Methods for improving stent retention on a balloon catheter

• US 9,259,341 B2
• Filed: 02/27/2013
• Issued: 02/16/2016
• Est. Priority Date: 06/19/2006
• Status: Expired due to Fees

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Huang, Bin, Gale, David C., Castro, Daniel
• Primary Examiner(s): Bryant, David
• Assistant Examiner(s): Travers, Matthew P
• Application Number:
  US13/779,636
• Publication Number:
  US 20130269168A1
• Time in Patent Office: 1,084 Days
• US Class Current: 1/1
• CPC Class Codes: A61F 2/9522 Means for mounting a stent or stent-graft onto or into a placement instrument
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• 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 2002/9583 Means for holding the stent on the balloon, e.g. using protrusions, adhesives or an outer sleeve
• CPC Class Codes: A61F 2002/9586 the means being inside the balloon
• CPC Class Codes: B23P 11/005 by expanding or crimping
• CPC Class Codes: Y10T 29/49863 with prestressing of part
• CPC Class Codes: Y10T 29/49913 by constricting outer annulus
• CPC Class Codes: Y10T 29/49925 Inward deformation of aperture or hollow body wall
• CPC Class Codes: Y10T 29/49927 Hollow body is axially joined cup or tube
• CPC Class Codes: Y10T 29/53065 with means to fasten by deformation
• CPC Class Codes: Y10T 29/53987 Tube, sleeve or ferrule

Abstract

A method of crimping a stent on a balloon of a catheter assembly is provided. A polymeric stent is disposed over a balloon in an inflated configuration. The stent is crimped over the inflated balloon to a reduced crimped configuration so that the stent is secured onto the balloon. The balloon wall membrane is wedged or pinched between the strut elements of the stent for increasing the retention of the stent on the balloon.

Claims

1. A method of crimping a stent on a balloon of a catheter assembly, comprising:

providing a polymeric stent disposed over a balloon in an inflated configuration;

crimping the stent over the inflated balloon to a reduced crimped configuration for securing the stent on the balloon;

holding pressure at the reduced crimped configuration for a duration of time prior to a release of pressure; and

releasing pressure in the balloon during the crimping when a compression pressure in the balloon caused by the crimping is higher than a set value.

2. The method of claim 1, wherein the providing comprises:

inserting the balloon in a collapsed configuration into the stent; and

expanding the balloon to the inflated configuration, wherein the inflated configuration is equal to or less than an intended expansion configuration of the balloon.

3. The method of claim 2, further comprising placing the balloon and the stent into a crimping device.

4. The method of claim 3, wherein, after crimping, a membrane or wall of the balloon is disposed between structural elements of the stent.

5. The method of claim 4, wherein expanding the balloon to the inflated configuration comprises inflating the balloon at a pressure of 30 psi.

6. The method of claim 5, wherein the pressure in the balloon is released by a valve.

7. The method of claim 1, wherein the inflated configuration is a configuration which provides for a membrane or wall of the balloon to protrude into gaps between structural elements of the stent.

8. The method of claim 1, wherein subsequent to crimping the stent on the balloon, a membrane or wall of the balloon is pinched and wedged between structural elements of the stent.

9. The method of claim 1, wherein the pressure in the balloon is released by a valve.

10. The method of claim 1, wherein providing the polymeric stent comprises inserting the balloon in a collapsed configuration into the stent and expanding the balloon, and wherein the reduced crimped configuration comprises a larger diameter or size than the collapsed configuration.

11. The method of claim 1, wherein the stent is a biodegradable polymeric stent.

12. The method of claim 1, wherein the stent is a biodegradable polymeric stent with a biodegradable metallic component.

13. The method of claim 1, additionally including applying a solvent to the balloon prior to the providing the stent disposed over the balloon.

14. The method of claim 13, wherein the solvent is acetone.

15. The method of claim 1, wherein the polymeric stent includes a drug coating.

16. The method of claim 1, additionally including applying a balloon softening fluid to the balloon prior to the providing the stent disposed over the balloon.

17. The method of claim 1, wherein the balloon is inflated by a heated fluid.

18. The method of claim 1, wherein the balloon is inflated by a heated fluid having a temperature not greater than 200°

C.

19. The method of claim 1, wherein the balloon is inflated by a heated fluid having a temperature not greater than 150°

C.

20. The method of claim 1, wherein the balloon is inflated by a heated fluid having a temperature not greater than 100°

C.

21. The method of claim 1, wherein the balloon is inflated by a heated fluid having a temperature not greater than 75°

C.

22. A method of crimping a stent on a balloon, comprising the following acts in the order as listed:

(a) providing a stent disposed over a balloon in an inflated configuration.

(b) crimping the stent to a first reduced diameter;

(c) at least partially deflating the balloon to a collapsed configuration smaller than the inner diameter of the stent;

(d) inflating the balloon to at least an inner diameter of the stent; and

(e) crimping the stent to a second reduced diameter.

23. The method of claim 22, wherein the second reduced diameter is the final crimped diameter.

24. The method of claim 22, additionally comprising, following act (e):

(f) at least partially deflating the balloon;

followed by

(g) inflating the balloon to at least an inner diameter of the stent;

followed by

(h) crimping the stent to a third reduced diameter.

25. The method of claim 24, wherein the third reduced diameter is the final crimped diameter.