Stentless support structure
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.
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:
an elongate body;
at least one unfolded preformed fold in the elongate body dividing the elongate body into at least a first portion and a second portion;
whereby in the second configuration, the at least one preformed fold is folded, causing the second portion to invert into the first portion, thereby 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 tubular structure comprises an unbraided end.
7. The stentless support structure of claim 1 wherein said tubular structure comprises a folded end.
8. The stentless support structure of claim 6 wherein said unbraided end comprises a plurality of commissural attachment points.
9. The stentless support structure of claim 1 wherein said tubular structure 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 further comprising a wire form attached to an end of said tubular structure and 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 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 that causes one portion of the elongate body to invert into another portion of the elongate body, thereby 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.