFE structure are pressure laminated together to provide said composite prosthesis having a bond peel strength of at of at least 32 g/mm and a variation of said bond peel strength of less than about 4.

24. A composite vascular prosthesis comprising:

a tubular ePTFE structure having a microporous structure of nodes interconnected by fibrils;

a tubular textile structure; and

a cured elastomeric bonding agent adhesively securing said ePTFE structure and said textile structure;

wherein said textile structure and said ePTFE structure are pressure laminated together to provide said composite prosthesis having an increased bond peel strength of at least 15 percent as compared to non-pressure laminated ePTFE and textile assemblies

25. A composite vascular prosthesis comprising:

a tubular ePTFE structure having a microporous structure of nodes interconnected by fibrils;

a tubular textile structure;

a distensible stent and

a cured elastomeric bonding agent adhesively securing said ePTFE structure, said textile structure and said stent;

wherein said textile structure and said ePTFE structure are pressure laminated to said stent to provide said composite prosthesis having a bond shear strength of at least 5.5 g/mm² and a variation of said bond shear strength of less than about 2.

26. A composite vascular prosthesis comprising:

a tubular ePTFE structure having a microporous structure of nodes interconnected by fibrils;

a tubular textile structure;

a distensible stent and

a cured elastomeric bonding agent adhesively securing said ePTFE structure, said textile structure and said stent;

wherein said textile structure and said ePTFE structure are pressure laminated to said stent to provide said composite prosthesis having an increased bond shear strength of at least 20 percent as compared to non-pressure laminated ePTFE and textile assemblies.