1. University of Kragujevac, Faculty of Medical Sciences , Department of Surgery , Kragujevac , Serbia
2. Department of General and Thoracic Surgery , Clinical Center Kragujevac , Serbia
3. University of Kragujevac , Faculty of Medical Sciences, Department of Pathology , Kragujevac , Serbia
4. Department of Anesthesiology , Clinical Center Kragujevac , Serbia
5. University of Kragujevac , Faculty of Medical Sciences, Department of Anatomy , Kragujevac , Serbia