Pathological Evaluation of the Therapeutic Effects of Argon Plasma Coagulation in Gastric Low-Grade Dysplasia.

Objectives: Gastric dysplasia is primarily treated using endoscopic resection. Although argon plasma coagulation (APC) is an alternative treatment for older patients or those with bleeding tendencies, studies have reported a higher rate of local recurrence after APC than after endoscopic resection. Using pathological examinations, this study aimed to investigate the incidence and associated causative factors of residual dysplasia following APC. Methods: This prospective study recruited patients with low-grade gastric dysplasia from March 2020 to February 2021 and conducted follow-up examinations for 15 months after enrollment of the last patient. The patients were randomly assigned to undergo APC at an output power setting of 45, 60, or 80 W. Results: Residual lesions were found in 13 of 68 patients (19.1%) during the 24-h follow-up endoscopy and biopsy. The Ki-67 index, a marker of cellular proliferation, was significantly associated with the presence of residual lesions. The presence of residual dysplasia at the three-month follow-up was associated with the presence of residual lesions at the 24-h follow-up and a positive Ki-67 index. Only three of the 13 patients with residual lesions 24 h after APC demonstrated residual lesions at the three-month follow up. No post-procedural complications were observed. Conclusions: Residual dysplasia may persist even after APC and cause local recurrence. If Ki-67-positive cells are detected in the remnant tissue following APC, additional interventions should be considered.