1. Department of Interdisciplinary Endoscopy, Hamburg-Eppendorf University Hospital, Hamburg, Germany
2. Mannheim University Hospital, Heidelberg University Medical School, Mannheim, Germany
3. Department of Gastroenterology, Hepatology and Oncology, Ludwigsburg Hospital, Ludwigsburg, Germany
4. Department of Surgery, McGill University Health Centre, Montreal, Quebec, Canada
5. Department of Surgery, Mannheim University Hospital, Mannheim, Germany