A prospective multicenter study of submucosal injection to improve endoscopic snare papillectomy for ampullary adenoma

Background and Aims Whether or not submucosal injection of a diluted epinephrine solution should be used to lift ampullary tumors during endoscopic snare papillectomy is unclear. This study aimed to investigate the clinical efficacy of a simple snaring method versus submucosal injection for papillectomy. Methods A prospective multicenter study was performed at 4 tertiary referral centers. Patients with papillary lesions were randomized to undergo either simple snare papillectomy (SSP) or submucosal injection papillectomy (SIP) using 1:10,000 diluted epinephrine. The main outcome measures were complete resection rate and post-papillectomy adverse events. Results A total of 50 patients with biopsy-proven papillary adenomas were enrolled. Complete resection rates in the SSP and SIP groups were 80.8% (21/26) and 50.0% (12/24), respectively ( P = .02). However, tumor persistence at 1 month (15.4% vs 8.3%, P = .62) and recurrence at 12 months (12.0% vs 9.5%, P = .58) did not differ despite initial differences in the prevalence of a positive resection margin. The mean tumor size was 12 mm in the SSP group and 9.29 mm in the SIP group. Post-papillectomy bleeding developed in 42.3% (11/26) and 45.8% (11/24) of patients, respectively ( P = .80). Delayed bleeding (>12 h) occurred in 27.3% (3/11) and 36.4% (4/11) of patients, respectively ( P = .50). Post-procedure pancreatitis occurred in 15.4% (4/26) and 25% (6/24) of patients, respectively ( P = .49). Pancreatitis severity did not differ between the groups, and there were no procedure-related mortalities. Conclusions Although the recurrence rate was similar between the SSP and SIP groups, SIP showed no advantage over SSP in terms of achieving complete resection or decreasing the frequency of post-papillectomy adverse events, such as bleeding. SSP may thus be a simpler and primarily recommendable technique. (Clinical trial registration number: NCT02165852.)