STENTS AND CATHETERS HAVING IMPROVED STENT DEPLOYMENT

• US 20100070015A1
• Filed: 09/10/2009
• Published: 03/18/2010
• Est. Priority Date: 09/10/2008
• Status: Abandoned Application

• Current Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Original Assignee: ev3, Inc. (Medtronic Plc)
• Inventors: Ladd, Bryan Matthew, Kusleika, Richard, Kallio, Sandra, Schneider, Lucas Tradd, Kravik, Rick
• Application Number:
  US12/556,997
• Publication Number:
  US 20100070015A1
• Time in Patent Office: Days
• US Class Current: 623/1.110
• CPC Class Codes: A61F 2/844 folded prior to deployment
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2002/9505 having retaining means other than an outer sleeve, e.g. male-female connector between stent and instrument
• CPC Class Codes: A61F 2002/9665 with additional retaining means
• CPC Class Codes: A61F 2210/0004 bioabsorbable

Abstract

An implant delivery system and method comprises an implant, for example, a stent, and a delivery catheter. The stent has a scaffold with a coating or a shell that retains the scaffold in a collapsed configuration. The coating or shell is made of a material that dissolves or biodegrades upon exposure to a dissolution or biodegradation media. The stent is used with an implant delivery system which has a catheter with a catheter, wherein the stent is mounted on the catheter shaft. The catheter shaft is configured to be withdrawn through the patient'"'"'s vessel when the scaffold is in its expanded configuration. Advantageously, the implant is thereby prevented from changing length during implant delivery and implant deployment.

Claims

1. A stent for insertion into a body lumen, comprising:

a scaffold having a collapsed and a diametrically expanded configuration; and

a coating or a shell surrounding the scaffold that retains the scaffold in its collapsed configuration, said coating or shell made of a material that dissolves or biodegrades upon exposure to a dissolution or biodegradation media;

wherein the scaffold is expanded from its collapsed to its expanded configuration through exposure of the coating or shell to the dissolution or biodegradation media.

2. The stent of claim 1, wherein the coating comprises a material selected from the group consisting of sugar, carbowax, polyethylene oxide, and poly vinyl alcohol.

3. The stent of claim 1, wherein the coating or shell comprises a bioactive material selected from the group consisting of antirestenotic agents, anti-inflammatory agents, antithrombotic agents, antiatheromatic (antiatheroma) agents, and antioxidative agents.

4. The stent of claim 1, wherein the shell comprises a material selected from the group consisting of sugar, carbowax, polyethylene oxide, poly vinyl alcohol, poly lactic acid (PLA), poly glycolic acid (PGA), poly lactic glycolic acid (PLGA), poly (ε

-caprolactone) copolymers, polydioxanone, poly(propylene fumarate) poly(trimethylene carbonate) copolymers, polyhydroxy alkanoates, polyphosphazenes, polyanhydrides, poly(ortho esters), poly(amino acids), or “

pseudo”

-poly(amino acids).

5. The stent of claim 1, wherein the shell comprises tubing into which the scaffold is inserted, or a film which is wrapped around the compressed scaffold.

6. The stent of claim 5, wherein the shell comprises a longitudinal slit or is perforated.

7. The stent of claim 1, wherein the scaffold is self-expanding.

8. The stent of claim 1, wherein the scaffold is balloon-expandable.

9. An implant delivery system for deploying a stent in a patient'"'"'s vessel, the system comprising:

a catheter having a catheter shaft;

a stent mounted on the catheter shaft, said stent comprising a scaffold having a collapsed configuration and a diametrically expanded configuration; and

a coating or a shell surrounding the scaffold and retaining the scaffold in its collapsed configuration, said coating or shell made of a material that dissolves or biodegrades upon exposure to a dissolution or biodegradation media;

wherein the scaffold is expanded from its collapsed to its expanded configuration through exposure of the coating or shell to the dissolution or biodegradation media and wherein the catheter shaft is configured to be withdrawn through the patient'"'"'s vessel when the scaffold is in its expanded configuration.

10. The system of claim 9, wherein the stent is self-expanding.

11. The system of claim 9, further comprising a slidable tubular sheath surrounding the stent in the collapsed configuration on the catheter shaft, said tubular sheath protecting the coating or a shell from exposure to the dissolution or biodegradation media.

12. The system of claim 9, further comprising an inflatable balloon disposed between the stent and the catheter shaft, said balloon fracturing the coating or shell upon inflation.

13. The system of claim 12, wherein the balloon is sealingly attached to both a proximal end and a distal end of the catheter shaft.

14. The system of claim 12, further comprising a slidable tubular sheath surrounding the stent in the collapsed configuration on the catheter shaft, wherein the balloon is constructed such that a force of friction of the balloon in contact with the stent is greater than a force of friction of the sheath in contact with the stent.

15. A method for delivering a stent to a treatment site, comprising the steps of:

providing an implant delivery system having a stent mounted on a catheter shaft, said stent having a scaffold with a coating or a shell surrounding the scaffold and retaining the scaffold in its collapsed configuration, and a tubular sheath surrounding the stent in the collapsed configuration on the catheter shaft;

advancing the implant delivery system to the treatment site;

withdrawing the tubular sheath to expose the coating or shell to a dissolution or biodegradation media; and

withdrawing the catheter shaft from the treatment site.

16. The method of claim 15, wherein the stent is self-expanding.

17. The method of claim 15, wherein the delivery system further comprises a balloon interposed between the stent and the catheter shaft, the method further comprising the step of inflating the balloon to cause expansion of the stent before withdrawing the catheter shaft.

18. The method of claim 17, wherein inflating the balloon comprises pressurizing a balloon inflation lumen with fluid or gas until a force of sliding friction of the stent against the balloon exceeds a force of sliding friction of the stent against the tubular sheath.

19. A method for delivering a stent to a treatment site, comprising the steps of:

providing an implant delivery system having a stent mounted on a catheter shaft, a balloon interposed between the stent and the catheter shaft, and a tubular sheath surrounding the stent in the collapsed configuration on the catheter shaft;

advancing the implant delivery system to the treatment site;

inflating the balloon to cause expansion of the stent before withdrawing the tubular sheath;

withdrawing the tubular sheath; and

withdrawing the catheter shaft from the treatment site.

20. The method of claim 19, wherein the stent is self-expanding.

21. The method of claim 19, wherein inflating the balloon comprises pressurizing a balloon inflation lumen with fluid or gas until a force of sliding friction of the stent against the balloon exceeds a force of sliding friction of the stent against the tubular sheath.