Material removal catheter and method

Abstract

A catheter device and methods useable to extract material from a body conduit, e.g., a blood vessel, are provided. The catheter comprises a flexible catheter advanceable into the body conduit, an opening in a wall of the catheter in fluid communication with a material collection chamber, and a controllably arcuate segment near the distal tip of the catheter and the opening. The catheter may include a sliding member, located within a lumen of the catheter, used to move the material entering the catheter through the arcuate segment opening, into the material collection chamber and away from said opening. The catheter may include a single mechanism utilized to both generate a vacuum to cause material to enter the catheter at the arcuate segment opening and also cause the sliding member to travel, inside the catheter, moving material away from the opening and into the material collection chamber.

1 . A transluminal method for removing material from a biological conduit, said method comprising the steps of:
 providing a catheter device that comprises:   an elongated catheter shaft having a proximal end and a distal end;   a controllably arcuate segment configured to selectively transition between a relatively straight configuration and a relatively curved configuration having an axial offset with respect to the catheter shaft, the controllably arcuate segment defining at least one opening in fluid communication with the proximal end; and   a mechanism at the proximal end of the catheter shaft configured to selectively transition the controllably arcuate segment between the relatively straight and relatively curved configurations in response to manipulation of the mechanism;   percutaneously or surgically inserting and transluminally advancing the controllably arcuate segment into the biological conduit;   subsequently manipulating the mechanism to change the controllably arcuate segment from the relatively straight configuration to the relatively curved configuration; and   subsequently applying suction to the at least one opening in the controllably arcuate segment.   
     
     
         2 . A transluminal method for removing material from a biological conduit, said method comprising the steps of:
 providing a catheter device that comprises:
 an elongated catheter shaft having a proximal end, a distal portion and a distal end; and 
 a controllably arcuate segment positioned in the distal portion of the catheter shaft, proximal to the catheter shaft distal end, the controllably arcuate segment configured to selectively transition between a relatively straight shape and a relatively curved shape, the relatively curved shape having an axial offset with respect to the catheter shaft, the controllably arcuate segment including at least one opening in fluid communication with the proximal end of the catheter shaft; and 
 a control configured to engage the controllably arcuate segment to selectively effect the transition between the relatively straight and relatively curved shapes in response to activation of the control; 
   percutaneously or surgically inserting the catheter distal portion into the biological conduit and transluminally advancing the controllably arcuate segment through the biological conduit to a location proximate a material to be removed;   activating the control to change the controllably arcuate segment from a relatively straight shape to a relatively curved shape; and   removing the material from the biological conduit via the at least one opening of the controllably arcuate segment having the relatively curved shape.   
     
     
         3 . The method of  claim 2 , further comprising applying suction to the at least one opening in the controllably arcuate segment to remove the material from the biologically conduit. 
     
     
         4 . The method of  claim 3 , wherein the catheter device further comprises a suction device configured to apply the suction to the at least one opening in the controllably arcuate segment. 
     
     
         5 . The method of  claim 3 , wherein the catheter device further comprises a plunger assembly, and wherein the control comprises a grasper operably attached to the plunger assembly such that movement of the grasper applies the suction to the at least one opening. 
     
     
         6 . The method of  claim 2 , wherein the catheter device further comprises a sliding member movable within the elongated catheter shaft and controllably arcuate segment, and wherein the method further comprises:
 retracting the sliding member to move the material away from the at least one opening and toward the proximal end of the elongated catheter shaft.   
     
     
         7 . The catheter of  claim 2 , wherein the catheter device further comprises a sliding member movable within the elongated catheter shaft and controllably arcuate segment, wherein the controllably arcuate segment has a normally curved bias, and wherein the method further comprises:
 positioning the sliding member within the controllably arcuate segment to cause the arcuate segment to take the relatively straight shape.   
     
     
         8 . The method of  claim 2 , wherein the relatively curved shape of the controllably arcuate segment is formed by arcing the controllably arcuate segment in a first direction to create external convex and concave surfaces of the controllably arcuate segment in the first direction where the proximal and distal ends of the catheter shaft remain aligned along a longitudinal axis of the catheter. 
     
     
         9 . The method of  claim 8 , wherein the at least one opening is located at the convex portion of the controllably arcuate segment when the arcuate segment takes the relatively curved shape. 
     
     
         10 . The method of  claim 2 , further comprising, when the controllably arcuate segment takes the relatively curved shape, maintaining substantially straight portions of the elongated catheter shaft on both sides of the controllably arcuate segment that are co-axial with a longitudinal axis of the catheter. 
     
     
         11 . The method of  claim 2 , wherein the material to be removed is disposed on a wall of the biological conduit. 
     
     
         12 . The method of  claim 2 , wherein the controllably arcuate segment comprises a normally curved bias. 
     
     
         13 . The method of  claim 2 , wherein the catheter device further comprises a flexible linkage and a sliding member attached to the flexible linkage, and wherein the control comprises a grasper operably attached to the flexible linkage, and wherein the method further comprises:
 moving the grasper to move the sliding member relative to the controllably arcuate segment.   
     
     
         14 . The method of  claim 13 , wherein movement of the grasper causes the controllably arcuate segment to transition between the relatively straight shape and the relatively curved shape. 
     
     
         15 . The method of  claim 13 , wherein movement of the grasper causes the controllably arcuate segment to selectively traverse the at least one opening to move the material away from the at least one opening. 
     
     
         16 . The method of  claim 2 , wherein the catheter device further comprises an electrically activatable component positioned within the controllably arcuate segment and attached to at least one electrical wire, and wherein the control comprises a switch attached to the at least one electrical wire, and wherein the method further comprises:
 activating the switch to cause the controllably arcuate segment to transition between the relatively straight shape and the relatively curved shape.   
     
     
         17 . The method of  claim 16 , wherein the electrically activatable component comprises a component selected from the group consisting of piezo element; electromagnetic assembly; shaped memory component; shaped memory alloy; shaped memory polymer; and combinations of at least two thereof 
     
     
         18 . The method of  claim 16 , wherein the catheter device further comprises a power source configured to provide power to the electrically activatable component. 
     
     
         19 . The method of  claim 2 , wherein the catheter device further comprises a visualization marker configured to indicate the angular orientation of the at least one opening, and wherein the method further comprises:
 rotating the catheter shaft and controllably arcuate segment based on the positioned of the visualization marker.   
     
     
         20 . The method of  claim 19 , wherein the visualization marker is located on a portion of the controllably arcuate segment.