Method of making a medical device having a thin wall tubular membrane over a structural frame

• US 20030225447A1
• Filed: 05/06/2003
• Published: 12/04/2003
• Est. Priority Date: 05/10/2002
• Status: Abandoned Application

• Current Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Original Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Inventors: Grewe, David, Majercak, David Christopher
• Application Number:
  US10/430,113
• Publication Number:
  US 20030225447A1
• Time in Patent Office: Days
• US Class Current: 623/1.13
• CPC Class Codes: A61F 2/2412 with soft flexible valve members, e.g. tissue valves shaped like natural valves check valves with flexible valve members in general F16K15/14
• CPC Class Codes: A61F 2/2415 Manufacturing methods
• CPC Class Codes: A61F 2/2418 Scaffolds therefor, e.g. support stents
• CPC Class Codes: A61F 2/2475 Venous valves
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/825 having longitudinal struts
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2002/91583 by a bridge, whereby at least one of its ends is connected along the length of a strut between two consecutive apices within a band
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2230/0078 hyperboloidal

Abstract

The present invention relates to a medical device and method for making the medical device. In particular, the present invention relates to membrane covered structural frame, and to a method of forming a tubular membrane on a structural frame. In one aspect, a polymeric tube is provided having a first diameter and a first tube wall thickness. A radially expandable and contractible structural frame is radially contracted, and inserted into at least a portion of the structural frame. The radially contracted structural frame then expands to expand the polymeric tube to a second diameter, wherein the second diameter is greater than the first diameter. As the polymeric tube radially expands, the tube wall thickness becomes thinner, so that the polymeric tube becomes a thin walled tubular membrane. The polymeric tube and structural frame are then mechanically attached to each other.

Claims

1. A method of making a medical device having a thin wall tubular structure over a radially contractible and expandable structural frame, the method comprising the steps of:

providing a polymeric tube having a first diameter and a first wall thickness;

radially contracting the structural frame;

placing the radially contracted structural frame at least partially into the polymeric tube;

expanding the structural frame to expand at least a portion of the polymeric tube to a second diameter having a second wall thickness, the second diameter of the polymeric tube being greater than the first diameter, the second wall thickness being smaller than the first wall thickness; and

mechanically attaching the expanded polymeric tube to the expanded structural frame.

2. The method of claim 1 wherein the step of radially contracting the structural frame comprises inserting the structural frame into a sheath, the sheath being sized to have an inside diameter that is smaller than the outside diameter of the structural frame.

3. The method of claim 1 wherein the step of radially contracting the structural frame comprises:

radially crimping the structural frame with a crimping device to a reduced diameter; and

cooling the radially crimped structural frame to temporarily maintain the radially contracted configuration.

4. The method of claim 1 wherein the step of radially expanding the structural frame comprises:

inserting a radial expansion device into the structural frame along the structural frame'"'"'s longitudinal axis;

radially expanding the radial expansion device to expand the structural frame.

5. The method of claim 4 wherein the radial expansion device is an inflation balloon.

6. The method of claim 4 wherein the radial expansion device is a radially expanding cage assembly.

7. The method of claim 4 wherein the radial expansion device is a radially expanding mandrel.

8. The method of claim 4 wherein the radial expansion device is a tapered mandrel.

9. The method of claim 1 wherein the step of radially expanding the structural frame comprises removing a sheath constraining the radially contracted structural frame, thereby allowing the structural frame to radially expand.

10. The method of claim 1 wherein the step of radially expanding the structural frame comprises heating the radially contracted structural frame.

11. The medical device of claim 1 wherein the step of mechanically attaching the expanded polymeric tube to the expanded structural frame comprises suturing the polymeric tube to the structural frame.

12. The medical device of claim 1 wherein the step of mechanically attaching the expanded polymeric tube to the expanded structural frame comprises welding the polymeric tube to the structural frame.

13. The medical device of claim 1 wherein the step of mechanically attaching the expanded polymeric tube to the expanded structural frame comprises adhering the polymeric tube to the structural frame with an adhesive.

14. The medical device of claim 1 wherein the step of mechanically attaching the expanded polymeric tube to the expanded structural frame comprises coating at least a porting of the expanded polymeric tube and the structural frame with a polymer.

15. The method of claim 14 wherein the step of coating comprises spraying a polymer solution over at least a portion of the expanded polymeric tube and structural frame.

16. The method of claim 14 wherein the step of coating comprises dipping at least a portion of the expanded polymeric tube and structural frame in a polymer solution.

17. The method of claim 14 wherein the step of coating comprises:

dipping at least a portion of the expanded polymeric tube and structural frame in a polymer solution; and

spinning the dip coated expanded polymeric tube and structural frame to evenly distribute the coating.

20. The method of claim 1 further comprising performing post processing of the expanded polymeric tube.

21. The method of claim 20 wherein the step of post processing includes reshaping the expanded polymeric tube.

22. The method of claim 20 wherein the step of post processing includes thinning at least a portion of the expanded polymeric tube.

23. The method of claim 20 wherein the step of post processing includes thickening at least a portion of the expanded polymeric tube.

24. The method of claim 20 wherein the step of post processing includes forming cusps in the expanded polymeric tube.

18. A method of placing a tubular structure about a radially contractible and expandable structural frame, the method comprising the steps of:

providing a porous polymeric tube having a first diameter and a first wall thickness;

radially contracting the structural frame;

placing the radially contracted structural frame at least partially into the porous polymeric tube;

expanding the structural frame to expand at least a part of the porous polymeric tube to a second diameter, the second diameter of the porous polymeric tube being greater than the first diameter; and

coating at least a portion of the expanded porous polymeric tube and the expanded structural frame, thereby mechanically attaching the expanded porous polymeric tube to the expanded structural frame.

19. The method of claim 18 wherein the step of mechanically attaching the expanded porous polymeric tube to the expanded structural frame comprises:

filling the at least a portion of the pores in the coated porous polymeric tube with a polymer solution; and

curing the polymer solution, thereby mechanically bonding the porous polymeric tube to the coated structural frame.

25. A medical device having a tubular membrane structure comprising:

a radially expandable and collapsible structural frame;

a thin wall membrane positioned over the radially expandable and collapsible structural frame, the membrane formed at least in part by radially expanding a polymeric tube with the structural frame; and

a coating over the thin wall membrane, the coating and thin wall membrane forming the tubular membrane structure, and wherein the coating mechanically attaches the thin wall membrane to the structural frame.

26. The medical device of claim 25 wherein the structural frame comprises a lattice of interconnected elements, and having a substantially cylindrical configurations with first and second open ends and a longitudinal axis extending there between.

27. The medical device of claim 25 wherein the thin wall membrane comprises ePTFE.

28. The medical device of claim 25 wherein the polymeric tube has a wall thickness before radial expansion in the range from about 25 μ

m to about 50 μ

m.

29. The medical device of claim 25 wherein the thin wall membrane has a wall thickness after radial expansion in the range from about 12 μ

m to about 25 μ

m.

30. The medical device of claim 25 wherein the coating comprises a polymer.

31. The medical device of claim 30 wherein the polymer coating comprises an elastomeric polymer.

32. The medical device of claim 31 wherein the elastomeric polymer comprises an elastomeric fluoropolymer.

33. The medical device of claim 32 wherein the elastomeric fluoropolymer comprises a vinylidene fluoride/hexafluoropropylene/tetrafluoroethylene.

34. The medical device of claim 31 wherein the elastomeric polymer comprises siliconized polyurethane.

35. The medical device of claim 34 wherein the siliconized polyurethane comprises segmented polyetherurethane.

36. The medical device of claim 25 wherein the coating has a wall thickness from about 12 μ

m to about 25 μ

m.

37. The medical device of claim 25 wherein the thin wall membrane comprises a therapeutic agent.

38. The medical device of claim 25 wherein the thin wall membrane comprises a pharmaceutic agent.

39. The medical device of claim 25 wherein the coating comprises a therapeutic agent.

40. The medical device of claim 25 wherein the coating comprises a pharmaceutic agent.

41. The medical device of claim 25 wherein at least a porting of the structural frame is coated with a therapeutic agent.

42. The medical device of claim 25 wherein at least a portion of the structural frame is coated with a pharmaceutic agent.