Role of Endoscopic Ultrasound in diagnosis of unexplained distal Common Bile Duct stricture

Abstract

Abstract Purpose Determining the etiology of a distal biliary stricture without an identifiable mass on imaging is crucial to the provision of appropriate therapy. This study aims to assess the ability of Endoscopic Ultrasound (EUS) to diagnose distal biliary strictures for which cross-sectional imaging modalities such as Computed Tomography (CT) scan and Magnetic Resonance Imaging (MRI) could not detect a causative mass or bile duct thickening. Methods Prospective study on 80 patients with unexplained distal biliary stricture diagnosed by Magnetic Resonance Cholangiopancreatography (MRCP), Endoscopic Retrograde Cholangiopancreatography (ERCP), CT or MRI underwent EUS. Results 80 patients (50 male; mean age 57.9 ± 9.8 years) were studied. Based on EUS findings; 51 patients were diagnosed with malignant strictures 63.75% (21 distal cholangiocarcinoma, 17 pancreatic head mass, 11 ampullary mass lesion and 2 intraductal papillary mucinous neoplasm) and rest of patients were diagnosed with benign strictures 36.25%. ROC analysis between malignant and benign strictures for distal CBD wall thickness has shown a cutoff value > 3.2 (Sensitivity 80.39%, Specificity 89.66%, Positive predictive value (PPV) 93.2, Negative predictive value (NPV) 72.2 and accuracy 85.7%). Conclusion EUS is a useful investigational modality for patients with unexplained distal CBD stricture and can be predictive of the nature of the stricture.