The role of serum liver enzymes in the diagnosis of choledocholithiasis

Background/Aims: The introduction of laparoscopic cholecystectomy has increased the need for preoperative diagnosis of common bile duct stones. The purpose of this study is to verify the sensitivity of the liver function tests in the detection of duct stones. Methodology: We evaluated 438 patients (223 retrospectively and 215 prospectively) who underwent endoscopic papillotomy for bile duct stones in two different services. In every case, blood samples for liver function tests levels were collected prior to endoscopic retrograde cholangiopancreatography. Results: The most sensitive test was gamma -glutamyl transpeptidase, that was abnormal in 92.2% of the cases. Alkaline phosphatase was elevated in 74.7% of the patients with choledocholithiasis. The least sensitive parameter was AST, altered in only 50.8% of times. The sensitivity of all liver tests for the diagnosis of choledochal stones taken together was 94.3% Conclusions: Liver function tests are very sensitive in the detection of common bile duct stones, however these blood tests are in the normal range of about 5% of endoscopically treated patients.