Percutaneous mechanical fragmentation catheter system

Abstract

A percutaneous thrombolytic device, also referred to herein as a percutaneous mechanical fragmentation catheter system, that includes a wire cage or basket attached to a rotational drive motor. The fragmentation basket, ensheathed in an outer catheter, is introduced into the clotted graft or vessel via an introducer sheath. When deployed, the basket will automatically conform to the inner dimensions of the vessel lumen. The rotating basket is slowly withdrawn through the clotted graft, mechanically fragmenting the clot. The fragmented, homogenized debris can be flushed into the venous system or aspirated.

What is claimed is:  
     
         1 . A method for fragmenting thrombotic material in a vascular conduit comprising the steps of: 
 advancing a fragmentation catheter in a vascular conduit to a thrombotic occlusion;    deploying the fragmentation catheter, the fragmentation catheter having a distal fragmentation member that automatically expands to conform to the shape and size of the inner lumen of the vascular conduct;    rotating the fragmentation member at a speed of at least about 2,000 r.p.m. to homogenize the thrombotic material; and    at least one of allowing the debris to enter the venous system and aspirating the debris.    
     
     
         2 . The method of    claim 1   , wherein said step of advancing comprises advancing a fragmentation catheter comprising a drive cable with a fragmentation basket as the fragmentation member on a distal end thereof and operatively coupled to a rotator unit at a proximal end thereof, and an outer sheath assembly slidably disposed on said drive cable for selectively receiving said fragmentation basket therewithin.  
     
     
         3 . The method of    claim 2   , wherein said step of advancing comprises advancing a fragmentation catheter having a flexible plastic tip distal on said fragmentation cage.  
     
     
         4 . The method of    claim 2   , wherein said step of advancing comprises advancing a fragmentation catheter having an outer sheath coupled to said rotator unit so as to be selectively disposed in one of at least two positions relative to said fragmentation basket.  
     
     
         5 . The method of    claim 2   , wherein said step of advancing comprises advancing said fragmentation catheter with said fragmentation basket received within said outer sheath.  
     
     
         6 . The method of    claim 1   , wherein said step of rotating comprises rotating at a speed of about 2000-4,500 rpm.  
     
     
         7 . The method of    claim 6   , wherein said step of rotating comprises rotating at a speed of about 3000 rpm.  
     
     
         8 . The method of    claim 1   , wherein said advancing step includes introducing an introducer sheath into a dialysis fistulae.  
     
     
         9 . The method of    claim 1   , wherein said advancing step includes introducing an introducer sheath into a synthetic vascular graft.  
     
     
         10 . The method of    claim 1   , wherein said advancing step includes introducing an introducer sheath into an indwelling catheter.  
     
     
         11 . The method of    claim 1   , wherein said advancing step includes introducing an introducer sheath into a Hickman catheter.  
     
     
         12 . The method of    claim 1   , wherein said advancing step includes introducing an introducer sheath into a peripheral graft.  
     
     
         13 . A percutaneous mechanical fragmentation catheter system for fragmenting thrombotic material in a vascular conduit comprising: 
 a fragmentation catheter comprising a drive cable with a fragmentation basket as a fragmentation member on a distal end thereof and an outer sheath assembly slidably disposed on said drive cable for selectively receiving said fragmentation basket therewithin, said fragmentation member automatically expanding to conform to a shape and size of an inner lumen of the vascular conduct;    a rotary unit operatively coupled to a proximal end of said drive cable of said fragmentation catheter for selectively rotating the fragmentation member at a speed of at least about 2,000 r.p.m. to homogenize the thrombolytic material; and    wherein said drive cable is coupled to said rotary unit so as to be substantially axially immovable with respect to said rotary unit;    wherein said an outer sheath is slidable relative to and is selectively engaged with said rotator unit so as to be selectively disposed in one of at least two positions relative to said fragmentation basket, one of said at least two positions defining a deployed position wherein said fragmentation basket projects beyond a distalmost end of said outer sheath, an other of said at least two positions defining a compressed position, wherein said fragmentation basket is disposed within said outer sheath.    
     
     
         14 . The system of    claim 13   , wherein said fragmentation catheter has a soft, flexible plastic tip provided at a distalmost end thereof.