Bioresorbable stent

• US 6,991,647 B2
• Filed: 01/31/2001
• Issued: 01/31/2006
• Est. Priority Date: 06/03/1999
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Ams Research Corporation (Endo International PLC)
• Inventors: Jadhav, Balkrishna S.
• Primary Examiner(s): Isabella, David J.
• Application Number:
  US09/774,516
• Publication Number:
  US 20010029398A1
• Time in Patent Office: 1,826 Days
• Field of Search: 623/1.22, 623/1.15, 623/1.2, 424/422, 424/423, 424/426, 424/443, 424/444
• US Class Current: 623/1.2
• CPC Class Codes: A61L 31/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: D04C 1/06 Braid or lace serving particular purposes
• CPC Class Codes: D10B 2509/06 Vascular grafts; stents

Abstract

A bio-compatible and bioresorbable stent is disclosed that is intended to restore or maintain patency following surgical procedures, traumatic injury or stricture formation. The stent is composed of a blend of at least two polymers that is either extruded as a monofilament then woven into a braid-like embodiment, or injection molded or extruded as a tube with fenestrations in the wall. Methods for manufacturing the stent are also disclosed.

Claims

1. A bioresorbable, self-expanding stent comprising a tubular-shaped bioresorbable member having first and second ends, said bioresorbable member comprising a blend of at least two bioresorbable, bio-compatible homopolymers, wherein one of the two homopolymers is poly-ε

-caprolactone having a molecular weight of approximately 200,000 daltons or greater, the stent having a non-compressed diameter of between approximately 12 millimeters and 18 millimeters.

2. The bioresorbable, self-expanding stent of claim 1 comprising comprising poly-L-lactide and poly-ε

-caprolactone homopolymers.

3. The stent of claim 2, wherein poly-L-lactide and poly-ε

-caprolactone are present at a ratio between approximately 80;

20 and 99;

1.

4. The stent of claim 1 comprising:

a walled surface disposed between said first and second ends;

said walled surface comprising a helical shape of woven monofilaments comprising the blend of two bioresorbable, bio-compatible homopolymers.

5. The stent of claim 4, wherein said walled surface has approximately 30 monofilaments.

6. The stent of claim 4, wherein said polymer blend possesses a tensile strength in the range of approximately 40,000 psi to 120,000 psi.

7. The stent of claim 4, wherein said polymer blend possesses a tensile modulus in the range of approximately 400,000 psi to 2,000,000 psi.

8. The stent of claim 4, wherein said stent has a compressed first diameter of between approximately 6 mm and 10 mm and a second non-compressed diameter of between approximately 12 mm and 18 mm.

9. The stent of claim 4, wherein said woven monofilaments have a crossing angle of between approximately 100 degrees and 150 degrees in the non-compressed resting state.

10. The stent of claim 3, wherein the ratio is approximately 90:

10.

11. The stent of claim 2 wherein the poly-L-lactide has a molecular weight of approximately 450,000 daltons or greater.

12. The stent of claim 2 wherein the poly-L-lactide has a molecular weight of approximately 750,000 daltons or greater.

13. The stent of claim 4

said walled surface comprising a plurality of substantially parallel pairs of monofilaments;

said substantially parallel pairs of monofilaments woven in a helical shape such that substantially one-half of said substantially parallel pairs of monofilaments are wound clockwise in the longitudinal direction and one-half of said substantially parallel pairs of monofilaments are wound counterclockwise in the longitudinal direction such that an alternating, over-under plait of said substantially parallel pairs of monofilaments results.

14. The stent of claim 13, comprising approximately twenty-four substantially parallel pairs of monofilaments.

15. The stent of claim 13, wherein said polymer blend possesses a tensile strength in the range of approximately 40,000 psi to 120,000 psi.

16. The stent of claim 13, wherein said polymer blend possesses a tensile modulus in the range of approximately 400,000 psi to 2,000,000 psi.

17. The bioresorbable stent of claim 13, wherein said stent has a compressed first diameter of between approximately 6 mm and 10 mm and a second non-compressed diameter of between approximately 12 mm and 18 mm.

18. The bioresorbable stent of claim 13 wherein said woven monofilaments have a crossing angle of between approximately 100 degrees and 150 degrees in the non-compressed resting state.

21. The stent of claim 1, wherein the stent is a urethral stent.

19. A bioresorbable, self-expanding stent having a non-compressed diameter of between approximately 12 millimeters and 18 millimeters comprising

a radially self-expanding tubular-shaped bioresorbable member having first and second ends, a walled surface disposed between said first and second ends;

said walled surface comprising a plurality of substantially parallel pairs of monofilaments;

said substantially parallel pairs of monofilaments woven in a helical shape such that substantially one-half of said substantially parallel pairs of monofilaments are wound clockwise in the longitudinal direction and one-half of said substantially parallel pairs of monofilaments are wound counterclockwise in the longitudinal direction such that an alternating, over-under plait of said substantially parallel pairs of monofilaments results;

said monofilaments consisting essentially of poly-L-lactide and poly-ε

-caprolactone, wherein the poly-ε

-caprolactone has a molecular weight of approximately 200,000 daltons or greater.

20. The stent of claim 19, wherein poly-L-lactide and poly-ε

-caprolactone are present at a ratio between approximately 80;

20 and 99;

1.