Diagnosis of common bile duct stones by intravenous cholangiography: Prediction by ultrasound and liver function tests compared with endoscopic retrograde cholangiography

Background: Routine intravenous cholangiography using the safer contrast medium, meglumine iotroxate, may be a useful investigation prior to laparoscopic cholecystectomy for the detection of suspected common bile duct stones. We compared this with endoscopic cholangiography. Methods: Eighty-one consecutive nonjaundiced patients (mean age 62 years; range 20 to 90) with suspected common bile duct stones referred for endoscopic cholangiography to one center underwent intravenous cholangiography that was considered positive if it detected ductal stones. The ability of ultrasound scans and liver function tests to predict ductal stones was also assessed. Results: Sixty patients had both endoscopic and intravenous cholangiograms performed. Thirteen out of 27 patients with ductal stones confirmed by endoscopic cholangiography had positive intravenous cholangiograms, and 29 out of 30 with no stones had negative intravenous cholangiograms, The sensitivity for intravenous cholangiography was 48%, specificity 97%, positive predictive value 93%, negative predictive value 67%, and accuracy 73%, For ultrasound scans the positive predictive value was 69%; negative predictive value was 78%. For liver function tests the positive predictive value was 68%; negative predictive value was 93%. Conclusions: Intravenous cholangiography cannot be recommended instead of endoscopic cholangiography except in situations where the latter is not readily available. Ultrasound and liver function tests are useful in predicting ductal stones.