APPARATUS FOR ABLATION OF TISSUE MASSES

A volumetric tissue ablation apparatus (10) includes a probe (12) having a plurality of wires (24) journaled through a catheter (26) with a proximal end connected to the active terminal (16) of a generator (14 ) and a distal end projecting from a distal end of the catheter (26). The probe wire distal ends (24a) are arranged in an array with the distal ends (24a) located generally radially and uniformly spaced apart from the catheter distal end (26a). A conductor (22) connected to the return terminal (18) of the generator is located relative to the probe wire array (28) to form a closed electrical circuit through tissue to be ablated. Preferably, the probe wire array (28) includes ten wires, each formed in an arch from the catheter distal end (26a). The conductor (22) can be either a conventional ground plate (20) upon which the tissue is supported, or a conductor wire extending through the pro be (12) and electrically insulated from the probe wires (24).