1. Pediatric Surgery Unit, Federico II University of Naples, Naples, Italy.
2. Pediatric Urology Unit, Meyer Children Hospital, Florence, Italy.
3. Pediatric Urology Unit, Medical University of Padua, Padua, Italy.
4. Pediatric Surgery Unit, Children's Hospital G. Di Cristina, ARNAS Civico-Di Cristina-Benfratelli, Palermo, Italy.
5. Pediatric Urology Unit, Bambin Gesù Children Hospital, Rome, Italy.
6. Pediatric Surgery Unit, G. D'Annunzio University of Chieti, Pescara, Italy.
7. Pediatric Surgery Unit, Azienda Ospedaliero-Universitaria, Ancona, Italy.
8. Pediatric Surgery Unit, Medical University of Padua, Padua, Italy.
9. Pediatric Surgery Unit, University Hospital of Catania, Catania, Italy.