Tu1401 EVALUATION OF ASPIRATION FLUID CYTOLOGY AS AN ADJUNCT WITH SINGLE OPERATOR CHOLANGIOSCOPY AND TARGETED BIOPSY TO IMPROVE THE DIAGNOSTIC YIELD IN INDETERMINATE BILIARY STRICTURES.

Abstract

Endoscopic Retrograde Cholangio-Pancreatography (ERCP) with Digital Single Operator Cholangioscopy (dSOC) has been shown to increase the sensitivity of detecting malignancy in indeterminate biliary strictures (IBS). However, IBS remain a diagnostic challenge. Water irrigation is commonly used during dSOC to improve duct visualization. We hypothesize that fluid aspiration of water used to irrigate the common bile duct (CBD) during dSOC could increase the diagnostic yield in IBS. The aim of this study is to evaluate whether the addition of aspiration fluid cytology (AFC) collected during water irrigation of the CBD before and after dSOC targeted biopsy (CBx) could improve the diagnostic sensitivity of detecting malignancy in IBS. We conducted a retrospective analysis of all patients at a tertiary medical center who underwent ERCP with dSOC and CBx for evaluation of biliary strictures. We included patients who had aspiration of fluid from the CBD during water irrigation before and after the CBx and was sent for cytology from January to October 2017. Diagnosis was made on the basis of final pathology or follow up over 6-8 months. The comparison of sensitivities of CBx alone and CBx with AFC in diagnosing malignancy was performed using McNemar (chi-square) test. 56 patients had ERCP with dSOC for biliary stricture in the study time period. 35 patients satisfied the inclusion criteria. 22 (62%) patients were male and the average age was 65 years. Two patients with malignant biliary stricture had only atypical cells on CBx but AFC showed malignant cells. One patient had benign cells on CBx where AFC showed malignant cells. On considering atypical cells as benign; the sensitivity, specificity, positive and negative predictive values (PPV, NPV) for CBx were 66.66%, 100%, 100% and 80% respectively. When combined with AFC the above values increased to 80%, 100%, 100% and 86.95% respectively. When atypical cells were considered as malignant, the sensitivity, specificity, PPV and NPV for CBx were 80%, 80%, 75%, 84.2% and increased to 86.6%, 70%, 68.4% and 87.5% respectively after adding AFC to the biopsies. CBx with AFC had significantly improved sensitivity when compared with CBx alone with a p-value of 0.014 (for both when atypical is used as benign or malignant). For patients undergoing ERCP with dSOC for indication of biliary stricture, the addition of aspiration fluid cytology to dSOC targeted biopsies significantly improves the sensitivity for detecting malignancy. Irrigation during cholangioscopy is done routinely for visualization of the duct and aspirating the fluid for cytology can be done without increasing the length of the procedure and significantly enhancing the diagnostic sensitivity.View Large Image Figure ViewerDownload Hi-res image Download (PPT)