ARGON PLASMA COAGULATION: IN VIVO TISSUE DAMAGE TO THE ESOPHAGUS AND STOMACH AND CLINICAL EFFICACY FOR EARLY ESOPHAGEAL AND GASTRIC CANCER

Abstract

Background: Argon plasma coagulation (APC) has been proven to be safe in vitro, and has been widely introduced to therapeutic endoscopy. We evaluated the thermal effects on esophageal or gastric wall in vivo, and its effectiveness as an adjunct to incomplete resection of early esophageal and gastric cancer after endoscopic mucosal resection (EMR).Methods: Thermal injuries were made using endoscopic APC irradiation in porcine esophagus and stomach under various conditions during general anesthesia, and depth of tissue damage was determined histopathologically. Patients with early gastric cancer (n = 24) and early esophageal cancer (n = 5) were treated with additional APC following microscopically incomplete EMR. APC was applied to coagulate the entire edge of EMR‐induced ulcer 1 week after resection at power/gas settings of 50 W and 1.5 L/min in the stomach, and 40 W and 1.5 L/min in the esophagus for less than 5 s at each point.Results: Depth of tissue damage was related to pulse duration and power output. At power/gas settings of 60 W and 2.0 L/min, thermal damage extended across the submucosal layer with 5‐s pulse duration in the stomach. Thermal damage with 5‐s pulse duration at power/gas settings of 40 W and 2.0 L/min extended to the muscularis propria in the esophagus. In the clinical study of additional APC therapy, the recurrence rate was 6.9% (two of 29 cases).Conclusion: To avoid perforation, we recommend an APC power setting of 40–60 W for less than 5 s in the stomach and a lower power setting with shorter duration in the esophagus. APC seems to reduce recurrence of esophageal or gastric cancer after incomplete EMR.