Endoscopic Ultrasound and Fine-needle Aspiration of Unexplained Bile Duct Strictures

Objectives: The aim of this study was to assess the utility of endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) in patients with unexplained common bile duct strictures after endoscopic retrograde cholangiopancreatography (ERCP) and intraductal tissue sampling.

Methods: Records were reviewed for all subjects undergoing EUS for evaluation of unexplained bile duct strictures at our institution. 40 subjects had either a final histologic diagnosis (24) or no evidence of malignancy after at least 1 yr of follow-up (16).

Results: The finding of a pancreatic head mass and/or an irregular bile duct wall had sensitivity for malignancy of 88%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 84%. Bile duct wall thickness >/=3 mm had a sensitivity for malignancy of 79%, specificity of 79%, positive predictive value of 73%, and negative predictive value of 80%. Sensitivity of EUS FNA for malignancy was 47% with specificity 100%, positive predictive value 100%, and negative predictive value 50%.

Conclusions: Sonographic features may be more sensitive than EUS FNA for diagnosis of unexplained bile duct strictures and include presence of a pancreatic mass, an irregular bile duct wall, or bile duct wall thickness > 3 mm. EUS FNA cytology is specific but insensitive for diagnosis. EUS improves the diagnosis of otherwise unexplained bile duct strictures.