Argon Plasma Coagulation (APC) for Treatment of Hemorrhagic Radiation Proctitis: Optimum Setting for APC Cauterization

Abstract

Aim: Recently it has been reported that Argon Plasma Coagulation (APC) is effective for hemorrhagic radiation proctitis. However, these studies documented complications such as ulcer, stricture and perforation in 0 - 20%. Therefore, in this study, we first determined the optimum irradiation conditions of APC using animal model, and then treated patients with hemorrhagic radiation proctitis to assess effectiveness and safety of APC treatment. Patients and Methods: We performed ex vivo animal experiments using 2 swine rectal walls and determined irradiation conditions for APC treatment. The optimum APC treatment condition was a current of 40 W with a maximum irradiation time of 2 s, which was enough to affect complete cauterisation of the submucosal layer but not the muscle layer. Thirty patients (M/F, 22/8; a median age, 69) with a confirmed diagnosis of radiation proctitis were enrolled after informed consents were obtained. All patients presented with overt rectal bleeding. The clinical scoring of rectal bleeding and endoscopic scoring were graded from 0 to 4, according to the criteria of Chutkan et al. and Canade et al., respectively. APC was performed at one or two weeks intervals until all visible telangiectatic lesions had been cauterized, and all patients were followed up for at least 3 months. Results. A total of 58 APC treatment sessions were performed, and the mean number of APC sessions was 2.3 (range 2 - 4). All patients had a marked reduction in rectal bleeding. The mean clinical score of rectal bleeding before treatment (2.67) was significantly deceased after APC treatment (0.67, p<0.001). Of the 30 patients, only 2 had shown a minor persistent rectal bleeding, and required two repeat APC sessions later. Minor recurrent rectal bleeding was observed in 3 patients, but disappeared spontaneously. No recurrent rectal bleeding was observed in the remaining 25 patients. No patients required blood transfusions after APC treatment. The mean hemoglobin concentration increased from 10.1 g/dL before treatment to 12.4 g/dL 6 months after treatment (P < 0.002). Endoscopic improvement was noted in all patients with near total resolution of telangiectasiae, ulceration and contact bleeding. The endoscopic score fell from 1.6 to 0.3 (P < 0.002) in the 28/28 patients after 3 months. All APC sessions were well tolerated. There were no long-term complications such as fistulas, ulcers, or strictures during the median follow up of 14 months. Conclusion: We determined the optimum irradiation condition for APC treatment of radiation proctitis, and demonstrated that APC is an effective, safe, and well-tolerated treatment for hemorrhagic radiation proctitis.