1. Department of General Surgery, University Hospital of Larissa, University of Thessaly, Biopolis, 41110 Larissa, Greece
2. Department of Surgery, General Hospital Papageorgiou, Aristotle University of Thessaloniki, 56429 Thessaloniki, Greece
3. Department of Cardiothoracic Surgery, University Hospital of Larissa, University of Thessaly, Biopolis, 41110 Larissa, Greece