1. Department of Urology, Haukeland University Hospital, Jonas Lies vei 65, 5021 Bergen, Norway
2. Department of Urology, University Hospital Zurich, University of Zurich, Zurich, Switzerland EAU YAU Urolithiasis Group, Arnhem, The Netherlands
3. Second Department of Urology, National and Kapodistrian University of Athens, Sismanogleio General Hospital, Athens, Greece EAU YAU Urolithiasis Group, Arnhem, The Netherlands
4. Department of Urology, Haukeland University Hospital, Bergen, NorwayDepartment of Clinical Medicine, University of Bergen, Bergen, Norway
5. Department of Urology, University Hospital Southampton, Southampton, UK
6. Department of Urology, Haukeland University Hospital, Bergen, Norway
7. Haukeland University Hospital, Bergen, NorwayDepartment of Clinical Medicine, University of Bergen, Bergen, Norway