Abstract: A coaxial electrosurgical instrument has an elongate inner electrode insulated from and contained coaxially within a hollow tubular elongate outer electrode, each electrode having a distal uninsulated end portion contactable simultaneously to tissue. A controlled, high-frequency, potential difference is provided between the electrodes so that an electrical current flows substantially only through contacted tissue which lies between the contacting portions of the inner and outer electrodes. An undamped voltage enables incision of the tissue. Cauterization and coagulation are performed by applying a periodically damped voltage. The outer electrode has an end surface of an uninsulated distal end portion to form a leading edge. An axially oriented cutout extends inwardly from the leading edge and accommodates a distal end portion of the insulating sleeve, permitting selective location of the inner and outer electrode surfaces contacting tissue during use.

Abstract: A laser-powered surgical tool comprises an elongate distal end portion suitable for laparoscopic surgery, and contains an extreme distal end portion by which a laser-powered tip is applied to tissue to generate incisions of predetermined but adjustable depth therein. The tissue being incised is held by suction in an optimum position for advancing the incision while, simultaneously, any gases and incidental fluids generated or released by the advancing incision are removed by suction applied immediately around the incision point as the incision proceeds.