1. Department of General, Visceral, Vascular, and Thoracic Surgery, Hospital of Baselland, Rheinstrasse 26, 4410 Liestal, Switzerland
2. Department of Visceral and Transplant Surgery, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland
3. Institute of Pathology, Mühlemattstrasse 11, 4410 Liestal, Switzerland
4. Department of Gastroenterology, Hirslanden-Clinic Beau-Site, Schänzlihalde 1, 3000 Bern-25, 3013 Bern, Switzerland
5. Department of Surgery, Hirslanden-Clinic Beau-Site, Schänzlihalde 1, 3000 Bern-25, 3013 Bern, Switzerland