AF.61 PROSPECTIVE, OBSERVATIONAL STUDY OF PROPHYLACTIC VEDOLIZUMAB TREATMENT IN PREVENTING POSTOPERATIVE RECURRENCE (POR) IN HIGH-RISK CROHN'S PATIENTS. (September 2021) - Valvano, M.; Stefanelli, G.; Vernia, F.; Longo, S.; Magistroni, M.; Mancusi, A.; Fabiani, S.; Viscido, A.; Latella, G.; Frieri, G.