Electrosurgical generators and monopolar and bipolar electrosurgery

Abstract

Electrosurgery is the most commonly used and misunderstood technology by all surgical and medical disciplines. A lack of basic knowledge or ignorance of principles of electrosurgery and equipment among obstetricians and gynecologists is reported. As a result, thermal injuries during laparoscopic electrosurgery occur, which frequently lead to significant morbidity and mortality and medicolegal actions. Surveys indicate that up to 90% of general surgeons and gynecologists use monopolar radiofrequency (RF) during laparoscopy, 18% have experienced visceral burns, and 13% admitted 1 or more ongoing cases of litigations associated with such burns. This article describes the basics of electrosurgery beginning with the generation of electrons and their physical characteristics and governing laws before their arrival in the operating room where they are fed to an electrosurgical unit (ESU) to boost their frequency with step-up transformers from 60 Hz to >500 000 Hz. This RF creates heat, resulting in dissection, desiccation, coagulation, and fulguration of tissues without neuromuscular stimulation, pain, or burn to the patient. The ESU delivers power (wattage = volts × amps) in monopolar or bipolar (1 vs 2 high-density electrodes) configuration. Because of RF, monopolar electrosurgery compared with other energy sources is associated with unique characteristics, inherent risks, and complications caused by the requirement of a return/dispersive electrode, inadvertent direct and/or capacitive coupling, or insulation failure of instruments. These dangers become particularly important with the popular and frequent use of monopolar electrodes (hook, needle, and scissors) during cholecystectomy; robot-assisted surgeries; and the re-emergence of single-port laparoscopy, which requires close proximity and crossing of multiple intraabdominal instruments outside the surgeon's field of view. Presently, we identify all these potential risks and complications associated with the use of electrosurgery and provide suggestions and solutions to mitigate/minimize these risks based on good clinical practice and sound biophysical principles.