Catheter with needles for ablating tissue layers in vessel

Abstract

A catheter has a catheter body and a distal tip section with needles that are positioned radially to extend outside of the distal tip section to pierce and penetrate tissue layers of a vessel or tubular region. The needles are supported in a retracted position inside the distal tip section on an elongated support member. For deployment, the needles are lifted and a portion thereof pushed through openings in the distal tip section by an actuator that is longitudinally slidable on the elongated support member. The actuator has a tapered end to help lift the needle onto the actuator. In another embodiment, an inflatable balloon member with needles is movable between retracted and deployed positions.

What is claimed is: 
     
         1 . A catheter comprising:
 a catheter body; and   a distal tip section having:
 a tubing with at least one opening, the tubing having a lumen; 
 an inflatable balloon member in the lumen; 
 at least one needle affixed to an outer surface of the balloon member; 
   a control handle proximal of the catheter body;   a fluid tubing extending through at least the catheter body and the distal tip section, the fluid tubing adapted to pass fluid in and out of the balloon member,   wherein the at least one needle has a treatment portion deployed outside the distal tip section via the at least one opening when the balloon member is inflated and the at least one needle is retracted in the distal tip section when the balloon member is deflated.   
     
     
         2 . The catheter of  claim 1 , wherein the at least one needle extends outwardly in a radial direction. 
     
     
         3 . The catheter of  claim 1 , wherein the tubing of the distal tip section comprises an elastic material adapted to resist expansion. 
     
     
         4 . The catheter of  claim 1 , wherein the distal tip section comprises a plurality of needles, each affixed to the outer surface of the balloon member.