Vascular graft with improved flow surfaces

• US 6,517,571 B1
• Filed: 01/22/1999
• Issued: 02/11/2003
• Est. Priority Date: 01/22/1999
• Status: Expired due to Term

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: Gore Enterprise Holdings Incorporated (W.L. Gore and Associates)
• Inventors: Davidson, Daniel Francis, Ulm, Mark Joseph, Butters, Leslie Charles, Brauker, James Howard
• Primary Examiner(s): Milano, Michael J.
• Assistant Examiner(s): Bui, Vy Q.
• Application Number:
  US09/235,214
• Time in Patent Office: 1,481 Days
• Field of Search: 623/1, 623/11, 623/12, 606/108, 606/191, 606/194, 606/195, 606/198
• US Class Current: 623/1.13
• 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 27/34 Macromolecular materials
• 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: A61L 33/064 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L33/062 takes precedence
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene

Abstract

An ePTFE vascular graft having a smooth PTFE luminal surface which is substantially non-adhesive to occlusive blood components. Preferably the graft is a longitudinally extruded and expanded ePTFE tube of about 10-30 microns mean fibril length and is provided with a luminal surface covering of an ePTFE film of small mean fibril length (5 microns of less) which provides the smooth luminal PTFE surface. The graft is anticipated to be particularly effective as a small diameter graft (6 mm or smaller). It is anticipated to have utility as a conventional vascular graft, as a cardiovascular patch and as an intraluminal vascular graft and as a covering for stents.

Claims

1. A vascular graft comprising:

a substrate; and

a luminal surface comprising polytetrafluoroethylene provided to the substrate, the luminal surface havinq a surface value of about 1.7 microns RMS, or less; and

the luminal surface being oriented as a blood contact surface for the vascular graft.

2. A vascular graft according to claim 1 having a luminal surface with a surface value of about 1.6 microns RMS or less.

3. A vascular graft according to claim 1 having a luminal surface with a surface value of about 1.4 microns RMS or less.

4. A vascular graft according to claim 1 having a luminal surface with a surface value of about 1.2 microns RMS or less.

5. A vascular graft according to claim 4 wherein the luminal surface comprises a film of porous expanded polytetrafluoroethylene having a microstructure of interconnected fibrils.

6. A vascular graft according to claim 4 wherein the luminal surface has a substrate comprising a porous expanded polytetrafluoroethylene tube having a mean fibril length between about 5 and 90 microns.

7. A vascular graft according to claim 4 wherein the vascular graft comprises a cardiovascular patch.

8. A vascular graft according to claim 4 wherein the vascular graft comprises an intraluminal graft.

9. A vascular graft according to claim 4 wherein the vascular graft comprises a covering over at least a portion of a stent'"'"'s exterior surface.

10. A vascular graft according to claim 4 wherein the vascular graft comprises a covering over at least a portion of a stent'"'"'s luminal surface.

11. A vascular graft according to claim 1 having a luminal surface with a surface value of about 1.0 microns RMS or less.

12. A vascular graft according to claim 11 wherein the luminal surface comprises a film of porous expanded polytetrafluoroethylene having a microstructure of interconnected fibrils.

13. A vascular graft according to claim 11 wherein the luminal surface has a substrate comprising a porous expanded polytetrafluoroethylene tube having a mean fibril length between about 5 and 60 microns.

14. A vascular graft according to claim 11 wherein the vascular graft comprises a cardiovascular patch.

15. A vascular graft according to claim 11 wherein the vascular graft comprises an intraluminal graft.

16. A vascular graft according to claim 11 wherein the vascular graft comprises a covering over at least a portion of a stent'"'"'s exterior surface.

17. A vascular graft according to claim 11 wherein the vascular graft comprises a covering over at least a portion of a stent'"'"'s luminal surface.

18. A vascular graft according to claim 1 having a luminal surface with a surface value of about 0.8 microns RMS or less.

19. A vascular graft according to claim 1 having a luminal surface with a surface value of about 0.6 microns RMS or less.

20. A vascular graft according to claim 1 having a luminal surface with a surface value of about 0.4 microns RMS or less.

21. A vascular graft according to claim 1 wherein said vascular graft is microporous having void spaces which contain a therapeutic agent.

22. A vascular graft according to claim 1 wherein said vascular graft is capable of being stretched and then rapidly recovering more than about 6% of its stretched length.

23. A vascular graft according to claim 1 having a density of less than about 1.2 g/cc.

24. A vascular graft according to claim 23 wherein said luminal surface has a surface value of about 1.2 microns RMS or less.

25. A vascular graft according to claim 23 wherein said luminal surface has a surface value of about 1.0 microns RMS or less.

26. A vascular graft according to claim 23 wherein said luminal surface has a surface value of about 0.6 microns RMS or less.

27. A vascular graft according to claim 23 wherein said vascular graft has a density of less than about 1.0 g/cc.

28. A vascular graft according to claim 27 wherein said luminal surface has a surface value of about 1.2 microns RMS or less.

29. A vascular graft according to claim 27 wherein said luminal surface has a surface value of about 1.0 microns RMS or less.

30. A vascular graft according to claim 27 wherein said luminal surface has a surface value of about 0.6 microns RMS or less.

31. A vascular graft according to claim 23 wherein said vascular graft has a density of less than about 0.8 g/cc.

32. A vascular graft according to claim 31 wherein said luminal surface has a surface value of about 1.2 microns RMS or less.

33. A vascular graft according to claim 31 wherein said luminal surface has a surface value of about 1.0 microns RMS or less.

34. A vascular graft according to claim 31 wherein said luminal surface has a surface value of about 0.6 microns RMS or less.

35. A vascular graft according to claim 1 wherein said luminal surface comprises a layer of porous expanded polytetrafluoroethylene film.

36. A vascular graft according to claim 35 wherein said porous expanded polytetrafluoroethylene film comprises a network of interconnected fibrils wherein said film has a direction of higher strength which is substantially perpendicular to a longitudinal axis of the tube.

37. A vascular graft according to claim 35 wherein said porous expanded polytetrafluoroethylene film provides a luminal surface having a surface value of less than about 1.2 microns RMS.

38. A vascular graft according to claim 35 wherein said porous expanded polytetrafluoroethylene film comprises a network of interconnected fibrils wherein said film has a direction of higher strength oriented substantially parallel to the longitudinal axis of the tube.

39. A vascular graft according to claim 35 wherein said substrate tube comprises porous expanded polytetrafluoroethylene.

40. A vascular graft according to claim 39 wherein said film has a mean fibril length substantially less than a. mean fibril length of the porous expanded polytetrafluoroethylene tube.

41. A vascular graft according to claim 35 wherein the film layer has a seam extending between ends of the substrate.

42. A vascular graft according to claim 35 wherein said luminal surface has a surface value of about 1.2 microns RMS or less.

43. A vascular graft according to claim 35 wherein said luminal surface has a surface value of about 0.6 microns RMS or less.

44. A method of using a vascular graft wherein said vascular graft comprises a substrate having a luminal surface of polytetrafluoroethylene provided to the substrate and wherein the luminal surface has a surface value of about 1.7 microns RMS or less, said method comprising implanting said vascular graft in a living body with the luminal surface in contact with blood.

45. A method of using a vascular graft according to claim 44 wherein the luminal surface has a surface value of about 1.6 microns RMS or less.

46. A method of using a vascular graft according to claim 44 wherein the luminat surface has a surface value of about 1.4 microns RMS or less.

47. A method of using a vascular graft according to claim 44 wherein the luminal surface has a surface value of about 1.2 microns RMS or less.

48. A method of using a vascular graft according to claim 47 wherein the luminal surface comprises a film of porous expanded polytetrafluoroethylene having a microstructure of interconnected fibrils.

49. A method of using a vascular graft according to claim 47 wherein the luminal surface has a substrate comprising a porous expanded polytetrafluoroethylene tube having a mean fibril length between about 5 and 90 microns.

50. A method of using a vascular graft according to claim 47 wherein the vascular graft comprises a cardiovascular patch.

51. A method of using a vascular graft according to claim 47 wherein the vascular graft comprises an intraluminal graft.

52. A method of using a vascular graft according to claim 47 wherein the vascular graft comprises a covering over at least a portion of a stent'"'"'s exterior surface.

53. A method of using a vascular graft according to claim 47 wherein the vascular graft comprises a covering over at least a portion of a stent'"'"'s luminal surface.

54. A method of using a vascular graft according to claim 47 wherein the luminal surface has a surface value of about 1.0 microns RMS or less.

55. A method of using a vascular graft according to claim 54 wherein the luminal surface comprises a film of porous expanded polytetrafluoroethylene having a microstructure of interconnected fibrils.

56. A method of using a vascular graft according to claim 54 wherein the luminal surface has a substrate comprising a porous expanded polytetrafluoroethylene tube having a mean fibril length between about 5 and 60 microns.

57. A method of using a vascular graft according to claim 54 wherein the vascular graft comprises a cardiovascular patch.

58. A method of using a vascular graft according to claim 54 wherein the vascular graft comprises an intraluminal graft.

59. A method of using a vascular graft according to claim 54 wherein the vascular graft comprises a covering over at least a portion of a stent'"'"'s exterior surface.

60. A method of using a vascular graft according to claim 54 wherein the vascular graft comprises a covering over at least a portion of a stent'"'"'s luminal surface.

61. A method of using a vascular graft according to claim 44 wherein the luminal surface has a surface value of about 0.8 microns RMS or less.

62. A method of using a vascular graft according to claim 44 wherein the luminal surface has a surface value of about 0.6 microns RMS or less.

63. A method of using a vascular graft according to claim 44 wherein the luminal surface has a surface value of about 0.4 microns RMS or less.

64. A method of using a vascular graft according to claim 44 wherein said vascular graft is microporous having void spaces which contain a therapeutic agent.

65. A method of using a vascular graft according to claim 44 wherein said vascular graft is capable of being stretched and then rapidly recovering more than about 6% of its stretched length.

66. A method of using a vascular graft according to claim 44 wherein said vascular graft has a density of less than about 1.2 g/cc.

67. A method of using a vascular graft according to claim 66 wherein said luminal surface has a surface value of about 1.2 microns RMS or less.

68. A method of using a vascular graft according to claim 66 wherein said luminal surface has a surface value of about 1.0 microns RMS or less.

69. A method of using a vascular graft according to claim 66 wherein said luminal surface has a surface value of about 0.6 microns RMS or less.

70. A method of using a vascular graft according to claim 66 wherein said vascular graft has a density of less than about 1.0 g/cc.

71. A method of using a vascular graft according to claim 70 wherein said luminal surface has a surface value of about 1.2 microns RMS or less.

72. A method of using a vascular graft according to claim 70 wherein said luminal surface has a surface value of about 1.0 microns RMS or less.

73. A method of using a vascular graft according to claim 70 wherein said luminal surface has a surface value of about 0.6 microns RMS or less.

74. A method of usirg a vascular graft according to claim 66 wherein said vascular graft has a density of less than about 0.8 g/cc.

75. A method of using a vascular graft according to claim 74 wherein said luminal surface has a surface value of about 1.2 microns RMS or less.

76. A method of using a vascular graft according to claim 74 wherein said luminal surface has a surface value of about 1.0 microns RMS or less.

77. A method of using a vascular graft according to claim 74 wherein said luminal surface has a surface value of about 0.6 microns RMS or less.

78. A method of using a vascular graft according to claim 44 wherein said luminal surface comprises a layer of porous expanded polytetrafluoroethylene film.

79. A method of using a vascular graft according to claim 78 wherein said porous expanded polytetrafluoroethylene film comprises a network of interconnected fibrils wherein said film has a direction of higher strength which is substantially perpendicular to a longitudinal axis of the tube.

80. A method of using a vascular graft according to claim 78 wherein said porous expanded polytetrafluoroethylene film provides a luminal surface having a surface value of less than about 1.2 microns RMS.

81. A method of using a vascular graft according to claim 78 wherein said porous expanded polytetrafluoroethylene film comprises a network of interconnected fibrils wherein said film has a direction of higher strength oriented substantially parallel to the longitudinal axis of the tube.

82. A method of using a vascular graft according to claim 78 wherein said substrate tube comprises porous expanded polytetrafluoroethylene.

83. A method of using a vascular graft according to claim 82 wherein said film has a mean fibri length substantially less than a mean fibril length of the porous expanded polytetrafluoroethylene tube.

84. A method of using a vascular graft according to claim 78 wherein the film layer has a seam extending between ends of the substrate.

85. A method of using a vascular graft according to claim 78 wherein said luminal surface has a surface value of about 1.0 microns RMS or less.

86. A method of using a vascular graft according to claim 78 wherein said luminal surface has a surface value of about 0.6 microns RMS or less.