An electrosurgical system (20) preferably used for denervation procedures of nerve tissue has a control unit (22) and a pluggable electrode assembly (24). The electrode assembly (24) has a preferably disposable cannula (28) and a preservable supply electrode assembly (36). The cannula (28) has a tubular body (29) that projects axially from a preferably pointed distal end for piercing tissue to a proximal end engaged to a first coupling assembly (44) of the cannula (28). The body (29) carries a first contact (68) exposed directly to the nerve tissue and connected electrically to a terminal (86) of the first coupling assembly (44). The supply electrode assembly (36) has a second coupling assembly (116) and a supply electrode (118) that projects axially and removably into a through-bore (57) of the body (29) when the tool is in an operating state. The second coupling assembly (116) carries a terminal (140) that abuts the first coupling assembly (44) when the coupling assemblies (44, 116) are mated. Preferably the supply electrode (118) carries a temperature sensor (120) for temperature measurement of the targeted tissue and processing by the control unit (22). Preferably, the electrode assembly (24) also includes a stylet (30) having a rod (80) that fits into the through-bore (57) of the body (29) when the supply electrode assembly (36) is removed and the tool (24) is in a tissue penetrating state.
