Electrosurgical vaporization of the prostate in the canine model

To investigate the histopathologic changes and heating patterns caused by electrosurgical vaporization of the prostate in the living canine model. Prostate electrosurgical vaporization was undertaken in the canine model. Temperatures within and near the prostate and of the irrigation fluid were measured during a single pass and during the creation of a vaporized cavity. The prostate and adjacent tissues were examined by gross and microscopic pathology. Coagulation occurred deep to the vaporization zone for 1.38 to 1.44 mm for a single pass of the rolling cylinder and up to 2.52 mm for multiple passes. Thermometry revealed temperature increases of only 4 °C 5 mm away from the vaporization site. The largest temperature increases were found in the irrigation fluid as it passed through the prostatic fossa. Microscopic pathology revealed no damage to adjacent tissues. Electrosurgical vaporization creates minimal deep heating and coagulation beyond the vaporized cavity. The majority of the heat is removed by the irrigation fluid.