Radiopaque intraluminal stents comprising cobalt-based alloys containing one or more platinum group metals, refractory metals, or combinations thereof

• US 10,441,445 B2
• Filed: 02/10/2017
• Issued: 10/15/2019
• Est. Priority Date: 11/17/2010
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Kramer-Brown, Pamela A., Calvert, Kayla L., Simpson, John A., Pacetti, Stephen D., Leach, Austin M.
• Primary Examiner(s): Roe, Jessee R
• Application Number:
  US15/429,339
• Publication Number:
  US 20170296365A1
• Time in Patent Office: 977 Days
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• 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 1/0433 Nickel- or cobalt-based alloys
• CPC Class Codes: C22C 19/05 with chromium
• CPC Class Codes: C22C 19/07 based on cobalt
• CPC Class Codes: C22C 27/00 Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00
• CPC Class Codes: C22C 27/04 Alloys based on tungsten or molybdenum
• CPC Class Codes: C22C 27/06 Alloys based on chromium

Abstract

Embodiments are directed to radiopaque implantable structures (e.g., stents) formed of cobalt-based alloys that comprise cobalt, chromium and one or more platinum group metals, refractory metals, precious metals, or combinations thereof. Platinum group metals include platinum, palladium, ruthenium, rhodium, osmium, and iridium. Refractory metals include zirconium, niobium, rhodium, molybdenum, hafnium, tantalum, tungsten, rhenium, and precious metals include silver and gold. In one embodiment, the one or more included platinum group or refractory metals substitute at least partially for nickel, such that the alloy exhibits reduced nickel content, or is substantially nickel free. The stents exhibit improved radiopacity as compared to similar alloys including greater amounts of nickel.

Claims

1. A radiopaque stent, comprising:

a cylindrical main body comprising a cobalt-based alloy comprising cobalt, chromium, an austenitic stabilizer for cobalt including a combination of manganese and nickel, and one or more platinum group metals or precious metals selected from the group of platinum, palladium, rhodium, iridium, osmium, ruthenium, silver and gold;

wherein the cobalt-based alloy comprises from 31 weight percent to 51 weight percent cobalt, from 15 weight percent to 20 weight percent chromium, from 8 weight percent to 30 weight percent of the one or more platinum group metals or precious metals;

wherein the cobalt-based alloy comprising up to 8 weight percent nickel, up to 20 weight percent manganese, a combined weight percentage of manganese and nickel being up to 25 weight percent, the cobalt-based alloy comprising no more than about 20 percent by weight iron,

wherein an entirety of the stent is formed from the cobalt-based alloy.

2. The radiopaque stent of claim 1, wherein the cobalt-based alloy includes from 5.8 weight percent to 7.1 weight percent nickel and includes a combined weight percentage of manganese and nickel that is from 7.7 weight percent to 9.7 weight percent.

3. The radiopaque stent of claim 1, wherein the cobalt-based alloy has a radiopacity from 4.6 barnes/cm³ to 6.5 barnes/cm³.

4. The radiopaque stent of claim 1, wherein the cobalt-based alloy includes 5 weight percent to 8 weight percent nickel.

5. The radiopaque stent of claim 1, wherein the cobalt-based alloy includes from 1 to 5 weight percent manganese.

6. The radiopaque stent of claim 1, wherein the cobalt-based alloy includes a combined weight percentage of manganese and nickel from 7 weight percent to 10 weight percent.

7. The radiopaque stent of claim 1, wherein the cobalt-based alloy includes no more than about 4 percent by weight iron.

8. The radiopaque stent of claim 1, wherein the platinum group metal or precious metal comprises at least one of platinum or palladium.

9. The radiopaque stent of claim 1, wherein the platinum group metal or precious metal comprises both platinum and palladium.

10. The radiopaque stent of claim 1, wherein the alloy further comprises tungsten.

11. The radiopaque stent of claim 1, wherein the alloy further comprises up to 15 weight percent tungsten.

12. The radiopaque stent of claim 1, wherein an entirety of the stent is formed from the cobalt-based alloy.

13. The radiopaque stent of claim 12, wherein the cobalt-based alloy includes from 5.8 weight percent to 7.1 weight percent nickel and includes a combined weight percentage of manganese and nickel that is from 7.7 weight percent to 9.7 weight percent.

14. The radiopaque stent of claim 12, wherein the cobalt-based alloy has a radiopacity from 4.6 barnes/cm³ to 6.5 barnes/cm³.

15. The radiopaque stent of claim 12, wherein the platinum group metal or precious metal comprises at least one of platinum or palladium.

16. The radiopaque stent of claim 12, wherein the platinum group metal or precious metal comprises both platinum and palladium.

17. The radiopaque stent of claim 12, wherein the alloy further comprises tungsten.

18. The radiopaque stent of claim 12, wherein the alloy further comprises up to 15 weight percent tungsten.

19. A radiopaque stent, comprising:

a cylindrical main body comprising a cobalt-based alloy comprising cobalt, chromium, an austenitic stabilizer for cobalt including a combination of manganese and nickel, and one or more platinum group metals or precious metals selected from the group consisting of platinum, palladium, rhodium, iridium, osmium, ruthenium, silver and gold;

wherein the cobalt-based alloy comprises from 31 weight percent to 51 weight percent cobalt, from 15 weight percent to 20 weight percent chromium, from 8 weight percent to 30 weight percent of the one or more platinum group metals or precious metals;

wherein the cobalt-based alloy comprises 5 weight percent to 8 weight percent nickel, from 1 weight percent to 5 weight percent manganese, a combined weight percentage of manganese and nickel being from 7 weight percent to 10 weight percent, the cobalt-based alloy comprising no more than about 4 percent by weight iron.

20. The radiopaque stent of claim 19, wherein:

(i) the cobalt-based alloy includes from 5.8 weight percent to 7.1 weight percent nickel and includes a combined weight percentage of manganese and nickel that is from 7.7 weight percent to 9.7 weight percent; and

/or

(ii) wherein the cobalt-based alloy has a radiopacity from 4.6 barnes/cm³ to 6.5 barnes/cm³.

21. A radiopaque stent, comprising:

a cylindrical main body comprising a cobalt-based alloy comprising cobalt, chromium, an austenitic stabilizer for cobalt including a combination of manganese and nickel, and one or more platinum group metals or precious metals selected from the group of platinum, palladium, rhodium, iridium, osmium, ruthenium, silver and gold;

wherein the cobalt-based alloy comprises from 31 weight percent to 51 weight percent cobalt, from 15 weight percent to 20 weight percent chromium, from 8 weight percent to 30 weight percent of the one or more platinum group metals or precious metals;

wherein the cobalt-based alloy includes up to 8 weight percent nickel, up to 20 weight percent manganese, a combined weight percentage of manganese and nickel being up to 25 weight percent, the cobalt-based alloy comprising no more than about 20 percent by weight iron,

wherein the cobalt-based alloy has a radiopacity from 4.6 barnes/cm³ to 6.5 barnes/cm³.