Does Endoscopic Ultrasonography Influence the Management of Patients with Dilated Common Bile Duct?

Abstract

Purpose: Precise evaluation of patients with dilated common bile duct (CBD) is extremely important. Computed tomography (CT) shows high sensitivity in detecting dilated CBD as well as the level of obstruction, and is usually used as the first modality. In some cases however, CT can not demonstrate the cause. This study is designed to evaluate the usefulness of endoscopic ultrasonography (EUS) in detecting the cause of CBD dilatation in patients in whom CT could not detect the cause or only revealed equivocal findings. Methods: In this study, we retrospectively analyzed 114 available cases with dilated CBD detected with CT (>9 mm in diameter) between April 2000 and August 2005. Final diagnoses were determined by endoscopic retrograde cholangiopancreatography and surgical exploration, and all cases diagnosed as only dilated CBD were followed up at least 6 months after diagnosed. As CBD stones and biliopancreatic carcinomas (BPC) are determinant factors for the management of patients with CBD dilatation, we evaluate the diagnostic accuracy in detecting these diseases in the following diagnostic processes. First, we evaluated these diseases solely using CT in all cases. When CBD stones were detected, we performed endoscopic treatment without EUS. Second, we performed EUS additionally for all cases and reconsidered the management of patients according to EUS findings. All cases were classified into 3 groups: dilated CBD only, with CBD stones, with BPC. Results: The number of each group was as follows: dilated CBD only, 20 (including post gastrectomy 2, post cholecystectomy 5); with CBD stones, 44; with BPC, 50 (gallbladder carcinoma 2, extra hepatic bile duct carcinoma 24, carcinoma of the ampulla of Vater 8 and pancreatic carcinoma 16). Solely using CT, 10 of 44 cases with CBD stones were misdiagnosed as dilated CBD only and 4 cases with BPC were missed (extra hepatic bile duct carcinoma 2 and ampullary carcinoma 2). So 14 cases were incorrectly diagnosed in total, and the over all accuracy was 87.7% (100/114). EUS was performed in 80 cases, and 10 cases with CBD stones and 4 cases with BPC were correctly diagnosed additionally. So, an additional EUS influenced all 14 misdiagnosed cases. Though CT could reveal equivocal findings in extra hepatic bile duct carcinomas, neither CT nor MRI could detect any findings except for CBD dilatation in non invasive minute ampullary carcinomas. Conclusions: EUS is very useful in detecting the CBD stones and BPC, particularly minute carcinoma of the ampulla of Vater. We recommend EUS in patients in whom CT could not detect any cause or only revealed equivocal findings.