Methods improving endoscopic retrograde cholangiopancreatography brush cytology in malignant biliary strictures

Accurate diagnosis of biliary strictures is crucial as malignant causes are associated with high morbidity and mortality, and unnecessary surgery for benign disease carries substantial risk. Endoscopic retrograde cholangiopancreatography with brush cytology remains the most widely used tissue sampling technique, but its sensitivity in distinguishing benign from malignant strictures is limited. This review summarized current and emerging strategies aimed at improving the diagnostic yield of endoscopic retrograde cholangiopancreatography brush cytology. Technical refinements such as rapid on-site evaluation, sheath-rinse collection, and increased brushing passes have shown incremental improvements. Combining brushing with bile aspiration or intraductal biopsy further enhances sensitivity. In parallel, molecular approaches including fluorescence in situ hybridization, next-generation sequencing, and microRNA profiling offer promising advances in early and accurate detection. A multimodal approach that integrates optimized cytological sampling with molecular diagnostics appears most effective in improving accuracy. Standardization and validation of these combined methods in prospective studies are needed to establish their role in clinical practice and to improve outcomes for patients with indeterminate biliary strictures.