1. Department of Surgery, Karolinska Hospital, Stockholm, Sweden
2. Department of Surgery, Akranes Hospital, Akranes, Iceland
3. Department of Surgery, Örebro University Hospital, Örebro, Sweden
4. Department of Surgery, St Göran's Hospital, Stockholm, Sweden
5. Department of Surgery, Frölunda Specialist Hospital, Frölunda, Sweden
6. Department of Surgery, Västerås Hospital, Västerås, Sweden
7. Department of Surgery, Helsingborg Hospital, Helsingborg, Sweden
8. Department of Surgery, Central Hospital, Karlstad, Sweden
9. Department of Surgery, Malmö University Hospital, Malmö, Sweden