Diagnostic Value of Endoscopic Ultrasonography in Symptomatic Patients with High and Intermediate Probabilities of Common Bile Duct Stones and a Negative Computed Tomography Scan

Background/Aims When computed tomography (CT) does not indicate choledocholithiasis in highly suspicious patients, there is no definite consensus on the subsequent modality. Endoscopic ultrasonography (EUS) indicates fewer procedure-related complications than endoscopic retrograde cholangiopancreatography (ERCP) and has a lower cost than magnetic resonance cholangiopancreatography. Therefore, we aimed to investigate the diagnostic value of EUS in patients with suspected choledocholithiasis and negative CT findings. Methods Between March 2008 and November 2014, we retrospectively evaluated 200 patients with negative CT findings and high or intermediate probabilities of choledocholithiasis. All patients initially underwent EUS followed by ERCP as a confirmatory criterion standard. The primary outcome in these patients was the accuracy of EUS in the detection of choledocholithiasis. The secondary outcome was the clinical prediction of common bile duct (CBD) stones in this group. Results EUS indicated choledocholithiasis in 165 of the 200 patients, and ERCP confirmed choledocholithiasis in 161 patients (80.5%). The accuracy of EUS in the detection of choledocholithiasis was 94.0% (sensitivity, 97.5%; specificity, 79.5%; positive predictive value, 95.2%; negative predictive value, 88.6%). A multivariate analysis demonstrated that choledocholithiasis was strongly predicted by EUS detection of choledocholithiasis, an age >55 years and a clinical diagnosis of cholangitis. Conclusions An EUS-first approach is recommended for patients with suspected CBD stones and negative CT findings.