作者单位:Departments of Surgery and Anesthesiology, North Karelia Central Hospital, Tikkamaentie 16, 80201[1]Department of Surgery, Helsinki University Hospital, Stenbackinkatu 9, 00029 Helsinki, Finland[2]Department of Surgery, Kuopio University Hospital, Puijonlaaksontie 2, 70211 Kuopio, Finland[3]