Distal protection device

Abstract

The present invention describes a catheter suitable for introduction into a tubular tissue for dissolving blockages in such tissue. The catheter is particularly useful for removing thrombi within blood vessels. In accordance with the preferred embodiments, a combination of vibrating motion and injection of a lysing agent is utilized to break up blockages in vessels. The vessels may be veins, arteries, ducts, intestines, or any lumen within the body that may become blocked from the material that flows through it. As a particular example, dissolution of vascular thrombi facilitated by advancing a catheter through the occluded vessel, the catheter causing a vibrating, stirring action in and around the thrombus usually in combination with the dispensing of a thrombolytic agent such as urokinase into the thrombus. The catheter has an inflatable or expandable member near the distal tip which, when inflated or expanded, prevents the passage of dislodged thrombus around the catheter. The dislodged portions of thrombus are directed through a perfusion channel in the catheter, where they are removed by filtration means housed within the perfusion channel before the blood exists the tip of the catheter. Catheters that allow both low frequency (1-100 Hz) vibratory motion and delivery of such agents to a blockage and a method for using such catheters are disclosed. A distal protection system comprising a braided structure capable of moving from a contracted condition to an expanded condition and adapted to inhibit particles from moving completely through the braided structure when expanded is also disclosed.

We claim:  
     
         1 . A device for the removal of particles from a lumen within the body comprising: 
 an outer, hollow tube having a tube distal end;    an inner member housed within the tube and having an inner member distal end positioned distally of the tube distal end;    a porous braided structure having a distal part secured to the inner member distal end and a proximal part secured to the tube distal end;    the braided structure movable from a contracted condition to an expanded condition by moving at least one of the tube and inner member distal ends towards the other; and    the braided structure adapted to inhibit particles from moving completely through the braided structure when in the expanded condition.    
     
     
         2 . The device as in  claim 1  where said braided structure has a porous proximal side and a porous distal side.  
     
     
         3 . The device a sin  claim 2  wherein said distal side has smaller pores than the proximal side.  
     
     
         4 . The device as in  claim 3  wherein said braided structure comprises a section of a tubular, porous braided structure having alternating first and second braided sections, said first braided sections, corresponding to said distal side, having pore sizes smaller than the second braided sections, corresponding to said proximal side.  
     
     
         5 . A device for the removal of particles from a lumen within the body comprising: 
 an outer, hollow tube having a tube distal end;    in inner member housed within the tube and having an inner member distal end positioned distally of the tube distal end;    a porous mesh structure having a distal part secured to the inner member distal end and a proximal part secured to the tube distal end;    the mesh structure movable from a contracted condition to an expanded condition by moving at least one of the tube and inner member distal ends towards the other; and    the mesh structure adapted to inhibit particles form moving completely through the mesh structure when in the expanded condition.    
     
     
         6 . The device as in  claim 5  where said mesh structure has a porous proximal side and a porous distal side.  
     
     
         7 . The device as in  claim 6  wherein said distal side has smaller pores than the proximal side.  
     
     
         8 . The device as in  claim 7  wherein said mesh structure comprises a section of a tubular, porous mesh structure having alternating first and second mesh sections, said first mesh sections, corresponding to said distal side, having pore sizes smaller than the second mesh sections, corresponding to said proximal side.