Rapid exchange delivery system for self-expanding stent

• US 20030028235A1
• Filed: 07/31/2001
• Published: 02/06/2003
• Est. Priority Date: 07/31/2001
• Status: Active Grant

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Tarapata, Christopher J., McIntosh, Winnette S.
• Granted Patent: US 6,679,909 B2
• Time in Patent Office: Days
• US Class Current: 623/1.11
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of 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

Abstract

A catheter assembly is provided having an inner member and an outer member extending along a longitudinal axis, the inner member and the outer member having a coaxial configuration and dimensioned for relative axial movement. The outer member has a wall defining a longitudinal slot; a leaf spring is connected to the inner member, the leaf spring being adapted to engage with the longitudinal slot so as to maintain rotational alignment between inner member and outer member.

Claims

1. A catheter assembly comprising:

an elongated catheter having an inner member and an outer member extending along a longitudinal axis, the inner member and the outer member having a coaxial configuration and dimensioned for relative axial movement, and wherein the outer member has a wall defining a longitudinal slot;

a leaf spring connected to the inner member and being adapted to engage with the longitudinal slot so as to maintain rotational alignment between inner member and outer member.

2. The catheter assembly of claim 1 wherein the leaf-spring has opposing ends, further comprising a tubular sleeve defining a lumen, the ends of the leaf-spring being positioned within the sleeve lumen and the sleeve being positioned externally around and coaxially aligned with the inner member.

3. The catheter assembly of claim 2 wherein the sleeve is attached to the inner member by friction fit.

4. The catheter assembly of claim 2 wherein the sleeve is attached to the inner member by adhesive.

5. The catheter assembly of claim 2 wherein the sleeve is attached to the inner member by heat welding.

6. The catheter assembly of claim 1 wherein the sleeve is attached to the inner member by laser welding.

7. The catheter assembly of claim 1 wherein the leaf-spring is adapted to flexibly deform sufficiently to disengage from the slot and allow relative axial movement between inner member and outer member.

8. The catheter assembly of claim 1 wherein the leaf-spring is made of a nickel-titanium alloy.

9. The catheter assembly of claim 1 wherein the leaf-spring is made of a chromium-cobalt-nickel alloy.

10. The catheter assembly of claim 1 wherein the leaf-spring in short cross section is generally rectangular.

11. The catheter assembly of claim 1 wherein the leaf-spring in short cross section is generally non-rectangular.

12. The catheter assembly of claim 11 wherein the leaf-spring in short cross section is generally “

V”

shaped.

13. The catheter assembly of claim 11 wherein the leaf-spring in short cross section is generally “

U”

shaped.

14. The catheter assembly of claim 1 wherein the outer member has a wall, the thickness of the wall adjacent the longitudinal edges of the slot being greater than the average thickness of the wall over the length of the outer member.

15. The catheter assembly of claim 1 wherein the slot is formed in the outer member wall by laser cutting.

16. The catheter assembly of claim 1 wherein the slot is formed in the outer member wall by a sharp edge.

17. A method of implanting a stent in a body lumen comprising:

selecting a delivery assembly having an inner member and an outer member extending along a longitudinal axis, the inner member and the outer member having a coaxial configuration and dimensioned for relative axial movement, and wherein the outer member defines a longitudinal slot and the inner member has a leaf spring adapted to engage with the longitudinal slot so as to maintain rotational alignment between inner member and outer member;

inserting a guide wire into a lumen of the catheter; and

advancing the guide wire through the lumen so that the guide wire encounters the leaf-spring and advances through the slot.

18. The method of claim 17 comprising the further step of sliding the outer member distally relative to the inner member.

19. The method of claim 18 wherein the catheter is so adapted that sliding the outer member distally relative to the inner member disengages the leaf-spring from the slot.

20. A method of assembling a delivery catheter having an inner member and an outer member extending along a longitudinal axis, the inner member and the outer member having a coaxial configuration and dimensioned for relative axial movement, and wherein the outer member defines a longitudinal slot and the inner member has a leaf spring adapted to engage with the longitudinal slot so as to maintain rotational alignment between inner member and outer member, comprising the steps:

selecting a leaf spring with opposing ends separated by a center portion;

selecting a tubular sleeve having a wall defining a lumen;

inserting the ends of the leaf spring through the wall of the sleeve so that the ends are positioned within the lumen and the center portion of the leaf-spring is positioned without the lumen; and

then

sliding the sleeve over the inner member to a desired position on the inner member.

21. The method of claim 20 comprising the further step of fixing the sleeve to the inner member by laser welding.

22. The method of claim 20 comprising the further step of fixing the sleeve to the inner member by adhesive.

23. The method of claim 20 comprising the further step of fixing the sleeve to the inner member by heat welding.

24. The method of claim 20 comprising the further step of heating the sleeve prior to sliding it over the inner member so as to achieve a friction fit between sleeve and inner member.