Is endoscopic ultrasound needed as an add-on test for gallstone diseases without choledocholithiasis on multidetector computed tomography?

Background: Choledocholithiasis commonly occurs in patients with symptomatic cholelithiasis. Although the recently developed multidetector computed tomography (MDCT) scan enhances the ability to diagnose choledocholithiasis, this technique is considered to have some limitations for evaluating the common bile duct (CBD).

Aim: The purpose of this study was to evaluate the necessity for performing endoscopic ultrasound (EUS) as an add-on test to detect choledocholithiasis in patients who were diagnosed with gallstone disease without choledocholithiasis based on MDCT.

Methods: Three hundred twenty patients with gallstone disease and no evidence of CBD stones according to MDCT underwent EUS between March 2006 and April 2011. If CBD stones were suspected based on the EUS results or clinical symptoms, a final diagnosis was obtained by endoscopic retrograde cholangiopancreatography (ERCP). The patients' medical records were retrospectively analyzed based on clinical symptoms, biochemical findings, and results of the imaging studies.

Results: CBD stones were not detected with MDCT in 41 (12.8 %) out of 320 patients with gallstone disease. The causes for these discrepancies could be attributed to small stone size (n = 19, 46.3 %), isodensity (n = 18, 43.9 %), impacted stones (n = 1, 2.4 %), and misdiagnosis (n = 3, 7.3 %). If EUS were used as a triage tool, unnecessary diagnostic ERCP and its complications could be avoided for 245 (76.6 %) patients.

Conclusions: MDCT may not be a primary technique for detecting CBD stones. EUS should be performed instead as an add-on test to evaluate the CBD for patients with gallstone-related disease. In particular, EUS should be routinely recommended for patients with abnormal liver enzyme levels, pancreatitis, and dilated CBD.