1. Department of Surgery ,N1, Yerevan State Medical University after M.Heratsi , Yerevan , Armenia
2. Department of General and Abdominal Surgery, ArtMed MRC , Yerevan , Armenia
3. Clinic of Surgery, Mickaelyan Institute of Surgery , Yerevan , Armenia
4. The Intervention Center, Oslo University Hospital Rikshospitalet , Oslo , Norway