METHOD OF DENSIFYING ePTFE TUBE

• US 20090319034A1
• Filed: 06/19/2008
• Published: 12/24/2009
• Est. Priority Date: 06/19/2008
• Status: Abandoned Application

• Current Assignee: Lifeshield Sciences LLC (Acacia Research Corporation)
• Original Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Inventors: Sowinski, Krzysztof
• Application Number:
  US12/142,144
• Publication Number:
  US 20090319034A1
• Time in Patent Office: Days
• US Class Current: 623/1.460
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: B29C 2043/3665 cores or inserts, e.g. pins, mandrels, sliders
• CPC Class Codes: B29C 43/003 characterised by the choice of material
• CPC Class Codes: B29C 43/46 Rollers
• CPC Class Codes: B29C 71/00 After-treatment of articles without altering their shape; Apparatus therefor B29C44/56, B29C73/00 take precedence; surface shaping B29C59/00 ; for joined or sealed parts B29C66/03; after-treatment specially adapted for vulcanising tyres B29D30/0633
• CPC Class Codes: B29K 2027/18 PTFE, i.e. polytetrafluorethene , e.g. ePTFE, i.e. expanded polytetrafluorethene
• CPC Class Codes: B29K 2995/0063 Density
• CPC Class Codes: B29L 2023/00 Tubular articles B29L2024/00 takes precedence ; catheters B29L2031/7542
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene

Abstract

The present invention relates to a prosthetic structure, including a densified layer of expanded polytetrafluoroethylene (ePTFE) and a method for manufacturing the same. The invention includes the steps of providing a layer of ePTFE, desirably a tubular layer; applying the layer of ePTFE to a mandrel; mechanically compressing the layer of ePTFE on the mandrel; and removing the compressed ePTFE; where the compressed ePTFE is denser than uncompressed ePTFE. The compressed ePTFE has a water entry pressure (WEP) value of at least 15 psi, and desirably a WEP of at least about 20 psi.

Claims

1. A method for manufacturing compressed ePTFE, comprising the steps of:

a. providing a layer of ePTFE;

b. applying said layer of ePTFE to a mandrel;

c. mechanically compressing said layer of ePTFE on said mandrel; and

d. removing said compressed ePTFE;

wherein said compressed ePTFE is denser than uncompressed ePTFE.

2. The method of claim 1, wherein said compressed ePTFE is tubular in shape.

3. The method of claim 1, further comprising the step of at least partially covering said compressed ePTFE with a layer of silicone.

4. The method of claim 3, further comprising the step of at least partially sintering said compressed ePTFE and said silicone layer.

5. The method of claim 4, wherein said sintering is achieved by heating said ePTFE and said silicone layer at a temperature of about 625°

F. for about 10 to about 12 minutes.

6. The method of claim 1, wherein said step of mechanically compressing said layer of ePTFE on said mandrel comprises exerting a pressure on said ePTFE of about 300 to about 500 psi.

7. The method of claim 1, wherein said compressed ePTFE has a WEP value of at least about 20 psi.

8. The method of claim 1, wherein said compressed ePTFE has an average density of from about 1.0 to about 1.5 grams/cc.

9. An ePTFE tube, comprising at least one layer of compressed ePTFE, wherein said ePTFE has a WEP value of at least about 20 psi and a density of from about 1.0 to about 1.5 grams/cc.

10. The tube of claim 9, further comprising a layer of silicone at least partially covering the outside of said tube.

11. The tube of claim 9, further comprising a stent layer.

12. The tube of claim 9, further comprising at least one additional layer of ePTFE, wherein said additional layer of ePTFE comprises a WEP value of at least about 20 psi and a density of from about 1.0 to about 1.5 grams/cc.

13. The tube of claim 12, further comprising a stent between said layers of ePTFE.

14. A prosthetic structure, comprising at least one layer of ePTFE, wherein said ePTFE comprises a WEP value of at least about 20 psi and a density of about 1.0 to about 1.5 grams/cc.

15. The prosthetic structure of claim 14, wherein said prosthetic structure is selected from the group consisting of a tube, sheet, tape, or combinations thereof.

16. The prosthetic structure of claim 15, wherein said tube is round, oval, tapered, flared, or other non-cylindrical shape.

17. The prosthetic structure of claim 14, wherein said prosthetic structure is adapted to repair an abdominal aortic aneurysm.

18. The prosthetic structure of claim 14, wherein said prosthetic structure is adapted to repair a thoracic aortic aneurysm.

19. The prosthetic structure of claim 14, further comprising a stent layer.

20. The prosthetic structure of claim 19, wherein said stent layer is located between two layers of said ePTFE.

21. The prosthetic structure of claim 14, further comprising a layer of silicone at least partially covering said layer of ePTFE.

22. An apparatus for conveying fluid, comprising an ePTFE tube, said ePTFE tube comprising at least one layer of compressed ePTFE, wherein said ePTFE has a WEP value of at least about 20 psi and a density of from about 1.0 to about 1.5 grams/cc.

23. The apparatus of claim 22, further comprising a layer of silicone at least partially covering the outside of said tube.

24. The apparatus of claim 22, further comprising a stent layer.

25. The apparatus of claim 22, further comprising at least one additional layer of ePTFE, wherein said additional layer of ePTFE comprises a WEP value of at least about 20 psi and a density of from about 1.0 to about 1.5 grams/cc.

26. The apparatus of claim 25, further comprising a stent between said layers of ePTFE.

27. A means for conveying fluid, comprising an ePTFE tube, said ePTFE tube comprising at least one layer of compressed ePTFE.