1. General Surgery Unit, Sandro Pertini Hospital, ASL Roma 2, Rome
2. General Surgery Unit, “C.&G. Mazzoni” Hospital, Ascoli Piceno
3. General Surgery Unit, University of L’Aquila, L’Aquila
4. Department of Applied Clinical Sciences and Biotechnology, University of L’Aquila, L’Aquila
5. General Surgery Unit, IRCCS Sacro Cuore Don Calabria Hospital, Negrar di Valpolicella (VR)
6. General Surgery Unit, Cardinale G. Panico Hospital, Tricase (LE)
7. Oncologic Surgery Unit, Candiolo Cancer Institute, FPO-IRCCS, Candiolo (TO)
8. General & Oncologic Surgery Unit, Department of Surgery, Santa Croce e Carle Hospital, Cuneo
9. General Surgery Unit, ASST Ovest Milanese, Legnano (MI)
10. General Surgery Unit, ASST Nord Milano, Sesto San Giovanni (MI)
11. General Surgery Unit, Santa Maria Annunziata & Serristori Hospital, Firenze, Italy