1. Department of Surgery, Klinikum Neumarkt, Neumarkt, Germany; the
2. Department of General and Thoracic Surgery, Klinikum Nuremberg, Nuremberg, Germany;
3. Szent István University, Budapest, Hungary;
4. Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain;
5. Department of Surgery, Paracelsus Medical University, Salzburg, Austria