Optimizing the Evaluation and Management of Patients With Suspected Choledocholithiasis

Choledocholithiasis (stone(s) in the common bile duct) is common. Untreated or missed, choledocholithiasis has high morbidity and mortality. Endoscopic retrograde cholangio-pancreatography (ERCP) is recognized as the first-line modality for management. While effective, ERCP is associated with adverse events. Thus, the selection of patients for ERCP should be accompanied by a high pre-test suspicion of choledocholithiasis. Choledocholithiasis is suspected based on clinical, biochemical and radiographic findings. The most relied-upon strategy for risk stratification of choledocholithiasis is based on guidelines from The American Society for Gastrointestinal Endoscopy (ASGE). In it, clinical predictors are defined as "very strong", "strong" or "moderate", and the presence of one or more of these is meant to suggest "high" or "intermediate" probability of choledocholithiasis. A knowledge gap exists in the performance characteristics of intermediate-probability criteria, where overall accuracy is \<50% from limited data. Patients in this group are recommended to a) undergo endoscopic ultrasound (EUS) or magnetic resonance cholangio-pancreatography (MRCP), b) undergo cholecystectomy with intra-operative cholangiography (IOC), or c) proceed directly to ERCP. At centres where EUS and MRCP are readily available, these are preferred options, as they are least invasive and sensitive; however, they are often unavailable. Thus, in clinical practice, a high proportion of intermediate-risk patients ultimately proceed directly to ERCP, where likelihood of benefit is only moderate, while procedural risk remains. The role of liver enzyme changes has not been evaluated; however, dynamic changes may offer another method for evaluating patients at intermediate risk of CBD stones that is safe and available. Incorporation of dynamic liver enzymes may improve the test-performance characteristics of the existing framework.