1. First Department of Surgery, National and Kapodistrian University of Athens, Laikon General Hospital, Athens, Greece
2. Third Department of Surgery, National and Kapodistrian University of Athens, Attikon University Hopsital, Athens, Greece
3. General Surgical Department, Royal Sussex County Hospital, Brighton, UK
4. First Propedeutic Department of Surgery, National and Kapodistrian University of Athens, Hippocration General Hospital, Athens, Greece
5. Division of Surgery, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm, Sweden
6. Department of Upper Abdominal Diseases, Karolinska University Hospital, Stockholm, Sweden
7. Department of Surgery, University Medical Center Utrecht, Utrecht, The Netherlands