1. Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
2. Department of Visceral, Thoracic, Vascular Surgery and Angiology, City Hospital Triemli, Birmensdorferstrasse 497, 8063 Zürich, Switzerland
3. Department of General and Visceral Surgery, Asklepios Hospital Altona, Paul-Ehrlich-Straße 1, 22763 Hamburg, Germany