First Year Fellows Endoscopy Course (July 30-31)

3-Electrocautery
Pdf Summary
Electrocautery is described as potentially the most dangerous tool used in endoscopy. It operates by producing high-frequency alternating current, which generates heat at the cellular level to achieve different temperature/thermal effects. The heat produced by electrocautery allows for cutting and coagulation of tissue. Cutting is performed at a higher voltage and high current density, while coagulation is achieved at a lower voltage and lower current density. The temperature of the tissue determines the effect, with temperatures ranging from reversible cellular trauma to coagulation and cutting.<br /><br />The effectiveness of electrocautery is impacted by various factors including resistance, current density, and snare closure. Resistance, measured in ohms, determines the flow of current, with greater resistance leading to less current flow. Snare closure affects the focus of the energy, with a tighter snare resulting in higher current density. The complete circuit of electric current involves an electrocautery generator, the tissue, and either a bipolar or monopolar configuration. A bipolar configuration carries the delivery and return electrodes within the device, minimizing the effect on surrounding tissue. A monopolar configuration, on the other hand, requires a grounding pad and conducts current through the body.<br /><br />Proper safety measures are crucial when using electrocautery. This includes placing the grounding pad in a clean and dry area, avoiding bony prominences or prosthetics, and maintaining a suitable distance between the active electrode and EKG electrodes. Hair increases resistance and builds current density, making it flammable. Pad placement should also be considered, with a recommended location on the leg, away from the body. Additional precautions must be taken for patients with pacemakers or implanted cardioverter-defibrillators (ICDs), including having a magnet and external defibrillator with transcutaneous pacing ability readily available.<br /><br />One modality of electrocautery is argon plasma coagulation, which utilizes ionized argon gas to deliver monopolar current to tissue. It offers advantages such as non-contact application, even and uniform coagulation, and a shallow depth of coagulation. Argon plasma coagulation can be used for various applications including the treatment of vascular ectasias, tissue ablation, and as an adjunct to fistula closure.<br /><br />Overall, it is crucial for physicians to have a deep understanding of their current generator and electrocautery devices and to take responsibility for setting up the equipment. Simplifying the electrical concepts behind electrocautery and focusing on the generation of heat can help ensure safe and effective use of this tool.
Keywords
Electrocautery
Endoscopy
High-frequency alternating current
Cutting
Coagulation
Resistance
Current density
Snare closure
Bipolar configuration
Monopolar configuration