THE ROLE OF "ROSE" FOR ERCP-GUIDED BRUSHING ON INDETERMINATE BILIARY STRICTURES: EXPERIENCE OF A REFERRAL CENTER

Background and aim: Endoscopic Retrograde CholangioPancreatography (ERCP), although nowadays used only for therapeutic purposes, still has a prominent diagnostic role in patients with indeterminate biliary strictures and no evidence of mass lesion at EUS or CT scan. The use of biliary stricture brushing is a safe, easy, cheap and fast way to acquire cytological specimen from the determination of the etiology, but the sensitivity can be as low as 50%. Rapid On-Site Evaluation (ROSE) of the sample has been used for years in referral centers for the determination of the adequacy of EUS-guided FNA cytological specimens, improving its sensitivity and specificity. Nevertheless, there are currently no studies evaluating its role for ERCP brushing. The aim of this study was to assess the diagnostic yield of ERCP brushing of indeterminate biliary strictures when supported by ROSE. Methods: We conducted a retrospective single center study enrolling consecutive patients undergoing ERCP and brush cytology supported by ROSE for indeterminate biliary strictures, including patients from January 1st 2010 to May 31st 2018. Data recorded included patient's characteristics, clinical/ radiological and EUS features, ERCP features including stricture features, number of passages performed with the brush, final cytology or histology when biopsy was performed as an adjunct, use of cholangioscopy or confocal laser endomicroscopy, final diagnosis after surgery or follow-up when the patient would not undergo a resection. The diagnostic yield of ERCP guided brushing with ROSE was then calculated. Results: 96 patients underwent ERCP for indeterminate biliary stenosis, with 50% being males, mean age 68.1 years, 80% having an extrahepatic biliary stricture. 90 patients underwent brushing with ROSE and were included in the analysis, with 86.7% of patients having an adequate sample at ROSE. The preliminary diagnostic yield calculated showed a sensitivity of 80%, a specificity of 82%, an accuracy of 81%, a positive predictive value of 92% and a negative predictive value of 61%. Conclu sions: The availability of ROSE in patients undergoing ERCP with indeterminate biliary stricture without a mass lesion increases the diagnostic yield of brushing, decreasing the need of further procedures, such as cholangioscopy and confocal laser endomicroscopy and can, therefore, decrease costs and increase safety.