The role of endoscopic ultrasound in biliary obstruction.

The role of endoscopic ultrasound (EUS) in the diagnosis of biliary obstruction is well established, and emerging evidence suggests it may also play a therapeutic role. Differentiating between benign and malignant causes of biliary obstruction can be challenging, but EUS is a crucial tool in the armamentarium of the physician. Evolving technologies such as elastography and contrast enhancement may further supplement the diagnostic abilities of EUS. Therapeutic applications of EUS are evolving rapidly, and EUS-guided cholangiography may aid biliary decompression when endoscopic retrograde cholangiopancreatography (ERCP) has failed or is not possible.