First Year Fellows Endoscopy Course (August 5 - 6)

3-Electrocautery
Pdf Summary
Electrocautery is a potentially dangerous tool used in endoscopy. It is important to understand the basic terms associated with electrosurgery, such as current, circuit, voltage, and current density. An electrosurgical generator produces high-frequency alternating current, which is used for cutting and coagulation. There are two types of circuits: monopolar and bipolar. Electrosurgery produces heat at the cellular level, which can cause different effects depending on the temperature reached, including reversible and irreversible cellular trauma, coagulation, cutting, and carbonization. The type of effect can be changed by adjusting the waveform. Electric current travels in a complete circuit, and in monopolar electrosurgery, the current is conducted by the body and requires a grounding pad. The grounding pad completes the electrical circuit and disperses the current. There are certain safety considerations when it comes to pad placement. Hair increases resistance and can build up current density, thus it should be avoided. In patients with pacemakers, caution should be taken, and in cases of prolonged monopolar cautery, consultation with a cardiologist may be necessary. Current density is higher when the snare is tighter. Argon plasma coagulation (APC) is a non-contact method of delivering monopolar current to the tissue using ionized argon gas. It has advantages such as even and uniform coagulation and thinner eschar formation. APC can be used for various applications, such as treating vascular ectasias, tissue ablation, and adjunct to fistula closure. There are various variables to consider when using APC, including intention (coagulation vs. ablation), anatomic considerations, water content of tissue, probe type and distance from tissue, power, argon flow rate, and frequency of delivery. It is important for physicians to understand and be familiar with their current generator and electrocautery devices.
Keywords
Electrocautery
Endoscopy
Electrosurgery
Current
Circuit
Voltage
Current density
Monopolar
Bipolar
Grounding pad