Abstract: A plasma ablation system includes a plasma guide wire having a conductive first electrode formed on a distal end portion, a catheter having a conductive second electrode formed on a distal end side and a lumen through which the plasma guide wire is inserted, and a radio frequency (RF) generator electrically connected to each of the plasma guide wire and the catheter to output a high frequency electric power to the first electrode and the second electrode. The plasma guide wire can ablate a living body tissue by discharge between the first electrode and the second electrode, and the RF generator outputs the high frequency electric power that is 50 W or higher and 100 W or lower during discharge and pulse-modulated to have a duty ratio of 7.4% or higher and 40.0% or lower.

Abstract: A catheter includes a hollow shaft; a distal end electrode provided on a distal end portion of the hollow shaft; a proximal end electrode provided on a proximal end portion of the hollow shaft, and which is electrically connected to the distal end electrode via the hollow shaft; and a connection portion which is capable of being attached to and detached from the proximal end electrode and which, by being attached to the proximal end electrode, electrically connects an external voltage output device and the proximal end electrode via a lead wire.