Stent with enhanced friction

• US 8,236,047 B2
• Filed: 07/22/2004
• Issued: 08/07/2012
• Est. Priority Date: 09/23/1999
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Inventors: Thompson, Paul J.
• Primary Examiner(s): Pellegrino, Brian
• Assistant Examiner(s): MILLER, CHERYL L
• Application Number:
  US10/896,533
• Publication Number:
  US 20040260388A1
• Time in Patent Office: 2,938 Days
• Field of Search: 623/1.39, 623/1.4, 623/23.74, 623/1.12, 623/1.11, 623/1.15, 623/1.36
• US Class Current: 623/1.39
• 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 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/9522 Means for mounting a stent or stent-graft onto or into a placement instrument
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/9583 Means for holding the stent on the balloon, e.g. using protrusions, adhesives or an outer sleeve
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0063 Three-dimensional shapes
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0025 differing in roughness
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device
• CPC Class Codes: Y10S 623/921 Blood vessel

Abstract

A stent for placement in a body lumen is fabricated by forming a tube having an un-deployed diameter sized for the tube to be placed on a deployment balloon and advanced through a body lumen to a deployment site. The tube is expandable upon inflation of the balloon to an enlarged diameter sized for the tube to be retained within the lumen at the site upon deflation and withdrawal of the balloon. The tube has a stent axis extending between first and second axial ends of the tube. The tube has an exterior surface and an interior surface. The tube is polished to polish the exterior surface to a smooth surface finish and with at least a portion of the interior surface having a rough surface finish rougher than the surface finish of the exterior surface.

Claims

1. A method for fabricating a stent for placement in the body lumen, the method comprising:

forming an expandable stent body having a plurality of ribs defining a plurality of open cells, the stent body being sized to be advanced through a body lumen to a deployment site, the stent body having a stent axis extending between first and second axial ends of the stent body, the plurality of ribs having an exterior surface and an interior surface, the interior surface being configured to engage a balloon; and

directing a stream of particulate at the interior surface of at least a region of the plurality of ribs to selectively remove material from the interior surface of said region to make the interior surface of said region rougher than before said directing commenced, a surface finish of the interior surface being rougher than a surface finish of the exterior surface.

2. The method of claim 1, further comprising polishing at least one of the exterior surface and the interior surface of the ribs prior to the step of directing a stream.

3. The method of claim 2, wherein said polishing includes removing balloon-threatening burrs.

4. The method of claim 2, further comprising polishing the interior surface of the ribs prior to the step of directing a stream.

5. The method of claim 1, wherein the rougher surface finish is provided on at least opposite sides of a center of the stent body.

6. The method of claim 1, wherein the rougher surface finish is provided substantially along an entire axial length of the interior surface.

7. The method of claim 1, wherein the stent body is sized to be placed on a deployment balloon.

8. The method of claim 1, wherein the step of directing a stream comprising discharging the stream from an orifice at a pressure of about 60 pounds per square inch.

9. The method of claim 1, further including rotating the stent body while the stream of particulate is directed at the interior surface of the ribs.

10. The method of claim 1, wherein the stent body is made of a metal material, and wherein the interior surface of the stent body is roughened by removing portions of the metal material.

11. The method of claim 1, wherein the stream of particulate is directed at said interior surface from the first axial end of the stent body.

12. The method of claim 11, further including directing the stream of particulate at said interior surface from the second axial end of the stent body.

13. The method of claim 1, wherein the step of directing includes substantially uniformly covering said region of said interior surface with pits.

14. The method of claim 13, wherein the pits are approximately 3 to 20 microns in size.

15. The method of claim 1, wherein the step of directing a stream of particulate includes directing a stream of silicon carbide particulate.

16. The method of claim 15, wherein the silicon carbide particulate comprises a powder having a particle size of about 50 microns.

17. A method of deploying a stent in a body lumen, the method comprising:

fabricating a stent by

forming an expandable stent body having a plurality of ribs defining a plurality of open cells, the stent body being sized to be advanced through the body lumen to a deployment site, the stent body having a stent axis extending between first and second axial ends of the stent body, the plurality of ribs having an exterior surface and an interior surface, and

directing a stream of particulate at the interior surface of at least a region of the plurality of ribs to selectively remove material from the interior surface of said region to make the interior surface of said region rougher than before said directing commenced, a surface finish of the interior surface being rougher than a surface finish of the exterior surface;

placing the stent on a balloon-tipped catheter such that the region of said interior surface of the plurality of ribs roughened by the stream of particulate frictionally engages a balloon; and

advancing the catheter and the stent to the deployment site in the body lumen.

18. The method of claim 17, further comprising polishing at least one of the exterior surface and the interior surface of the ribs prior to the step of directing a stream.

19. The method of claim 17, wherein the step of directing a stream comprising discharging the stream from an orifice at a pressure of about 60 pounds per square inch.

20. The method of claim 17, further including rotating the stent body while the stream of particulate is directed at the interior surface of the ribs.

21. The method of claim 17, wherein the step of directing a stream of particulate includes directing a stream of silicon carbide particulate.

22. The method of claim 21, wherein the silicon carbide particulate comprises a powder having a particle size of about 50 microns.

23. A method for fabricating a stent for placement in a body lumen, the method comprising:

forming an expandable stent body having a plurality of ribs defining a plurality of open cells, the stent body being sized to be advanced through the body lumen to a deployment site, the stent body having a stent axis extending between first and second axial ends of the stent body, the plurality of ribs having an exterior surface and an interior surface, the interior surface being configured to engage a balloon; and

directing a stream of particulate at the interior surface of at least a region of the plurality of ribs to selectively remove material from the interior surface of said region to so as to substantially uniformly cover said region of said interior surface with pits approximately 3 to 20 microns in size, a surface finish of the interior surface being rougher than a surface finish of the exterior surface.

24. The method of claim 23, wherein the step of directing a stream of particulate includes directing a stream of silicon carbide particulate.