Method of fabricating a stent with features by blow molding

• US 20080001333A1
• Filed: 06/30/2006
• Published: 01/03/2008
• Est. Priority Date: 06/30/2006
• Status: Active Grant

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Kleine, Klaus, Gale, David C.
• Granted Patent: US 7,740,791 B2
• Time in Patent Office: Days
• US Class Current: 264/564
• CPC Class Codes: A61F 2/844 folded prior to deployment
• 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 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir
• CPC Class Codes: B29C 2793/009 after shaping
• CPC Class Codes: B29C 2949/08 Preforms made of several individual parts, e.g. by welding or gluing parts together
• CPC Class Codes: B29C 49/071 Preforms or parisons characterised by their configuration, e.g. geometry, dimensions or physical properties
• CPC Class Codes: B29C 49/4278 Cutting
• CPC Class Codes: B29C 49/48 Moulds
• CPC Class Codes: B29C 49/54 for undercut articles
• CPC Class Codes: B29K 2067/046 PLA, i.e. polylactic acid or polylactide
• CPC Class Codes: B29K 2995/0056 Biocompatible, e.g. biopolymers or bioelastomers
• CPC Class Codes: B29L 2031/7534 Cardiovascular protheses

Abstract

The invention provides a method of manufacturing a stent, the method comprising: disposing a polymeric tube into a cylindrical mold, the cylindrical mold having a variable diameter along a portion of the inside surface of the mold; radially expanding the tube by blowing a gas or liquid into the cylindrical mold, the outside surface of the tube conforming to the variable diameter portion of the outside surface of the mold, causing the radially expanded tube to have a variable diameter along the conformed length of the tube; and fabricating a stent from the expanded tube.

Claims

1. Method of manufacturing a stent, the method comprising:

disposing a polymeric tube into a cylindrical mold, the cylindrical mold having a variable diameter along a portion of the inside surface of the mold;

radially expanding the tube by blowing a gas or liquid into the cylindrical mold, the outside surface of the tube conforming to the variable diameter portion of the inside surface of the mold, causing the radially expanded tube to have a variable diameter along the conformed length of the tube; and

fabricating a stent from the expanded tube.

2. The method according to claim 1, wherein the variable diameter of the formed tube is tapered from a larger diameter to a smaller diameter along the length of the tube.

3. The method according to claim 1, wherein the variable diameter of the formed tube is tapered from a larger diameter to a smaller diameter from the central portion of the tube to the ends of the tube.

4. The method according to claim 1, wherein the tube is a biodegradable and/or biostable polymer.

5. The method according to claim 1, further comprising heating the tube with the liquid or gas to a temperature above Tg of the polymer before and/or during expansion.

6. The method according to claim 1, wherein fabricating is laser cutting a pattern in the tube.

7. A stent formed by the method of claim 1.

8. A method of manufacturing a stent, the method comprising:

disposing a polymeric tube into a cylindrical mold, the cylindrical mold having a protrusion or indentation on the inside surface of the mold;

radially expanding the tube by blowing a gas or liquid into the cylindrical mold, the outside surface of the tube conforming to protrusion or indentation on the inside surface of the mold, the protrusion in the mold causing an indentation on the outside surface of the tube, or the indentation in the mold causing a protrusion on the outside surface of the tube; and

fabricating a stent with the expanded tube.

9. The method according to claim 8, wherein the thickness at the protrusion on the expanded tube is greater than other portions of the expanded tube.

10. The method according to claim 8, wherein the thickness at the indentation on the expanded tube is less than other portions of the expanded tube.

11. The method according to claim 8, wherein the stent is fabricated so that bending portions are located in the thicker portions.

12. The method according to claim 8, wherein fabricating a stent from the polymeric tube comprises laser cutting a pattern having the indentation or protrusion on the surface of a strut.

13. The method according to claim 8, wherein the indentation comprises a groove.

14. The method according to claim 8, wherein the tube comprises a biodegradable and/or biostable polymer.

15. The method according to claim 8, further comprising heating the tube with the liquid or gas to a temperature above Tg of the polymer before and/or during expansion.

16. A stent formed by the method of claim 8.

17. A method of manufacturing a stent, the method comprising:

disposing a polymeric tube into a cylindrical mold, the cylindrical mold having an indentation or a protrusion on the inside surface of the mold;

radially expanding the tube by blowing a gas or liquid into the cylindrical mold, the outside surface of the tube conforming to the indentation or protrusion of the inside surface of the mold, the indentation or protrusion on the mold causing a feature on the outside surface of the tube; and

fabricating a stent with the expanded tube.

18. The method according to claim 17, wherein the feature formed on the outside surface of the tube is an indentation, and the method further comprises filling the indentation with a radio-opaque material.

19. The method according to claim 17, wherein the feature formed on the outside surface of the tube is an indentation, and the method further comprises filling the indentation with a drug.

20. The method according to claim 17, wherein the cylindrical mold has both an indentation and a protrusion on the inside surface, thereby forming both a protrusion and an indentation on the outside surface of the tube.