1. 1 Ss. Cyril and Methodius University in Skopje, Medical Faculty , Skopje , RN Macedonia
2. 2 Department of General Surgery , General Hospital , Prilep , RN Macedonia
3. 3 Department of General Surgery , General Hospital , Ohrid , RN Macedonia
4. 4 University Surgery Hospital “St. Naum Ohridski” , Ss. Cyril and Methodius University in Skopje , Skopje , RN Macedonia