1. National and Kapodistrian University of Athens Third Department of Surgery, Attikon University Hospital, , Athens, Greece
2. Université Libre de Bruxelles Department of Abdominal Surgery, Erasme Hospital, , Brussels, Belgium
3. Department of Surgery, Lister Hospital, East and North Hertfordshire NHS Trust , Stevenage, UK
4. University Hospital of Ioannina Department of Surgery, , Ioannina, Greece
5. National and Kapodistrian University of Athens First Department of Surgery, Laikon General Hospital, , Athens, Greece