Tissue heating device and rf heating method with tissue attachment feature

Abstract

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.

1 . A device for heating tissue comprising: an elongate catheter having a proximal end and a distal end, a catheter wall defining a compartment within the catheter, a window through the catheter wall open to the compartment, and at least one lumen passing between a first opening in the proximal end and a second opening in the compartment, the first opening being connected to a vacuum source; a cartridge at least partially disposed within the compartment, the cartridge having a surface with a heating element disposed along the cartridge, and an energy source operatively coupled to the heating element, the cartridge being operable to urge tissue into the compartment when the first opening is connected to the vacuum source; and a controller coupled to the cartridge and operable to selectively position and move the cartridge relative to the catheter and thereby provide a controlled movement of the heating surface along the window.