Long term outcome of EUS-based strategy for suspected choledocholithiasis but negative CT finding

The American Society for Gastrointestinal Endoscopy (ASGE) guidelines offered the risk-stratified approach in suspected choledocholithiasis. Previous studies have raised concern about the insufficient accuracy of the guideline, especially in high probability group. The purposes of this study were to authenticate the stratification and clinical predictors of the guidelines for suspected choledocholithiasis with no visible choledocholithiasis on computed tomography (CT) and to make clear the clinical strategy of endoscopic ultrasonography (EUS).

We carried out the retrospective single-center study of 156 patients with suspected choledocholithiasis but negative findings on CT who underwent EUS for about 8 years at Samsung Medical Center. We assessed the clinical predictors of the ASGE guidelines in predicting the presence of choledocholithiasis and the outcome of the EUS.

Fifty-three of the 156 patients had positive findings on EUS that included choledocholithiasis (n = 43, 27.6%) or obstructive papillitis (n = 10, 6.4%). Among the 53 patients, 51 (96.2%) had choledocholithiasis or obstructive papillitis on ERCP. The 101 patients of 103 patients with negative finding on EUS did not show biliary events during follow-up period. EUS accuracy was 98.7% (sensitivity 100%; specificity 98.1%). Among the 49 patients with high probability, 21 (42.9%) had choledocholithiasis on ERCP. In 107 patients who were classified as intermediate probability, 30 (27.3%) had choledocholithiasis. There were no complications related to EUS.

Not only intermediate probability group but also high probability group without definite acute cholangitis may require EUS. Application of EUS for suspected choledocholithiasis is highly accurate, safe and reduces unnecessary invasive ERCP in 57.1% of patients with high probability group.