Recapturable stent with minimum crossing profile

• US 20070043424A1
• Filed: 08/17/2005
• Published: 02/22/2007
• Est. Priority Date: 08/17/2005
• Status: Active Grant

• Current Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Inventors: Pryor, Jack
• Granted Patent: US 7,473,272 B2
• Time in Patent Office: Days
• US Class Current: 623/1.120
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• 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: A61F 2002/91516 the meander having a change in frequency along the band
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/9528 for retrieval of stents
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped

Abstract

A self-expanding stent includes a plurality of segments having an alternating repeating pattern; each of the segments having connected crowns and unconnected crowns, wherein the unconnected crowns can be fully straightened without damage or permanent distortion to the unconnected crowns; and connectors extending between and connecting adjacent connected crowns of adjacent segments. The self-expanding stent catheter has a minimum crossing profile and the stent compressed for deployment therein is recapturable.

Claims

1. A self-expanding stent comprising:

a plurality of segments having an alternating repeating pattern;

each of said segments having connected crowns and unconnected crowns, wherein said unconnected crowns can be fully straightened without damage or permanent distortion to said unconnected crowns;

connectors extending between and connecting adjacent connected crowns of adjacent segments.

2. The self-expanding stent of claim 1 wherein there are two of said unconnected crowns for each of said connected crowns in at least one of said segments.

3. The self-expanding stent of claim 1 wherein said unconnected crowns have an absence of sharp bends.

4. The self-expanding stent of claim 1 wherein said unconnected crowns have a substantial absence of a bend.

5. The self-expanding stent of claim 1 wherein said unconnected crowns have a diameter of 0.007 inches or greater.

6. The self-expanding stent of claim 1 wherein said self-expanding stent comprises a memory metal.

7. The self-expanding stent of claim 1 wherein when said unconnected crowns are pulled straight, said unconnected crowns are subject to an eight percent strain.

8. A method comprising:

stretching a self-expanding stent along a longitudinal axis of said self-expanding stent, wherein prior to said stretching, said self-expanding stent comprises;

a plurality of segments having an alternating repeating pattern;

each of said segments having connected crowns and unconnected crowns, said unconnected crowns comprising smooth curves (or large radius);

connectors extending between and connecting adjacent connected crowns of adjacent segments;

said stretching comprising straightening said unconnected crowns.

9. The method of claim 8 wherein said straightening said unconnected crowns comprises causing said unconnected crowns to extend into a straight position.

10. The method of claim 8 wherein said unconnected crowns are straightened without damage or permanent distortion to said unconnected crowns.

11. The method of claim 8 wherein said stretching is performed until said self-expanding stent is nearly fully stretched along said longitudinal axis.

12. The method of claim 11 wherein when said to self-expanding stent is nearly fully stretched, said segments include straight sections between adjacent connected crowns.

13. The method of claim 12 wherein said straight sections are approximately parallel to said longitudinal axis.

14. The method as claim 12 wherein each of said straight sections when relaxed comprises at least one straightened unconnected crowns.

15. The method of claim 12 wherein each of said straight sections when relaxed comprises two straightened unconnected crowns.

16. A stent delivery system comprising:

an inner member;

a nearly fully stretched self-expanding stent over said inner member, said nearly fully stretched self-expanding stent comprising;

a plurality of segments;

each of said segments comprising connected crowns and straight sections extending between adjacent ones of said connected crowns, said straight sections when relaxed comprising unconnected crowns that have been straightened;

connectors extending between and connecting adjacent connected crowns of adjacent segments; and

a sheath radially constraining said fully stretched self-expanding stent.

17. The stent delivery system of claim 16 further comprising a guide wire extending through a lumen of said inner member.

18. A method comprising:

inserting a stent delivery system into a vessel, said stent delivery system comprising;

a nearly fully stretched self-expanding stent comprising;

a plurality of segments;

each of said segments comprising connected crowns and straight sections extending between adjacent ones of said connected crowns, said straight sections when relaxed comprising unconnected crowns that have been straightened;

connectors extending between and connecting adjacent connected crowns of adjacent segments;

a sheath radially constraining said nearly fully stretched self-expanding stent; and

retracting said sheath to expose at least a first segment of said stent, said first segment of said stent self-curling and radially self-expanding.

19. The method of claim 18 wherein said self-curling comprises returning said unconnected crowns to a smooth curve relaxed configuration.

20. The method of claim 19 wherein said returning said unconnected crowns to a smooth curve relaxed configuration comprises returning said straight sections to a curved relaxed configuration.

21. The method of claim 18 further comprising advancing said sheath to recapture said stent.

22. The method of claim 21 wherein said advancing said sheath comprises pulling said stent straight and into said sheath.

23. The method of claim 22 wherein said stent has an absence of loose ends or other protrusions that cam catch on a distal end of said sheath.

24. The method of claim 22 wherein said pulling said stent straight comprises straightening said unconnected crowns.