Medical devices
View Patent ↗Alloy compositions suitable for fabricating medical devices, such as stents, are disclosed. In certain embodiments, the compositions have small amounts of nickel, e.g., the compositions can be substantially free of nickel.
1. An endoprosthesis, comprising:
a tubular member capable of supporting a body passageway, the tubular member being formed of a non-magnetic alloy comprising at least 40% by weight of iron, from about 5% by weight to about 20% by weight of chromium, and greater than about 5% by weight of a first element having a density greater than 9.9 g/cc, the alloy having less than or equal to 1% by weight of nickel and having a radiopacity greater than the radiopacity of UNS S31673.
2. The endoprosthesis of claim 1 , wherein the alloy is fully austenitic.
3. The endoprosthesis of claim 1 , wherein the radiopacity is greater than about 105% of the radiopacity of UNS S31673 at 80 keV for a thickness of 0.005 inch.
4. The endoprosthesis of claim 1 , wherein the radiopacity is greater than about 110% of the radiopacity of UNS S31673 at 80 keV for a thickness of 0.005 inch.
5. The endoprosthesis of claim 1 , wherein the radiopacity is greater than about 115% of the radiopacity of UNS S31673 at 80 keV for a thickness of 0.005 inch.
6. The endoprosthesis of claim 1 , wherein the radiopacity is greater than about 120% of the radiopacity of UNS S31673 at 80 keV for a thickness of 0.005 inch.
7. The endoprosthesis of claim 1 , wherein the radiopacity is greater than about 125% of the radiopacity of UNS S31673 at 80 keV for a thickness of 0.005 inch.
8. The endoprosthesis of claim 1 , wherein the alloy, after annealing, has a tensile strength greater than about 490 MPa.
9. The endonrosthesis of claim 1 , wherein the alloy, after annealing, has a yield strength of greater than about 190 MPa.
10. The endoprosthesis of claim 1 , wherein the alloy has a pitting resistance equivalent greater than about 26.
11. The endoprosthesis of claim 1 , wherein first element is selected from the group consisting of platinum, ruthenium, palladium, iridium, rhodium, gold, and osmium.
12. The endoprosthesis of claim 11 , wherein the alloy comprises a plurality of first elements.
13. The endonrosthesis of claim 11 , wherein the alloy comprises greater than about 5% by weight to about 40% by weight of the first element.
14. The endoprosthesis of claim 1 , in the form of a stent.
15. An endoprosthesis, comprising:
a tubular member capable of supporting a body passageway, the tubular member being formed of a non-magnetic alloy comprising at least 40% by weight of iron, from about 5% to about 20% by weight of chromium, greater than about 5% by weight of a first element having a density greater than 9.9 g/cc, and less than four weight percent of nickel, the alloy being fully austenitic and having a radiopacity greater than the radiopacity of UNS S31673.
16. The endoprosthesis of claim 15 , wherein the alloy comprises less than about three weight percent of nickel.
17. The endoprosthesis of claim 15 , wherein the alloy comprises less than about one weight percent of nickel.
18. The endonrosthesis of claim 15 , wherein the radiopacity is greater than about 105% of the radiopacity of UNS S31673 at 80 keV for a thickness of 0.005 inch.
19. The endoprosthesis of claim 15 , wherein the radiopacity is greater than about 110% of the radiopacity of UNS S31673 at 80 keV for a thickness of 0.005 inch.
20. The endoprosthesis of claim 15 , wherein the radiopacity is greater than about 115% of the radiopacity of UNS S31673 at 80 keV for a thickness of 0.005 inch.
21. The endoprosthesis of claim 15 , wherein the radiopacity is greater than about 120% of the radiopacity of UNS S31673 at 80 kcV for a thickness of 0.005 inch.
22. The endoprosthesis of claim 15 , wherein the radiopacity is greater than about 125% of the radiopacity of UNS S31673 at 80 keV for a thickness of 0.005 inch.
23. The endonrosthesis of claim 15 , wherein the alloy further comprises between about 0.01% and about 1.0% by weight percent of nitrogen.
24. The endoprosthesis of claim 15 , wherein the alloy further comprises between about 0.07% and about 55% by weight of cobalt.
25. The endoprosthesis of claim 15 , wherein the alloy further comprises between about 0.07% and about 32% by weight of cobalt.
26. The endoprosthesis of claim 15 , wherein the alloy further comprises between about 0.5% and about 20% by weight of manganese.
27. The endoprosthesis of claim 15 , wherein the alloy further comprises between about 0.03% and about 6% by weight of copper.
28. The endoprosthesis of claim 15 , wherein the first element is selected from the group consisting of platinum, ruthenium, palladium, iridium, rhodium, gold, and osmium.
29. The endoprosthesis of claim 28 , wherein the alloy comprises a plurality of first elements.
30. The endoprosthesis of claim 28 , wherein the alloy comprises greater than about 5% by weight to about 40% by weight of the first element.
31. The endonrosthesis of claim 15 , wherein the alloy, after annealing, has a tensile strength greater than about 490 MPa.
32. The endoprosthesis of claim 15 , wherein the alloy, after annealing, has a yield strength of greater than about 190 MPa.
33. The endoprosthesis of claim 15 , wherein the alloy has a pitting resistance equivalent greater than about 26.
34. The endoprosthesis of claim 15 , wherein the alloy comprises less than about 17% by weight of chromium.
35. The endoprosthesis of claim 15 , wherein the alloy comprises less than about 14% by weight of chromium.
36. The endonrosthesis of claim 15 , wherein the alloy further comprises less than about 3% by weight of molybdenum.
37. The endoDrosthesis of claim 15 , wherein the alloy further comprises less than about 1.0% by weight of nitrogen.
38. The endoprosthesis of claim 15 , in the form of a stent.
39. An endoprosthesis, comprising:
a tubular member capable of supporting a body passageway, the tubular member being formed of a non-magnetic alloy comprising
at least 40% by weight of iron,
between about 5% and about 30% by weight of chromium,
less than about 3% by weight of molybdenum,
less than about 55% by weight of cobalt,
less than about 20% by weight of manganese,
less than about 6% by weight of copper,
less than about 0.03% by weight of nickel,
less than about 1.0% by weight of nitrogen, and
between about 0.5% and about 40% by weight of a first element selected from a group consisting of platinum, ruthenium, palladium, iridium, rhodium, gold, and osmium,
the alloy being substantially austenitic.
40. The endoprosthesis of claim 39 , in the form of a stent.
41. The endoprosthesis of claim 39 , comprising a plurality of first elements.
42. The endoprosthesis of claim 39 , wherein the alloy comprises between about 0.01% and 1.0% by weight of nitrogen.
43. The endoprosthesis of claim 39 , wherein the alloy comprises between about 0.07% and about 32% by weight of cobalt.
44. The endoprosthesis of claim 39 , wherein the alloy comprises between about 0.5% and about 20% by weight of manganese.
45. The endoprosthesis of claim 39 , wherein the alloy comprises between about 0.03% and about 6% by weight of copper.
46. A method of making an endourosthesis, the method comprising:
selecting a non-magnetic alloy comprising at least 40% by weight of iron, from about 5% to about 20% by weight of chromium, greater than about 5% by weight of a first element having a density greater than 9.9 g/cc, and less than 4% by weight of nickel, the alloy being substantially austenitic and having at least one of the following properties:
(a) a radiopacity greater than the radiopacity of UNS S3 1673,
(b) a tensile strength, after annealing, greater than about 490 MPa,
(c) a yield strength, after annealing, greater than about 190 MPa, or
(d) a pitting resistance equivalent greater than about 26,
incorporating the alloy in a tubular member of the endoprosthesis, the tubular member capable of supporting a body passageway.
47. The method of claim 46 , wherein the alloy has at least two of the properties.
48. The method of claim 46 , wherein the alloy has at least three of the properties.
49. The method of claim 46 , wherein the alloy is substantially free of nickel.
50. The method of claim 46 , wherein the alloy comprises between about 0.5% and about 40% by weight of a first element selected from a group consisting of platinum, ruthenium, palladium, iridium, rhodium, gold, and osmium.
51. The method of claim 46 , wherein the endoprosthesis is a stent.
52. The endoprosthesis of claim 1 , wherein the alloy comprises between about 40% and about 60% by weight of iron.
53. The endoprosthesis of claim 15 , wherein the alloy comprises between about 40% and about 60% by weight of iron.
54. The endoprosthesis of claim 39 , wherein the alloy comprises between about 40% and about 60% by weight of iron.
55. The method of claim 46 , wherein the alloy comprises between about 40% and about 60% by weight of iron.
56. The endoprosthesis of claim 1 , where in the alloy comprises from about 10% by weight to about 40% by weight of the first element.
57. The endoprosthesis of claim 15 , wherein the alloy comprises from about 10% by weight to about 40% by weight of the first element.
58. The endoprosthesis of claim 39 , wherein the alloy comprises from about 10% by weight to about 40% by weight of the first element.
59. The endoprosthesis of claim 46 , wherein the alloy comprises from about 10% by weight to about 40% by weight of the first element.