DEFORMABLE UNDERLAYER FOR STENT

• US 20090118820A1
• Filed: 11/02/2007
• Published: 05/07/2009
• Est. Priority Date: 11/02/2007
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Gregorich, Daniel J., Sorenson, Shawn
• Granted Patent: US 7,938,855 B2
• Time in Patent Office: Days
• US Class Current: 623/1.440
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61L 2300/00 Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices
• CPC Class Codes: A61L 31/088 Other specific inorganic materials not covered by A61L31/084 or A61L31/086
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: A61L 31/18 Materials at least partially X-ray or laser opaque

Abstract

An endoprosthesis includes a brittle layer, e.g. a ceramic and an underlayer to accommodate dimensional changes as the endoprosthesis is flexed.

Claims

1. An endoprosthesis, comprising:

a stent wall including a stent body and ceramic having a defined grain or globular morphology, and an underlayer between the stent body and the ceramic, the underlayer being more easily deformed than the ceramic and the stent body.

2. The endoprosthesis of claim 1 wherein underlayer has a bulk modulus that is about 75% or less than the modulus of the stent body.

3. The endoprosthesis of claim 1 wherein the underlayer has a thickness of about 1% or less than the stent body and 200% to 1% of the thickness of the ceramic.

4. The endoprosthesis of claim 1 wherein the underlayer is a metal.

5. The endoprosthesis of claim 1 wherein the underlayer is more dense than the stent body.

6. The endoprosthesis of claim 1 wherein the underlayer includes a polymer.

7. The endoprosthesis of claim 1 wherein the ceramic forms a relatively continuous layer having a globular morphology.

8. The endoprosthesis of claim 1 wherein the ceramic has a defined grain morphology.

9. The endoprosthesis of claim 1 wherein the ceramic is in particulate form.

10. The endoprosthesis of claim 1 wherein the underlayer includes a drug.

11. The endoprosthesis of claim 1 wherein the ceramic is iridium oxide.

12. The endoprosthesis of claim 1 wherein the underlayer includes a higher density radiopaque component.

13. The endoprosthesis of claim 1 wherein the ceramic and underlayer are on the abluminal surface only.

14. The endoprosthesis of claim 1 wherein the ceramic and underlayer are on the abluminal and adluminal surfaces.

15. The endoprosthesis of claim 1 wherein the underlayer on the abluminal and adluminal surfaces have different thicknesses or compositions.

16. The endoprosthesis of claim 1 wherein the ceramic on the abluminal and adluminal surfaces have different morphologies or compositions.

17. The endoprosthesis of claim 1 wherein the ceramic is directly atop the underlayer and the underlayer is directly atop the stent body.

18. The endoprosthesis of claim 1 wherein the stent body is stainless steel.

19. An endorprosthesis, comprising

a stent wall including a stent body formed of metal and ceramic formed of an oxide and an underlayer formed of metal between the stent body and ceramic, the underlayer having a bulk modulus that is about 75% or less than the modulus of the stent body and the ceramic having a globular morphology.

20. The endoprosthesis of claim 19, wherein the thickness of the undercoating is less than the thickness of the ceramic and the undercoating has a density greater than the density of the stent body.

21. A method of forming an endoprosthesis, comprising:

providing a substrate,

providing on a first surface of the substrate a metal layer, the metal layer having a first thickness less than the thickness of the substrate,

providing a ceramic on the metal layer,

providing a metal layer on a second surface of the substrate, the metal layer having a second thickness less than the thickness of the substrate, and different than the first thickness,

providing a ceramic on the first metal layer, and

utilizing the substrate in a stent.

22. The method of claim 21 wherein the first surface corresponds to the luminal surface and the second surface corresponds to the adluminal surface.

23. The method of claim 21 wherein the first thickness is greater than the second thickness.