N E Samalavicius1,2, V Janusonis3, E Smolskas1, A Dulskas2,4,5. 1. Department of Surgery, Klaipeda University Hospital, Klaipeda, Lithuania. 2. Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius, Lithuania. 3. Klaipeda University Hospital, Klaipeda, Lithuania. 4. Faculty of Health Care, University of Applied Sciences, Vilnius, Lithuania. 5. Department of Surgical Oncology, National Cancer Institute, Vilnius, Lithuania.