1. Department of Gastroenterology, General Hospital “Hippokration, Athens, Greece
2. Department of Pediatric Surgery, “ATTIKON” General University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
3. Third Department of Surgery, “Attikon” General University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
4. Second Department of Pediatrics, P. & A. Kyriakou Children’s Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece