1. Department of Cardiac Surgery, Sana Herzchirurgie Stuttgart, Baden-Württemberg, Germany
2. Department of Thoracic Surgery, University of Tubingen Faculty of Science, Tubingen, Baden-Württemberg, Germany
3. Department of Otorhinolaryngology, Klinikum Stuttgart Katharinenhospital, Olgahospital, Stuttgart, Baden-Württemberg, Germany