Biliary stents and methods

Abstract

A tissue lumen stent is provided with a body having an elongated tubular configuration and a foreshortened configuration. In the foreshortened configuration, downstream and upstream ends of the body expand radially into downstream and upstream flange structures, leaving a generally cylindrical saddle region therebetween. In some embodiments, the flange structures are non-symmetrical with respect to one another. Systems and methods of using the stents are also disclosed.

What is claimed is: 
     
         1 . A tissue lumen stent comprising a body having an elongated tubular configuration and a foreshortened configuration where a downstream end of the body expands radially into a downstream flange structure and an upstream end of the body expands into a distally and radially outward inclined structure. 
     
     
         2 . The tissue lumen stent of  claim 1 , wherein the body upstream of the downstream flange structure continuously increases in diameter as the body extends to the upstream end. 
     
     
         3 . The tissue lumen stent of  claim 1 , wherein the upstream and downstream flange structures are non-symmetrical with respect to one another. 
     
     
         4 . The tissue lumen stent of  claim 1 , wherein the downstream flange structure comprises a larger maximum lateral diameter than that of the upstream flange structure when the body is in the foreshortened configuration. 
     
     
         5 . The tissue lumen stent of  claim 1 , wherein the upstream flange structure and downstream flange structure are substantially symmetric when the body is in the extended configuration. 
     
     
         6 . The tissue lumen stent of  claim 1 , further comprising a covering or membrane over the cylindrical saddle portion of the stent. 
     
     
         7 . The tissue lumen stent of  claim 6 , wherein the covering extends over the downstream flange structure. 
     
     
         8 . The tissue lumen stent of  claim 6 , wherein the covering extends over the upstream flange structure. 
     
     
         9 . The tissue lumen stent of  claim 6 , wherein the upstream flange structure is uncovered and the downstream flange structure is covered. 
     
     
         10 . The tissue lumen stent of  claim 1 , wherein the one or more of the downstream and upstream flange structures have a pull-out force of greater than about 2.94N. 
     
     
         11 . A tissue lumen stent comprising a body having an elongated tubular configuration and a foreshortened configuration where each of the downstream and/or upstream ends of the body expand radially into downstream and upstream flange structures leaving a generally cylindrical saddle region therebetween, the upstream and downstream flange structures being non-symmetrical with respect to one another. 
     
     
         12 . The tissue lumen stent of  claim 11 , wherein the upstream flange structure comprises a larger maximum lateral diameter than that of the downstream flange structure when the body is in the foreshortened configuration. 
     
     
         13 . The tissue lumen stent of  claim 11 , wherein the upstream flange structure comprises a larger maximum axial width than that of the downstream flange structure when the body is in the foreshortened configuration. 
     
     
         14 . The tissue lumen stent of  claim 11 , wherein the upstream flange structure comprises both a larger maximum lateral diameter and a larger maximum axial width than those of the downstream flange structure when the body is in the foreshortened configuration. 
     
     
         15 . The tissue lumen stent of  claim 11 , further comprising a covering or membrane over the body of the stent. 
     
     
         16 . The tissue lumen stent of  claim 15 , wherein the covering extends over the downstream flange structure. 
     
     
         17 . The tissue lumen stent of  claim 15 , wherein the covering extends over the upstream flange structure. 
     
     
         18 . The tissue lumen stent of  claim 15 , wherein the upstream flange structure is uncovered and the downstream flange structure is covered. 
     
     
         19 . A method of treating a patient, comprising:
 accessing a biliary system of a patient with an endoscope; and   deploying, within a the biliary system of the patient, a tissue lumen stent having a foreshortened configuration defining non-symmetrical upstream and downstream flange structures and a cylindrical portion extending therebetween.   
     
     
         20 . The method of  claim 19 , wherein the tissue lumen stent contacts a lumen selected from the group consisting of the common bile duct, the pancreatic duct, and the hepatic duct.