WOVEN INTRAVASCULAR DEVICES AND METHODS FOR MAKING THE SAME

• US 20090099643A1
• Filed: 05/22/2008
• Published: 04/16/2009
• Est. Priority Date: 02/01/1999
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Hyodoh, Hideki, Wright, Kenneth C., Konya, Andras
• Granted Patent: US 8,414,635 B2
• Time in Patent Office: Days
• US Class Current: 623/1.15
• CPC Class Codes: A61B 2017/00526 Methods of manufacturing
• CPC Class Codes: A61F 2/0105 Open ended, i.e. legs gathered only at one side
• CPC Class Codes: A61F 2/0108 Both ends closed, i.e. legs gathered at both ends
• CPC Class Codes: A61F 2/011 Instruments for their placement or removal
• CPC Class Codes: A61F 2/04 Hollow or tubular parts of organs, e.g. bladders, tracheae, bronchi or bile ducts A61F2/18, A61F2/20 take precedence; devices, other than stent-grafts, providing patency to, or preventing collapsing of, tubular structures of the body other than stent-grafts, e.g. stents A61F2/82; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/962 having an outer sleeve
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61F 2002/018 made from tubes or sheets of material, e.g. by etching or laser-cutting
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2002/077 having means to fill the space between stent-graft and aneurysm wall, e.g. a sleeve
• CPC Class Codes: A61F 2002/9511 the retaining means being filaments or wires
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2210/0014 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2220/0016 with sharp anchoring protrusions, e.g. barbs, pins, spikes
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded
• CPC Class Codes: A61F 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0006 : circular
• CPC Class Codes: A61F 2230/001 : Figure-8-shaped, e.g. hourglass-shaped
• CPC Class Codes: A61F 2230/0015 : Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2230/0065 : toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2230/0067 : conical
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0076 : ellipsoidal or ovoid
• CPC Class Codes: A61F 2230/0078 : hyperboloidal
• CPC Class Codes: A61F 2230/008 : paraboloidal
• CPC Class Codes: A61F 2230/0091 : helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61F 2230/0093 : Umbrella-shaped, e.g. mushroom-shaped
• CPC Class Codes: A61F 2250/0039 : differing in diameter
• CPC Class Codes: D04C 1/06 : Braid or lace serving particular purposes
• CPC Class Codes: D04C 3/48 : Auxiliary devices
• CPC Class Codes: D10B 2509/06 : Vascular grafts; stents

Abstract

Self-expandable, woven intravascular devices for use as stents (both straight and tapered), filters (both temporary and permanent) and occluders for insertion and implantation into a variety of anatomical structures. The devices may be formed from shape memory metals such as nitinol. The devices may also be formed from biodegradable materials. Delivery systems for the devices include two hollow tubes that operate coaxially. A device is secured to the tubes prior to the implantation and delivery of the device by securing one end of the device to the outside of the inner tube and by securing the other end of the device to the outside of the outer tube. The stents may be partially or completely covered by graft materials, but may also be bare. The devices may be formed from a single wire. The devices may be formed by either hand or machine weaving. The devices may be created by bending shape memory wires around tabs projecting from a template, and weaving the ends of the wires to create the body of the device such that the wires cross each other to form a plurality of angles, at least one of the angles being obtuse. The value of the obtuse angle may be increased by axially compressing the body.

Claims

1. A medical stent comprising:

a plurality of geometric cells defining a stent, the stent having first and second opposed open ends; and

a plurality of wire strands woven to form a plurality of crossed regions defining said geometric cells;

wherein each wire strand has strand ends and the strand ends are disposed at said second end of said stent.

2. The stent of claim 1, wherein the wire stands are bent to define said first end of said stent.

3. The stent of claim 1, wherein the wire strands at least one of said crossed regions cross at an angle, which angle decreases when the stent is radially compressed.

4. The stent of claim 1, wherein the wire strands at least one of said crossed regions cross at an angle, which angle increases when the stent is radially expanded.

5. The stent of claim 4, wherein the angle is increasingly obtuse as the stent is radially expanded.

6. The stent of claim 4, where the angle is from about 70°

to about 100°

.

7. The stent of claim 4, where the angle is from about 20°

to about 160°

.

8. The stent of claim 4, where the angle is from about 90°

to less than about 180°

.

9. The stent of claim 4, where the angle is from about 140°

to about 160°

.

10. The stent of claim 4, where the angle is from greater than about 0°

to about 45°

.

11. The stent of claim 4, where the angle is less than about 90°

.

12. The stent of claim 4, where the angle is greater than or equal to about 90°

.

13. The stent of claim 4, where the angle is acute.

14. The stent of claim 4, where the angle is obtuse.

15. The stent of claim 4, wherein the stent foreshortens when the stent is radially expanded.

16. The stent of claim 1, wherein said wire strands are nitinol wire strands.

17. The stent of claim 1, wherein said crossed regions comprise crossed regions without having said strands being helically wrapped thereat.

18. The stent of claim 1, wherein the wire strands at the crossing points are not twisted.

19. The stent of claim 1, wherein the geometric cells have a diamond shape.

20. The stent of claim 1, wherein each strand has a diameter from about 0.004 inches to about 0.008 inches.

21. The stent of claim 1, wherein each strand has a diameter from about 0.003 inches to about 0.015 inches.

22. The stent of claim 1, wherein each strand has a diameter from about 0.003 inches to about 0.006 inches.

23. The stent of claim 1, wherein each strand has a diameter from about 0.005 inches to about 0.012 inches.

24. The stent of claim 1, wherein each strand has a diameter from about 0.006 inches to about 0.012 inches.

25. The stent of claim 1, wherein each strand has a diameter from about 0.006 inches to about 0.009 inches.

26. The stent of claim 1, wherein each strand has a diameter from about 0.009 inches to about 0.013 inches.

27. The stent of claim 1, wherein each strand has a diameter from about 0.008 inches to about 0.015 inches.

28. The stent of claim 1, wherein each strand has a diameter of about 0.007 inches.

29. The stent of claim 1, wherein each strand has a diameter of about 0.009 inches.

30. The stent of claim 1, wherein each strand has a diameter of about 0.011 inches.

31. The stent of claim 1, wherein pairs of the strands at said second end are attached to one and the other.

32. The stent of claim 1, wherein the strands at said second end are secured to one and the other.

33. The stent of claim 1, wherein the strands at said second end are helically twisted.

34. The stent of claim 1, wherein the stent is coated with silicone.

35. The stent of claim 1, further comprising a covering.

36. A medical stent comprising:

a plurality of geometric cells defining a stent, the stent having first and second opposed open ends; and

a plurality of wire strands woven to form a plurality of crossed regions defining said geometric cells;

wherein the wire stands are bent to define said first end of said stent and further wherein each wire strand has strand ends and the strand ends are disposed at said second end of said stent.

37. The stent of claim 36, wherein said crossed regions comprise crossed regions without having said strands being helically wrapped thereat.

38. The stent of claim 36, wherein the wire strands at the crossing points are not twisted.

39. The stent of claim 36, wherein the geometric cells have a diamond shape.

40. The stent of claim 36, wherein the wire strands at least one of said crossed regions cross at an angle, which angle decreases when the stent is radially compressed.

41. The stent of claim 36, wherein the wire strands at least one of said crossed regions cross at an angle, which angle increases when the stent is radially expanded.

42. The stent of claim 41, wherein the angle is increasingly obtuse as the stent is radially expanded.

43. The stent of claim 41, where the angle is from about 70°

to about 100°

.

44. The stent of claim 41, where the angle is from about 20°

to about 160°

.

45. The stent of claim 44, wherein the stent foreshortens when the stent is radially expanded.

46. The stent of claim 41, where the angle is from about 90°

to less than about 180°

.

47. The stent of claim 41, where the angle is from about 140°

to about 160°

.

48. The stent of claim 41, where the angle is from greater than about 0°

to about 45°

.

49. The stent of claim 41, where the angle is less than about 90°

.

50. The stent of claim 41, where the angle is greater than or equal to about 90°

.

51. The stent of claim 41, where the angle is acute.

52. The stent of claim 41, where the angle is obtuse.

53. The stent of claim 36, wherein said wire strands are nitinol wire strands.

54. The stent of claim 36, wherein the strands at said second end are helically twisted.

55. A method of making a medical stent, comprising:

providing a plurality of wire strands, each strand having strand ends;

bending the wire strands to form a first end of the stent; and

diagonally weaving the wires to produce a plurality crossed regions defining a plurality of geometric cells;

wherein

said strand ends form a second end of the stent.

56. The method of claim 55, wherein the step of weaving comprises forming the plurality of crossing points without having the wire strands helically wrapped thereat.

57. The method of claim 55, wherein the step of weaving comprises forming the plurality of crossing points without having the wire strands twisted thereat.

58. The method of claim 55, wherein the wire strands at least one of said crossed regions cross at an angle, which angle decreases when the stent is radially compressed.

59. The method of claim 55, wherein the wire strands at least one of said crossed regions cross at an angle, which angle increases when the stent is radially expanded.

60. The method of claim 59, wherein the angle is increasingly obtuse as the stent is radially expanded.

61. The method of claim 59, where the angle is from about 70°

to about 100°

.

62. The method of claim 59, where the angle is from about 20°

to about 160°

.

63. The method of claim 62, wherein the stent foreshortens when the stent is radially expanded.

64. The method of claim 59, where the angle is from about 90°

to less than about 180°

.

65. The method of claim 59, where the angle is from about 1400 to about 160°

.

66. The method of claim 59, where the angle is from greater than about 0°

to about 45°

.

67. The method of claim 59, where the angle is less than about 90°

.

68. The method of claim 59, where the angle is greater than or equal to about 90°

.

69. The method of claim 59, where the angle is acute.

70. The method of claim 59, where the angle is obtuse.

71. The method of claim 55, wherein said wire strands are nitinol wire strands.

72. The method of claim 55, wherein the geometric cells have a diamond shape.

73. The method of claim 55, wherein each strand has a diameter from bout 0.004 inches to about 0.008 inches.

74. The method of claim 55, wherein each strand has a diameter from about 0.003 inches to about 0.015 inches.

75. The method of claim 55, wherein each strand has a diameter from about 0.003 inches to about 0.006 inches.

76. The method of claim 55, wherein each strand has a diameter from about 0.005 inches to about 0.012 inches.

77. The method of claim 55, wherein each strand has a diameter from about 0.006 inches to about 0.012 inches.

78. The method of claim 55, wherein each strand has a diameter from about 0.006 inches to about 0.009 inches.

79. The method of claim 55, wherein each strand has a diameter from about 0.009 inches to about 0.013 inches.

80. The method of claim 55, wherein each strand has a diameter from about 0.008 inches to about 0.015 inches.

81. The method of claim 55, wherein each strand has a diameter of about 0.007 inches.

82. The method of claim 55, wherein each strand has a diameter of about 0.009 inches.

83. The method of claim 55, wherein each strand has a diameter of about 0.011 inches.

84. The method of claim 55, wherein pairs of the strands at said second end are attached to one and the other.

85. The method of claim 55, wherein the strands at said second end are secured to one and the other.

86. The method of claim 55, further comprising:

coating the stent with silicone.

87. The method of claim 55, further comprising:

providing a covering to the stent.

88. A medical stent comprising:

a plurality of geometric cells defining a stent, the stent having first and second opposed open ends; and

a plurality of wire strands woven to form a plurality of crossed regions defining said geometric cells;

wherein the wire stands are bent to define said first end of said stent and further wherein each wire strand has strand ends and the strand ends are helically twisted and disposed at said second end of said stent.

89. A medical stent comprising:

a plurality of geometric cells defining a stent, the stent having first and second opposed open ends; and

a plurality of wire strands woven to form a plurality of crossed regions defining said geometric cells, the crossed regions having at least one angle which increases when the stent is radially expanded;

wherein the wire stands are bent to define said first end of said stent and further wherein each wire strand has strand ends and the strand ends are disposed at said second end of said stent.

90. The stent of claim 89, where the angle is from about 70°

to about 100°

.

91. The stent of claim 89, where the angle is from about 20°

to about 160°

.

92. The stent of claim 89, where the angle is from about 90°

to less than about 180°

.

93. The stent of claim 89, where the angle is from about 140°

to about 160°

.

94. The stent of claim 89, where the angle is from greater than about 0°

to about 45°

.

95. The stent of claim 89, where the angle is less than about 90°

.

96. The stent of claim 89, where the angle is greater than or equal to about 90°

.

97. The stent of claim 89, where the angle is acute.

98. The stent of claim 89, where the angle is obtuse.

99. The stent of claim 89, wherein the stent foreshortens when the stent is radially expanded.

100. A medical stent comprising:

a plurality of geometric cells defining a stent, the stent having first and second opposed open ends; and

a plurality of wire strands woven to form a plurality of crossed regions defining said geometric cells, the crossed regions having at least one obtuse angle which increases when the stent is radially expanded;

wherein the wire stands are bent to define said first end of said stent and further wherein each wire strand has strand ends and the strand ends are disposed at said second end of said stent.

101. A stent comprising:

a plurality of wires arranged in a weave to define an elastically deformable body having a proximal end and a distal end;

wherein the wires cross each other to form a plurality of angles, and wherein ends of the plurality of wires are located proximate to the proximal end of the body.

102. The stent of claim 101, wherein at least one of the angles is obtuse.

103. The stent of claim 102, wherein the value of the obtuse angle is configured to increase when the body is axially compressed.

104. The stent of claim 102, wherein the value of the obtuse angle is configured to increase when the body is radially expanded.

105. The stent of claim 101, wherein the body is configured to foreshorten when the body is radially expanded.

106. The stent of claim 101, wherein the weave comprises a plain weave.

107. The stent of claim 101, wherein the weave comprises at least some of the wires being twisted to each other where at least some of the wires cross.

108. The stent of claim 101, wherein at least some of the wires are coupled at the proximal end.

109. The stent of claim 108, wherein at least some of the wires are twisted at the proximal end.

110. The stent of claim 101, wherein at least some of the wires comprise a memory shape alloy.

111. The stent of claim 110, wherein the memory shape alloy comprises nitinol.

112. The stent of claim 101, further comprising a coating comprising silicone.

113. A method of forming a stent, the method comprising weaving a plurality of wires to define an elastically deformable body having a proximal end and a distal end;

wherein weaving comprises crossing the wires at a plurality of angles, and wherein ends of the plurality of wires are located proximate to the proximal end of the body.

114. The method of claim 113, wherein weaving comprises bending the wires to form the distal end of the body.

115. The method of claim 113, wherein weaving comprises crossing the wires without twisting the wires.

116. The method of claim 113, wherein weaving comprises twisting the wires where at least some of the wires cross.

117. The method of claim 113, further comprising coupling the ends of the wires at the proximal end.

118. The method of claim 117, wherein coupling the ends of the wires comprises twisting the wires at the proximal end.

119. The method of claim 117, wherein coupling the ends of the wires comprises soldering the wires at the proximal end.

120. The method of claim 113, further comprising coating the body with silicone.