874 Sensitivity of Endoscopic Modalities for Diagnosis of Malignant Biliary Strictures: Experiences From Referral Hospitals in Eastern and Western Countries

Abstract

INTRODUCTION: Indeterminate biliary strictures require further investigations to exclude malignancy. Cholangioscopy allows direct visualization of the bile duct as well as the ability to target the specific area for biopsy. This study aims to evaluate the sensitivity of endoscopic modalities including cholangioscopy-guided (miniature) biopsies ± brushings and/or fluoroscopy-guided biopsy (regular) biopsies for diagnosis of malignant biliary strictures in a real-world practice. METHODS: Endoscopy databases between 2015-2018 from two referral hospitals, one in USA and the other in Thailand, were retrospectively reviewed. Patients with indeterminate biliary stricture underwent ERCP and digital cholangioscopy-guided biopsy were included. Malignancy was confirmed by cytology or histology obtained by ERCP, surgery, or intervention-guided biopsy. Benign disease was confirmed by no disease progression and patient survived more than 6 months. RESULTS: A total of 58 patients (USA = 20 and Thailand = 38) with indeterminate biliary stricture underwent ERCP and cholangioscopy-guided biopsy were included. Forty-three patients had malignant strictures and 15 patients had benign strictures. The most common cause of malignant biliary stricture was cholangiocarcinoma (76.7%) and the most common cause of benign biliary stricture was IgG4-sclerosing cholangitis (46.7%). The majority of tissue acquisition was obtained by a combination of miniature biopsies + brushings + regular biopsies in 24 patients (41.4%) followed by a combination of miniature biopsies + regular biopsies in 20 patients (34.5%). Miniature biopsies alone was more frequently used in the USA site (30%) when compare with the Thailand site (5.3%). Sensitivity per methods of tissue acquisition were 12%, 48.8%, and 64.7% in brushings, miniature biopsies, and regular biopsies, respectively. Brushings had the lowest sensitivity in both centers (0% in USA and 18.8% in Thailand). Miniature biopsies had the highest sensitivity in the USA site (42.9%) and biopsy had the highest sensitivity in the Thailand site (65.4%). A combination of tissue acquisition methods provided the highest sensitivity, which was able to increase the sensitivity up to 10.5%. CONCLUSION: Cholangioscopy-guided biopsies are able to diagnose cancer in a half of patient who presented with indeterminate biliary stricture. Nevertheless, a combination of miniature biopsies with other tissue acquisition methods was more commonly utilized and had higher diagnostic yield than miniature biopsy alone.