[1] Haukeland Hosp, Dept Gynecol & Obstet, N-5021 Bergen, Norway
[2] Haukeland Hosp, Dept Anesthesiol, N-5021 Bergen, Norway
[3] Univ Surrey, Adv Gynecol Endoscopy Program, Bergen, Norway
[4] Royal Surrey Cty Hosp, Guildford, Surrey, England
[5] Univ Bergen, Dept Clin Med, Bergen, Norway