Cutting balloon catheter

Abstract

A system for removing matter from a partially or totally occluded stent includes a cutter that is urged radially outward toward the inner surface of the stent. Preferably, the cutter has a hardness that is less than or equal to the hardness of the material used to make the stent. Aspiration may be provided to remove portions of the occluding material from the vessel.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A system for removing deposits from a partially or totally occluded stent balloon catheter, comprising:
 a catheter shaft configured to be routed over a guidewire; 
 an expandable cutter disposed over a guide wire coupled to the catheter shaft, the cutter including a coiled member having a proximal end directly affixed to a distal end of the catheter shaft and a distal end directly affixed to a distal bearing through which the guidewire is routed; and 
 a balloon disposed within the coiled member that expands to urge the cutter radially outward, the balloon being a separate component from the expandable cutter, a proximal end of the balloon directly affixed to the distal end of the catheter shaft proximate the proximal end of the coiled member and a distal end of the balloon directly affixed to the distal bearing proximate the distal end of the coiled member, wherein the balloon is inflated when the cutter is within the occluded stent to urge the cutter toward an inner wall of the occluded stent, the expandable cutter being rotatable in the occluded stent to remove occluding matter with a fluid delivered through the catheter shaft. 
 
     
     
       2. The system balloon catheter of  claim 1 , wherein the coiled member is a diamond coated helical wire. 
     
     
       3. The system balloon catheter of  claim 1 , wherein the coiled member is a flat spring having a sharpened outer edge. 
     
     
       4. The system balloon catheter of  claim 1 , wherein the coiled member is a semi-cylindrical wire having a sharpened edge. 
     
     
       5. A method for removing restenotic tissue from within a stent, comprising:
 advancing a cutter into the stent, the cutter being secured to a drive shaft and including an expandable coil having a cutting surface, wherein the cutting surface is positioned on the coil such that the cutting surface does not contact the stent when removing restenotic tissue from within the stent;   rotating the cutter; and   aspirating ablated particles of the restenotic tissue.   
     
     
       6. The balloon catheter of claim 1, wherein the cutter is rotatable to remove occluding matter during use. 
     
     
       7. A medical device, comprising:
 a catheter shaft having a proximal and a distal end, the catheter shaft being configured to be routed over a guidewire;   an inflatable balloon having a proximal end directly affixed to the distal end of the catheter shaft and a distal end directly affixed to a distal member through which the guidewire is routed; and   a helical cutter disposed over a portion of the inflatable balloon such that the balloon is disposed within the helical cutter, the helical cutter being a separate component from the inflatable balloon, a proximal end of the helical cutter being directly affixed to the distal end of the catheter shaft proximate the proximal end of the inflatable balloon and a distal end of the helical cutter being directly affixed to the distal member proximate the distal end of the inflatable balloon;   wherein the inflatable balloon is inflated with a fluid delivered through the catheter shaft to move the helical cutter radially outward.   
     
     
       8. The medical device of claim 7, wherein the helical cutter includes an abrasive. 
     
     
       9. The medical device of claim 8, wherein the abrasive is a diamond coating. 
     
     
       10. The medical device of claim 7, wherein the helical cutter is a flat spring. 
     
     
       11. The medical device of claim 7, wherein the helical cutter is a wire. 
     
     
       12. The medical device of claim 7, wherein the helical cutter is rotatable to remove occluding matter during use. 
     
     
       13. The medical device of claim 7, wherein the distal member is a distal bearing.