1. Skellefteå Research Unit, Department of Surgical and Perioperative Sciences, Umeå University , Umeå , Sweden
2. Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet , Stockholm , Sweden
3. Department of Surgery and Anaesthesiology, Ersta Hospital , Stockholm , Sweden
4. Department of Surgery, Mora Hospital , Mora , Sweden
5. Department of Clinical Sciences, Intervention and Technology (CLINTEC), Karolinska Institutet , Stockholm , Sweden