1. Department of Surgery Institute of Clinical Sciences Sahlgrenska Academy Scandinavian Surgical Outcomes Research Group University of Gothenburg Gothenburg Sweden
2. Department of Surgery Region Västra Götaland Sahlgrenska University Hospital/Östra Gothenburg Sweden
3. Department of Radiology Sahlgrenska University Hospital Gothenburg Sweden
4. Department of Surgery, Herlev and Gentofte Hospital University of Copenhagen Herlev Denmark