Electrosurgical resector tool

Various embodiments provide an electrosurgical resector tool comprising: an energy conveying structure for carrying radiofrequency (RF) electromagnetic (EM) energy and microwave EM energy, the energy conveying structure comprising a coaxial transmission line 202 having an inner conductor 234 separated from an outer conductor 236 by a dielectric material 238; and an instrument tip 200 mounted at a distal end of the energy conveying structure. The instrument tip 200 comprises a first jaw 206 and a second jaw 208. The second jaw 208 is movable relative to the first jaw 206 between a closed position in which the first jaw 206 and the second jaw 208 lie alongside each other, and an open position in which the second jaw 208 is spaced from the first jaw 206 by a gap for receiving biological tissue. The first jaw 206 comprises a first pair of electrodes that are electrically isolated from one another. The second jaw 208 comprises a second pair of electrodes that are electrically isolated from one another. The first pair of electrodes is coupled to the energy conveying structure, such that the first pair of electrodes is operable as active and return electrodes for delivering RF EM energy carried by the energy conveying structure. The second pair of electrodes is coupled to the energy conveying structure, such that the second pair of electrodes is operable as active and return electrodes for delivering RF EM energy carried by the energy conveying structure. The first and second pairs of electrodes are operable as a microwave field emitting structure for emitting microwave EM energy carried by the energy conveying structure.