Flexible hoop and link sheath for a stent delivery system

• US 6,428,566 B1
• Filed: 10/31/2000
• Issued: 08/06/2002
• Est. Priority Date: 10/31/2000
• Status: Active Grant

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Holt, Vivianne M.
• Primary Examiner(s): Nguyen, Dinh X.
• Assistant Examiner(s): MILLER, CHERYL L
• Application Number:
  US09/703,859
• Time in Patent Office: 644 Days
• Field of Search: 604/523, 604/524, 604/526, 604/525, 604/534, 604/535, 600/585, 600/139, 600/141, 600/146-151, 623/1.11, 623/1.23, 606/108
• 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 2/958 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

Abstract

A delivery sheath including a series of longitudinally spaced apart retainer rings interconnected by flexible links. This configuration provides for sections of reduced cross-sectional area along the length of the sheath, thus increasing flexibility in those sections and in the overall sheath. The reduction of the cross-sectional area of the sheath also effectively reduces the area of contact between the inside surface of the sheath and the outside surface of the compressed stent. This reduction in contact area serves to reduce the frictional force generated as the sheath is retracted relative to the stent during deployment.

Claims

1. A flexible stent delivery system, comprising:

an elongated flexible inner member having a stent mounting region for receiving a stent in a delivery configuration;

a deployment sheath including a plurality of retainer rings spaced longitudinally apart with flexible links connecting the rings together, the deployment sheath being coaxially disposed over the stent mounting region to form an annular space for mounting the stent in the delivery configuration; and

means for moving the deployment sheath longitudinally along the inner member.

2. The flexible stent delivery system of claim 1, wherein:

the retainer rings have an inner surface and and outer surface and include low friction material on the inner surface for providing low frictional contact with the stent.

3. The flexible stent delivery system of claim 1, wherein:

the retainer rings and links are constructed from metal.

4. The flexible stent delivery system of claim 1, wherein:

the retainer rings and links are constructed from a polymer material.

5. The flexible stent delivery system of claim 1, wherein:

the retainer rings and links are constructed from a fiber material.

6. The flexible stent delivery system of claim 1, wherein:

the deployment sheath includes three retainer rings.

7. The flexible stent delivery system of claim 1, wherein:

the links are configured with a circular cross-section.

8. The flexible stent delivery system of claim 1, wherein:

the retainer rings are configured to cooperate with the stent in the compressed delivery configuration to exert a predetermined frictional force resisting relative movement therebetween; and

the links are configured with sufficient column strength to maintain the retainer rings spaced longitudinally apart as the delivery apparatus is advanced distally within a body lumen.

9. The flexible stent delivery system of claim 1, wherein:

the hoop strength of the retainer rings and the flexible links is sufficient to maintain the stent in the delivery configuration; and

the longitudinal lengths of the retainer rings and links in combination are sufficient to cover the length of the stent.

10. The flexible stent delivery system of claim 1, wherein:

means for moving the deployment sheath is an outer tubular member coaxially disposed and moveable over the inner member that is attached to the deployment sheath.

11. The flexible stent delivery system of claim 10, wherein:

the links are symmetrically arranged about the longitudinal axis of the outer tubular member and are longitudinally disposed between the retainer rings.

12. The flexible stent delivery system of claim 10, wherein:

the links include filaments symmetrically arranged about the lonitudinal axis of the outer tubular member and continuous from one end of the deployment sheath to an opposite end.

13. The flexible stent delivery system of claim 1, wherein:

the stent mounting region is an expandable member and deployment of the stent is achieved by expansion of the expandable member.

14. The flexible stent delivery system of claim 1, wherein:

the flexible links are disposed to contract the stent and the retainer rings are placed around the flexible links.

15. The flexible stent delivery system of claim 10, wherein:

the deployment sheath has a diameter greater than the diameter of the outer tubular member.

16. A flexible sheath for use in conjunction with a stent delivery apparatus comprising:

a plurality of longitudinally spaced apart retainer rings; and

flexible links connecting the retainer rings together;

the sheath slidably movable in a longitudinal direction about a stent.

17. The flexible sheath of claim 16, wherein:

the retainer rings have an inner surface and an outer surface and are configured with low friction material on the inner surface for low frictional contact with the stent.

18. The flexible sheath of claim 16, wherein:

the retainer rings and links are constructed from metal.

19. The flexible sheath of claim 16, wherein:

the retainer rings and links are constructed from a polymer material.

20. A flexible sheath of claim 16, wherein:

the retainer rings and links are constructed from a fiber material.

21. The flexible sheath of claim 16 that includes:

three retainer rings.

22. The flexible sheath of claim 16, wherein:

the links are configured with a circular cross-section.

23. The flexible sheath of claim 16, wherein:

the links are configured with sufficient column strength to maintain the position of the retainer rings relative to the stent as the stent delivery apparatus is advanced distally within a body lumen; and

the links are configured with sufficient tensile strength to enable the retainer rings to move proximally to deploy the stent.

24. The flexible sheath of claim 16, wherein:

the links are symmetrically arranged about the longitudinal axis of the sheath and are longitudinally disposed on an inner surface of the retainer rings.

25. The flexible sheath of claim 16, wherein:

the links include filaments symmetrically arranged about the longitudinal axis of the sheath that are continuous from one end of the sheath to an other end.