Hydraulic controlled retractable tip filter retrieval catheter

Abstract

Distal protection filter retrieval devices and methods of retrieving a distal protection filter. A filter retrieval catheter may comprise an inner tube, an outer tube disposed over the inner tube, an annular lumen disposed between the inner tube and the outer tube, and a tapered member coupled to the lumen. The tapered member may be movable between a first position for passing a lesion and a second position retrieving a filter.

1 . A filter retrieval catheter, comprising: 
 an inner tube having a proximal end, a distal end, and an inner lumen extending therethrough;    an outer tube disposed over the inner tube, the outer tube including a proximal end and a distal end, wherein an annular lumen is defined between the inner tube and the outer tube; and    a tip member slidably disposed in the annular lumen for movement between a first position and a second position under the influence of fluid pressure.    
   
   
       2 . The filter retrieval catheter in accordance with  claim 1 , wherein a quantity of fluid is disposed within the annular lumen.  
   
   
       3 . The filter retrieval catheter in accordance with  claim 1 , wherein, in the first position at least a portion of the tip member extends distal of the distal end of the outer tube.  
   
   
       4 . The filter retrieval catheter in accordance with  claim 1 , wherein, in the second position the tip member is disposed proximal to the distal end of the outer tube.  
   
   
       5 . The filter retrieval catheter in accordance with  claim 1 , further comprising a shaft disposed within the inner lumen.  
   
   
       6 . The filter retrieval catheter in accordance with  claim 5 , wherein the shaft includes a filter coupled to the shaft.  
   
   
       7 . A method of retrieving a filter from a blood vessel, comprising the steps of: 
 providing a catheter having a distal tip movable between first and second positions under the influence of fluid pressure;    advancing the catheter to the filter;    altering the fluid pressure to allow the tip to move between the first and the second position;    enclosing the filter at least in part within the catheter; and    removing the catheter and filter proximally from the blood vessel.    
   
   
       8 . The method in accordance with  claim 7 , wherein the step of altering the fluid pressure includes decreasing the fluid pressure, and wherein decreasing the fluid pressure shifts the tip from the first position to the second position.  
   
   
       9 . The method in accordance with  claim 7 , wherein the step of altering the fluid pressure includes increasing the fluid pressure, and wherein increasing the fluid pressure shifts the tip from the first position to the second position.