FP649IN SEARCH OF AN OPTIMAL SCREENING PROGRAM FOR DETECTING STENOSIS AND PREDICTING THROMBOSIS IN ARTERIOVENOUS GRAFT: A DIAGNOSTIC COMPARATIVE ANALYSIS OF THE CURRENTLY AVAILABLE TOOLS. (13th June 2019) - Tessitore, Nicola; Pessolano, Giuseppina; Bedogna, Valeria; Lipari, Giovanni; Contro, Alberto; Mansueto, Giancarlo; Poli, Albino