“These findings should contribute to informing women and their physicians on making the best choice of treatment for their needs. Randomized controlled trials are needed to further validate these findings,” the study authors wrote.
The review included 14 UAE articles and 15 MRIgHIFU articles published between 2000 and 2020. None of the studies were randomized controlled trials, and none compared the treatments against each other. Additionally, only 7 papers reported percentage reductions.
To perform what they said was the first systematic comparison between UAE and MRIgHIFU, authors calculated weighted-average fibroid percentage changes from baseline through 24 months post-procedure for a total of 1383 UAE-treated patients and 835 treated with MRIgHIFU.
Differences between fibroid reduction rates were statistically significant at 6, 12, and 24 months, with shrinkage increasing over time.1 Among 22 papers reporting fibroid shrinkage through 6 months’ follow-up, weighted-average percentage reductions for UAE and MRIgHIFU were 50.57% (± 15.70%) and 30.06% (± 12.76%), respectively. The corresponding figures at 12 months (6 papers) were 62.78% (± 17.10%) and 25.91% (± 12.64%), respectively, and at 24 months (3 papers), 68.18% and 34.96% (± 4.88%), respectively (p=0.0001 in 6, 12, and 24-month analyses).
Mean percentage reductions for UAE and MRIgHIFU at 3 months were 35.59% (± 19.41%) and 38.31% (± 4.29%), respectively. The fact that the percentage shrinkage for UAE nearly doubled between months 3 and 24 could stem from the gradual effect of the treatment, which can cause progressive ischemia of the fibroid by blocking the uterine artery that supplies it, authors wrote. The 25% to 40% shrinkage associated with MRIgHIFU could be explained by thermal ablation of targeted tissue, leading to cell death and fibroid shrinkage.
A previous review by Taheri et al. assessed fibroid volume changes following UAE, ultrasound-guided HIFU, and radiofrequency ablation. These authors also found greater fibroid shrinkage for UAE than for HIFU at all intervals up to 26 months.2 However, according to the authors of the review in BMC Women’s Health, Taheri et al. did not exclude patients with prior treatments, other pelvic diseases, or postmenopausal status, all of which can confound results. For example, postmenopausal women might experience lower UAE efficacy due to their reduced estrogen levels.
Among 7 papers reporting UAE complications and 12 reporting MRIgHIFU complications, fever, pain, nausea, vomiting, anorexia, fatigue, abdominal distention, and amenorrhea—transient and permanent—topped the list of combined complications. More patients treated with UAE reported fever, nausea, vomiting, abdominal distention, rashes, and amenorrhea, whereas patients who underwent MRIgHIFU reported more pain, numbness, and skin lesions.
Study limitations included the fact that it did not assess re-intervention rates, symptomatic improvements, quality of life, pregnancy and ovarian reserves, and cost differences between UAE and MRIgHIFU. Although the study included all types of fibroids, authors added, further studies are needed to stratify fibroids based on anatomic location because intramural fibroids may undergo greater volume shrinkage post-UAE.
1. Yerezhepbayeva M, Terzic M, Aimagambetova G, Crape B. Comparison of two invasive non-surgical treatment options for uterine myomas: uterine artery embolization and magnetic resonance guided high intensity focused ultrasound-systematic review. BMC Women’s Health† 2022;22(1):55. Published 2022 Mar 3. doi:10.1186/s12905-022-01627-y
2. Taheri M, Galo L, Potts C, Sakhel K, Quinn SD. Nonresective treatments for uterine fibroids: a systematic review of uterine and fibroid volume reductions. Int J Hyperthermia† 2019;36(1):295-301.