Balloon catheter stent delivery system with ridges

Abstract

A balloon catheter and stent delivery system for medical treatment of a patient includes a balloon having a pattern of ridges in an initial deflated state. The ridges may cooperate with structural elements of a stent crimped onto the balloon, to increase and enhance longitudinal retention of the stent while the catheter system is advanced or withdrawn. Upon inflation, the balloon recovers to an inflated shape having a cylindrical working portion. The balloon catheter thus provides for uniform expansion of the stent when the balloon is inflated. The present invention also tends to protect the leading or distal end of the stent during advancement, and tends to protect the leading or distal end of the stent during advancement, and tends to protect the proximal end of the stent during any withdrawal of the catheter system.

1 - 17 . (canceled) 
   
   
       18 . A balloon catheter, comprising:
 a flexible shaft having a proximal and a distal end;   a hub affixed to the proximal end of the shaft;   a balloon affixed to the shaft near the distal end, the balloon being inflatable from a deflated state to an inflated state, the shaft defining an inflation lumen for conducting inflation fluid from an inflation port defined by the hub to an interior of the balloon;   wherein the balloon in an initial deflated state is pleated and wrapped around the shaft; the balloon in the initial deflated state having a plurality of ridges;   the ridges each extending radially outward a first radial distance which is greater than a default radial dimension defined by portions of the balloon between each of the ridges;   a pair of shoulders defined by the balloon flanking the central series of ridges and disposed near a proximal and distal end of the balloon respectively; each of the shoulders generally extending circumferentially around the balloon, and each shoulder extending radially outward a second radial distance which is greater than the first radial distance;   the ridges and shoulders being adapted to receive a stent and resist longitudinal movement of a stent crimped onto the balloon.   
   
   
       19 . The balloon catheter of  claim 18  wherein the ridges extend generally circumferentially around the balloon. 
   
   
       20 - 24 . (canceled)