Impact of periampullary diverticulum and relevant cannulation techniques on the outcomes of endoscopic retrograde cholangiopancreatography: a retrospective study.

BACKGROUND: Periampullary diverticulum (PAD) is an incidental finding during endoscopic retrograde cholangiopancreatography (ERCP), occurring more frequently in elderly patients. The influence of PAD on the ERCP procedure has been a subject of debate. The aim of this study was to investigate the impact of PAD on ERCP outcomes. METHODS: Medical records of patients with naïve papilla who underwent ERCP between 2022–2024 were retrospectively reviewed. Patients were classified into PAD and non-PAD groups. Patients with PAD were subclassified into three groups: type I, II, and II, with the location of papilla inside, at the margins, and outside the PAD. Cannulation success, ERCP findings, and adverse events were compared between the groups. RESULTS: A total of 179 and 884 patients were included in the PAD and non-PAD groups, respectively. After 1:1 propensity score matching (151 patients in each group), there was no significant difference between the PAD and non-PAD groups regarding the rate of successful biliary cannulation (96.7% vs. 98.0%, p = 0.361), difficult cannulation (49.0% vs. 40.4%, p = 0.132), successful stone extraction (85.8% vs. 93.0%, p = 0.64), and post-ERCP pancreatitis (PEP) (13.9% vs. 14.5%, p = 0.869). Additionally, there was no significant difference in the rate of PEP when the same cannulation techniques were compared between the two groups (p > 0.05). Among the three subtypes of PAD, no significant difference was observed in cannulation success and adverse event rates (p > 0.05). CONCLUSIONS: Presence of a PAD is not associated with increased risk of cannulation difficulty, procedural failure, or adverse events. Different cannulation techniques, if applied carefully and in accordance with the endoscopist's experience, could all be successful in patients with PAD.