Prediction of common bile duct stones by noninvasive tests

Objective To define accurate and useful predictors of common bile duct stones (CBDS). Summary Background Data The ability to predict CBDS with noninvasive tests can avoid unnecessary, c ostly, or risky procedures. Methods All patients referred for examination for CBDS by endoscopic ultrasonograph y (EUS) from 1993-1996 were prospectively entered in a database. In a first sample selected randomly from the whole population, predictors of CBDS wer e determined by univariate analysis and logistic regression. Predictors wer e subsequently tested in that sample and in the rest of the population. A s eparate analysis was done for patients planned for cholecystectomy. Results Eight hundred and eighty patients (328 men, 552 women), aged 57.8 +/- 17 ye ars (range 16-94), were included. The prevalence of CBDS was 18.8%. Age, se rum levels of bilirubin, aspartate aminotransferase, alanine aminotransfera se, gamma-glutamyl transferase (GGT), and alkaline phosphatase, and the exi stence of jaundice and fever, a dilated bile duct, and a pathologic gallbla dder were found to be associated with CBDS, Logistic regression was underta ken separately for patients younger than 70 years (predictors: GGT >7xnorma l; pathologic gallbladder; dilated bile duel) and older than 70 years (pred ictors: GGT >7xnormal; fever > 38 degrees C; dilated bile duct). Odds ratio s were 3 to 6.7. The model was satisfactorily applicable to the second samp le; age <70 years: chi(2) = 3.3 (NS); age >70 years: chi(2) = 3.8 (NS). In patients younger than age 70 and planned for cholecystectomy, the combinati on of the level of GOT and dilated bile duct predicted CBDS accurately. Conclusions A simple screening of patients at risk for CBDS can be achieved with three predictive criteria adapted for the patient's age.