1. Neonatal Surgery Unit, Department of Medical and Surgical Neonatology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
2. Unit of Pediatric Surgery, Department of Surgery, G. Gaslini Institute, Genoa, Italy.
3. Unit of Anesthesiology, Department of Anesthesiology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.