Stent with flexible sections in high strain regions

Abstract

A stent for treating a bodily lumen with a flexible section in a high strain region is disclosed. A flexible section may be selectively positioned to reduce an amount of strain in the high strain region when subjected to the applied stress during use to inhibit or prevent fracturing in the high strain region.

1 . A structural element of a stent comprising: 
 a flexible section embedded within a high strain region of a structural element, the flexible section extending through the high strain region from an abluminal surface of the high strain region to a luminal surface of the high strain region, the flexible section comprising a greater flexibility than a majority of the structural element outside of the flexible section;    wherein the high strain region comprises a higher strain as compared to other regions of the structural element when the stent is subjected to an applied stress during use,    wherein the section is selectively positioned to increase resistance to strain in the high strain region to inhibit or prevent fracturing in the high strain region when subjected to the applied stress during use.    
   
   
       2 . The stent of  claim 1 , wherein the stent comprises a biostable polymer and/or a bioabsorbable polymer.  
   
   
       3 . The stent of  claim 1 , wherein the flexible section comprises a biostable polymer and/or a bioabsorbable polymer.  
   
   
       4 . The stent of  claim 1 , wherein the flexible section comprises a lower modulus than a majority of the structural element outside of the flexible section.  
   
   
       5 . The stent of  claim 1 , wherein the flexible section comprises a glass transition temperature at or below body temperature.  
   
   
       6 . The stent of  claim 1 , wherein the high strain region comprises a region of the stent configured to bend when the structural element is under an applied stress during use.  
   
   
       7 . The stent of  claim 1 , wherein the section is selectively positioned proximate a center of a width of a bending portion of the structural element.  
   
   
       8 . The stent of  claim 1 , wherein the section is selectively positioned proximate a neutral axis of a bending portion of the structural element.  
   
   
       9 . The stent of  claim 1 , wherein a cross-section of the section is slot-shaped and positioned along at least a portion of a length of the high strain region.  
   
   
       10 . The stent of  claim 1 , wherein a width of the flexible section varies along the length of the high strain region.  
   
   
       11 . The stent of  claim 1 , wherein a width of the section along the length is directly proportional to strain along a length of the high strain region when the structural element is under stress.  
   
   
       12 . The stent of  claim 1 , wherein a width of the section is widest at a center of a bending portion of the high strain region and decreases along a length of the high strain region.  
   
   
       13 . A method of forming a stent comprising: 
 forming a cavity within a high strain region of a structural element, the cavity extending through the high strain region from an abluminal surface of the high strain region to a luminal surface of the high strain region, wherein the high strain region comprises a higher strain as compared to other regions of the structural element when the stent is subjected to an applied stress during use;    forming a flexible section within all or substantially all of the cavity, the flexible section comprising a greater flexibility than a majority of the structural element outside of the flexible section, wherein the section is selectively positioned to reduce an amount of strain in the high strain region to inhibit or prevent fracturing in the high strain region when subjected to the applied stress during use.    
   
   
       14 . The method of  claim 13 , wherein the stent comprises a biostable polymer and/or a bioabsorbable polymer.  
   
   
       15 . The method of  claim 13 , wherein the flexible section comprises a biostable polymer and/or a bioabsorbable polymer.  
   
   
       16 . The method of  claim 13 , wherein the flexible section comprises a lower modulus than a majority of the structural element outside of the flexible section.  
   
   
       17 . The method of  claim 13 , wherein the cavity is formed by laser cutting the high strain region.  
   
   
       18 . The method of  claim 13 , wherein the flexible section is formed by depositing a polymer-solvent mixture into the cavity.