A debulking catheter comprising a tissue debulking assembly for removing a continuous strand of material from a body lumen. Catheters of the present invention generally include a catheter body having proximal and distal portions and a tissue debulking assembly disposed at least partially within the distal portion. The tissue debulking assembly is radially movable to expose at least a portion of the assembly through a window on the catheter body. The catheter is advanced transluminally through the body lumen to contact material in the body lumen and remove a plane of continuous material that has a length that is typically longer than a length of the window on the catheter. The continuous material may be directed into a collection chamber. Thereafter, the material may be removed from the collection chamber and preserved or tested.
