SURGICAL INSTRUMENT

A device for morcellating tissue within a body cavity of a patient comprises a stationary tube (8) having a distal end portion, and a bipolar electrosurgical electrode assembly (13) located at the distal end of the tube. The electrosurgical electrode assembly (13) comprises first and second electrodes (14, 16) separated by an insulation member (15). When an electrosurgical cutting voltage is applied to the electrode assembly (13), and relative movement is initiated between the tube (8) and the tissue, a slug of severed tissue is formed within the tube such that it can be removed from the body cavity of the patient. The bipolar electrosurgical assembly (13) has a first circumferential region (A) and a second circumferential region (B), the first circumferential region (A) being longer than the second circumferential region (B). In the first circumferential region (A), the first electrode (14) is disposed further forwardly as compared with the second electrode (16); and, in the second circumferential region (B), the second electrode (16) is disposed at least as far forwardly as compared with the first electrode (14).