A tissue
cutting device includes a
catheter with a window at its distal tip for admitting tissue into a
catheter compartment. A cylindrical
cartridge in the compartment has a
cutting edge that supports an
electrically conductive cutting element, e.g. a band or wire. The cutting element and adjacent tissue can be heated to a selected temperature by generating an
electrical current through the cutting element. The
catheter is maneuverable to position its distal end near the tissue to be
cut. The catheter incorporates a dilatation
balloon or other feature to urge the catheter against the tissue, so that at least part of the tissue may enter the compartment through the window. Then, the
cartridge is manipulated from the catheter's proximal end to move the cutting edge across the window, cutting the tissue. According to alternative embodiments, the
cartridge is either rotated or moved axially relative to the catheter and, in either event may be capable of closing the catheter window when the
cut is complete. Further alternatives involve either placing an
indifferent electrode on the patient and providing an RF
signal via a single conductor to the cutting element for ohmic heating, or providing an RF (or a DC) current through the cutting element and two separate conductors for direct resistive heating of the cutting element.