1. Proctology Unit, Department of Surgical Sciences, Catholic University, Rome, Italy
2. Department of Surgery P, Aarhus University Hospital, Aarhus, Denmark
3. Department of Visceral, Transplant and Thoracic Surgery, Innsbruck Medical University, Innsbruck, Austria
4. Department of General, Visceral and Transplant Surgery, Charité Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany
5. Department of Emergency and Organ Transplantation, General Surgery Unit, University of Bari, Bari, Italy
6. Department of General Surgery, Nuovo Ospedale Civile Sant'Agostino Estense, Modena, Italy