Abstract
IntroductionBiliary brush cytology is an important investigation in the assessment of bile duct strictures. A meta-analysis1 showed that the pooled sensitivities and specificities of biliary brush cytology for the diagnosis of malignant biliary strictures were 45% and 99% respectively when done in tertiary centres. The aim of this study was to evaluate the diagnostic performance of ERCP guided brush cytology for the assessment of biliary strictures in our organisation.MethodsWe carried out a retrospective review of all biliary brushings (identified from our endoscopy database) obtained during ERCP between January 2012 and April 2017. Data collected included patient demographics, cross-sectional imaging, cytopathological classification (based on locally agreed terminology) and treatment modality. Final diagnosis was confirmed from biliary brush cytology, histology obtained by other methods (endoscopic ultrasound, cholangioscopy, PTC or ultrasound guided biopsy), surgical resection specimens or cross-sectional imaging discussed at MDT setting (if histology negative). Patients were followed up for at least 6 months.Results215 patients (median age 73 years, 50.7% males) underwent 250 procedures - 153 patients had a final diagnosis of malignancy and underwent 163 procedures, 62 patients had a final diagnosis of benign pathology and underwent 87 procedures. 246 (98.4%) samples were deemed adequate for cytological analysis.Results of biliary brushings are enclosed in the table 1Abstract PTH-014 Table 1Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 55.1%, 95.4%, 95.6%, and 53.9% respectively [with atypia included as false negative in patients with cancer as final diagnosis]. The overall accuracy of the test was 69.3%.ConclusionOur study confirms that ERCP guided brush cytology for assessment of biliary stricture can be effective in a non-HPB centre with comparable rates of diagnostic yield to tertiary HPB centres. The low sensitivity (55.1%) indicates that biliary brushing alone is insufficient to rule out malignancy in a significant proportion of patients with a final diagnosis of malignancy. Further adjuncts like EUS and cholangioscopy are required to increase the diagnostic yield in biliary strictures.ReferencesNavaneethan U, Njei B, Lourdusamy V, et al. Comparative effectiveness of biliary brush cytology and intraductal biopsy for detection of malignant biliary strictures: a systematic review and meta-analysis. Gastrointest Endosc 2015;81:168–76.