EUS assessment for intermediate risk of choledocholithiasis after a negative magnetic resonance cholangiopancreatography

BACKGROUND AND AIMS: Guidelines recommend either EUS or magnetic resonance cholangiopancreatography (MRCP) for intermediate risk of choledocholithiasis. There is a lack of evidence that supports proceeding with EUS if the MRCP is negative and if clinical suspicion still exists. METHODS: This is a retrospective study of all patients who underwent EUS to assess for choledocholithiasis at a tertiary care referral center from July 2013 to October 2019. RESULTS: A total of 593 patients underwent EUS for evaluation for choledocholithiasis. Of the 593 patients, 35.2% (209/593) had an MRCP. 73.2% (153/209) had a negative MRCP while 26.8% (56/209) had a positive MRCP. Of the group of patients who underwent EUS with a negative MRCP, 15% (23/153) were positive for choledocholithiasis on EUS. Of these, 91% (21/23) were also positive for sludge or stones on endoscopic retrograde cholangiopancreatography and thus 14% (21/153) of the EUS were “true positives.” There were no clinical or laboratory factors predictive of choledocholithiasis on univariate analysis in the EUS plus negative MRCP group. When further analyzing the MRCP negative group into MRCP-/EUS+ and MRCP-/EUS-subgroups, a total bilirubin >3 mg/dL predicted a bile duct stone (55% vs. 32%, P = 0.05). CONCLUSION: The diagnostic yield of EUS for suspected choledocholithiasis in the setting of a negative MRCP is 14% in our cohort. EUS should be considered in patients with intermediate risk of choledocholithiasis with a negative MRCP if the clinical suspicion is still present, and especially if the total bilirubin is above 3 mg/dL.