1. Department for General , Visceral, Cancer and Transplant Surgery, Faculty of Medicine, , Cologne , Germany
2. University of Cologne, University Hospital Cologne , Visceral, Cancer and Transplant Surgery, Faculty of Medicine, , Cologne , Germany
3. Center for Esophagogastric Cancer Surgery, St. Elisabethen Hospital Frankfurt , Frankfurt , Germany
4. Department for Upper GI Surgery, Portsmouth Hospitals University NHS Trust , Portsmouth , UK