[Predictors of choledocholithiasis in patients sustaining gallstones].

Background: The aim of this study was to identify clinical, biochemical and ultrasonographic predictors of choledocholithiasis in patients sustaining gallstones assessed by cholangiography.

Methods: In a prospective study, 148 patients were analyzed regarding clinical, biochemical and ultrasonographic data. All patients underwent cholangiography, either preoperative endoscopic or during cholecystectomy. Each variable was compared between the ones who sustained lithiasis in the biliary tree and the others, in order to find out the predictors of choledocholithiasis. Sensibility, specificity, positive predictive value, negative predictive value (NPV) and accuracy were calculated. Spearman correlation, Odds ratio and logistic regression were employed for the statistical analysis, considering p<0.05 as significant.

Results: The variables that showed statistical significance were: presence of jaundice, elevated blood serum levels of alkaline phosphatase, g glutamyltransferase (gamma GT), aspartate aminotransferase, alanine aminotransferase, total bilirrubin, and biliary tract dilatation or choledocholithiasis in the ultrasound. The logistic regression presented an equation capable of predicting the probability of choledocholithiasis based in the variables: jaundice, presence of choledocholithiasis in the ultrasound, and blood levels of gamma GT. The best option to exclude the presence of choledocholithiasis was gamma GT, as it held the higher NPV. Every patient with choledocholithiasis in this sample sustained at least one of the preoperative criteria analyzed.

Conclusions: Jaundice and choledocholithiasis at the ultrasound were the best predictors of choledocholithiasis; as well as gamma GT was the most reliable factor to exclude this diagnosis.