Pleated deployment sheath

Abstract

A deployment sheath for medical devices is provided that includes one or more pleats in its pre-deployment state that are allowed to open during deployment so as to facilitate easier device deployment and sheath removal. Preferably, the sheath is removed by everting it over itself during the delivery process. By orienting the pleats along the length of the sheath, preferably helically around the sheath, the sheath undergoes a predictable enlargement during deployment so as to relieve friction of the everted sheath sliding along itself during deployment. This allows the sheath to be removed with less tension than previous everting sheath constructions and assures more accurate device placement in a patient.

What is claimed is: 
     
         1 . A medical device delivery system comprising
 a tubular sheath, having a length, mounted about and containing a medical device;   wherein said tubular sheath includes at least one pleat oriented along at least a portion of the length; and wherein a portion of the pleat is reinforced with a reinforcing material having variable properties along the length of the pleat.   
     
     
         2 . The medical device delivery system of  claim 1  wherein the pleat is oriented helically along at least a portion of the length of the sheath. 
     
     
         3 . The medical device delivery system of  claim 1  wherein the variable property is pitch. 
     
     
         4 . The medical device delivery system of  claim 1  wherein the variable property is width. 
     
     
         5 . The medical device delivery system of  claim 2  wherein the pleat has variable pitch along a portion of the length of the tubular sheath. 
     
     
         6 . The medical device delivery system of  claim 5  wherein the tubular sheath is tapered. 
     
     
         7 . A medical device delivery system comprising
 a tubular sheath, having a length, mounted about and containing a medical device;   wherein said tubular sheath includes at least one pleat oriented along at least a portion of the length; and wherein the pleat is defined by hinge lines to provide preferential folding.   
     
     
         8 . A medical device delivery system according to  claim 7 , wherein the hinge lines comprise lines of reduced thickness in the tubular sheath. 
     
     
         9 . A medical device delivery system according to  claim 8 , wherein the pleat is oriented helically along at least a portion of the length of the sheath. 
     
     
         10 . The medical device delivery system of  claim 1  wherein a portion of the pleat is reinforced with a reinforcing material having variable properties along the length of the tubular sheath. 
     
     
         11 . The medical device delivery system of  claim 10  wherein the variable property is pitch. 
     
     
         12 . The medical device delivery system of  claim 10  wherein the variable property is width. 
     
     
         13 . The medical device delivery system of  claim 9  wherein the pleat has variable pitch along a portion of the length of the tubular sheath. 
     
     
         14 . The medical device delivery system of  claim 13  wherein the tubular sheath is tapered.