Management of Suspected Choledocholithiasis: A Decision Analysis for Choosing the Optimal Imaging Modality.

BACKGROUND AND AIMS: Magnetic resonance cholangiography (MRC), endoscopic ultrasound (EUS), and endoscopic retrograde cholangio-pancreatography (ERCP) all represent viable options to establish the diagnosis of choledocholithiasis. The aim of the study was to assess how the three imaging modalities perform in head-to-head comparisons and in what order to apply them when using these procedures sequentially.

METHODS

A threshold analysis using a decision tree was modeled to compare the costs associated with different imaging techniques of the biliary system in a patient with suspected cholestasis secondary to choledocholithiasis. The main outcome parameter was the pre-test probability of common bile duct (CBD) stones that would guide the physician towards starting the work-up with MRC or EUS versus going straight to ERCP as the primary procedure.

RESULTS

For low pre-test probabilities of CBD stones in the common bile duct, MRC represents the procedure of choice. For pre-test probabilities ranging between 40 and 91 %, EUS should be the preferred imaging modality. If CBD stones are suspected with an even higher pre-test probability, patients could go straight to ERCP as their first procedure. Low costs associated with any of the three procedures increase its range of applicability at the expense of the other competing imaging modalities.

CONCLUSIONS

MRC, EUS, and ERCP should be used in sequence and dependent on the pre-test probability of choledocholithiasis.