1. Department of General, Visceral and Cancer Surgery, University of Cologne, Cologne, Germany
2. Department of General, Visceral und Vascular Surgery, Ludwig-Maximilian-University (LMU), Munich, Germany
3. Cologne Interventional Immunology, University of Cologne, Cologne, Germany
4. Department of General, Visceral und Vascular Surgery, Otto von Guericke University, Magdeburg, Germany