1. Department of Surgery, Kuopio University Hospital and School of Medicine, University of Eastern, Kuopio, Finland;
2. Department of Surgery, Helsinki University Central Hospital, Helsinki, Finland;
3. Science Service Centre, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland;
4. Department of Anaesthesia and Operative Services, Kuopio University Hospital and School of Medicine, University of Eastern Finland, Kuopio, Finland;
5. Department of Clinical Chemistry, Institute of Clinical Medicine, University of Eastern Finland and Eastern Finland Laboratory Centre, Kuopio, Finland