Micro-porous mesh stent with hybrid structure

Abstract

A prosthesis for treating a body passage includes a micro-porous tubular element and a support element. The tubular element is formed from a thin-walled sheet having a wall thickness of 25 micrometers or less, preferably a coiled-sheet exhibiting temperature-activated shape memory properties. The mesh pattern includes a plurality of openings in the sheet having a maximum dimension of not more than about 200 micrometers, thereby acting as a filter trapping embolic material while facilitating endothelial growth therethrough. The support element includes a plurality of struts, preferably having a thickness of 100-150 micrometers. The support element is preferably an independent component from the tubular element. Alternatively, the support element may be attached to or integrally formed as part of the tubular element. The tubular and support elements are placed on a catheter in contracted conditions and advanced endoluminally to a treatment location within a body passage. The tubular element is deployed, and the support element is expanded to an enlarged condition at the treatment location to engage an interior surface of the tubular element, thereby securing the tubular element and holding the lumen of the treatment location open.

1 . A micro-porous mesh structure for supporting a wall of a body passage, comprising: 
 a non-polymeric, non-silicone generally tubular body having a contracted condition for facilitating delivery into the body passage, and an enlarged condition for engaging the wall of the body passage, the tubular body being biased to its enlarged conditions the tubular body having a plurality of openings defining a micro-porous mesh pattern therein.    
   
   
       2 . The micro-porous mesh structure of  claim 1 , wherein the tubular body is biased to the enlarged condition at body temperature for substantially securing the tubular body against the wall of the body passage.  
   
   
       3 . The micro-porous mesh structure of  claim 1 , wherein the plurality of openings each have a maximum dimension of not more than about 400 micrometers (0.016 inch).  
   
   
       4 . The micro-porous mesh structure of  claim 1 , wherein the tubular body comprises a coiled-sheet having overlapping inner and outer sections.  
   
   
       5 . The micro-porous mesh structure of  claim 1 , wherein the tubular body comprises a shape memory alloy.  
   
   
       6 . The micro-porous mesh structure of  claim 5 , wherein the shape memory alloy has a transition temperature between substantially ambient temperatures and body temperature, whereby the tubular element is biased to its enlarged condition when exposed to body temperature.  
   
   
       7 . The micro-porous mesh structure of  claim 5 , wherein the shape memory alloy comprises Nitinol having a transition temperature between a substantially ambient temperature and body temperature.  
   
   
       8 . The micro-porous mesh structure of  claim 1 , wherein the tubular body has a wall thickness of not more than about 25 micrometers (0.001 inch).