1. Department of Surgery & Medical-Surgical Specialties, Surgical Clinic Unit, University Hospital of Catania (CAST), University of Catania, 95122 Catania, Italy
2. Semmelweiss University of Budapest, Asklepios Campus Hamburg, Germany
3. Oncology Unit, Asklepios Barmbek Hospital, Hamburg, Germany
4. Department of General, Visceral, Thoracic & Pediatric Surgery, Saarbrucken Hospital, Saarbrucken-Saarland, Germany
5. Department of General & Abdominal Surgery, Asklepios Barmbek Hospital, Hamburg, Germany