Diagnostic accuracy of endoscopic ultrasound in evaluation of patients with obstructive jaundice: single-center experience

Background/aims We prospectively evaluated the role of endoscopic ultrasound (EUS) in detecting the cause of common bile duct (CBD) dilatation in patients in whom trans-abdominal ultrasound (TUS) could not demonstrate the cause of dilation as a proper second step in the diagnostic workup of patients with obstructive jaundice compared to magnetic resonance cholangiopancreatography (MRCP). Methods This study was conducted on patients with obstructive jaundice admitted to the inpatient ward or the outpatient endoscopy unit of Theodor Bilharz Research Institute (TBRI) during the period between January 2019 and August 2019. A patient with obstructive jaundice and TUS showed CBD dilatation with internal diameter ≥ 7 mm and biliary stricture. Results During the period between January 2019 and August 2019, 136 were recruited; 8 patients who were pregnant and 3 patients who had gastric bypass surgery were excluded. Sixty-five patients were diagnosed confidently by TUS as biliary stones and were excluded from the analysis. Sixty patients with obstructive jaundice and indefinite etiology on TUS were included in the final analysis. The final diagnosis of patients was 38 patients (63.33%) of malignant etiology [26 pancreatic cancer (43.33%), 4 cholangiocarcinoma (6.66%), and 8 with ampullary cancer (13.33%)] and 22 patients (36.67%) of benign etiology [10 calcular obstruction (16.66%), 8 benign stricture (13.33%), and 4 pancreatitis (6.66%)]. The sensitivity and specificity values for malignant stricture detected by EUS were 100% and 86.36%, respectively, with positive predictive value of 92.68%, negative predictive value of 100%, and accuracy of 95%, while MRI showed 82.14% sensitivity and 25% specificity with positive predictive value of 79.31 and accuracy of 69.4%. EUS supported correct diagnosis in 57 patients (95%: CI 86.08 to 98.96%) while MRI did it in 36 patients (69.44%: CI 51.89% to 83.65%).Only 43 (71.7%) patients needed endoscopic retrograde cholangiopancreatography (ERCP) for management of obstructive jaundice, sparing 17 patients (28.3%) unnecessary invasive procedures. Conclusions EUS is a minimally invasive method with low incidence of complications with high diagnostic accuracy in patients with dilated CBD and normal MRCP.