Argon Plasma Coagulation (APC)

Argon plasma coagulation (APC) is a non-contact thermal coagulation modality that uses ionized argon gas to deliver electrical energy to tissue. Because the energy arcs through the gas to the nearest tissue surface, APC produces uniform superficial coagulation without direct contact, which makes it ideal for treating diffuse, broad, or hard-to-reach mucosal lesions.

Common applications include angiodysplasias and GAVE, radiation proctitis, Barrett's epithelium ablation, post-polypectomy bleeding control, and ablation of residual adenomatous tissue at EMR margins. APC is also used for tumor de-bulking in luminal stenosis when the goal is symptom palliation rather than cure.

Settings vary by tissue and indication. Typical power settings are 30–60 W for GAVE and angiodysplasias and 40–80 W for thicker tissue. Pulsed and forced modes deliver different energy profiles — pulsed for shallow uniform burns, forced for deeper coagulation. The probe is held 2–8 mm from the mucosa; closer contact risks deep injury and perforation, particularly in the right colon or thin-walled cecum. Cap-assisted APC and use of a transparent distal cap improve targeting in the cecum and around folds.