The Role of Endoscopic Ultrasonography (EUS) and Endoscopic Retrograde Cholangiography (ERC) in Diagnosing Choledocholithiasis

Choledocholithiasis is a common clinical condition that poses a risk for pancreatitis, jaundice, and cholangitis. The need to determine the presence or absence of bile duct stones is most often an issue in patients with symptomatic cholelithiasis and planned cholecystectomy, and in patients with biliary pancreatitis. This review highlights the role of endoscopic ultrasound (EUS) and endoscopic retrograde cholangiography (ERC) in the detection of choledocholithiasis, including a description of the recommended techniques and best practices when performing these endoscopic procedures. Patients can be categorized based upon clinical presentation and laboratory values into low, moderate, and high probability for common bile duct stones, and this likelihood governs the diagnostic approach. ERC is reserved for patients at high risk for bile duct stones; on the strength of accurate and less invasive tests such as EUS and magnetic resonance cholangiography, ERC has largely evolved into a therapeutic intervention, rather than a diagnostic exam. EUS-guided ERC is an approach with recent appropriate attention, as it can be performed with the same sedation, obviates > 50% of planned ERCs (thus reducing morbidity), and is cost-effective. Single-operator cholangioscopy and intraductal ultrasonography are useful ancillary techniques that are valuable in certain clinical settings related to choledocholithiasis detection.