1. Department of General, Visceral and Transplant Surgery, University Hospital Essen, Essen, Germany
2. Department of General, Visceral and Transplant Surgery, University Hospital Münster, Alber-Schweitzer-Campus 1, 48140 Münster, Germany
3. Department of General and Visceral Surgery, St. Bernhard-Hospital Kamp-Lintfort, Kamp-Lintfort, Germany
4. MVZ Media Vita, Doctor’s Office for Surgery, Issum, Germany