Flexible expandable stent

• US 6,461,381 B2
• Filed: 06/21/1999
• Issued: 10/08/2002
• Est. Priority Date: 03/17/1994
• Status: Expired due to Term

• Current Assignee: Medinol Limited (Medinol USA Incorporated)
• Original Assignee: Medinol Limited (Medinol USA Incorporated)
• Inventors: Pinchasik, Gregory, Israel, Henry Marshall
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US09/337,629
• Publication Number:
  US 20010018595A1
• Time in Patent Office: 1,205 Days
• Field of Search: 606/1, 606/108, 606/192, 606/194, 606/198, 604/96, 623/1, 623/12, 623/1.1, 623/1.15, 623/1.16, 623/1.17
• US Class Current: 623/1.17
• CPC Class Codes: A61F 2/856 Single tubular stent with a side portal passage
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped

Abstract

There is disclosed a stent for implanting in the body. The stent is formed of a tube having a patterned shape which has first and second meander patterns having axes extending in first and second directions. The first meander patterns can be formed into even and odd first meander patterns. The even and odd first meander patterns are 180° out of phase with each other and the odd patterns occur between every two even patterns. The second meander patterns are intertwined with the first meander patterns. The first and second directions can be orthogonal to each other. The second meander patterns can also be formed of even and odd patterns.

Claims

1. A stent for implanting in the body and expanding to hold open a blood vessel, which stent both before and after its intended expansion, comprises:

a) a body-compatible metal mesh defining a tube having a plurality of longitudinally adjacent contiguous cells, each of the cells comprising one pair of longitudinally facing loops, each longitudinally facing loop having a generally curved apex and having portions with a substantial longitudinal component extending from said apex, said portions forming walls of the cells, wherein at least some of said portions are also walls of longitudinally adjacent cells, the pair of longitudinally facing loops generally opposite to and facing one another, each of the facing loops adapted to open further upon radial expansion of the stent which tends to foreshorten the stent longitudinally, and

b) each of the cells further comprising a pair of members that include flexible curved portions, which members are disposed between the adjacent pair of facing loops and integral therewith to complete each of the cells, the pair of members made of a metal such that, upon curvature of the stent, the members will bend to facilitate flexing of the stent along the longitudinal axis and will, upon expansion of the stent, bend to substantially offset foreshortening along the longitudinal axis.

2. The stent of claim 1 wherein:

(a) said plurality of cells includes all cells in said stent except for the cells disposed at the ends of the stent, and each wall of each of the plurality of cells also comprises the wall of an adjacent cell and,

(b) each facing loop of each of the plurality of cells is connected to a facing loop in another cell by one of said members.

3. The stent of claim 2 wherein one pair of facing loops is disposed between each pair of members.

4. The stent of claim 3 wherein the curved apices of a pair of facing loops are generally aligned along the longitudinal axis of the stent.

5. The stent of claim 4 wherein the flexible curved portions are u-shaped.

6. The stent of claim 3 wherein the flexible curved portions are u-shaped.

7. The stent of claim 1 wherein the stent is adapted to be positioned on a balloon which upon expansion causes the stent to expand to hold open the blood vessel.

8. The stent of claim 7 wherein the mesh is comprised of a metal which is balloon expandable.

9. The stent of claim 8, wherein the stent is provided with a coating.

10. The stent of claim 7 wherein one pair of facing loops is disposed between each pair of members.

11. The stent of claim 10 wherein the curved apices of a pair of facing loops are generally aligned along the longitudinal axis of the stent.

12. The stent of claim 11 wherein the flexible curved portions are u-shaped.

13. The stent of claim 10 wherein the flexible curved portions are u-shaped.

14. The stent of claim 7 wherein the curved apices of a pair of facing loops are generally aligned along the longitudinal axis of the stent.

15. The stent of claim 14 wherein the flexible curved portions are u-shaped.

16. The stent of claim 7 wherein the flexible curved portions are u-shaped.

17. The stent of claim 1, in which the expanded stent has approximately the same longitudinal length as the stent had prior to expansion.

18. The stent of claim 17 wherein one pair of facing loops is disposed between each pair of members.

19. The stent of claim 18 wherein the curved apices of a pair of facing loops are generally aligned along the longitudinal axis of the stent.

20. The stent of claim 19 wherein the flexible curved portions are u-shaped.

21. The stent of claim 18 wherein the flexible curved portions are u-shaped.

22. The stent of claim 17 wherein the curved apices of a pair of facing loops are generally aligned along the longitudinal axis of the stent.

23. The stent of claim 22 wherein the flexible curved portions are u-shaped.

24. The stent of claim 17 wherein the flexible curved portions are u-shaped.

25. The stent of claim 1 wherein the mesh is comprised of a metal which is balloon expandable.

26. The stent of claim 25, wherein the stent is provided with a coating.

27. The stent of claim 1 wherein one pair of facing loops is disposed between each pair of members.

28. The stent of claim 27 wherein the curved apices of a pair of facing loops are generally aligned along the longitudinal axis of the stent.

29. The stent of claim 28 wherein the flexible curved portions are u-shaped.

30. The stent of claim 27 wherein the flexible curved portions are u-shaped.

31. The stent of claim 1 wherein the curved apices of a pair of facing loops are generally aligned along the longitudinal axis of the stent.

32. The stent of claim 31 wherein the flexible curved portions are u-shaped.

33. The stent of claim 1 wherein the flexible curved portions are u-shaped.

34. The stent of claim 2 wherein the stent is adapted to be positioned on a balloon which upon expansion causes the stent to expand to hold open the blood vessel.

35. The stent of claim 2, in which the expanded stent has approximately the same longitudinal length as the stent had prior to expansion.

36. The stent of claim 2 wherein the mesh is comprised of a metal which is balloon expandable.

37. The stent of claim 2 wherein the flexible curved portions are u-shaped.

38. The stent of claim 2 wherein the curved apices of a pair of facing loops are generally aligned along the longitudinal axis of the stent.

39. A balloon expandable stent suitable for implantation into a lumen for expansion to support the lumen, said stent made of a unitary piece of metal and said stent in both the unexpanded and in the balloon-expanded state including:

a plurality of flexible cells adjacent to one another both circumferentially and longitudinally, each of said flexible cells comprising;

a) a first member having a first end and a second end;

b) a second member having a first end and a second end;

c) a third member having a first end and a second end;

d) a fourth member having a first end and a second end;

e) a first loop defining a first angle disposed between said first end of said first member and said first end of said second member;

f) a second loop defining a second angle disposed between said second end of said third member and said second end of said fourth member;

g) a first flexible link, including an arc, said first flexible link disposed between said second end of said first member and said first end of said third member; and

h) a second flexible link, including an arc, said second flexible link disposed between said second end of said second member and said first end of said fourth member,

wherein each of at least two members of said first, second, third and fourth members in each of said cells is also a first, second, third or fourth member of a longitudinally adjacent flexible cell, and

wherein in the expanded state the first, second, third, and fourth members have a substantial longitudinal component to provide coverage of the lumen.

40. A stent according to claim 39, wherein in the unexpanded state a radial plane perpendicular to a longitudinal axis of the stent can pass through the flexible links of the flexible cells and not pass through any of said first, second, third, or fourth members.

41. A stent according to claim 40, wherein the first and second loops are aligned with respect to each other along the longitudinal axis of the stent.

42. A stent according to claim 40, wherein the stent is provided with a coating.

43. A stent according to claim 40 with at least five cells circumferentially adjacent to each other.

44. A stent according to claim 40, wherein the first members of circumferentially adjacent cells are connected in a closed circumferential structure which contains at least five loops and the second members of circumferentially adjacent cells are connected in a closed circumferential structure which contains at least five loops.

45. A stent according to claim 40 where in each of said first and second flexible links has ends generally aligned with respect to each other along a longitudinal axis of the stent.

46. A stent according to claim 40 wherein said plurality of flexible cells provide substantially all the support for said stent.

47. A stent according to claim 39 with at least five cells circumferentially adjacent to each other.

48. A stent according to claim 47, wherein the stent is provided with a coating.

49. A stent according to claim 39, wherein the first members of circumferentially adjacent cells are connected in a closed circumferential structure which contains at least five loops and the second members of circumferentially adjacent cells are connected in a closed circumferential structure which contains at least five loops.

50. A stent according to claim 49, wherein the stent is provided with a coating.

51. A stent according to claim 39 wherein each of said first and second flexible links has ends generally aligned with respect to each other along a longitudinal axis of the stent.

52. A stent according to claim 39 wherein said plurality of flexible cells provide substantially all the support for said stent.

53. A stent according to claim 39, wherein the stent is provided with a coating.

54. A balloon expandable stent suitable for implantation into a lumen for expansion to support the lumen, said stent made of a unitary piece of metal and said stent in both the unexpanded and in the balloon-expanded state including:

a plurality of flexible cells adjacent to one another both circumferentially and longitudinally, each of said flexible cells comprising;

a) a first member having a first end and a second end;

b) a second member having a first end and a second end,

c) a third member having a first end and a second end;

d) a fourth member having a first end and a second end,

e) a first loop defining a first angle disposed between said first end of said first member and said first end of said second member;

f) a second loop defining a second angle disposed between said second end of said third member and said second end of said fourth member;

g) a first flexible link including an arc, said first flexible link disposed between said second end of said first member and said first end of said third member; and

h) a second flexible link including an arc, said second flexible link disposed between said second end of said second member and said first end of said fourth member,

wherein each of at least two members of said first, second, third and fourth members in each of said cells is also a first, second, third or fourth member of a longitudinally adjacent flexible cell, and

wherein said plurality of connected cells imparts radial strength to said stent and provides coverage of the surface of said lumen in an amount sufficient to support said lumen after said stent is expanded by a balloon from a delivery diameter to a deployment diameter.

55. A stent according to claim 54, wherein in the unexpanded state a radial plane perpendicular to a longitudinal axis of the stent can pass through the flexible links of the flexible cells and not pass through any of said first, second, third, or fourth members.

56. A balloon expandable stent for implantation into a lumen to support the lumen, said stent both in the unexpanded state and in the balloon-expanded state including:

a plurality of flexible cells adjacent to one another both circumferentially and longitudinally each of said flexible cells comprising;

a) a first flexible link including an arc, the first flexible link having a first longitudinal end and a second longitudinal end;

b) a second flexible link including an arc, the second flexible link having a first longitudinal end and a second longitudinal end;

c) a first circumferential member disposed between said first longitudinal end of said first flexible link and said first longitudinal end of said second flexible link and;

d) a second circumferential member disposed between said second longitudinal end of said first flexible link and said second longitudinal end of said second flexible link,

e) at least one of said first circumferential member and said second circumferential member in each of said cells having a portion with a substantial longitudinal component that is also a portion with a substantial longitudinal component of a first circumferential member or a second circumferential member in a longitudinally adjacent cell,

wherein in the expanded state the first and second circumferential members have a substantial longitudinal component to provide coverage of the lumen.

57. A stent according to claim 56, wherein in the unexpanded state, a radial plane perpendicular to a longitudinal axis can pass through the flexible links of the flexible cells and not pass through the circumferential members.

58. A stent according to claim 56 wherein each of said first and second flexible links has ends generally aligned with respect to each other along a longitudinal axis of the stent.

59. A stent according to claim 56 with at least five cells circumferentially adjacent to each other.

60. A stent according to claim 59 wherein the, stent is provided with a coating.

61. A stent according to claim 56, wherein the first members of circumferentially adjacent cells are connected in a closed circumferential structure which contains at least five loops and the second members of circumferentially adjacent cells are connected in a closed circumferential structure which contains at least five loops.

62. A stent according to claim 61 wherein the stent is provided with a coating.

63. A stent according to claim 56 wherein said plurality of flexible cells provide substantially all the support for said stent.

64. A stent according to claim 56, wherein the stent is provided with a coating.

65. A balloon expandable stent for implantation into a lumen to support the lumen, said stent both in the unexpanded state and in the balloon-expanded state including:

a plurality of flexible cells adjacent to one another both circumferentially and longitudinally each of said flexible adjacent cells comprising;

a) a first flexible link including an arc, the first flexible link having a first longitudinal end and a second longitudinal end;

b) a second flexible link including an arc, the second flexible link having a first longitudinal end and a second longitudinal end;

c) a first circumferential member disposed between said first longitudinal end of said first flexible link and said first longitudinal end of said second flexible link and;

d) a second circumferential member disposed between said second longitudinal end of said first flexible link and said second longitudinal end of said second flexible link,

e) at least one of said first circumferential member and said second circumferential member in each of said cells having a portion with a substantial longitudinal component that is also a portion with a substantial longitudinal component of a first circumferential member or a second circumferential member in a longitudinally adjacent cell,

f) wherein said plurality of connected flexible cells imparts radial strength to said stent and coverage of the surface of said lumen in an amount sufficient to support said lumen when said stent is expanded by a balloon from a delivery diameter to a deployment diameter.

66. A stent according to claim 65, wherein in the unexpanded state, a radial plane perpendicular to a longitudinal axis can pass through the flexible links of the flexible cells and not pass through the circumferential members.

67. A stent according to claim 65 with at least five cells circumferentially adjacent to each other.

68. A stent according to claim 65, wherein the first members of circumferentially adjacent cells are connected in a closed circumferential structure which contains at least five loops and the second members of circumferentially adjacent cells are connected in a closed circumferential structure which contains at least five loops.

69. A stent according to claim 65 wherein each of said first and second flexible links has ends generally aligned with respect to each other along a longitudinal axis of the stent.

70. A stent according to claim 65 wherein said plurality of flexible cells provide substantially all the support for said stent.

71. A stent according to claim 65, wherein the stent is provided with a coating.

72. A balloon expandable stent suitable for implantation into a lumen to support the lumen, wherein both in the unexpanded state and in the balloon-expanded state, the stent comprises

a plurality of flexible cells adjacent to one another both circumferentially and longitudinally each of said flexible cells comprising:

a) a first member having a first end and a second end;

b) a second member having a first end and a second end,

c) a third member having a first end and a second end;

d) a fourth member having a first end and a second end;

e) a first loop defining a first angle disposed between said first end of said first member and said first end of said second member;

f) a second loop defining a second angle disposed between said second end of said third member and said second end of said fourth member;

g) a first flexible link, including an arc, said first flexible link disposed between said first member and said third member; and

h) a second flexible link, including an arc, said second flexible link disposed between said second member and said fourth member,

wherein each of at least two members of said first, second, third and fourth members in each of said cells is also a first, second, third or fourth member of a longitudinally adjacent flexible cell, and

wherein in the expanded state each of the first, second, third, and fourth members has a substantial longitudinal component to provide coverage of the lumen.

73. A stent according to claim 72, wherein in the unexpanded state, a radial plane perpendicular to a longitudinal axis can pass through the flexible links of the flexible cells and not pass through the circumferential members.

74. A stent according to claim 73, wherein at least five first loops and five second loops are located around the circumference of the stent.

75. A stent according to claim 73, wherein the first flexible link is attached at the second end of the first member and the first end of the third member.

76. A stent according to claim 73, wherein the second flexible link is attached at the second end of the second member and the first end of the fourth member.

77. A stent according to claim 72, wherein at least five first loops and five second loops are located around the circumference of the stent.

78. A stent according to claim 72, wherein the first flexible link is attached at the second end of the first member and the first end of the third member.

79. A stent according to claim 72, wherein the second flexible link is attached at the second end of the second member and the first end of the fourth member.

80. A stent according to claim 72 with at least five cells circumferentially adjacent to each other.

81. A stent according to claim 72 wherein each of said first and second flexible links has ends generally aligned with respect to each other along a longitudinal axis of the stent.

82. A stent according to claim 72 wherein said plurality of flexible cells provides substantially all the support for said stent.

83. A stent according to claim 72 wherein the stent is provided with a coating.