Prospective validation and revision of predictive models for post-ERCP pancreatitis: focus on procedure-related factors and a novel risk stratification approach.

Introduction: Post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) is the most common serious adverse event after endoscopic retrograde cholangiopancreatography (ERCP). Although retrospective models to predict PEP have shown promise, their real-world applicability remains uncertain. Thus, we used prospectively derived cohort data to validate current prediction models.

Methods: We conducted a prospective cohort study involving patients who underwent ERCP between August 2020 and December 2023. We validated the original PEP-risk prediction models using prospective cohort data and, if necessary, refined them using logistic regression analysis.

Results: Among the 1112 study participants, the original PEP-risk prediction models had limited performance. Although PEP incidence tended to increase across risk groups, the differences were mostly insignificant. Logistic regression highlighted procedural factors-total procedure time [odds ratio (OR) 1.13, 95% confidence interval (CI) 1.01-1.26 per 5 min], unintended pancreatic duct cannulation (OR 2.56, 95% CI 1.11-5.93), and pancreatic opacification (OR 2.57, 95% CI 1.19-5.58)-as independent PEP risk factors. This led to a revised model that assigned 1, 8, and 8 points to these factors. Patients stratified into low- (0-2 points), intermediate- (3-10 points), and high-risk groups (≥ 11 points) exhibited PEP incidences of 2.6% (95% CI 1.5-4.1%), 7.1% (95% CI 4.8-10.3%), and 12.6% (95% CI 8.6-17.8%), respectively.

Conclusions: We highlighted limitations of existing PEP-prediction models that necessitate refinement based on procedural variables. Our revised model accounted for the prolonged total procedure time, unintended pancreatic duct cannulation, and pancreatic opacification, offering enhanced accuracy in predicting PEP risk.