A surgical snare comprising a means of delivering thermal plasma on to biological tissue encircled by the snare. The snare may be "cold" snare, i.e. formed from insulating material, or active, i.e. connected to receive RF and/or microwave energy to be radiated into the area encircled by the snare. The surgical snare may thus deliver into biological tissue encircled by a retractable loop any one of (i) a plasma to perform surface coagulation, (ii) a non-ionising microwave field (in the absence of plasma) to perform coagulation at a deeper level, and (iii) an RF field to assist with cutting.
