1. Department of Cardiovascular Surgery, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany
2. Department of Cardiac and Thoracic Vascular Surgery, University Hospital of Schleswig-Holstein, Lübeck, Germany
3. Clinic for Cardiac, Thoracic and Vascular Surgery, Klinikum Braunschweig gGmbH, Braunschweig, Germany
4. German Society for Thoracic and Cardiovascular Surgery, Berlin, Germany