Device for morcellating tissue

A device for morcellating tissue within a body cavity of a patient comprises a stationary tube having a distal end portion, and a bipolar electrosurgical electrode assembly located at the distal end of the tube. The electrosurgical electrode assembly comprises first and second electrodes separated by an insulation member. When an electrosurgical cutting voltage is applied to the electrode assembly, and relative movement is initiated between the tube and the tissue, a core of severed tissue is formed within the tube such that it can be removed from the body cavity of the patient. The tube comprises a twin-walled construction with an inner wall, an outer wall and an air gap therebetween. This twin-walled construction reduces the heat that is able to travel proximally along the tube.