Morphology of the major papilla predicts ERCP procedural outcomes and adverse events

Background: The morphology of the major papilla affects the difficulty of endoscopic retrograde cholangiopancreatography (ERCP), but no associations with adverse events have previously been established. We aimed to assess whether papillary morphology predicts ERCP adverse events. Methods: A retrospective analysis was performed of a prospective registry of patients undergoing ERCP for biliary indications. The primary outcome was post-ERCP pancreatitis (PEP), with secondary outcomes including other adverse events and procedural outcomes such as inadvertent pancreatic duct cannulation, cannulation time, and attempts. Papillae were classified as normal (Type I), small or flat (Type II), bulging (Type IIIa), pendulous (Type IIIb), creased (Type IV), or peri-diverticular (Type D). Outcomes were ascertained prospectively at 30 days from index procedures. Results: A total of 637 patients with native papillae were included. Compared to Type I papillae, Type II and Type IIIb papillae were associated with PEP, with adjusted odds ratios (AOR) of 7.28 (95% confidence intervals, CI, 1.84–28.74) and 4.25 (95% CI 1.26–14.32), respectively. Type II and IIIb papillae were associated with significantly longer cannulation times by 5.37 (95% CI 2.39–8.35) and 4.01 (95% CI 1.72–6.30) minutes, respectively. Type IIIb papillae were associated with lower deep cannulation success (AOR 0.17, 95% CI 0.06–0.48). Conclusion: Papillary morphology is an important factor influencing both ERCP success and outcomes. Understanding this is key for managing intraprocedural approaches and minimizing adverse events. Prospective registry registration: Clinicaltrials.gov identifier NCT04259580.