The role of endoscopic ultrasound in biliary strictures.

The role of endoscopic ultrasound (EUS) in the diagnosis of biliary strictures is well established, and emerging evidence suggests it may also play a therapeutic role. Differentiating between benign and malignant causes of biliary strictures can be challenging, but EUS can aid in their diagnosis and may predict resectability. The diagnostic yield of EUS combined with fine-needle aspiration (FNA) is excellent, especially in distal bile duct strictures, and far surpasses endoscopic retrograde cholangiopancreatography (ERCP) with brushings. Intraductal ultrasound may add to the diagnostic sensitivity of ERCP with brushings when no mass is seen on cross-sectional imaging or EUS, or when EUS with FNA is negative and suspicion of cancer persists. EUS-guided cholangiography is an emerging technique that may aid biliary decompression when ERCP has failed or is not possible; however, new therapeutic echoendoscopes or accessories are needed before the use of this technique can become more widespread.