Vascular Graft With Kink Resistance After Clamping

• US 20100179642A1
• Filed: 12/28/2005
• Published: 07/15/2010
• Est. Priority Date: 06/17/2005
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Bogert, David L., Abbott, Jamie
• Granted Patent: US 8,066,758 B2
• Time in Patent Office: Days
• US Class Current: 623/1.270
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61L 27/16 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/507 for artificial blood vessels apparatus for applying cells on a blood vessel prosthesis A61F2/062
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene

Abstract

A self-sealing vascular graft with kink resistance is described. The vascular graft includes a substrate that can be a PTFE, having a self-sealing region that may include several layers of material. The central section of the vascular graft may be constructed differently from surrounding self-sealing regions, in order to provide kink resistance following the clamping of the graft. Also described is a graft with a flared cuff attached to one or both ends, the attachment or transition region including reinforcement beading.

Claims

1. A self-sealing vascular graft, comprising:

a generally tubular ePTFE substrate, including a proximal end section, a distal end section and a central section positioned between the proximal end section and distal end section, at least one of the proximal end section, central section, and distal end section including a self-sealing region; and

a first beading contiguous to a surface of the ePTFE substrate along at least a portion of the central section.

2. The vascular graft according to claim 1, wherein the central section has a length in the range of about 5 cm to about 12 cm.

3. The vascular graft according to any of claims 1-2, wherein the sealant layer has a thickness in the range of about 10 microns to 300 microns.

4. The vascular graft according to any of claims 1-3, wherein the beading is helically positioned about the surface.

5. The vascular graft according to claim 4, wherein the spacing between adjacent windings of the helically positioned beading is in the range of about 1 mm to about 2 mm.

6. The vascular graft according to any of claims 1-5, wherein the proximal end section, the distal end section and the central section comprise a layer of polyurethane matrix defining a foam layer.

7. The vascular graft according to any of claims 1-6, wherein one of the proximal and central sections comprises a second beading, and wherein the first beading includes a portion contiguous to the ePTFE substrate.

8. The vascular graft according to claim 7, wherein at least one of the first and second beading comprises a radiopaque material selected from the group consisting essentially of barium sulfate, bismuth subcarbonate, bismuth trioxide, tungsten, or tantalum and combinations thereof.

9. The vascular graft according to claim 7, wherein the first beading comprises a first cross-sectional area and the second beading comprises a second cross-sectional area different from the first cross-sectional area.

10. The graft according to claim 8, wherein the second cross-sectional area is less than the first cross-sectional area.

11. The vascular graft according to any of claims 1-10, wherein at least one of the first and second beading comprises a material selected from the group consisting essentially of shape memory material, superelastic metals, stainless steel, polyester, nylon, polyurethane, PTFE, or ePTFE and combinations thereof.

12. The vascular graft according to any of claims 1-11, wherein the proximal end section, the distal end section and the central section comprise an outer ePTFE member.

13. The graft according to claim 12, wherein one of the distal and proximal end sections comprises another ePTFE member surrounding at least a portion of the outer ePTFE member.

14. The vascular graft according to any of claims 1-13, wherein at least one of the ePTFE substrate, foam layer and outer ePTFE member comprises a radiopaque material selected from the group consisting essentially of barium sulfate, bismuth subcarbonate, bismuth trioxide, tungsten, or tantalum and combinations thereof.

15. A vascular graft, comprising:

a generally tubular ePTFE substrate defining a longitudinal axis;

a layer of polyurethane matrix disposed about the ePTFE substrate; and

a first beading disposed in the polyurethane matrix.

16. The vascular graft according to claim 15, wherein the first beading is helically positioned about the ePTFE substrate.

17. The vascular graft according to claim 16, wherein the spacing between adjacent windings of the helically positioned beading is in the range of about 1 mm to about 2 mm.

18. The vascular graft according to any of claims 15-17, further comprising a second beading.

19. The vascular graft according to claim 18, wherein at least one of the first and second beading comprises a radiopaque material selected from the group consisting essentially of barium sulfate, bismuth subcarbonate, bismuth trioxide, tungsten, or tantalum and combinations thereof.

20. The vascular graft according to claim 18, wherein the first beading comprises a first cross-sectional area and the second beading comprises a second cross-sectional area different from the first cross-sectional area.

21. The graft according to claim 20, wherein the second cross-sectional area is less than the first cross-sectional area.

22. The vascular graft according to any of claims 15-21, wherein at least one of the first and second beading comprises a material selected from the group consisting essentially of shape memory material, superelastic metals, stainless steel, polyester, nylon, polyurethane, PTFE, or ePTFE and combinations thereof.

23. The vascular graft according to any of claims 15-22, wherein at least one of the ePTFE substrate and polyurethane matrix comprises a radiopaque material selected from the group consisting essentially of barium sulfate, bismuth subcarbonate, bismuth trioxide, tungsten, or tantalum and combinations thereof.

24. A method of making a kink resistant vascular graft, comprising:

providing a generally tubular ePTFE substrate, including a proximal end section, a distal end section and a central section positioned between the proximal end section and distal end section; and

bonding a first beading to a surface of the ePTFE substrate along at least a portion of the central section.

25. The method according to claim 24, wherein the first beading comprises a radiopaque material selected from the group consisting essentially of barium sulfate, bismuth subcarbonate, bismuth trioxide, tungsten, or tantalum and combinations thereof.

26. The method according to any of claims 24-25, wherein the first beading comprises a material selected from the group consisting essentially of shape memory material, superelastic metals, stainless steel, polyester, nylon, polyurethane, PTFE, or ePTFE and combinations thereof.

27. The method according to any of claims 24-26, wherein the bonding comprises moving the first beading through a solution including THF prior to contacting the beading with the ePTFE substrate.

28. The method according to claims 24-27, wherein the bonding comprises helically wrapping the beading under tension.

29. The method according to any of claims 24-28, further comprising disposing a first polymeric foam layer over at least a portion of the proximal end section, the distal end section and the central section.

30. The method according to claim 29, further comprising positioning a second beading about the ePTFE substrate in the proximal end section and distal end section.

31. The method according to any of claims 29-30, further comprising disposing a second polymeric foam layer over the first polymeric foam layer such that an overall wall thickness of the vascular graft is in the range of about 1 mm to about 2 mm.

32. The method according to claim 31, wherein the disposing comprises locating a portion of the beading in one of the first and second polymeric foam layers.

33. The method according to claim 32, further comprising helically wrapping a polymeric tape over the second polymeric foam layer such that edges of adjacent windings of the tape overlap.

34. The method according to claim 33, further comprising wrapping a third beading about the polymeric tape and covering the third beading with a second generally tubular ePTFE member.

35. The method according to claim 33, wherein the polymeric tape comprises ePTFE and wherein helically wrapping the tape comprises applying THF to the tape.

36. The method according to any of claims 33-35, wherein the polymeric tape comprises ePTFE and wherein helically wrapping the tape comprises applying tension to the tape.

37. The method according to any of claims 24-36, further comprising incorporating one or more bioactive agents in at least one of the ePTFE substrate, first polymeric foam layer and second polymeric foam layer.

38. The method according to any of claims 24-37, further comprising bonding a flared vascular cuff to an end of the substrate.

39. A self-sealing vascular cuff graft, comprising:

a generally tubular ePTFE substrate;

a self-sealing region extending along a length of the generally tubular substrate between a first and second end thereof, the self-sealing region including at least one of a sealant layer and a foam layer;

an outer ePTFE member positioned over at least a portion of the self-sealing region;

a first beading positioned over the substrate at the first end adjacent to the self-sealing region, the outer ePTFE member extending over at least a portion of the first beading;

a second beading positioned over the outer ePTFE member at the first end adjacent to the self-sealing region; and

a flared vascular cuff having a proximal end positioned over at least a portion of the first and second beadings.

40. The self-sealing vascular cuff graft according to claim 39, wherein the first beading contacts an outer surface of the substrate.

41. The self-sealing vascular cuff graft according to any of claims 39-40, wherein the first beading is helically wrapped about the substrate.

42. The self-sealing vascular cuff graft according to any of claims 39-41, wherein the second beading is helically wrapped about the outer ePTFE member.

43. The self-sealing vascular cuff graft according to any of claims 41-42, wherein each winding of the second beading is positioned between adjacent windings of the first beading.

44. The self-sealing vascular cuff graft according to any of claims 39-40, wherein at least one of the first and second beadings comprises a plurality of rings spaced apart along a length of the first end.

45. The self-sealing vascular cuff graft according to any of claims 39-44, wherein adjacent beading windings or rings are spaced from each other a distance in the range of about 1.2 mm to about 2.8 mm.

46. The self-sealing vascular cuff graft according to any of claims 39-45, wherein the second beading extends for a length in the range of about 0.5 cm to about 1.5 cm.

47. The self-sealing vascular cuff graft according to any of claims 39-46, wherein the first and second beadings have a circular cross-sectional area.

48. The self-sealing vascular cuff graft according to any of claims 39-47, wherein a cross-sectional area of the first and second beadings is approximately equivalent.

49. The self-sealing vascular cuff graft according to any of claims 39-48, wherein the self-sealing region comprises a third beading having a larger cross-sectional area than both the first and second beadings.

50. The self-sealing vascular cuff graft according to any of claims 39-49, wherein the ePTFE member comprises a length of ePTFE tape.

51. The self-sealing vascular cuff graft according to any of claims 39-50, wherein the self-sealing region comprises a first foam layer and a second foam layer.

52. The self-sealing vascular cuff graft according to any of claims 51, wherein a third beading contacts both the first and second foam layers.

53. A vascular graft, comprising:

a generally tubular ePTFE substrate defining a longitudinal axis extending through distal portions of the ePTFE substrate, the ePTFE substrate having a first cross-sectional area about the longitudinal axis; and

an elastomeric member disposed about the ePTFE substrate so that, as the ePTFE substrate is curved to contact the distal portions of the substrate to a generally circular pin having a diameter of about 20 millimeters or less, the ePTFE includes a second cross-sectional area of the ePTFE substrate of at least about 50% of the first cross-sectional area where the second cross-sectional area is located approximately 20 millimeters from the outer surface of the circular pin.

54. The vascular graft of claim 53, wherein the second cross-sectional area is about 66% of the first cross-sectional area.

55. The vascular graft of claim 54, wherein the elastomeric member comprises a polyurethane material.

56. A method of making a self-sealing vascular cuff graft, comprising:

providing a generally tubular ePTFE substrate, including a self-sealing region extending along a length of the generally tubular substrate between a first and second end thereof;

positioning a first beading over the substrate at the first end adjacent to the self-sealing region;

disposing an outer ePTFE member over at least a portion of the self-sealing region and the first beading;

positioning a second beading over the outer ePTFE member at the first end adjacent to the self-sealing region; and

attaching a flared vascular cuff to the substrate over at least a portion of the first and second beadings.

57. The method according to claim 56, wherein positioning the first beading comprises helically wrapping the beading so that the beading contacts an outer surface of the substrate.

58. The method according to any of claims 56-57, wherein positioning the second beading comprises helically wrapping the beading about the outer ePTFE member.

59. The method according to any of claims 56-58, wherein positioning the second beading comprises positioning each winding of the second beading between adjacent windings of the first beading.

60. The method according to any of claims 56-59, wherein positioning the first and second beadings comprises spacing adjacent beading windings from each other a distance in the range of about 1.2 mm to about 2.8 mm.

61. The method according to any of claims 56-60, wherein positioning the second beading comprises extending the second beading over a length in the range of about 0.5 cm to about 1.5 cm.

62. The method according to any of claims 56-61, wherein the outer ePTFE member comprises a length of ePTFE tape, and wherein disposing the ePTFE tape comprises contacting the ePTFE tape with a solvent.