STENT-GRAFT COVERING PROCESS

• US 20090211076A1
• Filed: 02/24/2009
• Published: 08/27/2009
• Est. Priority Date: 02/27/2008
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: SCHLUN, Martin
• Granted Patent: US 8,196,279 B2
• Time in Patent Office: Days
• US Class Current: 29/505
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: B29D 23/001 Pipes; Pipe joints pleated hoses B29D23/18
• CPC Class Codes: B29L 2023/007 Medical tubes other than catheters catheters B29L2031/7542
• CPC Class Codes: Y10T 29/49908 Joining by deforming

Abstract

A method of making a stent-graft includes providing a self-expanding stent having a collapsed configuration with a first diameter and an expanded configuration with a second diameter greater than the first diameter, the stent including a polymeric coating on at least an inner surface, disposing a graft on a mandrel having a third diameter greater than the second diameter, and contacting an outer surface of the graft with the coated inner surface of the stent, the stent applying a compressive force to the graft.

Claims

1. A method of making a stent-graft, comprising:

providing a self-expanding stent having a collapsed configuration with a first diameter and an expanded configuration with a second diameter greater than the first diameter, the stent including a polymeric coating on at least an inner surface;

disposing a graft on a mandrel having a third diameter greater than the second diameter; and

contacting an outer surface of the graft with the coated inner surface of the stent, the stent applying a compressive force to the graft.

2. The method according to claim 1, wherein the contacting step comprises expanding the stent to a fourth diameter greater than the third diameter, positioning the stent over the graft and releasing the stent.

3. The method according to claim 1, further comprising the step of heating the stent-graft.

4. The method according to claim 3, wherein the heating step includes processing at a temperature of about 340 degrees C. for a time period in the range of about 10 minutes to about 11 minutes.

5. The method according to claim 1, wherein the disposing step includes sliding a generally tubular ePTFE graft onto the mandrel.

6. The method according to claim 1, wherein the disposing step includes wrapping an ePTFE film about the mandrel, the ePTFE film having a thickness in the range of about 40 microns to about 100 microns.

7. The method according to claim 1, wherein the providing step includes providing a stent comprised of shape memory metal.

8. The method according to claim 1, wherein the third diameter is in the range of about 0.1 mm to about 1 mm greater than the second diameter.

9. The method according to claim 8, wherein the second diameter is in the range of about 4 mm to about 14 mm.

10. The method according to claim 1, wherein the polymeric coating comprises PTFE.

11. The method according to claim 1, wherein the bond strength of the stent-graft is in the range of about 2 gf/mm to about 13 gf/mm.

12. The method according to claim 1, further comprising wrapping ePTFE tape about an outer surface of the stent under tension and heating the stent-graft, wherein the tape is removed from the stent before the heating step.

13. The method according to claim 12, wherein the ePTFE tape is removed from the stent after a period in the range of about 5 minutes to about 10 minutes.

14. The method according to claim 12, wherein the wrapping step comprises helically wrapping a first and second layer of tape about the outer surface of the stent.

15. The method according to claim 12, wherein the bond strength of the stent-graft is in the range of about 4 gf/mm to about 14 gf/mm.

16. A method of making a stent-graft, comprising:

providing a self-expanding stent having a collapsed configuration with a first diameter and an expanded configuration with a second diameter greater than the first diameter, the stent including a polymeric material on at least a portion of an inner surface;

disposing an ePTFE graft on a mandrel having a third diameter about 1 mm greater than the second diameter;

placing the stent onto the graft by expanding the stent to a fourth diameter greater than the third diameter, positioning the stent over the graft and releasing the stent; and

heating the stent-graft.

17. A method of making a stent-graft, comprising:

providing a self-expanding stent having a collapsed configuration with a first diameter and an expanded configuration with a second diameter greater than the first diameter, the stent including a polymeric coating on at least an inner surface;

disposing an ePTFE graft on a mandrel having a third diameter greater than the second diameter;

expanding the stent to a fourth diameter greater than the third diameter, positioning the stent over the graft and releasing the stent, the coated inner surface of the stent contacting an outer surface of the ePTFE graft;

wrapping ePTFE tape about an outer surface of the stent under tension; and

removing the ePTFE tape prior to subjecting the stent-graft to a heating step.

18. The method according to claim 17, wherein the removing step is performed after a period in the range of about 5 minutes to about 10 minutes.

19. The method according to claim 17, wherein the third diameter is in the range of about 0.1 mm to about 1 mm greater than the second diameter.

20. The method according to claim 19, wherein the second diameter is in the range of about 4 mm to about 8 mm.