1. 1Department of General Surgery, University of Perugia, St. Maria Hospital, Terni, Italy
2. 2Department of General and Oncologic Surgery, University of Perugia, Perugia, Italy
3. 3Department of surgical specialties, Urological Andrological Surgery and Minimally Invasive Techniques, University of Perugia, Terni, Italy
4. 4Department of Digestive Surgery and Liver Unit, St. Maria Hospital, Terni, Italy