1. Department of Cardiothoracic and Vascular Surgery, Westpfalz Klinikum, 67655 Kaiserslautern, Germany
2. Department of Thoracic Surgery, General Hospital of Rhodos, 85133 Rhodos, Greece
3. Department of General Surgery, Patras University Hospital, 26504 Patras, Greece
4. Second Department of Surgery, Democritus University of Thrace Medical School, 68100 Alexandroupolis, Greece
5. Department of Thoracic Surgery and Thoracic Endoscopy, Ruhrlandklinik, West German Lung Center, University Hospital Essen, University Duisburg-Essen, 45239 Essen, Germany
6. Department of Cardiothoracic Surgery, General Hospital of Nicosia, 2031 Nicosia, Cyprus
7. Department of Thoracic Surgery, University Hospital of Heraklion, 71500 Heraklion, Greece
8. Department of Thoracic Surgery, KAT Attica General Hospital, 14561 Athens, Greece
9. Department of Cardiothoracic Surgery, Patras University Hospital, 26504 Patras, Greece