1. Faculty of Medicine, University of Heidelberg, Im Neuenheimer Feld 346, 69120 Heidelberg, Germany
2. CHIR-Net Coordinating Centre at the Study Center of the German Surgical Society, University of Heidelberg, Im Neuenheimer Feld 130.3, 69120 Heidelberg, Germany
3. Chirurgische Klinik, Campus Virchow-Klinikum, Charité, Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
4. Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany