Removable stent for body lumens

• US 6,494,908 B1
• Filed: 12/22/1999
• Issued: 12/17/2002
• Est. Priority Date: 12/22/1999
• Status: Expired due to Term

• Current Assignee: Ethicon Incorporated (Johnson & Johnson)
• Original Assignee: Ethicon Incorporated (Johnson & Johnson)
• Inventors: Huxel, Shawn Thayer, Skula, E. Richard, Li, Yufu, Datta, Arindam, Jamiolkowski, Dennis D.
• Primary Examiner(s): Milano, Michael J.
• Assistant Examiner(s): HO, TAN-UYEN THI
• Application Number:
  US09/470,620
• Time in Patent Office: 1,091 Days
• Field of Search: 623/1-5-, 623/1.18, 623/1.22, 623/1.21, 623/1.2, 623/1.19, 623/1.38, 623/1.44, 623/1.46, 623/1.47, 623/1.48, 623/1-9-, 606/200, 606/194, 606/154, 606/151
• US Class Current: 623/1.22
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: C08L 29/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C08L 33/26 Homopolymers or copolymers of acrylamide or methacrylamide
• CPC Class Codes: C08L 39/06 Homopolymers or copolymers of N-vinyl-pyrrolidones
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: C08L 71/02 Polyalkylene oxides

Abstract

A removable stent for implantation into a lumen in a human body. The stent is made from a soft, flexible fiber having an outer surface. An outer bioabsorbable/degradable coating is applied to the outer surface of the filament causing it to become rigid. The coating softens in vivo through absorption and/or degradation such that the stent is readily passed or removed from the lumen as a softened filament after a pre-determined period of time through normal flow of body fluids passing through the lumen or by manual removal.

Claims

1. A stent, comprising:

a helical structure having a plurality of coils, said structure having a longitudinal axis and said coils having a pitch, said structure having an internal longitudinal passage wherein said structure is made from a filament having a cross-section and an outer surface, said filament comprising;

a soft flexible elongated member having an outer surface; and

a bioabsorbable or biodegradable polymeric outer coating on the outer surface of the member;

wherein, the polymeric coating has sufficient mechanical integrity to effectively maintain the flexible member in a helical configuration, until the coating has sufficiently been degraded or absorbed in vivo to effectively convert the helical structure back into a soft, elongated member.

2. The stent of claim 1 wherein the coating comprises a melt polymer.

3. The stent of claim 1, wherein the coating comprises a solution polymer.

4. The stent of claim 1 wherein the filament comprises a surgical suture.

5. The stent of claim 4, wherein the suture comprises a monofilament.

6. The stent of claim 4, wherein the suture comprises a multifilament.

7. The stent of claim 4, wherein the suture comprises a non-absorbable suture.

8. The stent of claim 4 wherein the suture comprises an absorbable suture.

9. The stent of claim 1, wherein the coating comprises a polymer made from monomers selected from the group consisting of lactide, glycolide, para-dioxanone, caprolactone, and trimethylene carbonate, caprolactone, blends thereof and copolymers thereof.

10. The stent of claim 1, wherein the polymer of the coating has a glass transition temperature above 55 C.

11. The stent of claim 1 wherein the polymer of the coating has a glass transition temperature above 120 C.

12. The stent of claim 1, wherein the polymeric coating comprise a polymer selected from the group consisting of polyacrylamides, polyethylene glycols, polyethylene oxide, vinyl alcohols, and poly(N-vinyl pyrrolidones.

13. The stent of claim 1, wherein the polymeric coating additionally comprises polyamide.

14. The stent of claim 9 wherein the coating comprises a melt polymer.

15. The stent of claim 9, wherein the coating comprises a solution polymer.

16. The stent of claim 9 wherein the filament comprises a surgical suture.

17. The stent of claim 12, wherein the suture comprises a monofilament.

18. The stent of claim 12, wherein the suture comprises a multifilament.

19. The stent of claim 12, wherein the suture comprises a non-absorbable suture.

20. The stent of claim 12 wherein the suture comprises an absorbable suture.

21. The stent of claim 1, wherein the coating comprises a polymer made from monomers selected from the group consisting of lactide, glycolide, para-dioxanone, caprolactone, and trimethylene carbonate, caprolactone, blends thereof and copolymers thereof.

22. The stent of claim 1, wherein the polymer of the coating has a glass transition temperature above 55 C.

23. The stent of claim 1 wherein the polymer of the coating has a glass transition temperature above 120 C.

24. The stent of claim 1, wherein the polymeric coating comprise a polymer selected from the group consisting of polyacrylamides, polyethylene glycols, polyethylene oxide, vinyl alochols, and poly(N-vinyl pyrrolidones.

25. The stent of claim 1, wherein the polymeric coating additionally comprises polyamide.

26. A method of maintaining a passageway of a body lumen substantially open, comprising the steps of:

providing a stent, said stent comprising;

a helical structure having a plurality of coils, said structure having a longitudinal axis and a longitudinal passage, and said coils having a pitch, wherein said structure is made from a fiber, said fiber having a cross-section and said filament comprising;

an elongated flexible, filament member, having an external surface and a cross-section; and

,

a polymeric outer coating on the surface of the member, wherein, the polymeric coating has sufficient mechanical integrity to effectively maintain the flexible member in a helical configuration; and

,

implanting said stent in a body lumen and maintaining the stent in the body lumen for a sufficient period of time to effectively maintain the passageway of the lumen substantially open for a desired period of time until the exterior coating softens, thereby converting the stent structure into a soft, flexible filamentary structure.