P Gavriilidis1, R J Davies2, J Wheeler2, N de'Angelis3, S Di Saverio4,5. 1. Division of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, W12 0HS, UK. 2. Cambridge Colorectal Unit, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0QQ, UK. 3. Department of Digestive Surgery, Henri Mondor University Hospital, 94010, Créteil, France. 4. Cambridge Colorectal Unit, Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0QQ, UK. salo75@inwind.it. 5. Department of General Surgery, University of Insubria, University Hospital of Varese, ASST Sette Laghi, Regione Lombardia, Varese, Italy. salo75@inwind.it.