Detection of Common Bile Duct Stones in Mild Acute Biliary Pancreatitis Using Magnetic Resonance Cholangiopancreatography

BACKGROUND: All patients with mild acute biliary pancreatitis should undergo early cholecystectomy. Whether routine common bile duct (CBD) imaging should be employed before the surgical procedure in these patients is a matter of current controversy. The aim of this study was to investigate the rate of detection of CBD stones using magnetic resonance cholangiopancreatography (MRCP) at different time intervals from admission. METHODS: From January 1, 2011, through December 31, 2016, 72 patients with acute biliary pancreatitis underwent MRCP. Fifty-six (n=56) of them with mild biliary pancreatitis met the study criteria. The patients were divided into two groups. Group A did not have stones in the CBD (n=45), and Group B had stones in the CBD (n=11). The time from admission to MRCP was divided into several periods (day 1 through day 180), and the presence of the CBD stones on MRCP was weighted against remoteness from admission. Liver chemistry profiles were compared between the groups on admission and before the MRCP. RESULTS: The cumulative rate of choledocholithiasis was 19.7% (Group B, n=11). Forty-five patients (Group A, n=45, 80.3%) did not have gallstones in the CBD. Eight patients with choledocholithiasis (8/56, 14.2%) were detected during the first 10 days from admission out of 27 patients. In patients who underwent MRCP between days 11 and 20, choledocholithiasis was found in two patients (2/56, 3.5%) and in one patient between days 21 and 30 (1/56, 1.8%). No stones were found in patients who underwent MRCP beyond 30 days from admission. Liver chemistry profiles did not show a significant difference in both groups. CBD dilatation was observed at presentation in 11 patients (n=11/56), 6 in Group A (6/45, 13.3%) and 5 in Group B (5/11, 45.5%) (p=0.016). CONCLUSIONS: Routine CBD evaluation should be encouraged after mild acute biliary pancreatitis. Early performance of MRCP gives high yield in selecting the patients for endoscopic retrograde cholangiopancreatography (ERCP) before cholecystectomy. A liver chemistry profile either on admission or before MRCP cannot predict the presence of CBD stones.