Implantable medical devices
A medical device includes a balloon catheter having an expandable member, e.g., an inflatable balloon, at its distal end and a stent or other endoprosthesis. The stent is, for example, an apertured tubular member formed of a polymer and is assembled about the balloon. The stent has an initial diameter for delivery into the body and can be expanded to a larger diameter by inflating the balloon.
1. A method of treating a non-vascular cavity or lumen in a mammal, the method comprising:
inserting, into the non-vascular lumen or cavity of the mammal, a polymeric stent comprising magnetic metal particles and having a portion in a collapsed position that can be reverted to an expanded position by heating by magnetic effects following insertion of the polymeric stent; and
heating the inserted stent sufficiently by magnetic effects to revert the portion in the collapsed position to the expanded position.
2. The method of claim 1 , further comprising:
heating the stent having the portion in the expanded position by magnetic effects sufficiently to soften the stent; and
removing the softened stent from the cavity or lumen.
3. The method of claim 1 , wherein the portion is at an end of the stent.
4. The method of claim 3 , wherein the portion in the collapsed position of the stent is at the end of the stent and is flared.
5. The method of claim 1 , wherein at least two portions of the stent have a collapsed position that can be reverted to an expanded position by heating by magnetic effects following insertion, and wherein during the heating by magnetic effects both portions revert to expanded positions.
6. The method of claim 1 , wherein the stent is in the form of a coiled elongated element.
7. The method of claim 1 , wherein the collapsed position that can be reverted to an expanded position following insertion is not an end of the stent.
8. The method of claim 6 , further comprising:
heating the stent by magnetic effects sufficiently to soften the stent; and
removing the softened stent from the cavity or lumen as a substantially uncoiled strand.
9. The method of claim 1 , wherein the heating is performed so that the temperature is less than about 55° C.
10. The method of claim 1 , wherein heating the magnetic metal particles by magnetic effects comprises heating the magnetic metal particles using inductive heating.
11. The method of claim 1 , wherein the lumen is a urethra.
12. The method of claim 1 , wherein the lumen is a biliary duct.
13. The method of claim 1 , wherein the lumen is a cystic duct.
14. The method of claim 1 , wherein the lumen is in the gastrointestinal system.
15. The method of claim 1 , wherein the lumen is in the pulmonary system.
16. The method of claim 1 , wherein the lumen is in the hepatic system.
17. The method of claim 1 , wherein the stent comprises a polymer selected from the group consisting of polynorbornene and copolymers of polynorbornene, polyethylene, styrenic block copolymer elastomers, polymethylmethacrylate, polyurethane, polyisoprene, polycaprolactone and copolymers of polycaprolactone, polylactic acid (PLA) and copolymers of polylactic acid, polyglycolic acid and copolymers of polyglycolic acid, copolymers of PLA and PGA, polyenes, nylons, polycyclooctene, polyvinyl acetate, polyvinylidene fluoride polyvinylchloride (PVC) and blends thereof.
18. The method of claim 1 , wherein the polymeric stent comprises a polymer that is selected from the group consisting of polynorbornene, polycaprolactone, polyenes, nylons, polycyclooctene (PCO), blends of PCO and styrene-butadiene rubber, polyvinyl acetate/polyvinylidinefluoride (PVAc/PVDF), blends of PVAc/PVDF/polymethylmethacrylate (PMMA), polyurethanes, styrene-butadiene copolymers, polyethylene, trans-isoprene, blends of polycaprolactone and n-butylacrylate, POSS polyurethane polymers, PVC, plasticized PVC, and blends thereof.
19. The method of claim 1 , wherein the portion in the collapsed position includes the magnetic meal particles.
20. The method of claim 1 , wherein the inserted stent is heated to a temperature above 37° C. to revert the portion in the collapsed position to the expanded position.
21. The method of claim 20 , wherein the inserted stent is heated to a temperature of between 40° C. and 60° C. to revert the portion in the collapsed position to the expanded position.
22. The method of claim 1 , wherein the polymeric stent includes a polymeric material having a glass transition temperature above 37° C., and wherein the inserted stent is heated to a temperature above 37° C. to revert the portion in the collapsed position to the expanded position.
23. The method of claim 22 , wherein the polymeric material has a glass transition temperature between 40° and 60° C., and wherein the inserted stent is heated to a temperature of between 40° C. and 60° C. to revert the portion in the collapsed position to the expanded position.
24. The method of claim 1 , wherein the polymeric stent includes a polymeric material having a melt temperature above 37° C., and wherein the inserted stent is heated to a temperature above 37° C. to revert the portion in the collapsed position to the expanded position.
25. The method of claim 24 , wherein the polymeric material has a melt temperature of between 40° C. and 60° C., and wherein the inserted stent is heated to a temperature of between 40° C. and 60° C. to revert the portion in the collapsed position to the expanded position.