Expandable Tip Delivery System and Method

• US 20080255652A1
• Filed: 04/12/2007
• Published: 10/16/2008
• Est. Priority Date: 04/12/2007
• Status: Active Grant

• Current Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Inventors: Thomas, Richard, Thomas, Charles, Gray, David, Chang, Janelle, Iftekhar, Arif, O'Leary, Aidan
• Granted Patent: US 8,133,266 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
• CPC Class Codes: A61M 2025/0681 Systems with catheter and outer tubing, e.g. sheath, sleeve or guide tube
• CPC Class Codes: A61M 25/0074 Dynamic characteristics of the catheter tip, e.g. openable, closable, expandable or deformable
• CPC Class Codes: A61M 25/04 in the body, e.g. expansible A61M25/10, A61M16/0488 take precedence

Abstract

A method of deploying a stent-graft in a curved vessel includes deploying an expandable tip to center a proximal end of the catheter containing a stent-graft in the curved vessel. A sheath is retracted to expose the stent-graft and the stent-graft self-expands into the curved vessel. By centering the catheter containing the stent-graft prior to deployment with the expandable tip, the accuracy of stent graft placement within the curved vessel is improved.

Claims

1. An expandable tip stent-graft delivery system comprising:

an expandable tip member comprising;

a plurality of splines, said splines comprising;

tip petals;

runners; and

elbows connecting said tip petals to said runners, said tip petals collectively forming an expandable tip of said expandable tip member.

2. The expandable tip stent-graft delivery system of claim 1 wherein said splines comprising long narrow strips of material selected from the group consisting of nitinol, stainless steel, and polymer.

3. The expandable tip stent-graft delivery system of claim 1 wherein distal ends of said splines are connected to one another to form a distal end of said expandable tip.

4. The expandable tip stent-graft delivery system of claim 3 wherein said distal end of said expandable tip comprises a guide wire opening.

5. The expandable tip stent-graft delivery system of claim 1 wherein a first spline of said plurality of splines comprises a first tip petal of said plurality of tip petals, a first runner of said plurality of runners, and a first elbow of said plurality of elbows, said first runner being connected to said first tip petal by said first elbow.

6. The expandable tip stent-graft delivery system of claim 1 wherein said tip petals extend proximally from a distal end of said expandable tip to said elbows.

7. The expandable tip stent-graft delivery system of claim 6 further comprising a handle, said runners extending proximally from said elbows to said handle.

8. The expandable tip stent-graft delivery system of claim 7 wherein said handle comprises a grip and screw threads, said grip being coupled to said runners and threadably engaged with said screw threads.

9. The expandable tip stent-graft delivery system of claim 8 wherein rotation of said grip causes axial translation of said runners.

10. The expandable tip stent-graft delivery system of claim 7 further comprising:

a stent-graft; and

a sheath radially constraining said stent-graft.

11. The expandable tip stent-graft delivery system of claim 33 wherein rotation of said grip causes axial translation of said sheath.

12. The expandable tip stent-graft delivery system of claim 1 wherein said expandable tip is in its collapsed configuration, said expandable tip comprising a tapered outer surface.

13. The expandable tip stent-graft delivery system of claim 12 wherein said tip petals have a minimum width at a distal end of said expandable tip and gradually increase in width proximally to have a maximum width at said elbows.

14. The expandable tip stent-graft delivery system of claim 12 wherein said tip petals are in contact with one another substantially along an entire length of said tip petals.

15. The expandable tip stent-graft delivery system of claim 1 wherein said runners have a substantially uniform width.

16. The expandable tip stent-graft delivery system of claim 1 wherein said runners have flared ends at distal ends at said runners.

17. The expandable tip stent-graft delivery system of claim 1 wherein said elbows have a smooth outer edge between said tip petals and said runners.

18. The expandable tip stent-graft delivery system of claim 1 further comprising an inner member, said expandable tip being seated on a distal end of said inner member.

19. The expandable tip stent-graft delivery system of claim 18 wherein said inner member radially constrains said expandable tip when said expandable tip is in its collapsed configuration.

22. The expandable tip stent-graft delivery system of claim 1 further comprising:

an inner member defining a lumen therein through which said runners extend;

a sheath defining a lumen therein through which said inner member extends; and

a stent-graft radially constrained in an annular space between said sheath and said inner member.

33. The expandable tip stent-graft delivery system of claim 10,

wherein said handle further comprises a grip and screw threads, said grip being coupled to said sheath and threadably engaged with said screw threads.

34. The expandable tip stent-graft delivery system of claim 1 wherein said elbows are hinged between said tip petals and said runners.

20. The expandable tip stent-graft delivery system of 19 wherein said expandable tip is released from said inner member when said expandable tip is in its relaxed configuration.

21. The expandable tip stent-graft delivery system of claim 20 wherein said expandable tip has a greater outer diameter in its relaxed configuration than in its collapsed configuration.

23. An expandable tip stent-graft delivery system comprising:

an inner member;

an expandable tip mounted on a distal end of said inner member, said expandable tip comprising a plurality of tip petals; and

a guide wire member having a distal end connected to a distal end of said expandable tip.

24. The expandable tip stent-graft delivery system of claim 23 wherein retraction of said guide wire member causes said tip petals to extend radially outwards increasing the overall diameter of said expandable tip.

25. A method of deploying a stent-graft in a vessel with an expandable tip stent-graft delivery system, said method comprising:

deploying an expandable tip of said expandable tip stent-graft delivery system to center a distal end of a catheter containing said stent-graft in said vessel;

retracting a sheath of said expandable tip stent-graft delivery system to expose said stent-graft, wherein said stent-graft self-expands into said vessel upon said retracting; and

collapsing said expandable tip.

26. The method of claim 25 wherein said deploying an expandable tip comprises advancing runners coupled to said expandable tip through an inner member of said expandable tip stent-graft delivery system.

27. The method of claim 26 wherein said inner member radially constrains said expandable tip prior to said deploying an expandable tip, wherein said advancing runners causes said inner member to release said expandable tip.

28. The method of claim 27 wherein said expandable tip self-expands upon said release.

29. The method of claim 26 wherein said collapsing said expandable tip comprises retracting said runners through said inner member.

30. The method of claim 29 wherein said retracting said runners causes said inner member to collapse said expandable tip.

31. The method of claim 25 wherein said deploying said expandable tip comprises retracting a guide wire member coupled to said expandable tip through an inner member of said expandable tip stent-graft delivery system.

32. The method of claim 31 wherein said retracting a guide wire member compresses said expandable tip longitudinally between a proximal end and distal end of said expandable tip.