A Comparative Study of Endoscopic Ultrasound Fine-Needle Aspiration (EUS-FNA) and Endoscopic Retrograde Cholangiopancreatography (ERCP)-Based Brush Cytology for Tissue Diagnosis in Malignant Biliary Obstruction.

Background and objective Patients with suspected malignant biliary strictures frequently undergo endoscopic retrograde cholangiopancreatography (ERCP)-based brush cytology and endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) for establishing the diagnosis. The outcomes of these tests aid in the further management of the patient. A comparison of these two modalities in establishing the diagnosis is seldom reported. In light of this, we aimed to compare the diagnostic efficacy between ERCP-based brush cytology and EUS-FNA for tissue diagnosis in malignant biliary obstruction. Our study involved a retrospective audit of all patients admitted to the Vydehi Institute of Medical Sciences and Research Centre for EUS and ERCP from 2015 to 2019. Methodology A Comparative study was conducted in the Department of Medical Gastroenterology at the Vydehi Institute of Medical Sciences and Research Centre over a five-year period. A total of 77 subjects who presented during the study period with biliary obstruction based on clinical presentation with altered liver function test in an obstructive pattern and evidence of biliary obstruction in the form of stricture or pancreaticobiliary mass on cross-sectional imaging were included in the study. All the patients included in the study underwent EUS and ERCP. Results The majority of the patients in the study were in the fifth decade of life with a slight female predominance. The most common CT finding was a periampullary mass with common bile duct (CBD) stricture (59.7%). In the study, EUS-FNA was more sensitive than ERCP-based tissue sampling. The overall sensitivity was 90.63% for EUS-FNA and 65.63% for ERCP sampling. EUS-FNA was found to have diagnostic accuracy of 92.63% in comparison to 71.43% for brush cytology. Conclusions Based on our findings, EUS-FNA is superior to ERCP-based tissue sampling with excellent sensitivity and diagnostic accuracy. Performing EUS before ERCP in all patients with suspected malignant biliary obstruction would definitely improve diagnostic accuracy and thereby help in the management of such cases.