Dynamic analysis of commonly used biochemical parameters to predict common bile duct stones in patients undergoing laparoscopic cholecystectomy.

backgroundThe prediction of persistent common bile duct stones (CBDS) in patients during choledocholithiasis crisis is challenging. We developed a model based on the course over time of commonly used biochemical parameters to reduce the rate of unnecessary endoscopic cholangiopancreatography (ERCP) and the risk of perioperative discovery of CBDS.

methodsMedical charts of patients who presented between 2010 and 2015 for symptomatic gallstone disease with suspected choledocholithiasis were reviewed and compared according to the presence/absence of CBDS on preoperative ERCP or during cholecystectomy.

results210 patients were included. Unnecessary ERCP and the discovery rate of CBDS were 9.0 and 22.4%, respectively. Multivariate analysis demonstrated age ≥80 years, neutrophils ≥12000/µL and gamma-glutamyl transpeptidase (GGT) ≥300 units/L at admission, alkaline phosphatase ≥180 units/L at days 3-5 post admission, and a decrease in C-reactive protein ≤10%, aspartate aminotransferase ≤35%, GGT ≤25%, and total bilirubin ≤15% between day 0 and days 3-5 to be predictive of CBDS. The area under the receiver-operator characteristic curve was 0.881. When used to select patients for preoperative ERCP, diagnostic accuracy was 94.8% when three predictors were present. Negative and positive predictive values were 100% in the absence of predictors and when five predictors were present, respectively. Unnecessary ERCP and CBDS discovery rates both decreased to 2.6%.

conclusionsCommonly used biochemical parameters correctly predict CBDS when they are analysed in a dynamic setting rather than at discrete time points. The proposed model constitutes a reliable tool to decrease unnecessary ERCP and perioperative discovery rates of CBDS.