ELECTROSURGICAL SYSTEM

Various embodiments disclose an electrosurgical system for treating biological tissue. The electrosurgical system comprises: an electrosurgical generator configured to supply microwave energy; a surgical scoping device having a steerable insertion cord for minimally invasive insertion to a treatment site within a body; and an electrosurgical instrument dimensioned to fit within an instrument channel that is located within the insertion cord. The electrosurgical instrument comprises: a flexible coaxial cable arranged to convey the microwave energy; and a radiating tip portion connected at a distal end of the coaxial cable and configured to receive the microwave energy, wherein the radiating tip portion has a maximum outer diameter that is 1.0 mm or less, and wherein the maximum outer diameter of the radiating tip portion is smaller than an outer diameter of the coaxial cable. Also, the radiating tip portion comprises: a proximal coaxial transmission line for conveying the microwave energy; and a distal needle tip mounted at a distal end of the proximal coaxial transmission line, wherein the electrosurgical instrument is slidable within the instrument channel to extend the distal needle tip beyond a distal end of the instrument channel to puncture biological tissue, and wherein the distal needle tip is arranged to deliver the microwave energy into biological tissue.