Implantable, self-expanding prosthetic device

Abstract

A prosthetic device for sustaining a vessel or hollow organ lumen (a stent) has a tubular wire frame ( 1 ) with rows of elongate cells ( 2 ) having a larger axis and a smaller axis. The cells are arranged with the larger axis in the circumferential direction of the frame ( 2 ) and the smaller axis parallel to the axial direction thereof. Each cell is formed by two U-shaped wire sections, and in a plane perpendicular to the longitudinal axis one of the branches of the U-shaped wire sections in one row form together a closed ring shape ( 4 ) which provides the frame ( 1 ) with large radial stiffness. In the axial direction the frame ( 1 ) has only low stiffness so that it easily conforms to the vascular wall even if this deforms due to external loads. The interconnection between the cells ( 2 ) may be flexible.

1 - 54 . (canceled)  
     
     
         55 . A prosthetic device comprising: 
 a flexible, tubular shaped frame of flexibly interconnected cells, each of the cells including first and second U-shaped sections forming together an approximately elongated oval with a larger axis and a smaller axis, wherein the larger axis of the oval is directed in a circumferential direction of the tubular shaped frame and the smaller axis is directed in a direction parallel to a longitudinal axis of the tubular shaped frame, and wherein in a plane perpendicular to the longitudinal axis of the tubular frame, one branch of each U-shaped section in one row together form a closed ring shape.    
     
     
         56 . The prosthetic device of  claim 55  wherein frame comprises a superelastic material.  
     
     
         57 . The prosthetic device of  claim 56  wherein the superelastic material comprises a nickel-titanium alloy.  
     
     
         58 . The prosthetic device of  claim 55  wherein the flexible, tubular shaped frame is self-expanding.  
     
     
         59 . The prosthetic device of  claim 55  wherein adjacent cells in neighboring rows are shifted by a predetermined amount of the larger axis of the oval with respect to each other in the direction of the larger axis.  
     
     
         60 . The prosthetic device of  claim 59  wherein adjacent cells in alternating rows are shifted by the smaller axis of the oval with respect to each other in the direction of the smaller axis.  
     
     
         61 . A prosthetic device comprising: 
 a frame having a flexible tubular shaped body with rows of interconnected cells, the flexible tubular shaped body having a reduced diameter during introduction with a tube or a delivery catheter, each of the cells having two U-shaped sections forming an approximately elongated oval with a larger axis and a smaller axis, wherein adjacent cells in neighboring rows are shifted by half of the larger axis of the oval with respect to each other in the direction of the larger axis, wherein the larger axis of the oval is directed in the circumferential direction of the tubular body and the smaller axis parallel to the axial direction thereof so that in a plane perpendicular to the longitudinal axis of the body, one branch of each U-shaped section in one row forms together a closed ring shape, and wherein adjacent cells in one row are interconnected in a flexible manner at an axially extending portion of the U-shaped sections.    
     
     
         62 . A prosthetic device of  claim 61  wherein the frame comprises a shape memory alloy exhibiting thermally activated shape memory properties.  
     
     
         63 . A prosthetic device of  claim 62  wherein the shape memory alloy comprises a nickel-titanium alloy.  
     
     
         64 . A prosthetic device of  claim 62  wherein the shape memory alloy exhibits superelastic properties.