Abstract
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.