Patent ID: 6027501
Filing Date: 2000-02-22
Classification: A61B

Abstract:
An electrosurgical instrument for the treatment of tissue in the presence of an electrically-conductive fluid, the instrument comprising an instrument shaft and an electrode assembly at one end of the shaft, the electrode assembly comprising:a tissue treatment electrode,a return electrode, andan insulation member which electrically insulates the return electrode from the tissue treatment electrode,the tissue treatment electrode being exposed at the extreme distal end of the instrument, andthe return electrode having a fluid contact surface axially spaced from the exposed end of the tissue treatment electrode by the insulation member so that, in use, the return electrode does not contact the tissue to be treated,wherein the instrument further comprises, a feeder for feeding cool electrically-conductive fluid to the region of the exposed end of the tissue treatment electrode in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode and the return electrode, andan extractor for removing heated electrically-conductive fluid from the region of the exposed end of the tissue treatment electrode.