Endoscopic ultrasound and fine-needle aspiration of unexplained bile duct strictures

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.

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).

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%.

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.