1. Department of Visceral, Thoracic and Vascular Surgery, Philipps University of Marburg, Marburg, Germany
2. Department of Psychology, University of Wurzburg, Wurzburg, Germany
3. Department of Psychotherapeutic and Psychosomatic Medicine, Zentralinstitut für Seelische Gesundheit Mannheim, Mannheim, Germany
4. Department of Visceral, Thoracic and Endocrine Surgery, Klinikum Offenbach, Offenbach, Germany