Preoperative assessment of choledocholithiasis in laparoscopic cholecystectomy.

In order to determine the predictive value of noninvasive investigations for choledocholithiasis, we conducted a prospective preoperative study on 82 patients with symptomatic gallstones who received laparoscopic cholecystectomy. Ultrasonography (US), liver function tests and endoscopic retrograde cholangiography (ERC) were routinely performed in all cases prior to operation. The results showed a strong correlation between noninvasive procedures (liver function tests and US) and the presence of choledocholithiasis as shown by ERC. Using ERC as a reference, the sensitivity and selectivity of ductal dilatation at US and the elevation of alkaline phosphatase (ALP), gamma-glutamyltransferase and total bilirubin in the serum were studied for the detection of common bile duct (CBD) stones. The values of the combination of these tests were also calculated. From receiver operator characteristics curves, the best cut-off point for US in conjunction with ALP was chosen. ERC should be restricted to patients with possible CBD stones, suspected after a combination of the noninvasive US and ALP tests. This study emphasized the necessity and timing of performing ERC as a preoperative modality in the detection of choledocholithiasis in patients who are to undergo laparoscopic cholecystectomy.