EUS versus MRCP to perform ERCP in patients with intermediate likelihood of choledocholithiasis: a randomised controlled trial.

OBJECTIVE: In patients with an intermediate likelihood of choledocholithiasis, European Society of Gastrointestinal Endoscopy (ESGE) guidelines recommend endoscopic ultrasound (EUS) or magnetic resonance cholangiopancreatography (MRCP) to diagnose choledocholithiasis to make the indication for endoscopic retrograde cholangiopancreatography (ERCP) treatment; there is no randomised control trial to compare both in this setting. DESIGN: Patients with suspected choledocholithiasis satisfying ESGE guideline's intermediate likelihood were screened for this single-centre randomised controlled trial between November 2019 and May 2020. The enrolled patients were randomised to either EUS or MRCP. ERCP was performed in stone positive cases or if clinical suspicion persisted during follow-up. Negative cases underwent a further 6-month clinical follow-up. Main outcome was accuracy (sensitivity/specificity) of both tests to diagnose choledocholithiasis, with ERCP or follow-up as a gold standard. RESULTS: Of 266 patients, 224 patients (mean age: 46.77±14.57 years; 50.9 % female) were enrolled; overall prevalence of choledocholithiasis was 49.6%, with a higher frequency in the MRCP group (63/112 vs 46/112 for EUS). Both sensitivity of EUS and MRCP were similarly high (92%-98%), without significant differences between the two groups. The negative predictive value and likelihood ratio + were significantly higher in EUS arm (p<0.05). The percentage of ERCPs either incorrectly halted back (false negatives: EUS: 2 vs MRCP: 5) or performed unnecessarily (false positives: EUS: 1 vs MRCP: 2) was low in both groups. CONCLUSION: The performance parameters of both EUS and MRCP are comparable for detecting choledocholithiasis in the intermediate-risk group of choledocholithiasis and the choice of a test should be based on local expertise, availability of resources and patient preference. TRIAL REGISTRATION NUMBER: NCT04173624.