[Biophysical principles of tissue electrovaporization]

The principles of electrosurgery are based upon well defined physical grounds, explaining the type and extent of the lesions induced by the electric current. Technological evolution has led to the creation of dedicated equipment, allowing efficient use of electrosurgical cutting and coagulation of tissues, both in open and endoscopic surgery. Electrovaporization is the thermal effect obtained when an alternating high power-high frequency current (300 W, 400-500 kHz) is applied to the tissue using an electrode with particular geometric aspects. The main feature is the presence of higher and lower current density zones. The first induce electrovaporization, whilst the second produce simultaneous hemostatic coagulation of the rims. New effective vaporizing electrodes have been recently introduced into clinical practice. Their use in the endoscopical treatment of bladder outlet obstructions, a stimulating alternative to standard resection or laser applications, is currently under evaluation.