Aspiration fluid cytology during single operator cholangioscopy with targeted biopsy to improves the diagnostic yield in indeterminate biliary strictures

Introduction Sensitivities of various sampling methods to detect malignant biliary strictures remain suboptimal. Irrigation during digital single operator cholangioscopy (dSOC) is done routinely for visualization of the duct. The aim of this study was to evaluate improvement of the sensitivity for detecting malignant biliary strictures when adding aspiration fluid cytology (AFC) from the irrigated fluid during cholangioscopy to cholangioscopic biopsy (CBx). Methods We conducted a retrospective analysis of patients at a tertiary medical center who underwent CBx for evaluation of their biliary strictures. We included patients who had aspiration of fluid from the bile duct after CBx and were sent for cytology from January 2017 to October 2017. Diagnosis was made on the basis of final pathology or follow-up over 9 months. Results Fifty-six patients had CBx obtained, out of which 35 patients had AFC in conjunction. Twenty-two (62%) patients were male and the average age was 65 years. Considering atypical cells as benign, the sensitivity, specificity, positive and negative predictive values (PPV, NPV) for CBx were 62.5%, 100%, 100%, and 76% respectively. When CBx combined with AFC, the above statistics went up to 81.25%, 100%, 100%, and 86.36% respectively. When atypical cells were considered malignant, the sensitivity, specificity, PPV and NPV for CBx were 81.25%, 84.21%, 81.25%, 84.21% and increased to 93.75%, 78.94%, 78.94%, and 93.75% respectively after adding AFC results. Conclusion For patients with biliary stricture, addition of AFC dSOC guided biopsies, significantly improves the sensitivity for detecting malignancy.