Utility of endoscopic ultrasonography in the evaluation of dilated common bile duct of undetermined etiology.

Introduction: Occasionally, common bile duct (CBD) dilatation is discovered while working up patients for various causes. Not infrequently, the usual imaging modalities fail to identify the cause and endoscopic ultrasonography (EUS) becomes necessary. The aim of this study is to assess the value of EUS in identifying the cause of CBD dilatation undiagnosed by transabdominal ultrasonography.
Patients and Methods: During 1 year, 152 consecutive patients who were referred for evaluation of dilated CBD (diameter ≥7 mm) discovered incidentally during transabdominal ultrasonography were included. Final diagnoses were confirmed by endoscopic retrograde cholangiopancreatography, EUS-guided fine-needle aspiration, surgical exploration, or clinical follow-up of at least 10 months.
Results: One hundred and fifty two patients (54% female) with dilated CBD were included. Mean age of patients was 60 ± 17 years. The final diagnoses was choledocholithiasis in 32 (21.1%), passed CBD stone in 35 (23%), opium-induced CBD dilation in 14 (9.2%), post-cholecystectomy states in 20 (13.1%), ampullary neoplasia in 15 (15.8%), cholangiocarcinoma in 14 (9.2%) and pancreatic head cancer in 9 (5.9%). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EUS for patients with abnormal EUS was 89.5%, 100.0%, 100.0%, 91.2%, and 90.9%, respectively.
Conclusion: After diagnosis of CBD dilation by transabdominal ultrasonography, EUS may be a reasonable next choice for determining the etiology of dilated CBD.