Vincenzo Ficarra1,2, Vincenzo Mirone3, Prokar Dasgupta4. 1. Department of Experimental and Clinic Medical Sciences, Urology Unit, University of Udine, Udine, Italy. 2. Academic Medical Centre Hospital Santa Maria della Misericordia, Udine, Italy. 3. Department of Urology, University of Naples Federico II, Naples, Italy. 4. King's College London, Guy's Hospital, London, UK.