Microcatheter introducer sheath

Abstract

The present invention includes an introducer sheath. The sheath may comprise a first proximal elongated section having a first outer diameter and a first inner diameter, and a main body elongated section having a second inner diameter and a second outer diameter, wherein the second outer diameter is larger than the first outer diameter. The sheath may further include a distal section having an outer wall that tapers from the second outer diameter of the main body elongated section to a smaller distal outer diameter.

1 . (canceled) 
     
     
         2 . An introducer sheath, comprising:
 a proximal portion having a first wall thickness defining a first outer diameter and a first inner diameter;   a main body portion having a second wall thickness defining a second outer diameter and a second inner diameter where the second wall thickness is greater than the first wall thickness such that the second outer diameter is greater than the first outer diameter; and   a distal portion having an outer wall that tapers from the second outer diameter of the main body elongated section to a smaller distal outer diameter.   
     
     
         3 . The introducer sheath of  claim 2 , wherein the first inner diameter is larger than the second inner diameter. 
     
     
         4 . The introducer sheath of  claim 2 , wherein the distal portion further includes an inner diameter that is smaller than the second inner diameter of the main body portion. 
     
     
         5 . The introduce sheath of  claim 2 , wherein the first diameter is substantially equal to the second inner diameter. 
     
     
         6 . The introducer sheath of  claim 2 , wherein first inner diameter is larger than the second inner diameter and the distal portion further includes an inner diameter that is smaller than the second inner diameter. 
     
     
         7 . The introducer sheath of  claim 2 , wherein the sheath includes a thermoplastic elastomer. 
     
     
         8 . The introducer sheath of  claim 2 , wherein the distal portion has a wall thickness that is less than the second wall thickness of the main body portion. 
     
     
         9 . A microcatheter system, comprising:
 a microcatheter; and   an introducer sheath, comprising:   a proximal portion having a first wall thickness defining a first outer diameter and a first inner diameter;   a main body portion having a second wall thickness defining a second outer diameter and a second inner diameter where the second wall thickness is greater than the first wall thickness such that the second outer diameter is greater than the first outer diameter; and   a distal portion having an outer wall that tapers from the second outer diameter of the main body elongated section to a smaller distal outer diameter.   
     
     
         10 . The system  claim 9 , wherein the first inner diameter is larger than the second inner diameter. 
     
     
         11 . The system of  claim 9 , wherein the distal portion further includes an inner diameter that is smaller than the second inner diameter of the main body portion. 
     
     
         12 . The system of  claim 10 , wherein the distal portion further includes an inner diameter that is smaller than the second inner diameter of the main body elongated section. 
     
     
         13 . The system of  claim 9 , wherein the distal portion has a wall thickness that is less than the second wall thickness of the main body portion. 
     
     
         14 . The system of  claim 9 , further comprising a coil for delivery through the sheath and the microcatheter. 
     
     
         15 . The system of  claim 14 , wherein the second inner diameter of the main body portion and coil are selected such that a difference between a cross-sectional area defined, at least in part by, by the second inner diameter of the main body portion and a cross-sectional area of the coil is less than 75%. 
     
     
         16 . A method of delivering an embolic coil through a microcatheter, the method comprising:
 advancing an introducer sheath to a predetermined location within a microcatheter, the introducer sheath comprising:   a proximal portion having a first wall thickness defining a first outer diameter and a first inner diameter;   a main body portion having a second wall thickness defining a second outer diameter and a second inner diameter where the second wall thickness is greater than the first wall thickness such that the second outer diameter is greater than the first outer diameter; and   a distal portion having an outer wall that tapers from the second outer diameter of the main body elongated section to a smaller distal outer diameter.   
     
     
         17 . The method of  claim 16 , further comprising securing an embolic coil within the introducer sheath prior to advancing the introducer sheath to the predetermined location within the microcatheter. 
     
     
         18 . The method of  claim 16 , further comprising releasing an embolic coil from the microcatheter. 
     
     
         19 . The method of  claim 16 , wherein the first inner diameter of the proximal portion is larger than the second inner diameter of the main body portion. 
     
     
         20 . The method of  claim 16 , wherein the distal portion further includes an inner diameter that is smaller than the second inner diameter of the main body portion. 
     
     
         21 . The method of  claim 16 , wherein the first inner diameter of the proximal portion is larger than the second inner diameter of the main body portion and the distal portion further includes an inner diameter that is smaller than the second inner diameter of the main body portion.