Post‐endoscopic retrograde cholangiopancreatography pancreatitis in single‐stage endoscopic common bile duct stone removal

BACKGROUND AND AIMS: Papillary treatment, such as endoscopic sphincterotomy or endoscopic papillary balloon dilation, and subsequent single‐stage endoscopic stone removal are often performed for choledocholithiasis; however, the incidence of postendoscopic retrograde cholangiopancreatography pancreatitis (PEP) is unclear. This study aimed to compare the overall incidence of PEP between single‐ and two‐stage stone removal groups and the incidence of PEP between these two groups based on cannulation time. METHODS: We included 897 patients with native papilla who underwent papillary treatment and stone removal for choledocholithiasis with no inflammation or mild‐to‐moderate acute cholangitis at three institutions between April 2012 and March 2018 in Japan. We performed a propensity‐matched analysis and regression adjustment by propensity score to adjust for potential confounding factors. RESULTS: In the propensity‐matched analysis with 234 pairs, there was no significant difference in the overall incidence of PEP between single‐ and two‐stage stone removal procedures (15/234, 6.4% vs 6/234, 2.6%, P = 0.072, respectively). Although single‐stage stone removal after a cannulation time of ≤15 min was not a significant risk factor of PEP, the procedure after a cannulation time of >15 min was a significant risk factor of PEP as estimated by regression adjustment by propensity score (P = 0.014, 95% CI = 1.4–19.4, odds ratio = 5.2). CONCLUSIONS: Single‐stage endoscopic stone removal after a long cannulation time of >15 min increased the incidence of PEP compared with the two‐stage stone removal procedure. Thus, single‐stage stone removal should be performed in patients with a cannulation time ≤ 15 min.