Compliant venous graft

• US 20050070995A1
• Filed: 04/28/2004
• Published: 03/31/2005
• Est. Priority Date: 04/28/2003
• Status: Active Grant

• Current Assignee: Vascular Graft Solutions Ltd.
• Original Assignee: Kips Bay Medical, Inc.
• Inventors: Yeoman, Mark S., Douk, Nareak, Rafiee, Nasser, Zilla, Peter Paul, Bezuidenhout, Deon, Bowles, Hellmut, Franz, Thomas, Wolf, Michael F.
• Granted Patent: US 8,057,537 B2
• Time in Patent Office: Days
• US Class Current: 623/1.320
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61L 27/14 Macromolecular materials
• CPC Class Codes: A61L 27/3625 Vascular tissue, e.g. heart valves

Abstract

A venous graft for replacement of a section of an artery and methods of making the graft. The graft comprises a flexible, resilient, generally tubular external support and a vein segment carried within and having an ablumenal surface in contact with and supported by the tubular support, the venous graft being capable of resilient radial expansion in a manner mimicking the radial compliance properties of an artery.

Claims

1. A flexible, resilient, generally tubular external support within which may be supported a vein segment to form a venous graft mimicking the compliance properties of a healthy artery, the tubular support being capable of resilient radial expansion in a manner providing compliance in the range of 3 to 30%/100 mm Hg.

2. The tubular external support of claim 1 in which said support comprises a knit wire mesh.

3. The tubular external support of claim 1 in which said support comprises a braided wire mesh including an element for controlling the degree of axial extension of the support.

4. The tubular external support of claim 3 in which said element comprises a thread attached to and carried internally of the support.

5. The tubular external support of claim 1 including a vein segment carried within the support, the vein segment having an ablumenal surface in contact with, and supported by, said tubular support.

21. The venous graft of claim 1 wherein the compliance of the venous graft ranges from 3 to 30%/100 mm Hg.

32. The tubular external support of claim 1 in which said a knit wire mesh support comprises loops that alternate in size circumferentially of the support.

6. A venous graft for replacement of a section of an artery, the graft comprising a flexible, resilient, generally tubular external support and a vein segment carried within and having an ablumenal surface in contact with and supported by the tubular support, the venous graft being capable of resilient radial expansion in a manner mimicking the compliance properties of an artery.

7. The venous graft of claim 6 wherein said tubular support is capable of said resilient radial expansion without significant axial dimensional changes.

8. The venous graft of claim 6 wherein the compliance of the graft ranges from 3 to 30%/100 mm Hg.

9. The venous graft of claim 6 wherein the external support comprises a generally tubular fiber mesh capable of expanding in diameter through resilient movement of wires of the mesh to accommodate radial expansion of the vein segment supported in it sufficient to provide the graft with said compliance.

10. The venous graft of claim 6 wherein said external support comprises a knit, tubular mesh capable of expanding radially to accommodate radial expansion of the vein segment supported in it within said compliance range.

11. The venous graft of claim 6 wherein said external support comprises a braided fiber mesh so configured as to exhibit radial expansion in said compliance range without significant reduction in the axial length of the support.

12. The venous graft of claim 11 wherein said fiber mesh is made of metal wire.

13. The venous graft of claim 12 wherein said metal wire is of stainless steel or of a cobalt chrome alloy.

14. The venous graft of claim 11 wherein said metal wire is a shape memory alloy.

15. The venous graft of claim 11 wherein said fiber mesh is polymeric.

16. The venous graft of claim 6 wherein the ablumenal surface of the vein segment is bonded to said tubular support.

17. The venous graft of claim 6 wherein the vein segment and the tubular support are axially coextensive.

18. The venous graft of claim 10 wherein said knitted tubular fiber mesh is made from crimped fibers.

19. The venous graft of claim 9 wherein said tubular fiber mesh is made from fibers that are crimped after having been formed into said tubular mesh.

20. A venous graft for replacement of a section of an artery, the graft comprising a flexible, resilient, knit wire mesh configured as a generally tubular external support and a vein segment carried within and having an ablumenal surface in contact with and supported by the tubular support, the support having resilient radial expansion and contraction characteristics that provide the venous graft with compliance properties mimicking those of an artery.

22. Method of producing a venous graft for use in replacing a section of an artery, comprising providing a segment of a vein and sheathing the segment in a generally tubular support in supportive contact with the ablumenal surface of the vein segment, the support being sufficiently flexible and radially resilient as to provide the graft with compliance properties mimicking the compliance properties of an artery.

23. The method of claim 22 including the step of cutting said venous graft from a longer section of vein sheathed in said tubular support, the ends of the vein and tubular support of the venous graft being coextensive.

24. The method of claim 22 including the step of supporting said generally tubular support upon an exterior surface of an applicator having an internal passage within which is positioned the vein segment, and removing the applicator to permit the tubular support to come into supportive contact with the ablumenal surface of the vein segment.

25. The method of claim 22 including the step of supporting said generally tubular support upon an exterior surface of an applicator having an internal passage, and, while passing the vein segment from within the applicator passage, drawing the tubular support onto the surface of the vein segment.

26. The method of claim 22 wherein said generally tubular support is chosen to be sufficiently radially resilient as to provide the venous graft with a compliance ranging from 3 to 30%/100 mm Hg.

27. The method of claim 24 wherein said tubular support is axially resilient, the method including the step of controlling axial dimension changes of the tubular support as the support comes into supportive contact with the vein segment to provide the venous graft with said compliance properties.

28. The method of claim 27 including the step of providing the tubular support with an axially extending, relatively inextensible element that restrains the tubular support from unwanted axial extension.

29. The method of claim 28 wherein said inextensible element comprises a flexible fiber positioned within the tubular support and between the tubular support and the ablumenal surface of the vein segment.

30. The method of claim 28 wherein the flexible fiber is a wire joined to the interior of the tubular support.

31. The method of claim 22 including the step of bonding the ablumenal surface of the vein segment to the tubular support.

33. The method of claim 22 including forming said tubular support from a knit wire mesh, wherein said mesh is formed with loops that alternate in size circumferentially of the support.