1. Department of General, Visceral and Transplantation Surgery; Charité - Universitätsmedizin; Berlin Germany
2. Department of General, Visceral and Vascular Surgery; Evangelisches Krankenhaus Paul Gerhardt Stift; Lutherstadt Wittenberg Germany
3. Department of General, Visceral and Transplant Surgery; Hannover Medical School; Hannover Germany
4. Department of General, Visceral and Vascular Surgery; University of Jena; Jena Germany
5. Department of Visceral, Transplant, Thoracic and Vascular Surgery; University Hospital Leipzig; Leipzig Germany
6. Department of Hepatobiliary and Transplantation Surgery; Johannes Gutenberg University; Mainz Germany
7. Department of General, Visceral and Oncological Surgery; Bremen Mitte Clinic; Bremen Germany
8. Department of General, Visceral, Vascular and Paediatric Surgery; University of Saarland; Homburg Germany
9. Department of General, Visceral, Vascular and Paediatric Surgery; University Hospital of Würzburg; Würzburg Germany