1. 4th Cardiac Surgery Department, Hygeia Hospital, 151 23 Marousi, Greece
2. Department of Cardiac Surgery, Medical School, National and Kapodistrian University, 157 72 Athens, Greece
3. Anesthesiology Department, Evangelismos General Hospital, 106 76 Athens, Greece
4. Cardiovascular and Thoracic Surgery Department, Evangelismos General Hospital, 106 76 Athens, Greece
5. Department of Vascular Surgery, Medical School, National and Kapodistrian University, 157 72 Athens, Greece