Radiopaque and MRI compatible nitinol alloys for medical devices

• US 7,128,757 B2
• Filed: 03/30/2004
• Issued: 10/31/2006
• Est. Priority Date: 12/27/2000
• Status: Expired due to Term

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Cox, Daniel L., Boylan, John F., Kramer-Brown, Pamela A.
• Primary Examiner(s): Willse, David H.
• Application Number:
  US10/814,326
• Publication Number:
  US 20040249447A1
• Time in Patent Office: 945 Days
• Field of Search: 623 115- 122
• US Class Current: 623/1.18
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91516 the meander having a change in frequency along the band
• CPC Class Codes: A61F 2002/91525 within the whole structure different bands showing different meander characteristics, e.g. frequency or amplitude
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61L 2400/16 Materials with shape-memory or superelastic properties
• CPC Class Codes: A61L 31/022 Metals or alloys
• CPC Class Codes: A61L 31/18 Materials at least partially X-ray or laser opaque
• CPC Class Codes: C22C 19/00 Alloys based on nickel or cobalt

Abstract

A radiopaque nitinol medical device such as a stent for use with or implantation in a body lumen is disclosed. The stent is made from a superelastic alloy such as nickel-titanium or nitinol, and includes a ternary element selected from the group of chemical elements consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, or hafnium. The nitinol stent has improved radiopacity yet retains its superelastic and shape memory behavior and further maintains a thin strut/wall thickness for high flexibility. Another embodiment includes a balloon expandable stent made from a radiopaque and MRI compatible alloy such as nitinol and includes a ternary element selected from the group of chemical elements consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, hafnium, osmium, zirconium, niobium, or molybdenum.

Claims

1. A medical device for use in a body lumen, comprising a tubular-shaped body having a wall defining a pattern of struts, wherein the tubular-shaped body comprises a nickel-titanium alloy, said nickel-titanium alloy further comprising at least one ternary element chosen from platinum and palladium, and wherein said struts have a thickness ranging from about 0.002 inches to about 0.006 inches.

2. The medical device of claim 1, wherein the tubular-shaped body is a stent.

3. The medical device of claim 2, wherein the device is radiopaque and MRI compatible.

4. The medical device of claim 1, wherein the at least one ternary element is present in the alloy in an amount ranging from about 5 to about 70 weight percent.

5. The medical device of claim 4, wherein the at least one ternary element is platinum, which is present in an amount ranging from about 5 to about 60 weight percent.

6. The medical device of claim 4, wherein the at least one ternary element is palladium, which is present in an amount ranging from about 5 to about 62 weight percent.

7. The medical device of claim 1, wherein the at least one ternary element is platinum, which is present in an amount ranging from about 2.5 to about 15 weight percent.

8. The medical device of claim 1, wherein the at least one ternary element is palladium, which is present in an amount ranging from about 2.5 to about 20 weight percent.

9. The medical device of claim 1, wherein the tubular-shaped body comprises a superelastic alloy.

10. The medical device of claim 1, wherein the tubular-shaped body comprises a non-superelastic alloy.

11. The medical device of claim 1, wherein the device is radiopaque and MRI compatible.

12. The medical device of claim 4, wherein the device is radiopaque and MRI compatible.

13. The medical device of claim 1, wherein the tubular-shaped body is in an austenitic phase at body temperature.

14. The medical device of claim 1, wherein said alloy further comprises at least one quaternary element.

15. A medical device for use in a body lumen, comprising a tubular-shaped body having a wall defining a pattern of struts, wherein the tubular-shaped body comprises a non-superelastic nickel-titanium alloy, said non-superelastic alloy further comprising at least one ternary element chosen from iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, hafnium, osmium, zirconium, niobium, and molybdenum, and wherein said struts have a thickness ranging from about 0.002 inches to about 0.006 inches.

16. The medical device of claim 15, wherein said tubular-shaped body is a stent.

17. The medical device of claim 15, wherein the at least one ternary element is chosen from platinum, palladium, and tungsten.

18. The medical device of claim 17, wherein the ternary element is chosen from platinum and palladium.

19. The medical device of claim 18, wherein the at least one ternary element is palladium, which is present in an amount ranging from about 2.5 to about 20 weight percent.

20. The medical device of claim 15, wherein the at least one ternary element is present in the alloy in an amount ranging from about 5 to about 70 percent by weight.

21. The medical device of claim 20, wherein the at least one ternary element is platinum, which is present in an amount ranging from about 5 to about 60 weight percent.

22. The medical device of claim 20, wherein the at least one ternary element is palladium, which is present in an amount ranging from 5 to 62 weight percent.

23. The medical device of claim 20, wherein the ternary element is tungsten, which is present in an amount ranging from about 8 to about 66 weight percent.

24. The medical device of claim 15, wherein the at least one ternary element is platinum, which is present in an amount ranging from about 2.5 to about 15 weight percent.

25. The medical device of claim 15, wherein the tubular-shaped body is in an austenitic phase at body temperature.

26. The medical device of claim 15, wherein said alloy further comprises at least one quaternary element.

27. A medical device for use in a body lumen, comprising a tubular-shaped body having a wall defining a pattern of struts, wherein the tubular-shaped body comprises a superelastic nickel-titanium alloy, said superelastic alloy further comprising at least one ternary element chosen from iridium, platinum, rhenium, palladium, rhodium, silver, ruthenium, osmium, zirconium, and molybdenum, and wherein said struts have a thickness ranging from about 0.002 inches to about 0.006 inches.

28. The medical device of claim 27, wherein said tubular-shaped body is a stent.

29. The medical device of claim 27, wherein the at least one ternary element is chosen from platinum and palladium.

30. The medical device of claim 29, wherein the ternary element is platinum, which is present in an amount ranging from about 2.5 to about 15 weight percent.

31. The medical device of claim 29, wherein the ternary element is palladium, which is present in an amount ranging from about 2.5 to about 20 weight percent.

32. The medical device of claim 27, wherein the at least one ternary element is present in the alloy in an amount ranging from about 5 to about 70 percent by weight.

33. The medical device of claim 32, wherein the ternary element is platinum, which is present in an amount ranging from about 5 to about 60 weight percent.

34. The medical device of claim 32, wherein the ternary element is palladium, which is present in an amount ranging from about 5 to about 62 weight percent.

35. The medical device of claim 27, wherein the tubular-shaped body is in an austenitic phase at body temperature.

36. The medical device of claim 27, wherein said alloy further comprises at least one quaternary element.

37. An MRI compatible and radiopaque stent for use in a body lumen, wherein said stent comprises a tubular-shaped body having a wall defining a pattern of struts, wherein said struts have a thickness ranging from about 0.002 inches to about 0.006 inches, and a superelastic, radiopaque, and MRI compatible alloy, said superelastic alloy comprising nickel-titanium and from about 5 to about 70 weight percent of a ternary element chosen from iridium, platinum, rhenium, palladium, rhodium, silver, ruthenium, osmium, zirconium, and molybdenum.

38. The MRI compatible and radiopaque stent of claim 37, wherein said ternary element is chosen from platinum and palladium.

39. The MRI compatible and radiopaque stent of claim 37, wherein the tubular-shaped body is in an austenitic phase at body temperature.

40. The medical device of claim 37, wherein said alloy further comprises at least one quaternary element.

41. An MRI compatible and radiopaque stent for use in a body lumen, wherein said stent comprises a tubular-shaped body having a wall defining a pattern of struts, wherein said struts have a thickness ranging from about 0.002 inches to about 0.006 inches, and a non-superelastic, radiopaque, and MRI compatible alloy, said non-superelastic alloy comprising nickel-titanium and from about 5 to about 70 weight percent of a ternary element chosen from iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, hafnium, osmium, zirconium, niobium, and molybdenum.

42. The MRI compatible and radiopaque stent of claim 41, wherein said ternary element is chosen from platinum and palladium.

43. The MRI compatible and radiopaque stent of claim 41, wherein the tubular-shaped body is in an austenitic phase at body temperature.

44. The medical device of claim 41, wherein said alloy further comprises at least one quaternary element.

45. An MRI compatible and radiopaque stent for use in a body lumen, wherein said stent comprises a superelastic, radiopaque, and MRI compatible alloy, said superelastic alloy comprising nickel-titanium, from about 5 to about 70 weight percent of a ternary element chosen from iridium, platinum, rhenium, palladium, rhodium, silver, ruthenium, osmium, zirconium, and molybdenum, and at least one quaternary element.

46. The MRI compatible and radiopaque stent of claim 45, wherein the superelastic alloy is in an austenitic phase at body temperature.

47. The MRI compatible and radiopaque stent of claim 45, wherein the at least one ternary element is chosen from platinum and palladium.

48. An MRI compatible and radiopaque stent for use in a body lumen, wherein said stent comprises a non-superelastic, radiopaque, and MRI compatible alloy, said non-superelastic alloy comprising nickel-titanium, from about 5 to about 70 weight percent of a ternary element chosen from iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, hafnium, osmium, zirconium, niobium, and molybdenum, and at least one quaternary element.

49. The MRI compatible and radiopaque stent of claim 48, wherein the at least one ternary element is chosen from platinum and palladium.