Balloon catheter system for treating vascular occlusions

Abstract

The present invention provides a balloon catheter comprising: a hollow inner shaft disposed within a hollow outer shaft; a balloon attached at its proximal end to said outer shaft and at its distal end to said inner shaft; wherein the inner shaft is constructed such that following radial expansion of the balloon to a first expanded state, said inner shaft is capable of responding to further longitudinal expansion of the balloon to a second expanded state by increasing its length from a resting value, and of responding to subsequent partial deflation back to said first expanded state by reducing its length back to said resting value.

1 .- 15 . (canceled) 
     
     
         16 . A method for treating vascular occlusions in a patient in need of such treatment, comprising the steps of:
 a) bringing a balloon into proximity with a vascular occlusion within a blood vessel to be treated;   b) causing said balloon to be cyclically inflated and partially deflated such that an element attached to said balloon is caused to oscillate along a distal-proximal axis in close proximity to the vascular occlusion, thereby causing complete or partial fracture of said occlusion.   
     
     
         17 . The method according to  claim 16 , wherein the element attached to the balloon is a catheter shaft. 
     
     
         18 . The method according to  claim 16 , wherein the catheter shaft is the inner shaft of a balloon catheter according to claim  1 . 
     
     
         19 . The method according to  claim 16 , wherein the catheter shaft is the distal portion of the conduit of a balloon catheter according to claim  11 . 
     
     
         20 . The method according to  claim 16 , wherein prior to the cyclical inflation and partial deflation of the balloon, said balloon is inflated to a first pressure, such that said balloon becomes anchored within the blood vessel being treated, and such that during the step of cyclical inflation and partial deflation, the balloon is inflated by increasing its internal pressure from said first pressure to a second pressure, and partially deflated by reducing its internal pressure from said second pressure to said first pressure. 
     
     
         21 . The method according to  claim 20 , wherein subsequent to anchoring of the balloon within the blood vessel, said method further comprises the step of moving the inner catheter shaft in a proximal direction such that the distal extremity of the balloon becomes intussuscepted. 
     
     
         22 .- 40 . (canceled) 
     
     
         41 . The method according to  claim 16 , wherein the element attached to the balloon is a guidewire immobilized within a catheter shaft. 
     
     
         42 . The method according to  claim 41 , wherein subsequent to the cyclical inflation and partial deflation of the balloon, said method further comprises the steps of:
 c) cyclically increasing the pressure in the balloon and decreasing the pressure therein, wherein said decreased pressure is lower than the pressure reached during said partial deflation, thereby permitting the guide wire to advance distally, and   d) repeating steps (b) and (c) until the desired result is obtained.