Role of endoscopic ultrasound in common bile duct stones

When the clinical features strongly suggest the presence of bile duct stones, management is fairly straightforward; diagnostic and therapeutic endoscopic retrograde cholangiography (ERC) may in some cases constitute the entire strategy. Unfortunately, the clinical picture is often equivocal or uncertain. Although stones are unlikely to be present in the bile duct when the clinical index of suspicion is low, their presence can never be completely ruled out based on clinical and biochemical parameters. Thus, an accurate, noninvasive, reliable, and safe method for bile duct imaging would be highly advantageous. Low-risk tests, such as endoscopic ultrasound (EUS), are emerging as reliable substitutes for diagnostic ERC. This review highlights the technical aspects of examining the extra-hepatic biliary duct system and the performance and results of EUS in diagnosing patients who present with possible common bile duct stones.