1. Department of Surgery, University Hospital of Donostia , Donostia-San Sebastián , Spain
2. Department of Surgery, Vall d´Hebron Hospital Universitari , Barcelona , Spain
3. Department of Medical Surgical Sciences and Translational Medicine, Sapienza University of Rome, Gastrointestinal Surgery Unit, Sant’Andrea University Hospital , Rome , Italy
4. Department of Surgical , Oncological and Gastroenterological Sciences, , Padova , Italy
5. Università di Padova , Oncological and Gastroenterological Sciences, , Padova , Italy
6. Department of Upper GI Surgery, Portsmouth Hospitals University , Portsmouth , UK
7. Department of General , Visceral and Transplant Surgery, , Mainz , Germany
8. University Medical Center Mainz , Visceral and Transplant Surgery, , Mainz , Germany
9. Department of Surgery, Catharina Hospital , Eindhoven , the Netherlands
10. Department of Molecular Medicine and Surgery , Karolinska Institutet, , Stockholm , Sweden
11. Karolinska University Hospital , Karolinska Institutet, , Stockholm , Sweden
12. Nuffield Department of Surgery, University of Oxford , Oxford , UK
13. Department of Surgery and Transplantation, Copenhagen University Hospital , Rigshospitalet , Denmark
14. Department of Surgery, University Medical Center Utrecht , Utrecht , the Netherlands