First Year Fellows Endoscopy Course ( August 6-7)

3-Electrocautery
Pdf Summary
Electrocautery is a potentially dangerous tool used in endoscopy that produces high frequency alternating current. The therapeutic basis of electrosurgery is the production of heat at a cellular level. Heat is produced by high-frequency alternating current flowing along a circuit that passes through tissue. Cutting is achieved with high voltage and high current density, causing cells to rapidly heat, boil, and burst, leading to tissue transection. Coagulation is achieved with lower voltage and lower current density, causing cells to heat more slowly, desiccate, and shrink, leading to clotting of blood vessels. Different temperature effects can be achieved by changing the waveform.<br /><br />The resistance to the flow of current in different materials determines the current flow. The tighter the snare, the more focused the energy (higher current density), but it should not be too tight. The electric current must travel in a complete circuit, and there are different methods for achieving this. Bipolar electrosurgery has no current through the body and uses a device with delivery and return electrodes for effect on contact tissue. Monopolar electrosurgery conducts current through the body and requires a grounding pad.<br /><br />Good grounding pad placement is crucial for safety, and it should be placed on a clean and dry area close to the electrosurgical site. Hair increases resistance, builds current density, and is flammable. Grounding pads should be placed on well-vascularized areas, ideally on the flank or alternatively on the thigh.<br /><br />In terms of safety considerations, grounding pads should be kept at least 15 cm away from any EKG electrode. In patients with pacemakers, consultation with cardiology is necessary for planned prolonged monopolar cautery. For patients with implantable cardioverter-defibrillators (ICD), immediate availability of a magnet and consultation with an arrhythmia specialist for interrogation and reprogramming is necessary. Argon plasma coagulation (APC) is a non-contact method that uses ionized argon gas to deliver monopolar current to the tissue. It can be used for vascular ectasias, tissue ablation, and as an adjunct to fistula closure. As a physician, it is important to have a good understanding of electrical concepts and how to set up the equipment for electrocautery.
Keywords
Electrocautery
endoscopy
high frequency alternating current
therapeutic basis
heat production
tissue transection
coagulation
current flow
bipolar electrosurgery
monopolar electrosurgery