Radially expandable polytetrafluoroethylene

• US 6,620,190 B1
• Filed: 12/26/1996
• Issued: 09/16/2003
• Est. Priority Date: 05/06/1994
• Status: Expired due to Term

• Current Assignee: Bard Peripheral Vascular Incorporated (Becton, Dickinson & Co)
• Original Assignee: IMPRA Incorporated (Becton, Dickinson & Co)
• Inventors: Colone, William M.
• Primary Examiner(s): Low, Christopher S. F.
• Assistant Examiner(s): Mohamed, Abdel A.
• Application Number:
  US08/773,281
• Time in Patent Office: 2,455 Days
• Field of Search: 526/255, 428/422, 428/398, 428/304.4, 623/1.1, 623/1.11, 623/1.12, 623/1.2, 623/1.14, 623/1.15, 623/1.21, 623/1.25, 606/194, 606/195
• US Class Current: 623/1.1
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: B29C 55/24 radial
• CPC Class Codes: B29K 2027/18 PTFE, i.e. polytetrafluorethene , e.g. ePTFE, i.e. expanded polytetrafluorethene
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/2975 Tubular or cellular
• CPC Class Codes: Y10T 428/31544 Addition polymer is perhalogenated

Abstract

Extruded, stretched, sintered tubular PTFE materials are produced which are suited for use in the medical field as liners and covers for expandable stents. The PTFE materials have an unusually low REC (Radial Expansion Coefficient) and RER (Radial Expansion Ratio).

Claims

1. An assembly for treating a body vessel, comprising:

a radially expandable stent, having an inner surface and an outer surface; and

a tubular liner consisting of expanded polytetrafluoroethylene, having a microstructure characterized by nodes interconnected by fibrils, wherein the liner is positioned along a length of the stent, covering at least one of the inner and outer surfaces;

wherein the assembly is permanently radially expandable in vivo from a first diameter to a larger second diameter, and wherein the tubular liner maintains structural integrity at the second diameter up to approximately 100% of the first diameter.

2. The assembly according to claim 1, wherein said tubular liner has a radial expansion coefficient of less than 2.0.

3. The assembly according to claim 1, wherein said tubular liner has a radial expansion coefficient of less than 1.7.

4. The assembly according to claim 1, wherein said tubular liner has a radial expansion coefficient of less than 1.5.

5. The assembly according to claim 1, wherein said tubular liner has a radial expansion coefficient of less than 1.0.

6. The assembly according to claim 1, wherein said tubular liner has a radial expansion coefficient of less than 30.

7. The assembly according to claim 1, wherein said tubular liner has a radial expansion coefficient of less than 2.

8. The assembly according to claim 1, wherein said tubular liner has a radial expansion coefficient of less than 10.

9. The assembly according to claim 1, wherein said tubular liner has a radial expansion coefficient of less than 5.

10. The assembly according to claim 1, wherein said tubular liner has a reduction ratio to lubricant level of about 5 or less.

11. The assembly according to claim 10, wherein said lubricant level is between 16 and 35%.

12. The assembly according to claim 10, wherein said lubricant level is between 16 and 35%.

13. The assembly according to claim 10, wherein said reduction ratio is less than 300:

1.

14. The assembly according to claim 10, wherein said reduction ratio is less than 200:

1.

15. The assembly according to claim 10, wherein said reduction ratio is less than 125:

1.