Medical devices

• US 20040143317A1
• Filed: 01/17/2003
• Published: 07/22/2004
• Est. Priority Date: 01/17/2003
• Status: Abandoned Application

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Vanderlaan, Robert A., Stinson, Jonathan S.
• Application Number:
  US10/346,487
• Publication Number:
  US 20040143317A1
• Time in Patent Office: Days
• US Class Current: 623/1.15
• CPC Class Codes: A61L 31/022 Metals or alloys
• CPC Class Codes: A61L 31/088 Other specific inorganic materials not covered by A61L31/084 or A61L31/086
• CPC Class Codes: A61L 31/18 Materials at least partially X-ray or laser opaque

Abstract

Medical devices, such as stents, stent-grafts, grafts, guidewires, and filters, having enhanced radiopacity are disclosed.

Claims

1. A stent, comprising:

a structure comprising

a first portion comprising a first composition, the first composition fracturing upon expansion of the structure, and

a second portion comprising a second composition less radiopaque than the first composition.

2. The stent of claim 1, wherein the second portion surrounds the first portion.

3. The stent of claim 1, wherein the second composition comprises a shape memory material.

4. The stent of claim 1, wherein the second composition has superelastic characteristics.

5. The stent of claim 1, wherein the second composition comprises a nickel-titanium alloy.

6. The stent of claim 1, wherein the second composition comprises stainless steel.

7. The stent of claim 1, wherein the second composition comprises titanium.

8. The stent of claim 1, wherein the second composition comprises a polymer.

9. The stent of claim 8, wherein the polymer is selected from the group consisting of polynorbomene, polycaprolactone, polyenes, nylons, polycyclooctene (PCO) and polyvinyl acetate/polyvinylidinefluoride.

10. The stent of claim 1, wherein the first composition has a density greater than about 9.9 g/cc.

11. The stent of claim 1, wherein the first composition comprises a material selected from the group consisting of gold, tantalum, palladium, and platinum.

12. The stent of claim 1, wherein the first composition is in the form of a powder.

13. The stent of claim 1, wherein the first composition is in the form of fibers.

14. The stent of claim 1, wherein the structure further comprises a third portion comprising the second composition, and the first portion is between the second and third portions.

15. The stent of claim 1, wherein the structure is in the form of a wire.

16. The stent of claim 1, wherein the structure is a tubular member.

17. The stent of claim 1, in the form of a self-expandable stent.

18. The stent of claim 1, in the form of a balloon-expandable stent.

19. The stent of claim 1, in the form of a stent-graft.

20. The stent of claim 19, wherein the stent-graft comprises a therapeutic agent.

21. A medical device, comprising:

a structure comprising

a first portion comprising a mixture including a radiopaque composition and a second composition, the mixture having a yield strength less than a yield strength of the substantially pure radiopaque composition, and

a second portion comprising a third composition less radiopaque than the mixture.

22. The device of claim 21, wherein the second composition is selected from the group consisting of carbon, nitrogen, hydrogen, calcium, potassium, bismuth, and oxygen.

23. The device of claim 21, wherein the first portion has a yield strength less than about 80 ksi.

24. The device of claim 21, wherein the second portion encapsulates the first portion.

25. The device of claim 21, wherein the third composition comprises a shape memory material.

26. The device of claim 21, wherein the third composition has superelastic characteristics.

27. The device of claim 21, wherein the third composition comprises a nickel-titanium alloy.

28. The device of claim 21, wherein the third composition comprises stainless steel.

29. The device of claim 21, wherein the third composition comprises a shape memory polymer.

30. The device of claim 21, wherein the first composition has a density greater than about 9.9 g/cc.

31. The device of claim 21, wherein the first composition comprises a material selected from the group consisting of gold, tantalum, palladium, and platinum.

32. The device of claim 21, wherein the first composition is in the form of a powder.

33. The device of claim 21, wherein the first composition is in the form of fibers.

34. The device of claim 21, wherein the structure further comprises a third portion comprising the third composition, and the first portion is between the second and third portions.

35. The device of claim 21, wherein the structure is in the form of a wire.

36. The device of claim 21, wherein the structure is a tubular member.

37. The device of claim 21, in the form of a self-expandable stent.

38. The device of claim 21, in the form of a balloon-expandable stent.

39. The device of claim 21, in the form of a stent-graft.

40. The device of claim 39, wherein the stent-graft comprises a therapeutic agent.

41. The device of claim 21, in the form of an intravascular filter.

42. A method of making a medical device, the method comprising:

reducing a yield strength of a radiopaque composition; and

incorporating the radiopaque composition into the medical device.

43. The method of claim 42, wherein reducing the yield strength comprises annealing the radiopaque composition.

44. The method of claim 42, wherein reducing the yield strength comprises reacting the radiopaque composition with a second composition comprising a material selected from the group consisting of carbon, nitrogen, hydrogen, calcium, potassium, bismuth, and oxygen.

45. The method of claim 42, wherein reducing the yield strength comprises removing selected portions of the radiopaque composition.

46. The method of claim 42, wherein the yield strength of radiopaque composition is reduced to less than about 80 ksi.

47. A method of making a medical device, comprising:

forming a structure having a first portion comprising a first composition, and a second portion comprising a second composition less radiopaque than the first composition;

incorporating the structure into the medical device; and

reducing a yield strength of the first composition.

48. The method of claim 47, wherein reducing the yield strength is performed after incorporating the structure into the medical device.

49. The method of claim 47, wherein reducing the yield strength comprises reacting the first composition with a third composition.

50. The method of claim 47, wherein reducing the yield strength comprises heating the first composition.

51. The method of claim 47, wherein the structure is in the form of a wire.

52. The method of claim 47, wherein the structure is in the form of a tube.

53. A method of making a medical device, comprising:

forming a structure having a first portion comprising a first composition, and a second portion comprising a second composition less radiopaque than the first composition; and

incorporating the structure into the medical device, the first composition weakening in response to the incorporating of the structure.

54. The method of claim 53, wherein the medical device includes a stent delivery system.

55. The method of claim 53, further comprising forming the structure into an endoprosthesis.