Increased post-endoscopic retrograde cholangiopancreatography pancreatitis for choledocholithiasis without acute cholangitis.

BACKGROUND AND AIM Choledocholithiasis is the most common indication for endoscopic retrograde cholangiopancreatography (ERCP). Identifying risk factors for post-ERCP pancreatitis (PEP) is important for reducing the risk of developing PEP after common bile duct (CBD) stone removal. However, studies examining the risk factors for PEP for CBD stones are scarce. The aim of this study was to examine whether the presence or absence of acute cholangitis is a clinical risk factor for PEP in patients with CBD stones. METHODS In this multicenter retrospective study, 1539 patients with naive papillae were divided into patients without and with acute cholangitis. We compared the incidence of PEP between the two groups using one-to-one propensity score matching to adjust for the potential confounding factors of PEP. RESULTS In the entire cohort, the rates of PEP in patients without and with acute cholangitis were 9.6% (52/542) and 1.8% (18/997), respectively (P < 0.001, odds ratio = 5.8). In the propensity-matched cohort, the rates of PEP in patients without and with acute cholangitis were 8.3% (27/326) and 2.5% (8/326), respectively (P = 0.002, odds ratio = 3.6). The rate of PEP was significantly higher in patients without acute cholangitis than in those with acute cholangitis after adjusting for the confounding factors of PEP. CONCLUSIONS The absence of acute cholangitis may be an important clinical risk factor for PEP due to CBD stone removal. In patients without acute cholangitis, endoscopists should explain the specific risk of PEP carefully and actively implement prophylaxis against PEP.