Stentless support structure

• US 20060271166A1
• Filed: 05/30/2006
• Published: 11/30/2006
• Est. Priority Date: 05/27/2005
• Status: Active Grant

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Heart Leaflet Technologies, Inc. (Bracco SPA)
• Inventors: Banick, Christopher M., Thill, Gary A., Gainor, John, Wilson, Robert Foster
• Granted Patent: US 8,974,523 B2
• Time in Patent Office: Days
• US Class Current: 623/1.230
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/2418 Scaffolds therefor, e.g. support stents
• CPC Class Codes: A61F 2/2436 Deployment by retracting a sheath
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/001 Figure-8-shaped, e.g. hourglass-shaped
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2250/0039 differing in diameter

Abstract

A stentless support structure capable of being at least partly assembled in situ. The support structure comprises a braided tube that is very flexible and, when elongated, becomes very long and very small in diameter, thereby being capable of placement within a small diameter catheter. The support structure is preferably constructed of one or more thin strands of a super-elastic or shape memory material such as Nitinol. When released from the catheter, the support structure folds itself into a longitudinally compact configuration. The support structure thus gains significant strength as the number of folds increase. This radial strength obviates the need for a support stent. The support structure may include attachment points for a prosthetic valve.

Claims

1. A stentless support structure comprising:

at least one strand braided to form a tubular structure having a first configuration and a second configuration;

whereby in the first configuration, the tubular structure includes;

a first end and a second end;

an elongate body between the first end and the second end;

whereby in the second configuration, the tubular structure includes at least one fold creating a section of the body having more than one ply.

2. The stentless support structure of claim 1 wherein said at least one fold shortens the body longitudinally in the second configuration.

3. The stentless support structure of claim 1 wherein said tubular structure comprises a single ply in the first configuration.

4. The stentless support structure of claim 1 wherein said tubular structure comprises a multi-ply section in the second configuration.

5. The stentless support structure of claim 1 whereby, in the first configuration, said stentless support structure is capable of being housed with a lumen of a 20 Fr catheter.

6. The stentless support structure of claim 1 wherein said first end comprises an unbraided end.

7. The stentless support structure of claim 1 wherein said second end comprises a folded end.

8. The stentless support structure of claim 1 wherein said first end comprises a plurality of commissural attachment points.

9. The stentless support structure of claim 1 wherein said first end comprises a plurality of unbraided strands combined to form at least one commissural attachment point.

10. The stentless support structure of claim 1 wherein said plurality of strands braided together to form a tubular structure comprises a plurality of strands of a first diameter and at least one fiber of a second diameter larger than the first diameter.

11. The stentless support structure of claim 1 wherein said first end comprises a wire form having a plurality of commissural attachment points.

12. The stentless support structure of claim 1 further comprising a lining in an inner wall of the tubular structure.

13. The stentless support structure of claim 4 further comprising a lining sandwiched between said first and second ply.

14. A method of implanting a support structure comprising:

(a) percutaneously delivering a support structure in an elongated state inside a catheter to a target site;

(b) retracting said catheter relative to said support structure such that a first portion of said support structure expands against native tissue of the target site;

(c) advancing a second portion of said support structure into said first portion such that a first fold is created between said first and second portions;

(d) retracting said catheter relative to said second portion until said second portion expands against an interior of said first portion, thereby creating a multi-layered support structure;

(e) repeating steps (c) and (d) if additional layers are desired;

(f) releasing the support structure and removing said catheter from the target site.

15. The method of claim 14 wherein step (b) comprises retracting said catheter relative to said support structure such that a first portion of said support structure expands against native tissue of the target site, said first portion including a distal end and a proximal end, the distal end including a cuff.

16. The method of claim 15 wherein step (b) comprises:

retracting said catheter relative to said support structure until said cuff expands and contacts the native tissue of the target site;

pulling said cuff in a proximal direction until the cuff contacts a distal side of a native valve;

retracting said catheter relative to said support structure until said proximal side of said first portion expands and contacts the native tissue of the target site.

17. A method of supporting native tissue of a target site comprising:

introducing material into the target site lacking sufficient structural integrity to support the native tissue;

building a supporting structure using said material in situ.

18. The method of claim 17 wherein introducing material into the target site lacking sufficient structural integrity to support the native tissue comprises introducing a braided, elongate mesh tube.

19. The method of claim 18 wherein introducing a braided, elongate mesh tube comprises introducing a braided, elongate mesh tube of at least one strand of a material selected from the group consisting of super-elastic and shape memory.

20. The method of claim 19 wherein introducing a braided, elongate mesh tube of at least one strand of a material selected from the group consisting of super-elastic and shape memory comprises introducing a braided, elongate mesh tube of a single Nitinol strand having been preformed to a folded configuration.

21. The method of claim 17 wherein building a supporting structure using said material in situ comprises folding said material upon itself until sufficient structural integrity to support the native tissue is attained.

22. The method of claim 21 wherein folding said material upon itself until sufficient structural integrity to support the native tissue is attained comprises:

introducing a delivery catheter to the target site containing said material in an elongated form;

exposing a first length of said material, thereby allowing said first length of material to expand;

advancing a second length of said material inside said first length;

exposing said second length of said material, thereby allowing said second length to expand against an inside surface of said first length.

23. The method of claim 22 further comprising:

advancing a third length of said material inside said second length;

exposing said third length of said material, thereby allowing said third length to expand against an inside surface of said second length.

24. A stentless support structure comprising:

a strand braided to form a tubular structure having a first configuration and a second configuration;

whereby in the first configuration, the tubular structure includes;

a first end and a second end;

an elongate tubular body between the first end and the second end;

whereby in the second configuration, the tubular structure includes;

at least one fold shortening the body and creating a section of the body having at least twice as many ply as the elongate body in the extended configuration.

25. A method of implanting a support structure comprising:

(a) percutaneously delivering a support structure in an elongated state inside a catheter to a target site;

(b) retracting said catheter relative to said support structure such that a first portion of said support structure expands outside of said catheter;

(c) advancing a second portion of said support structure into said first portion such that a first fold is created between said first and second portions;

(d) retracting said catheter relative to said second portion until said second portion expands against an interior of said first portion, thereby creating a multi-layered support structure;

(e) repeating steps (c) and (d) if additional layers are desired;

(f) releasing the support structure and removing said catheter from the target site.

26. The method of claim 25 wherein step (b) comprises retracting said catheter relative to said support structure such that a first portion of said support structure expands against native tissue of the target site, said first portion including a distal end and a proximal end, the distal end including a cuff.

27. The method of claim 26 wherein step (b) comprises:

retracting said catheter relative to said support structure until said cuff expands and contacts the native tissue of the target site;

pulling said cuff in a proximal direction until the cuff contacts a distal side of a native orifice;

retracting said catheter relative to said support structure until said proximal side of said first portion expands and contacts the native tissue of the target site.

28. The method of claim 25 wherein retracting said catheter relative to said support structure such that a first portion of said support structure expands outside of said catheter comprises retracting said catheter relative to said support structure such that a first portion of said support structure expands outside of said catheter against native tissue of the target site.

29. The method of claim 25 wherein step (b) comprises retracting said catheter relative to said support structure such that a first portion of said support structure expands against native tissue belonging to the group consisting of valve tissue, blood vessel tissue, and heart tissue.