1. Medical Faculty University of Cologne Cologne Germany
2. Center for Esophageal Diseases Elisabeth‐Krankenhaus Essen Essen Germany
3. Surgical Interventional Trials Unit, Nuffield Department of Surgery University of Oxford Oxford UK
4. Department of General, Visceral and Cancer Surgery University of Cologne Cologne Germany
5. Institute of Pathology, University of Cologne Cologne Germany
6. Department of Visceral Surgery Geneva University Hospitals Geneva Switzerland
7. Department of Visceral, Transplantation, Thoracic and Vascular Surgery University Hospital of Leipzig Leipzig Germany