Stentless Support Structure

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.

What is claimed is: 
     
         1 . A prosthetic heart valve frame that is radially expandable from a compressed configuration to an expanded configuration, comprising: a support portion adapted to anchor against a heart valve annulus, the support portion defining a lumen therethrough; and a wireform portion adapted to support at least one valve leaflet, wherein when the prosthetic valve frame is in the compressed configuration, at least a portion of the wireform portion is positioned within the lumen defined by the support portion, and wherein at least a part of the wireform portion is configured to undergo flexion during pulsatile loading. 
     
     
         2 . The prosthetic heart valve frame according to  claim 1 , wherein in the compressed configuration, at least a portion of the cusps are positioned inside the lumen of the support portion. 
     
     
         3 . The prosthetic heart valve frame according to  claim 1 , wherein in the expanded configuration, the cusps are configured to be spaced apart from the support portion along a longitudinal direction defined by the lumen of the support portion. 
     
     
         4 . The prosthetic heart valve frame according to  claim 1 , wherein an inflow end of the support portion is flared outward in the expanded configuration, the inflow end being opposite the wireform portion. 
     
     
         5 . The prosthetic heart valve of  claim 1  wherein said wireform portion configured to undergo flexion during pulsatile loading facilitates natural and efficient opening and closing of the at least one valve leaflet. 
     
     
         6 . The prosthetic heart valve of  claim 1  wherein said wireform comprises commissural points separated by arcuate portions. 
     
     
         7 . The prosthetic heart valve of  claim 6  wherein said arcuate portions are attached to an inside surface of the support portion. 
     
     
         8 . The prosthetic heart valve of  claim 6  wherein said arcuate portions are attached to an outside surface of said support portion, when said support portion is in said compressed configuration. 
     
     
         9 . The prosthetic heart valve of  claim 1  wherein said support portion comprises a mesh. 
     
     
         10 . The prosthetic heart valve of  claim 9  wherein said support portion folds in on itself when expanding from said compressed configuration. 
     
     
         11 . A method of implanting a prosthetic heart valve, comprising:
 radially compressing a prosthetic heart valve to a compressed configuration, wherein the prosthetic heart valve comprises a support portion configured to anchor the prosthetic heart valve to a patient's native valve and a leaflet-supporting structure;   delivering the compressed prosthetic heart valve to or near a patient's native valve annulus;   positioning the leaflet-supporting structure of the prosthetic heart valve supraannularly to a patient's aortic valve; and,   expanding the prosthetic heart valve to an expanded configuration, wherein the diameter of the prosthetic heart valve in the expanded configuration is greater than the diameter of the prosthetic heart valve in the compressed configuration, and wherein in the compressed configuration at least a portion of the leaflet-supporting structure is positioned within a lumen of the support portion, and in the expanded configuration the leaflet-supporting structure is positioned externally to the lumen of the support portion.   
     
     
         12 . The method according to  claim 11 , wherein the prosthetic heart valve includes a one-piece prosthetic heart valve frame. 
     
     
         13 . The method according to  claim 11 , wherein expanding the prosthetic heart valve effectively anchors the prosthetic heart valve without suturing the valve to the native valve. 
     
     
         14 . The method of  claim 11  further comprising:
 observing said prosthetic heart valve function to control the flow of blood prior to releasing said prosthetic heart valve. 
 
     
     
         15 . The method of  claim 11  wherein expanding the prosthetic heart valve to an expanded configuration comprises causing said support portion to fold in on itself, thereby shortening said support portion and increasing a thickness and radial strength of said support portion. 
     
     
         16 . The method of  claim 11  wherein expanding the prosthetic heart valve comprises:
 pushing a distal segment of said support portion out of a delivery catheter, thereby allowing said distal segment to self-expand; 
 pushing a proximal segment of said support portion into distal segment, said distal segment attached to said leaflet-supporting structure. 
 
     
     
         17 . The method of  claim 16  wherein said step of pushing a proximal segment of said support portion into said distal segment, results in a portion of said proximal segment to remain outside of said distal segment, such that said leaflet-supporting structure is axially spaced from said distal segment when expanded. 
     
     
         18 . The method of  claim 11  wherein said step of expanding the prosthetic heart valve to an expanded configuration results in said support portion to form at least one flared end, said flared end assisting in anchoring said prosthetic heart valve to the native valve without suturing. 
     
     
         19 . The method of  claim 11  wherein delivering the compressed prosthetic heart valve to or near a patient's native valve annulus comprises percutaneously delivering said compressed prosthetic heart valve via a delivery catheter. 
     
     
         20 . The method of  claim 11  wherein expanding the prosthetic heart valve to an expanded configuration comprises allowing said prosthetic heart valve to self-expand.