1. General Surgery Unit, Sandro Pertini Hospital, ASL Roma 2, 00157 Roma, Italy
2. General Surgery Unit, University of L’Aquila, 67100 L’Aquila, Italy
3. Department of Applied Clinical Sciences and Biotechnology, University of L’Aquila, 67100 L’Aquila, Italy
4. General Surgery Unit, Santa Lucia Hospital, 62100 Macerata, Italy
5. General Surgical Unit, Department of Clinical and Experimental Sciences, University of Brescia at the Azienda Socio Sanitaria Territoriale (ASST), 26100 Cremona, Italy
6. Digestive & Emergency Surgery Unit, Santa Maria Hospital, 05100 Terni, Italy
7. Oncologic Surgery Unit, Candiolo Cancer Institute, FPO-IRCCS, 10060 Candiolo, Italy
8. General & Emergency Surgery Unit, San Camillo-Forlanini Hospital, 00152 Roma, Italy
9. General Surgery Unit, Santa Maria Annunziata & Serristori Hospital, 50012 Firenze, Italy