Ureteral stent

Abstract

A ureteral stent comprises an internal portion, which comprises a first polymer, and an external portion, which comprises a second polymer. The external portion surrounds the internal portion and has a plurality of radial projections that extend along the length of the ureteral stent. The second polymer has a Shore D hardness of 20-40 Shore D. The first polymer has a Shore D hardness that is at least 10 units greater than the Shore D hardness of the second polymer.

What is claimed is: 
     
         1 . A ureteral stent, comprising:
 an internal portion, comprising a first polymer, and   an external portion surrounding the internal portion and having a plurality of radial projections that extend along the length of the ureteral stent, comprising a second polymer,   wherein the second polymer has a Shore D hardness of 20-40 Shore D, and   the first polymer has a Shore D hardness that is at least 10 units greater than the Shore D hardness of the second polymer.   
     
     
         2 . The ureteral stent of  claim 1 , further comprising a lumen, wherein the internal portion surrounds the lumen. 
     
     
         3 . The ureteral stent of  claim 1 , wherein the external portion comprises 2-10 radial projections. 
     
     
         4 . The ureteral stent of  claim 1 , wherein the external portion comprises 4-8 radial projections. 
     
     
         5 . The ureteral stent of  claim 1 , wherein the external portion comprises 6 radial projections. 
     
     
         6 . The ureteral stent of  claim 1 , wherein the ureteral stent does not include a lumen. 
     
     
         7 . The ureteral stent of  claim 1 , wherein the ureteral stent is not coiled. 
     
     
         8 . The ureteral stent of  claim 1 , wherein the first polymer has a hardness of 35-70 Shore D. 
     
     
         9 . The ureteral stent of  claim 1 , wherein the first polymer has a hardness of 50-60 Shore D. 
     
     
         10 . The ureteral stent of  claim 1 , wherein the first polymer has a hardness of 40 Shore D and the second polymer has a hardness of 25 Shore D. 
     
     
         11 . The ureteral stent of  claim 1 , wherein the first polymer and the second polymer comprise thermoplastic elastomers. 
     
     
         12 . The ureteral stent of  claim 1 , wherein the first polymer and the second polymer comprise polyether block amides (PEBAs). 
     
     
         13 . The ureteral stent of  claim 1 , wherein the radial projections are substantially normal to the external portion. 
     
     
         14 . The ureteral stent of  claim 1 , wherein the radial projections are curved. 
     
     
         15 . The ureteral stent of  claim 1 , wherein the radial projections comprise one or more lobes extending from the terminal portion of the radial projections. 
     
     
         16 . The ureteral stent of  claim 15 , wherein the radial projections comprise a single lobe. 
     
     
         17 . The ureteral stent of  claim 15 , wherein the radial projections comprise two lobes. 
     
     
         18 . The ureteral stent of  claim 17 , wherein the lobes extend in opposite directions from the radial projections. 
     
     
         19 . The ureteral stent of  claim 1 , wherein the ureteral stent is sterile. 
     
     
         20 . The ureteral stent of  claim 1 , further comprising a coating on the external portion, wherein the coating is selected from the group consisting of hydrophilic coatings, antibacterial coatings, antimicrobial coatings, and combinations thereof. 
     
     
         21 . The ureteral stent of  claim 1 , wherein the external portion comprises 6 radial projections,
 the first polymer has a hardness of 40 Shore D,   the second polymer has a hardness of 25 Shore D,   the first polymer and the second polymer comprise polyether block amides,   the radial projections are substantially normal to the external portion, and   the ureteral stent is sterile.   
     
     
         22 . The ureteral stent of  claim 1 , further comprising a middle portion, comprising a third polymer,
 wherein the middle portion surrounds the internal portion and the external portion surrounds the middle portion.   
     
     
         23 . A method of making the ureteral stent of  claim 1 , comprising:
 co-extruding the first polymer and the second polymer.   
     
     
         24 . A method of stenting a patient, comprising:
 inserting the ureteral stent of  claim 1  into a ureter.   
     
     
         25 . A kit, comprising:
 a guidewire, and   the ureteral stent of  claim 1 ,   wherein the guidewire and the ureteral stent are sterile.   
     
     
         26 . The kit of  claim 25 , further comprising a pusher. 
     
     
         27 . The kit of  claim 25 , wherein the guidewire is pre-threaded through the ureteral stent. 
     
     
         28 . The kit of  claim 25 , further comprising a container, wherein the guidewire and the ureteral stent are housed in the container. 
     
     
         29 . The kit of  claim 25 , further comprising a pusher,
 a container,   a lubricant, and   printed instructions,   wherein the guidewire and the ureteral stent are housed in the container, and   the guidewire is pre-threaded through the ureteral stent.   
     
     
         30 . The kit of  claim 29 , wherein the lubricant is on the ureteral stent.