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