1. Department of Surgery, Ystad Hospital, Ystad, Sweden Department of Clinical Sciences, Lund University, Lund, Sweden
2. Department of Clinical Sciences, Lund University, Lund, Sweden Department of Surgery, Skåne University Hospital, Lund, SwedenKjetil Søreide
3. Department of Gastrointestinal Surgery, Stavanger University Hospital, Stavanger, Norway Department of Clinical Medicine, University of Bergen, Bergen, Norway
4. Department of Surgery, Skåne University Hospital, Lund SE-222 42, Sweden