Voyles C R, Tucker R D
Surgical Clinic Associates, Jackson, Mississippi 39202.
Am J Surg. 1992 Jul;164(1):57-62. doi: 10.1016/s0002-9610(05)80648-8.
The potential problems of monopolar electrosurgery relate to unrecognized energy transfer ("stray current") outside the view of the laparoscope. Mechanisms of stray current and unrecognized tissue injury include: (1) insulation breaks in electrodes; (2) capacitive coupling, or induced currents through the intact insulation of the active electrode to surrounding cannulas or other instruments; and (3) direct coupling (or unintended contact) between the active electrode and other metal instruments or cannulas within the abdomen. Capacitive coupling poses the greatest risk for injury when the outer conductor (trocar cannula or irrigation cannula) is electrically isolated from the abdominal wall by a plastic nonconductor. Capacitive coupling is increased by the coagulation mode (versus cut), open circuit (versus tissue contact with the electrode), 5-mm cannulas (versus 11 mm), and higher voltage generators. The safety of electrosurgery can be enhanced by surgical education regarding the biophysics of radio frequency electrical energy, technical choices in instruments using all-metal cannula systems, and engineering developments with a dynamically monitored system for insulation failure and capacitive coupling.
单极电外科手术的潜在问题与腹腔镜视野外未被识别的能量转移（“杂散电流”）有关。杂散电流和未被识别的组织损伤机制包括：（1）电极绝缘破损；（2）电容耦合，即通过有源电极完整的绝缘层向周围套管或其他器械感应出电流；（3）有源电极与腹腔内其他金属器械或套管之间的直接耦合（或意外接触）。当外部导体（套管针或冲洗套管）通过塑料非导体与腹壁电隔离时，电容耦合造成损伤的风险最大。凝固模式（相对于切割模式）、开路（相对于电极与组织接触）、5毫米套管（相对于11毫米）以及更高电压的发生器会增加电容耦合。通过开展关于射频电能生物物理学的外科培训、选用使用全金属套管系统的器械以及采用具有绝缘故障和电容耦合动态监测系统的工程技术改进措施，可以提高电外科手术的安全性。
