Embolic protection device having an expandable trap

Abstract

An embolic protection device for use in medical, veterinary, non-medical or industrial applications where removal of an obstruction from a small diameter vessel or vessel-like structure could produce particles, which, if allowed to remain in the vessel, could cause undesirable complications and results. One embodiment comprises a catheter for insertion into a vessel and a trap operably connected to the catheter and to a rotatable member. Rotating the rotatable member relative to the catheter actuates the trap. One embodiment comprises a rotatable member that actuates a flexible strut between an arcuately expanded position and a helically twisted position, and a membrane operably connected to the flexible strut.

I claim:  
     
         1 . A device for capturing particles flowing through a vessel, the device comprising: 
 a catheter for insertion into the vessel, the catheter having a longitudinal lumen therein;    a moveable member disposed substantially within the longitudinal lumen; and    a plurality of flexible struts having a first end connected to the catheter and a second end connected to the moveable member, the struts having a contracted position wherein the struts are helically twisted around the moveable member and an expanded position wherein the struts extend arcuately outward from the moveable member;    wherein, in the contracted position, a longitudinal distance between the first and second ends of the struts is greater than the longitudinal distance in the expanded position.    
     
     
         2 . The device of  claim 1  wherein the moveable member is a guidewire.  
     
     
         3 . The device of  claim 2  wherein the guidewire is solid.  
     
     
         4 . The device of  claim 2  wherein the guidewire is at least partially hollow along a length.  
     
     
         5 . The device of  claim 1  wherein the moveable member is a second catheter adapted to fit within the longitudinal lumen.  
     
     
         6 . The device of  claim 5  wherein the second catheter has a second longitudinal lumen therein adapted to receive a guidewire.  
     
     
         7 . The device of  claim 1  wherein the catheter has at least one suction aperture in communication with the lumen.  
     
     
         8 . The device of  claim 1  further comprising a balloon adapted to compress an obstruction in the vessel and further wherein the catheter includes an inflation lumen in operable communication with the balloon.  
     
     
         9 . The device of  claim 8  wherein the inflation lumen terminates at an opening located near a proximal end of the balloon.  
     
     
         10 . The device of  claim 1  further comprising a membrane connected to the plurality of flexible struts to define a trap.  
     
     
         11 . The device of  claim 10  wherein the membrane is impermeable.  
     
     
         12 . The device of  claim 10  wherein the membrane is permeable.  
     
     
         13 . The device of  claim 1  wherein the flexible struts are helically twisted around the moveable member, such that a crossing profile of the device is generally equal to an outside diameter of the catheter.  
     
     
         14 . The device of  claim 1  wherein the plurality of struts are constructed from a shape-memory alloy.  
     
     
         15 . The device of  claim 14  wherein the plurality of struts are biased toward the expanded position.  
     
     
         16 . The device of  claim 14  wherein the plurality of struts are biased toward the contracted position.  
     
     
         17 . The device of  claim 1  further comprising an actuation mechanism coupling the moveable member to the catheter for causing a combined rotational and longitudinal motion of the first end of the struts relative to the second end.  
     
     
         18 . The device of  claim 17  wherein the actuation mechanism is a screw extension system wherein the ratio between the rotational and the longitudinal motion of the guidewire relative to the catheter is controlled by a pitch of the screw extension system.  
     
     
         19 . The device of  claim 17  wherein the actuation mechanism is a flexible membrane connected between the guidewire and the catheter, such that rotation of the guidewire relative to the catheter causes a corresponding longitudinal motion of the guidewire relative to the catheter.  
     
     
         20 . The device of  claim 1  wherein the moveable member, at a point where the second ends are affixed, has a diameter smaller than a diameter of the catheter.  
     
     
         21 . A method of providing distal protection within a vessel of a patient during an intravascular procedure on a treatment site, the method comprising: 
 providing a distal protection assembly comprising: 
 a catheter with a longitudinal lumen having a moveable member positioned therein;  
 a plurality of flexible struts having a first end connected to the catheter and a second end connected to the moveable member, the struts in a contracted position wherein the struts are helically twisted around the moveable member; and  
 a membrane connected to the struts to form a trap;  
   positioning the assembly within the vessel downstream from the treatment site; and    effecting a combined rotational and longitudinal motion of the first end of the struts relative to the second end, the motion placing the struts in an expanded position wherein the struts extend arcuately outward from both the catheter and the moveable member.    
     
     
         22 . The method of  claim 21  wherein a perimeter of the membrane is positioned near a midpoint of each strut.  
     
     
         23 . The method of  claim 22  wherein, in the expanded position, the struts are in contact with an inner surface of the vessel.  
     
     
         24 . The method of  claim 21  further comprising performing a treatment procedure at the treatment site.  
     
     
         25 . The method of  claim 24  further comprising capturing embolic particles in the trap during the treatment procedure.  
     
     
         26 . The method of  claim 24  further comprising effecting a combined rotational and longitudinal motion of the first end of the struts relative to the second end, the motion placing the struts in an at least partially contracted position and capturing the embolic particles beneath the trap.  
     
     
         27 . The method of  claim 21  wherein the assembly is positioned distal to the treatment site.  
     
     
         28 . The method of  claim 21  wherein the assembly is positioned proximal to the treatment site.