Flexible Expandable Stent

Abstract

A stent for implanting in the body to hold open a blood vessel includes cells with facing loops and the curved flexible links disposed and adapted to cooperate so that, when unexpanded, the stent can flex as it is moved through curved blood vessels to a site where it is to be expanded and so that, when the stent is expanded in a curved vessel, at that site, as compared to each other, cells on the outside of the curve are open in length, but narrow in width as compared to cells on the inside of the curve which are short in length but increased in width to result in a more constant stent cell area between the inside and the outside of the curve than would otherwise occur causing the stent, when coated with a medicine, to apply a more even dose to the inside wall of the lumen, avoiding the possibility that a toxic dose is supplied at one area while a less than effective dose is applied to another area.

1 . A stent comprising a mesh of adjacent, connected cells, each cell comprising: 
 an even number of fixed length, alternating, first and second loops, connected together in a closed cell, each loop having at least two portions with an area of inflection there between, said first and second loops defining first and second angles whose bisecting lines are at angles one to another;    the second angles defined by the second loops being greater than the first angles defined by the first loops.    
     
     
         2 . The stent according to  claim 1 , wherein the second angles defined by the second loops are obtuse.  
     
     
         3 . The stent according to  claim 1 , wherein the second angles defined by the second loops are acute.  
     
     
         4 . The stent according to  claim 3 , wherein the first angles defined by the first loops are acute.  
     
     
         5 . A stent comprising a mesh of adjacent, connected cells, each cell comprising: 
 an even number of fixed length, alternating, first and second loops, connected together in a closed cell, each loop having at least two portions with an area of inflection there between, said first and second loops defining first and second angles whose bisecting lines are at angles one to another;    the first angles defined by the first loops being acute;    the second angles defined by the second loops being obtuse.    
     
     
         6 . A stent comprising a mesh of adjacent, connected cells, each cell comprising: 
 an even number of fixed length, alternating, first and second loops, connected together in a closed cell, each loop having at least two portions with an area of inflection there between, said first and second loops defining first and second angles whose bisecting lines are at angles one to another;    the first angles defined by the first loops being acute;    the second angles defined by the second loops being right angles.