1. First Propaedeutic Department of General Surgery, National and Kapodistrian University of Athens, “Hippokrateion” General Hospital of Athens, Athens, Greece
2. Department of Surgery, University Hospital of Ioannina and School of Medicine, University of Ioannina, Ioannina, Greece
3. Department of Pathology, University Hospital of Ioannina and School of Medicine, University of Ioannina, Ioannina, Greece