1. Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
2. 1st Department of Medicine, University Medical Center Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
3. Department of Internal Medicine, Robert Koch Hospital Gehrden, Gehrden, Germany
4. Department of General, Visceral and Transplantation Surgery, Hannover Medical School, Hannover, Germany
5. Department of Surgery, University Medical Center Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
6. Clinic for General, Visceral, and Vascular Surgery, Robert Koch Hospital Gehrden, Gehrden, Germany