HIFU as an alternative modality for patients with uterine fibroids who require fertility-sparing treatment

Objectives To compare pregnancy outcomes after high-intensity focused ultrasound ablation (HIFU), myomectomy and uterine artery embolization (UAE) for fertility-sparing patients with uterine fibroids and to investigate the possible mechanism of improving pregnancy by HIFU. Materials and methods A meta-analysis of 54 studies containing 12,367 patients was conducted to compare the pregnancy outcomes of three fertility-sparing therapies. And a retrospective self-control study of 26 patients with uterine fibroids from May 2019 to December 2020 was performed to assess the blood flow impedance of bilateral uterine arteries before and after HIFU. Results In the analysis by treatment option, the pregnancy rate after myomectomy was 0.43 (95% CI 0.36-0.49), which was higher than 0.18 (95% CI 0.10-0.26) after HIFU, the latter was significantly higher than that after UAE (ratio 0.08, 95% CI 0.06-0.10). The miscarriage rate after HIFU was 0.08 (95% CI 0.04-0.12), which was similar to 0.15 (95% CI 0.09-0.21) after myomectomy and also similar to 0.16 after UAE (95% CI 0.01-0.30). In the subgroup analysis, women who received ultrasound guided HIFU (USgHIFU) were more likely to have ideal pregnancy outcomes than that after magnetic resonance imaging-guided HIFU. The pulsatility index and resistance index on the right side were significantly higher 3 months after HIFU than before (1.637 +/- 0.435 vs. 1.845 +/- 0.469; p = 0.033; 0.729 +/- 0.141 vs. 0.784 +/- 0.081, p = 0.039). Conclusions HIFU, especially USgHIFU, may be an alternative fertility-sparing modality for patients with uterine fibroids over 40 years old. HIFU may contribute to improving pregnancy rates by elevating uterine blood flow impedance.