The Efficacy of Argon Plasma Coagulation for the Salvage Treatment of Gastric Intramucosal Tumor

Abstract

Background: Currently endoscopic mucosal resection (EMR) is used to treat gastric tumors (early cancer and adenoma) and considered safe and effective. However, the number of patients with gastric tumors who have comorbidities that preclude either surgical resection or EMR is increasing. The aim of this study is to determine the efficacy of argon plasma coagulation (APC) for the salvage treatment of gastric tumors. Methods: This study included 14 patients (male:female 10:4, mean age 62.2 years). 7 patients had gastric adenomas (elevated lesion: 5 cases, flat lesion: 2 cases, mean size: 16 mm in diameter) and 7 patients had EGC (depressed lesion: 3 cases, elevated lesion: 4 cases, mean size: 14 mm in diameter). Ex-vivo experiment was performed to determine irradiation condition for APC treatment. Irradiation was performed with the electrode at a distance of 1-2 mm from the surgically resected fresh human gastric tissues after obtaining informed consent. The power of the high frequency currents was 30W, 50W, 70W and 90W, while irradiation times were 2, 4, 6, 8 and 10 seconds. Coagulation depth with various irradiation conditions based on histological analysis was scored from 0 to 4 (0: none or minimal, 1: confined to the mucosa, 2: <1/2 of submucosa, 3: >1/2 of submucosa, 4: extending into muscularis propria). Indication of APC was recurrence after EMR (1), remnant tumor after EMR (2), incomplete EMR due to severe bleeding (3) and untreatable patients due to old age or comorbidities (8). Results: According to the result of the ex vivo experiment, the optimum APC treatment condition for complete cauterization of mucosal and less than half of the submucosal layer was a current of 70W for 6 seconds. Mucosal cauterization after marking around each tumor, was performed in the manner determined by the ex-vivo experiments. The number of sessions for complete cauterization was 1.6 (1.4 for adenoma, 2 for EGC). No serious complications occurred. During the mean follow-up of 9 months (5-19 months), complete cauterization was achieved in 13 patients. One patient with EGC was found to have recurrence 2 months after treatment and managed by repeated APC Conclusions: APC could be considered as a salvage treatment for gastric tumors. Further study with long term follow up is required to evaluate the role of APC in the treatment of early gastric cancer untreatable by surgical resection or endoscopic mucosal resection.