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 method of delivering a support structure comprising:
positioning a support structure within a target location with a delivery device;
folding a portion of said support structure into itself as said portion is being ejected from said delivery device;
wherein said folding is at least partially effected by acting on a distal portion of said support structure with a pull wire while pushing on a proximal portion.
2. The method of claim 1 wherein folding said support structure into itself comprises folding said distal portion into said proximal portion.
3. The method of claim 1 wherein positioning said support structure within a target location comprises navigating a catheter containing said support structure through the apex of a heart, through the left ventricle and positioning a distal end of the catheter within or near the aortic valve of the heart.
4. The method of claim 1 wherein positioning said support structure within a target location comprises pushing said distal portion out of a delivery catheter distal of said target location.
5. The method of claim 4 wherein folding said support structure into itself comprises folding said distal portion into said proximal portion, said proximal portion being located at said target location.
6. The method of claim 1 wherein positioning said support structure within a target location comprises sliding a delivery catheter containing said support structure over a guidewire leading to said target location.
7. The method of claim 1 wherein said folding said support structure into itself is at least partially effected by a preformed fold formed in said support structure.
8. The method of claim 1 wherein said acting on a distal portion of said support structure with a pull wire while pushing on a proximal portion comprises preventing proximal movement of said support structure with a catheter while pulling proximally with said pull wire.
9. The method of claim 1 wherein acting on a distal portion of said support structure with a pull wire comprises acting on a distal portion of said support structure with a pull wire that passes through at least a portion of said support structure.
10. The method of claim 1 further comprising releasing said support structure.