1. Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital Düsseldorf, Medical Faculty of Heinrich Heine University Düsseldorf, Düsseldorf, Germany
2. Paracelsus Medical University, Klinikum Nürnberg, Nürnberg, Germany
3. Department of Surgery (A), University Hospital Düsseldorf, Medical Faculty of Heinrich Heine University Düsseldorf, Düsseldorf, Germany
4. Department of Visceral and Transplantation Surgery, University Hospital RWTH Aachen, Aachen, Germany