1. Paediatric Surgery Unit Polyclinic G.B. Morgagni Catania Italy
2. Unit of Paediatric Surgery Department of Human Pathology of Adult and Childhood “Gaetano Barresi” University of Messina Messina Italy
3. Section of Paediatric Urology Department of Surgical, Oncological and Gastrointestinal Sciences University Hospital of Padova Padua Italy
4. Paediatric Surgery Unit Federico II University of Naples Naples Italy