An electrosurgical apparatus comprises a housing having a passage extending therethrough, a flow tube disposed in the passage of the housing an insulating outer tube disposed around the flow tube with the proximal end of the outer tube coupled to the distal end of the housing, the flow tube being movable along a longitudinal axis of the housing and outer tube an electrode coupled to the distal end of the flow tube, and a transformer assembly disposed on the proximal end of the housing and including a first transformer receiving electrosurgical energy at a first value from an electrosurgical generator and an external input receiving electrosurgical energy at a second value from the electrosurgical generator, the transformer assembly further including a first switch for selectively coupling at least one of the first transformer and the external input to the electrode for providing electrosurgical energy thereto.
