Abstract: An endoscope comprises a telescope (12), an electrode assembly (13) comprising at least one electrode (13T), and elongate conductive means (13S) for supplying electrosurgical power to said at least electrode from the proximal end of the conductive means. Means are provided for supporting the electrode assembly (13) on the telescope (12) for pivotal movement, in a plane substantially normal to the axis of the telescope, towards, and away from, an operational position in which the conductive means (13S) is substantially parallel to the telescope. Sealing means (16,29) seals the electrode assembly (13) to prevent fluid passing from an operation site adjacent to said at least one electrode (13T) to the proximal end of the conductive means (13S).

Abstract: An electrode assembly for electrosurgical removal of tissue immersed in an electrically conductive liquid has an elongate support structure including at least a pair of wire conductors for carrying radio frequency current, and a bipolar electrode assembly, extending transversely between the two conductors. The tip assembly has a ribbed transversely extending active electrode and a smooth-surfaced transversely extending return electrode mounted on opposite faces of a ceramic insulator body. The electrodes comprise metallic plates on the insulator body, the surface area of the active electrode being between 1.25 to 2 times that of the return electrode. To provide for endoscope mounting, the wire conductors are secured to a spring chip for detachable mounting to the telescope tube of an endoscope.