Neurosurgery Monopolar coagulation of neutral tissue requires special care and very often the cut output is preferred for desiccation of tissue rather than the fulguration output. This is because when neutral tissue is fulgurated, i.e. using the coagulation output, a hard superficial plaque of eschar is formed. Whilst this is being produced, most of the water is driven off and the plaque shrinks. A possible effect of this shrinking is that new bleeding can occur at the point the coagulated tissue joins the normal tissue.

Desiccation of neutral tissue leaves the tissue soft, with less shrinking than caused by fulguration. There is therefore less likelihood of the tissue in being coagulated, promoting new bleeding due to the shrinking effect. As desiccation necessarily involves the electrode being kept in contact with the tissue to eliminate sparking, the desiccation technique can cause tissue adhesion to the surgical instrument. This possibility can be reduced by the use of irrigation and having instruments which have brightly polished tips.

The use of the Bipolar output is preferred for many neurosurgical procedures as bipolar forceps will desiccate rapidly with little, if any, sparking. The bipolar technique passes the electrosurgery current from one side of the forceps to the other with minimal radiated effect due to the high degree of isolation (from ground) of the bipolar generator.

Some machines are equipped with two bipolar outputs which are intended for micro and macro bipolar surgery. As the micro output normally gives a maximum of only 15 watts, this will normally be used for intra-cranial neurosurgery. Use of the macro output (which gives up to 50 watts) may occasionally be required for extra-cranial coagulation, i.e. for the stopping of bleeding in scalp incisions.