Expandable medical device with beneficial agent delivery mechanism

Abstract

An expandable tissue supporting device of the present invention employs ductile hinges at selected points in the expandable device. When expansion forces are applied to the device as a whole, the ductile hinges concentrate expansion stresses and strains in small well defined areas. The expandable medical device including ductile hinges provides the advantages of low expansion force requirements, relatively thick walls which are radio-opaque, improved crimping properties, high crush strength, reduced elastic recoil after implantation, and control of strain to a desired level. The expandable tissue supporting device includes a plurality of elongated beams arranged in a cylindrical device and connected together by a plurality of ductile hinges. Although many ductile hinge configurations are possible, the ductile hinges preferably have a substantially constant hinge cross sectional area which is smaller than a beam cross sectional area such that as the device is expanded from a first diameter to a second diameter, the ductile hinges experience plastic deformation while the beams are not plastically deformed.

1 - 26 . (canceled)  
     
     
         27 . An expandable medical device comprising: 
 first and second cylindrical tubes each formed of a plurality of essentially rigid structures interconnected by ductile hinges, the first and second cylindrical tubes expandable from a first diameter to a second diameter, wherein radial expansion or compression of the first and second cylindrical tubes is accommodated by the ductile hinges and the essentially rigid structures are substantially undeformed during expansion from the first diameter to the second diameter; and    a plurality of bridging elements connecting the first and second cylindrical tubes, each of the bridging elements attached at a first end to the essentially rigid structures of the first cylindrical tube and at a second end to the essentially rigid structures of the second cylindrical tube, the plurality of bridging elements having a curved shape and allowing the expandable medical device to bend axially when passing through the vasculature.    
     
     
         28 . The device of  claim 27 , wherein the bridging elements are S-shaped bridging elements.  
     
     
         29 . The device of  claim 28 , wherein the S-shaped bridging elements have an undulating shape extending through greater than 360 degrees.  
     
     
         30 . The device of  claim 27 , wherein the bridging elements are located at a diagonal orientation such that a line extending through the attachment points at the first and second ends of each of the bridging elements is located at an angle with respect to a longitudinal axis of the cylindrical tubes.  
     
     
         31 . The device of  claim 30 , wherein all the bridging elements interconnecting two adjacent ones of the cylindrical tubes are located at the same diagonal orientation.  
     
     
         32 . The device of  claim 27 , wherein the bridging elements have a width less than a width of the essentially rigid structures.  
     
     
         33 . The device of  claim 27 , wherein the essentially rigid structures include longitudinal struts and circumferential links.  
     
     
         34 . An expandable medical device comprising: 
 a plurality of cylindrical tubes each formed of a plurality of adjacent struts interconnected by ductile hinges to circumferential links, the plurality of cylindrical tubes expandable from a first diameter at which the adjacent struts are substantially parallel to one another to a second diameter at which the adjacent struts form substantially V-shapes, wherein the struts and circumferential links are substantially undeformed during expansion from the first diameter to the second diameter; and    a plurality of bridging elements connected between the circumferential links in adjacent cylindrical tubes.    
     
     
         35 . The device of  claim 34 , wherein the bridging elements are S-shaped bridging elements.  
     
     
         36 . The device of  claim 35 , wherein the S-shaped bridging elements have an undulating shape extending through greater than 360 degrees.  
     
     
         37 . The device of  claim 34 , wherein the bridging elements are located at a diagonal orientation such that a line extending through attachment points between the bridging elements and the circumferential links at opposite ends of each of the bridging elements is located at an angle with respect to a longitudinal axis of the cylindrical tubes.  
     
     
         38 . The device of  claim 37 , wherein all the bridging elements interconnecting two adjacent ones of the cylindrical tubes are located at the same diagonal orientation.  
     
     
         39 . The device of  claim 34 , wherein the bridging elements have a width less than a width of the essentially rigid structures.