Abstract: A surgical instrument comprises at least two elongate hollow tubes (14, 15), each having an aperture (18) at the distal end portion. The inner tube (14) is disposed within the other tube (15), and is mounted for rotation about its longitudinal axis. A cutting tool (4) is located at the distal end of the tube (14), and is positioned adjacent to the apertures (18). A motor (5) is provided for rotating the inner tube (14), and the inner tube (14) has a central lumen (21) through which tissue cut by the cutting tool (4) is removed under the action of a source of suction (12). Heat is supplied to the tissue, prior to, or simultaneously with, the cutting thereof, such that the tissue being cut by the cutting tool (4) is coagulated tissue. In one embodiment, there is a third tube (16), and saline is fed to the apertures (18) via a channel (19) between the tubes (15) and (16). The outer tube (16) constitutes an active electrode, and the inner tube (14) constitutes the return electrode of an electrosurgical device.