1. Department of Surgery, University Hospital Düsseldorf, Düsseldorf, Germany.
2. Center of Visceral Medicine, Department of General and Visceral Surgery, Protestant Hospital of Bethel Foundation, Bielefeld, Germany.
3. Center of Visceral Medicine, Department of Gastroenterology and Internal Medicine, Protestant Hospital of Bethel Foundation, Bielefeld, Germany.
4. Department of Thoracic Surgery, Protestant Hospital of Bethel Foundation, Bielefeld, Germany.