ARGON PLASMA COAGULATION (APC) IN GASTROENTEROLOGY - EXPERIMENTAL ANDCLINICAL-EXPERIENCES

Background: Diathermy procedures are indispensable in interventional e ndoscopy. Argon beam coagulation is an innovative no-touch electrocoag ulation technique in which high-frequency alternating current is deliv ered to the tissue through ionized argon gas. Methods and patients: Be fore clinical application, we conducted in-vitro studies to investigat e the depth and diameter of tissue coagulation in fresh operative spec imens from the stomach, small intestine and colon. Five different powe r/gas flow settings between 40 and 155W and 2 and 7 l/min were used. T he impact time (1-10s) and the incident angle of the probe (45 degrees and 90 degrees) were also varied. The maximum depth of necrosis was 2 .4 mm, the maximum diameter 1.1 cm. No perforation occurred even in cr itical areas such as the colon and duodenum. We therefore performed ar gon beam coagulation in 66 consecutive patients. Two power/gas flow se ttings of 40 and 70W and 2 and 3 l/min, respectively, were used. The i mpact time and incident angle were varied individually. Results: In 49 of the 50 patients with oozing haemorrhage from angiodysplastic lesio ns, polypectomy sites, erosions or ulcers or oozing of blood due to va scular penetration by tumours, definitive haemostasis was achieved in one to two sessions. In all 11 patients with residual sessile adenoma tissue, complete removal was possible. Oesophageal patency was restore d in all five patients with stenosing tumours. In one patient with ang iodysplasia of the caecal pole, an asymptomatic accumulation of gas in the submucosa was observed which resolved spontaneously. In two patie nts with extensive oesophageal carcinoma, there was a transitory - als o asymptomatic - accumulation of gas in the mediastinum and peritoneal cavity but no evidence of perforation. Conclusion: Argon plasma elect rocoagulation is an effective and relatively low-cost alternative to l aser therapy in gastrointestinal endoscopy.