Usefulness of intraductal ultrasonography in icteric patients with highly suspected choledocholithiasis showing normal endoscopic retrograde cholangiopancreatography

Choledocholithiasis is one of the causes of jaundice and may require urgent treatment. Endoscopic retrograde cholangiopancreatography (ERCP) has been the primary management strategy for choledocholithiasis. However, small stones can be overlooked during ERCP. The aim of this study was to evaluate the accuracy of intraductal ultrasonography (IDUS) for detecting choledocholithiasis in icteric patients with highly suspected common bile duct (CBD) stones without definite stone diagnosis on ERCP. Ninety-five icteric (bilirubin ≥3 mg/dL) patients who underwent ERCP for highly suspected choledocholithiasis without definite filling defects on cholangiography were prospectively enrolled in the present study. We evaluated the bile duct using IDUS for the presence of stones or sludge. Reference standard for choledocholithiasis was endoscopic extraction of stone or sludge. Bile duct stones were detected with IDUS in 31 of 95 patients (32.6 %). IDUS findings were confirmed by endoscopic stone extraction in all patients. The mean diameter of CBD stones detected by IDUS was 2.9 mm (range 1–7 mm). IDUS revealed biliary sludge in 24 patients (25.2 %) which was confirmed by sludge extraction in 21 patients (87.5 %). In dilated CBD, detection rate of bile duct stone/sludge based on IDUS was significantly higher than in non-dilated CBD (p = 0.004). IDUS is useful for the detection of occult CBD stone on ERCP in icteric patients with highly suspected CBD stones.