Introduction
Endoscopic ultrasound (EUS) is an important tool for the evaluation of patients with common bile duct (CBD) dilation without obvious identified aetiology after ultrasonography (US), computed tomography (CT) and/or magnetic resonance cholangiopancreatography (MRCP).
Aims & Methods
The aim of this study was to evaluate the diagnostic performance of EUS for CBD dilation in patients with a negative initial study.
Retrospective, unicentric and cohort study including patients who underwent EUS for CBD dilation (diameter ≥7mm if intact anatomy or ≥10mm if prior cholecystectomy) in the absence of obvious pathology on prior imaging, including US, CT and/or MRCP, from January 2016 until June 2022. All EUS procedures were performed with a linear echoendoscope.
Results
Totally, 109 patients were included, 50 patients without symptoms or altered liver biochemistry (45.9%). Among the 41 patients with positive EUS, 33 patients had choledocholithiasis (30.3%), 6 chronic pancreatitis (5.5%) and 2 had ampullary cancer (1.8%). Older age was associated with positive EUS (median 79 vs 71 years, p=0.030). Patients with jaundice, cholelithiasis and altered liver biochemistry were 16.2 (p=0.002), 3.1 (p=0.024) and 2.9 (p=0.009) times more likely to have positive EUS, respectively.
A total of 53 patients underwent MRCP with a negative result (48.6%). In this group, 12 patients had a positive EUS, 10 had choledocholithiasis (18.9%) and 2 had chronic pancreatitis (3.8%). Of those, patients with abdominal pain and jaundice were 15.4 (p<0.001) and 20.0 (p=0.007) times more likely to have positive EUS, respectively. CBD diameter in MRCP was not associated with finding a causative lesion (p=0.473).
Considering only asymptomatic patients without altered liver biochemistry, CBD diameter ≥8.5mm, evaluated by CT, had a sensibility of 100% and specificity of 75% in predicting a positive EUS (AUC 0.734, p=0.048).
Conclusion
EUS is a useful diagnostic method for patients with unexplained CBD dilation, with a higher yield, even in patients with negative MRCP, and especially in patients with older age, symptoms such as abdominal pain and jaundice, cholelithiasis and/or altered liver biochemistry. CBD diameter evaluated by CT had a moderate discriminative ability in predicting a positive EUS in asymptomatic patients without altered liver biochemistry.