Bi-axial oriented sheath

• US 20060111769A1
• Filed: 11/23/2004
• Published: 05/25/2006
• Est. Priority Date: 11/23/2004
• Status: Abandoned Application

• Current Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Inventors: Murray, Robert
• Application Number:
  US10/997,599
• Publication Number:
  US 20060111769A1
• Time in Patent Office: Days
• US Class Current: 623/1.120
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61L 29/041 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 29/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 67/00 Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain of polyester-amides C08L77/12; of polyester-imides C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C08L 77/00 Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08; Compositions of derivatives of such polymers

Abstract

A sheath and method of forming is disclosed for a bi-axial oriented made of high molecular weight polymers. The high molecular weight polymers provide a bi-axial oriented sheath with a high hoop stress and a thin wall thickness. A device and method of use is also disclosed for a device for delivery of a self-expanding prosthesis covered by a bi-axial oriented sheath made of high molecular weight polymers. The bi-axial oriented sheath may be moved from a first position constraining the self-expanding prosthesis to a second position releasing the self-expanding prosthesis. During delivery, the device is inserted into the vascular system of the patient, with the self-expanding prosthesis positioned at the location to be treated. The self-expanding prosthesis is then released by moving the bi-axial oriented sheath from the first to second positions, releasing the self-expanding prosthesis.

Claims

1. A sheath for constraining a self-expanding prosthesis, wherein the sheath comprises bi-axially oriented, high molecular weight polymer.

2. The sheath of claim 1, wherein the high molecular weight polymer is nylon 12.

3. The sheath of claim 1, wherein the high molecular weight polymer is PET.

4. The sheath of claim 1, wherein the high molecular weight polymer is PEBAX.

5. The sheath of claim 1, wherein the high molecular weight polymer is polyethylene.

6. The sheath of claim 1, wherein the bi-axially oriented, high molecular weight polymer has a hoop stress greater than 10,000 psi.

7. The sheath of claim 1, wherein the sheath has a diameter between 2.0 mm and 10.0 mm.

8. The sheath of claim 1, wherein the sheath has a wall thickness between 0.0005″

and 0.004″

.

9. A method for forming a sheath having bi-axial orientation for constraining a self-expanding prosthesis, the method comprising:

extruding tubing of high molecular weight polymer forming a parison having a first orientation, a first inner diameter (ID), a first outer diameter (OD) and a first wall thickness; and

radially expanding the parison in a mold forming a sheath having a second orientation in addition to the first orientation, a second ID, a second OD and a second wall thickness.

10. The method of claim 9, wherein the first orientation is an axial orientation.

11. The method of claim 9, wherein the second orientation is a radial orientation.

12. The method of claim 9, wherein radially expanding comprises blow molding the parison.

13. The method of claim 12, wherein blow molding the parison comprises heating and pressurizing the parison.

14. The method of claim 9, wherein the high molecular weight polymer is nylon 12.

15. The method of claim 9, wherein the high molecular weight polymer is PET.

16. The method of claim 9, wherein the high molecular weight polymer is PEBAX.

17. The method of claim 9, wherein the high molecular weight polymer is polyethylene.

18. The method of claim 9, wherein the second ID is 5 to 8 times the first ID.

19. The method of claim 9, wherein the sheath has a hoop stress greater than 10,000 psi.

20. The method of claim 9, wherein the second OD is 2.0 to 10.0 mm.

21. The method of claim 9, wherein the second wall thickness is between 0.0005″

to 0.004″

.

22. A device for delivering a self-expanding prosthesis, said device comprising:

a shaft having a distal end and a proximal end;

a self-expanding prosthesis positioned proximate the proximal end of the shaft; and

a bi-axial oriented sheath made of high molecular weight polymer, the bi-axial oriented sheath configured to cover the self-expanding prosthesis, the bi-axial oriented sheath being movable between a first position constraining the self-expanding prosthesis to a second position releasing the self-expanding prosthesis.

23. The device of claim 22, further comprising a handle at the proximal end of the shaft, the handle having a sheath moving mechanism configured to move the bi-axial oriented sheath from the first position to the second position.

24. The device of claim 22, wherein the shaft further includes a flexible tip at the distal end.

25. The device of claim 22, wherein the self-expanding prosthesis is made of nickel-titanium.

26. The device of claim 22, wherein the self-expanding prosthesis is made of mechanically compressible spring material.

27. The device of claim 22, wherein the high molecular weight polymer is nylon 12.

28. The device of claim 22, wherein the high molecular weight polymer is PET.

29. The device of claim 22, wherein the high molecular weight polymer is PEBAX.

30. The device of claim 22, wherein the high molecular weight polymer is polyethylene.

31. The device of claim 22, wherein the bi-axial oriented sheath has a diameter range of 2.0 to 10.0 mm.

32. The device of claim 22, wherein the bi-axial oriented sheath has a wall thickness range of 0.0005″

to 0.004″

.

33. A method for delivering of a self-expanding prosthesis, comprising:

inserting a device having a self-expanding prosthesis constrained by a bi-axial oriented sheath made of high molecular weight polymer into a vascular system of a patient;

positioning the self-expanding prosthesis in a body vessel proximal to an area to be treated; and

releasing the self-expanding prosthesis by moving the bi-axial oriented sheath.

34. The method of claim 33, wherein the bi-axial oriented sheath is movable between a first position constraining the self-expanding prosthesis to a second position releasing the self-expanding prosthesis, and releasing the self-expanding prosthesis includes moving the bi-axial oriented sheath from the first position to the second position

35. The method of claim 33, wherein the self-expanding prosthesis is made of nickel-titanium.

36. The method of claim 33, wherein the self-expanding prosthesis is made of mechanically compressible spring material.

37. The method of claim 33, wherein the high molecular weight polymer is nylon 12.

38. The method of claim 33, wherein the high molecular weight polymer is PET.

39. The method of claim 33, wherein the high molecular weight polymer is PEBAX.

40. The method of claim 33, wherein the high molecular weight polymer is polyethylene.

41. The method of claim 33, wherein the bi-axial oriented sheath has a diameter range of 2.0 to 10.0 mm.

42. The method of claim 33, wherein the bi-axial oriented sheath has a wall thickness range of 0.0005″

to 0.004″

.