PREDICTIVE FACTORS FOR SYNCHRONOUS COMMON BILE-DUCT STONES IN PATIENTS WITH CHOLELITHIASIS

Background: To determine the predictive factors of synchronous common bile duct (CBD) stones, data from 878 consecutive patients who underwe nt cholecystectomy in a university clinic from June 1991 to June 1996 were retrospectively analyzed. Methods: Based on clinical, biochemical , and ultrasonographic criteria, 194 patients were selected for ERCP, 180 preoperative and 14 postoperative. Results: Cannulation of CBD was successful in 192 (99%) patients. Stones were identified in 62 (32%) patients and sphincterotomy was performed in 56 (90%). Duct clearance was achieved in 43 (77%) cases. There was a high predictive value for the presense of CBD stones in patients with cholangitis, present jaund ice, and dilated CBD with evidence of stones on ultrasound (75%, 72%, and 67% respectively). A dilated CBD without stone on ultrasound and e levated liver enzymes had less than 40% positive predictive value. His tory of previous jaundice, pancreatitis, previously raised liver enzym es, and present pancreatitis was predictive in less than 20% of the ca ses. Univariate analyses revealed that clinical findings of cholangiti s and obstructive jaundice, elevated liver enzymes (previous and prese nt), and ultrasonographic findings of stones in a dilated CBD were sig nificant positive predictors. Subanalysis of each elevated liver enzym e revealed that alanine transaminase, aspartate transaminase, alkaline phosphatase, and gamma glutamyl transpeptidase were significant predi ctors. Both elevated conjugated and total bilirubins were also signifi cant predictors for CBD stones. Conclusion: Multivariate logistic regr ession analysis on these significant predictors showed that cholangiti s (odds ratio [OR]: 10.5), dilated CBD with evidence of stones on ultr asound (OR: 7.4), elevated aspartate transaminase (OR: 2.9), and conju gated bilirubin (OR: 5.3) were jointly significant. The likelihood of having stones in the duct without any of these predictors was 7%, but 99% when all the predictors were positive.