Temporary stent and method of use

• US 5,716,410 A
• Filed: 12/22/1995
• Issued: 02/10/1998
• Est. Priority Date: 04/30/1993
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Buscemi, Paul, Wang, Lixiao, Hastings, Roger, Tay, Sew-Wah
• Primary Examiner(s): Milano, Michael J.
• Application Number:
  US08/577,089
• Time in Patent Office: 781 Days
• Field of Search: 623/1, 623/12, 606/27, 606/32, 606/78, 606/108, 606/191, 606/198, 604/113, 604/280, 604/281, 604/282
• US Class Current: 606/191
• 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 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2210/0033 electrically, e.g. heated by resistor
• CPC Class Codes: A61F 2230/0017 Angular shapes
• CPC Class Codes: A61M 2025/0058 having an electroactive polymer material, e.g. for steering purposes, for control of flexibility, for locking, for opening or closing
• CPC Class Codes: A61M 2025/1004 Balloons with folds, e.g. folded or multifolded
• CPC Class Codes: A61M 25/1027 Making of balloon catheters

Abstract

A temporary stent comprises a coil of tubular thermoplastic material and a heating element inside the tubular material, or a film with a metal film resistive heating element coated thereon. A method of temporarily supporting the wall of a vessel comprises the steps of inserting a thermoplastic body having a first outer dimension less than the inside dimension of the vessel into the vessel to the desired support position; heating the thermoplastic above its softening transition temperature and expanding it to a second outer dimension larger than its first outer dimension; cooling the thermoplastic body to below its softening transition temperature while at its second outer dimension; allowing the cooled thermoplastic body to temporarily support the vessel; heating the thermoplastic above its softening transition temperature to soften the thermoplastic; and removing the softened thermoplastic body from the vessel.

Claims

1. A temporary stent for supporting a region of a patient'"'"'s vessel comprising:

an elongate shall having a proximal end and a distal end; and

a stenting portion connected to the distal end of said elongate shaft, said stenting portion being circumferentially continuous along its entire length and comprising a resistance wire inside said stenting portion, said stenting portion further comprising thermoplastic polymeric material which is rigid at body temperature and deforms at an elevated temperature greater than body temperature but less than about 100°

C., said stenting portion being configured such that at body temperature the stent provides vessel support and at said elevated temperature said stenting portion deforms from said support configuration to a second, smaller removal configuration for transluminal withdrawal from the vessel.

2. The temporary stent of claim 1 wherein the stenting portion comprises a polymer with a metal film coating, the metal film coating comprising a resistive heat element.

3. The temporary stent of claim 1 wherein the thermoplastic comprises a polymer with a heat-set memory.

4. The temporary stent of claim 3 wherein the stenting portion is made of a tube coiled in a helix, the helix having a heat-set diameter smaller than the diameter of the helix in its support configuration.

5. A temporary stent comprising:

a) a coil of tubular thermoplastic polymeric material having a glass transition temperature greater than body temperature but less than about 100°

C.; and

b) a heating element inside said tubular thermoplastic polymeric material, whereby the coil of thermoplastic polymeric material deforms in response to heat generated by the heating element.

6. The temporary stent of claim 5 wherein the thermoplastic material comprises shape-memory polyurethane having a glass transition temperature of about 45°

-55°

C.

7. The temporary stent of claim 5 further comprising a withdrawal element connected to the stent of sufficient length to extend proximally out of a patient'"'"'s body when the stent is transluminally deployed to temporarily support a vessel in the patient'"'"'s body.

8. A temporary stent comprising;

a) a coil of tubular thermoplastic polymeric material having a glass transition temperature greater than body temperature but less than about 100°

C.; and

b) an electrical resistance heating element inside said tubular thermoplastic polymeric material, the coil of thermoplastic polymeric material being adapted to deform in response to heat generated by the heating element.

9. A temporary stent comprising:

a) a coil of tubular thermoplastic polymeric material having a glass transition temperature greater than body temperature but less than about 100°

C., said tubular material having holes in a wall thereof spaced and sized so as to allow drug delivery through said wall to a vessel during temporary stenting; and

b) a heating element inside said tubular thermoplastic polymeric material, the coil of thermoplastic polymeric material being adapted to deform in response to heat generated by the heating element.

10. A temporary stent comprising:

a) a coil of tubular thermoplastic polymeric material having a glass transition temperature greater than body temperature but less than about 100°

C.. said tubular material further comprising a semi-permeable material to allow drug delivery through a wall of the tubular member to a vessel during temporary stenting; and

b) a heating element inside said tubular thermoplastic polymeric material, the coil of thermoplastic polymeric material being adapted to deform in response to heat generated by the heating element.

11. A temporary stent comprising:

a) a coil of tubular thermoplastic polymeric material having a glass transition temperature greater than body temperature but less than about 100°

C.; and

b) a heating element inside said tubular thermoplastic polymeric material, said heating element comprising a wire, at least a portion of which is insulated, wherein the coil of thermoplastic polymeric material is adapted to deform in response to heat generated by the heating element, and wherein the tubular thermoplastic material contains holes which allow migration of ionized drug from the stent to surrounding tissues upon application of a voltage applied between said wire and the tissue.

12. A stent, said stent being circumferentially continuous along its entire length and comprising thermoplastic polymeric tubing containing an electrical resistance heating element inside the tubing, whereby heat is applied to the thermoplastic polymeric tubing and the thermoplastic polymeric tubing deforms from a support configuration to a second smaller removal configuration, in response to heat generated by the heating element.

13. The stent of claim 12 wherein the stent comprises a polymer with a metal film coating, the metal film coating comprising a resistive heat element.

14. The stent of claim 12 wherein the thermoplastic comprises a polymer with a heat-set memory.

15. The stent of claim 14 wherein the stent is made of a tube coiled in a helix, the helix having a heat-set diameter smaller than the diameter of the helix in its support configuration.

16. A temporary stent for supporting a region of a patient'"'"'s vessel comprising:

an elongate shaft having a proximal end and a distal end; and

a circumferentially continuous stenting portion connected to the distal end of said elongate shaft, said stenting portion comprising thermoplastic polymeric material with a heat-set memory, said thermoplastic polymeric material being rigid at body temperature and adapted to deform at an elevated temperature greater than body temperature but less than about 100°

C., said stenting portion comprising, in its support configuration, a film wrapped to form a tube, and when heated to said elevated temperature, contracts to a smaller, heat-set size, said stenting portion being configured such that at body temperature the stent provides vessel support and at said elevated temperature said stenting portion is adapted to deform from said support configuration to a second, removal configuration for transluminal withdrawal from the vessel.

17. A temporary stent for supporting a region of a patient'"'"'s vessel comprising:

an elongate shaft having a proximal end and a distal end; and

a circumferentially continuous stenting portion connected to the distal end of said elongate shaft, said stenting portion comprising a thin wall tube of thermoplastic polymeric material with a heat-set memory, said thermoplastic polymeric material being rigid at body temperature and adapted to deform at an elevated temperature greater than body temperature but less than about 100°

C., said stenting portion being configured such that at body temperature the stent provides vessel support and at said elevated temperature said stenting portion is adapted to deform from said support configuration to a second, removal confirmation for transluminal withdrawal from the vessel, and wherein said stenting portion when heated to said elevated temperature, contracts to a folded star shape.

18. A temporary stent comprising:

a) a coil of tubular thermoplastic polymeric material having a glass transition temperature greater than body temperature but less than about 100°

C.; and

b) a heating element inside said tubular thermoplastic polymeric material, said heating element comprising a metal film, the coil of thermoplastic polymeric material being adapted to deform in response to heat generated by the heating element.