1. Department of General, Visceral and Transplant Surgery, University of Heidelberg, Heidelberg, Germany
2. St. Claraspital AG, Departement of Surgery, Basel, Switzerland
3. Department of Surgery, Klinik Stephanshorn, St. Gallen, Switzerland
4. Department of Gastroenterology, University of Heidelberg, Heidelberg, Germany
5. Institute of Pathology, University of Heidelberg, Heidelberg, Germany
6. Department of Surgery, Hospital STS Thun AG, Thun, Switzerland