1. Department of Anesthesiology, School of Medicine, University of Ioannina, 45110 Ioannina, Greece
2. Department of Surgery, Vascular Surgery Unit, School of Medicine, University of Ioannina, 45110 Ioannina, Greece
3. First Department of Surgery, Vascular Surgery Division, School of Medicine, University of Athens, 11527 Athens, Greece
4. 3rd Department of Surgery, Vascular Surgery Unit, Medical School, University of Athens, 11527 Athens, Greece