Helical stent

• US 20070129786A1
• Filed: 08/01/2006
• Published: 06/07/2007
• Est. Priority Date: 10/14/2005
• Status: Active Grant

• Current Assignee: Flexible Stenting Solutions, Inc (Cardinal Health, Inc.)
• Original Assignee: Flexible Stenting Solutions, Inc (Cardinal Health, Inc.)
• Inventors: Beach, Bradley, Burpee, Janet
• Granted Patent: US 8,956,400 B2
• Time in Patent Office: Days
• US Class Current: 623/1.150
• 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 2/91 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 2002/823 Stents, different from stent-grafts, adapted to cover an aneurysm
• CPC Class Codes: A61F 2002/8486 provided on at least one of the ends
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2220/0016 with sharp anchoring protrusions, e.g. barbs, pins, spikes
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2250/0039 differing in diameter

Abstract

The present invention relates to a stent providing a high percentage of vessel coverage, preferably at least about 50% of the portion of the vessel covered by the helical elements of the stent. The stent comprises helical elements interposed between strut members in which the helical elements are connected to the strut members by linking elements. The portion of the stent having helical elements provides a high percentage of covered area for example, in an aneurysm area. The linking elements provide part of a mechanism that allows vessel coverage to be maintained as the stent is deployed from a crimped state to an expanded state allowing the helical elements to change its helix angle (the angle at which the helical elements progresses around the circumference and along the length of the stent) and thereby the pitch of the helical elements as the stent is expanded.

Claims

1. A radially expandable stent comprising:

a pair of strut members; and

a plurality of helical elements extending helically about an axis of said strut members and interposed between said strut members;

said helical elements being connected to said strut members with linking elements providing a radially expandable tubular structure.

2. The stent of claim 1 wherein said linking elements allow a helix angle of said helical elements to change as a diameter of said stent is changed.

3. The stent of claim 1 wherein said linking elements are flexible.

4. The stent of claim 1 wherein said strut members comprise one or more strut ring portions, said strut ring portions being radially expandable.

5. The stent of claim 4 wherein said connecting elements connect said strut ring portions to one another at peaks of said strut ring portions.

6. The stent of claim 4 wherein said one or more strut ring portions wrap around a circumference of said stent.

7. The stent of claim 4 wherein said one or more strut ring portions wrap in a spiral around a circumference of said stent.

8. The stent of claim 4 wherein said strut ring portions comprise multiple strut ring portions and connecting elements diagonally connect said strut ring portions to one another at peaks of said strut ring portions in a first diagonal direction and/or a second diagonal direction.

9. The stent of claim 8 wherein said connecting elements are rigid of a predetermined length.

10. The stent of claim 8 wherein said connecting elements are flexible of a predetermined length.

11. The stent of claim 1 wherein each of said strut members is formed of a plurality of strut elements and each of said helical elements is connected to a respective one of said strut elements.

12. The stent of claim 1 wherein each of said strut members is formed of a plurality of strut elements and some of said helical elements are connected to respective ones of said strut elements.

13. The stent of claim 1 wherein each of said strut members is formed of a plurality of strut elements and every other one of said strut elements is connected by a respective one of said helical elements.

14. The stent of claim 1 wherein said strut members are flared.

15. The stent of claim 1 wherein said strut members have a larger diameter than said helical elements.

16. The stent of claim 1 wherein said helical elements have a larger diameter than said strut members.

17. The stent of claim 1 wherein one or both of said strut members include at least one barb.

18. The stent of claim 1 wherein said linking elements comprise straight links having a length of about 25% to about 50% of a circumference of said stent.

19. The stent of claim 1 wherein said linking elements comprise straight links having a length of about 10% to about 25% of a circumference of said stent.

20. The stent of claim 1 wherein said linking elements are curved.

21. The stent of claim 1 wherein said linking elements have a thickening which varies along the length of said linking element.

22. The stent of claim 1 wherein said helical elements comprise a pair of segments.

23. The stent of claim 1 wherein the helical elements comprise a plurality of segments.

24. The stent of claim 1 wherein said helical elements comprise one or more notches along a length thereof.

25. The stent of claim 1 wherein said helical elements have one or more thin sections having a thickness of about 10% to about 80% of adjacent thicker portions of said helical elements.

26. The stent of claim 1 wherein said helical elements have one or more curved thin sections having a thickness of about 10% to about 80% of adjacent thicker portions of said helical elements.

27. The stent of claim 1 wherein said helical elements having diagonal thin sections having a thickness of about 10% to about 80% of adjacent thicker portions of said helical elements.

28. The stent of claim 1 wherein a pitch of said helical elements changes along a length of said stent.

29. The stent of claim 28 wherein a pitch of said helical elements is longer on one side of said stent and said pitch of said helical elements is shorter on the other side of said stent.

30. The stent of claim 29 wherein said linking elements are curved.

31. The stent of claim 1 wherein said helical elements have a constant pitch.

32. The stent of claim 1 wherein said helical elements have a variable pitch.

33. The stent of claim 1 wherein when said stent is radially expanded from a crimped state, the diameter of said stent increases and the helix angle of the helical elements decreases.

34. The stent of claim 1 wherein said helical elements comprise straight sections, curved sections or both straight sections and curved sections.

35. A method for placing a stent within a mammal in a body lumen comprising placing one or more stents in said body lumen, said stent comprising:

a pair of strut members; and

a plurality of helical elements extending helically about an axis of said strut members and interposed between said strut members;

said helical elements being connected to said strut members with linking elements providing a radially expandable tubular structure.

36. The method of claim 35 wherein the mammal is a human and the body lumen is a vessel or duct.

37. The method of claim 35 wherein the mammal is a human and the body lumen is a brain aneurysm.

38. The method of claim 35 wherein the mammal is a human and the body lumen is an aneurysm.

39. The method of claim 35 wherein said inserted stent covers at least about 35% to about 90% of a portion of said body lumen covered by said helical elements of said stent.

40. The method of claim 35 wherein said inserted stent covers at least about 50% of a portion of said body lumen covered by said helical elements of said stent.

41. A method for treating a diseased vessel or duct in a mammal comprising the steps of:

placing one or more stents at a target site, said stent comprising;

a pair of strut members; and

a plurality of helical elements extending helically about an axis of said strut members and interposed between said strut members;

said helical elements being connected to said strut members with linking elements providing a radially expandable tubular structure.

42. The method of claim 41 wherein said stent covers about 35% to about 90% of a portion of said target site covered by said helical elements of said stent.

43. The method of claim 41 wherein said stent covers at least about 50% of a portion of said target site covered by said helical elements of said stent.

44. The method of claim 41 wherein the mammal is a human and the body lumen is a brain aneurysm.

45. The method of claim 41 wherein said target site is an aneurysm.

46. The method of claim 41 wherein said target site is a vascular site.

47. The method of claim 41 wherein the target site is a super femoral artery.

48. The method of claim 41 wherein the target site is a lesion.

49. The method of claim 41 wherein the target site is a non-vascular site.

52. The method of claim 45 when said pusher balloon is inflated with chilled fluid having a temperature in the range of about −

10°

C. to about 10°

C.

50. A method for delivering a stent in a body lumen, said stent comprising a pair of strut members, a plurality of helical elements extending helically about an axis of said strut members and interposed between said strut members said helical elements being connected to said strut members with linking elements, the method comprising the steps of:

twisting of a balloon in an opposite direction of said helical elements;

placing said stent on said balloon;

inflating said balloon,

wherein after said balloon is inflated, said balloon rotates reducing a helix angle of said helical elements.

51. A method for delivering a stent in a body lumen, said stent comprising a pair of strut members, a plurality of helical elements extending helically about an axis of said strut members and interposed between said strut members said helical elements being connected to said strut members with linking elements, the method comprising the steps of:

crimping said stent;

placing an outer sheath over said crimped stent;

placing a pusher balloon over an inner tube placed within said crimped stent; and

inflating said pusher balloon to a diameter about the same as an inside diameter of said crimped stent.

53. An improved stent of the type having at least one helical element extending helically about an axis wherein the improvement comprises said at least one helical element comprising a pair of segments.

54. An improved stent of the type having at least one helical element extending helically about an axis wherein the improvement comprises said at least one helical element comprising a plurality of segments.

55. An improved stent of the type having at least one helical element extending helically about an axis wherein the improvement comprises said at least one helical element having one or more notches along a length thereof.

56. An improved stent of the type having at least one helical element extending helically about an axis wherein the improvement comprises said helical elements having one or more thin sections having a thickness of about 10% to about 80% of adjacent thicker portions of said at least one helical element.

57. An improved stent of the type having at least one helical element extending helically about an axis wherein the improvement comprises said at least one helical element having one or more curved thin sections having a thickness of about 10% to about 80% of adjacent thicker portions of said at least one helical element.

58. An improved stent of the type having at least one helical element extending helically about an axis wherein the improvement comprises said at least one helical element having one or more diagonal thin sections having a thickness of about 10% to about 80% of adjacent thicker portions of said at least one helical element.

59. An improved stent of the type having at least one helical element extending helically about an axis wherein the improvement comprises a pitch of said at least one helical element changing along a length of said stent.

60. An improved stent of the type having at least one helical element extending helically about an axis wherein the improvement comprises a pitch of said at least one helical element being longer on one side of said stent and said pitch of said at least one helical element is shorter on the other side of said stent.

61. An improved stent of the type having at least one helical element extending helically about an axis when the improvement comprises said at least one helical element having a constant pitch.

62. An improved stent of the type having at least one helical element extending helically about an axis wherein the improvement comprises said at least one helical element having a variable pitch.

63. An improved stent of the type having at least one helical element extending helically about an axis wherein the improvement comprises said at least one helical element comprising straight sections, curved sections or both straight sections and curved sections.

64. A radially expandable stent system comprising:

a pair of strut members;

a plurality of helical elements extending helically about an axis of said strut members and interposed between said strut members;

said helical elements being connected to said strut members with linking elements providing a radially expandable tubular structure; and

a balloon within said stent.

65. The system of claim 64 wherein said balloon is twisted.