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

Background: The 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.

Methods: Medical 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.

Results: 210 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%.

Conclusions: Commonly 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.