Introducer sheath with encapsulated reinforcing member

Abstract

An introducer sheath and a method for making the sheath. The sheath includes a fluoropolymer liner having a passageway extending longitudinally therethrough. An inner jacket is positioned longitudinally over the liner, and the inner surface of the inner jacket is bonded to the outer surface of the liner. An outer jacket is positioned longitudinally over the inner jacket, and the inner surface of the outer jacket is bonded to the outer surface of the inner jacket. A reinforcing coil is encapsulated within the inner jacket and the outer jacket.

1 . A method for forming an introducer sheath, comprising:
 positioning an inner liner over a mandrel, said inner liner having a passageway extending therethrough, and having an outer surface;   applying a solution comprising a polymer dissolved in a solvent to said outer surface of said inner liner;   evaporating the solvent, leaving a layer of the polymer on the outer surface of the inner liner, said layer comprising an inner polymer layer;   positioning a reinforcing member around the inner polymer layer;   applying an outer polymer layer over the reinforcing member; and   exposing an assembly comprising the inner liner, inner polymer layer, reinforcing member and outer polymer layer to sufficient heat to at least partially melt the inner polymer layer and outer polymer layer such that a bond is formed therebetween, and such that said inner polymer layer is bonded to said liner outer surface, said reinforcing member being encapsulated within said inner and outer polymer layers.   
     
     
         2 . The method of  claim 1 , wherein said solution is applied to said liner outer surface by at least one of submersion of the liner and mandrel into the solution, spraying the solution onto the outer surface of the liner, and coating the solution on the outer surface of the liner. 
     
     
         3 . The method of  claim 1 , wherein said layer of polymer on the outer surface of the inner liner has a thickness between about 0.0001 and 0.001 inch (0.0025 and 0.025 mm) after evaporation of the solvent. 
     
     
         4 . The method of  claim 3 , wherein said thickness is about 0.001 inch (0.025 mm). 
     
     
         5 . The method of  claim 2 , wherein said liner comprises a lubricious fluoropolymer having a roughened outer surface, and said inner polymer layer bonds with said roughened outer surface upon said exposure to heat. 
     
     
         6 . The method of  claim 2 , wherein said dissolved polymer comprises at least one of a polyether block amide, nylon, and polyurethane. 
     
     
         7 . The method of  claim 6 , wherein said inner liner comprises a fluoropolymer, and said solvent comprises a non-polar solvent. 
     
     
         8 . The method of  claim 7 , wherein said fluoropolymer comprises PTFE. 
     
     
         9 . The method of  claim 1 , wherein said solvent comprises a phenolic solvent. 
     
     
         10 . The method of  claim 2 , wherein each of said inner and outer polymer layers comprises at least one of a polyether block amide, nylon, and polyurethane, and wherein said reinforcing member comprises a helical coil. 
     
     
         11 . The method of  claim 10 , wherein each of said inner and outer polymer layers comprises the same polymer composition. 
     
     
         12 . The method of  claim 1 , wherein said inner polymer layer extends substantially the length of said liner outer surface. 
     
     
         13 . The method of  claim 1 , wherein the assembly is exposed to said heat in a heat shrink enclosure. 
     
     
         14 . The method of  claim 13 , wherein the assembly is heated to a temperature of between about 400-500° F. (204-260° C.).