Danger of Thermal Burns by Forceps at Video-assisted Electrosurgery during Spray Coagulation

摘要

At video-assisted electrosurgery there is always a risk of causing thermal burn accidents, when high-frequency current flows into the non-targeted organs through forceps. It has been reported that the factors which cause the thermal burns are 1) capacitive coupling, 2) direct coupling, and 3) insulation failure or insulation puncture of monopolar forceps for video-assisted electrosurgery. The purpose of this study was to verify the possibility of the thermal burns by capacitive coupling current and insulation puncture using an experimental model. In this experiment, the conventional high-frequency surgical equipment and the monopolar forceps for video-assisted electrosurgery were used. We measured the capacitive coupling current which flows through the insulation tunic of forceps in each output mode of high-frequency surgical equipment. We also investigated the existence of electric discharge or insulation puncture, by changing the output of electric voltage and the thickness of the insulation tunic of forceps. We further evaluated detectability of the thinness of the insulation tunic with a commercial equipment to check the insulation failure of the forceps. The capacitive coupling current increased, as the length of trocar became longer, and was the largest in the spray coagulation mode. Electric discharge and insulation puncture occurred in the contact coagulation mode and the spray coagulation mode. The commercial tester to confirm the insulation of electrosurgical instrument was unable to detect abnormally thinned tunic for insulation. In order not to cause thermal burn accidents, it is important to avoid test hits in the spray coagulation mode, and to check the state of the insulation tunic before and after use.