1. Department of Thoracic and Cardiovascular Surgery; University Hospital of Saarland; Homburg/Saar Germany
2. Department of Anesthesiology, Intensive Care Medicine and Pain Medicine; University Hospital Schleswig-Holstein; Kiel Germany
3. Department of Thoracic and Cardiovascular Surgery; University Hospital Schleswig-Holstein; Kiel Germany
4. Institute for Clinical and Experimental Surgery; University Hospital of Saarland; Homburg/Saar Germany