Ultrasound guided microwave ablation compared to uterine artery embolization treatment for uterine fibroids - a randomized controlled trial

Objective: To evaluate the efficacy, feasibility and acceptability of microwave ablation (MWA) compared to uterine artery embolization (UAE) as treatment for uterine fibroids. Method: A randomized controlled superiority trial, including premenopausal women 30-55 years, with symptomatic uterine fibroids without any single fibroid exceeding mean diameter of eight centimeters. Patients were randomized to receive microwave ablation, performed abdominally or vaginally, or to uterine artery embolization. The primary outcome was volume difference of the three largest fibroids at 6 months post treatment evaluated by magnetic resonance imaging (MRI) by a blinded radiologist analyzed by Mann-Whitney U-test. Secondary outcomes included symptom severity score (SSS), health related quality of life (HR-QoL), amount of menstrual bleeding, postoperative pain, length of hospitalization, need for additional treatment, adverse events and if patients would recommend the treatment to a friend. Results: Patients were recruited from 30 January 2017 to 12 September 2019, with a total of 17 patients treated in each group from May 2017 to December 2019. Superiority of MWA could not be established. The volume reduction was 41.8% (Interquartile range, IQR, 14-63) in the MWA group compared to 62.2% (IQR 34.9 80.1) in the UAE group (p = 0.29). Effects on symptoms, HR-QoL and acceptability did not differ between groups. Days of hospitalization and sick leave were significantly fewer in the MWA group (p < 0.001 and p = 0.001). Conclusions: Although superiority of MWA could not be established, it is a promising technique for treating uterine fibroids. It was well tolerated and associated with lower use of health care resources.