Patent ID: 7147635

Claim:
A bipolar electrosurgical instrument comprising: an introducer having a handle portion and an outer shaft coupled to the handle portion, the introducer having a channel extending therein from an opening at a distal end of the introducer; a snare slidably positionable within the channel and slidable between an undeployed position wherein it is substantially retracted within the channel and a deployed position wherein a distal portion of the snare extends outwardly from the channel, wherein at least the distal portion of the snare is insulated substantially along its length except for a predetermined exposed section; a first electrically conductive member for coupling with a source of RF energy, the first electrically conductive member being positioned within the snare and having an active electrode exposed through the predetermined exposed section of the snare; a second electrically conductive member for coupling with a grounding element, the second electrically conductive member being positioned within the snare and having a return electrode portion exposed through the predetermined exposed section of the snare; a retention element at a distal end of the snare for securing the distal end of the snare to the introducer to thereby form a looped configuration of the snare; and at least one fluid delivery channel extending through the introducer between a fluid inlet at the proximal end of the introducer and a fluid outlet at the distal end of the introducer that is located in proximity to the exposed section of the snare; wherein the active electrode has a surface area sufficiently smaller than the return electrode such that application of RF energy to the active electrode causes vaporization of fluid between the active and return electrodes, forming a plasma bubble substantially adjacent to the active electrode.