The Effect of High-Intensity Focused Ultrasound Rays in the Treatment of Uterine Fibroids on Tissue Parameters of Endometrial Receptivity

Objective: To analyse the effect of the ultrasonic energy during MRI-guided high-intensity focused ultrasound ablation (HIFU) of uterine fibroids on molecular markers of endometrial receptivity in women of reproductive age.

Study design: A prospective comparative cohort study of 60 women of reproductive age was conducted. The main group consisted of 32 patients suffering from the symptomatic course of uterine fibroids who received treatment with HIFU ablation of uterine fibroids: 17 women with node localization at the front wall of the uterus and the reflected action of ultrasonic waves on the endometrium and 15 women with the back wall node localization and penetrating effect of the waves. The control group consisted of 28 healthy fertile women examined voluntarily. The endometrium obtained with pipelle-biopsia on days 20-22 of the cycle was examined by immunohistochemistry before and three months after the treatment. The results were processed by the method of variation statistics using the SPSS 22.0.

Results: A significant decrease in the stromal expression of CD95bright in the endometrium to the level comparable with control values was observed after HIFU ablation of uterine fibroids (from 70.22±9.77 c/s to 48.81±5.47 c/s; p<0.001; the control level – 47.80±2.13 c/s). The ratio and expression of steroid receptors, proliferation markers, p53-dependent apoptosis and itsblockers, regulators and markers of angiogenesis, LIF and LIF-R signalling molecules in thestroma and endometrial glands did not change significantly after treatment (p>0.05 in treatment dynamics). It was demonstrated that focused ultrasound causes an increase in the level of expression of estradiol alpha receptors in the endometrial glands (118.07±14.01 points vs.153.33±11.43 points; p=0.02) and a decrease in stromal p53 expression (30.80±21.61% vs.14.66±3.74%; p=0.007). No influence of the localization of fibroid node on the stromal expression of CD56bright+ was demonstrated. A significant increase in the stromal expression of CD34+ to the level statistically comparable with control values (from 26.00±1.63 c/s to 32.47±2.03 c/s; p=0.011; the control level - 37.99±1.23 c/s) was associated with ultrasound action.

Conclusion: This study did not reveal any significant negative effects of HIFU ablation of uterine fibroids on endometrial receptivity in women of reproductive age.

Keywords: Uterine fibroids; Magnetic resonance imaging guided high-intensity focused ultrasound ablation; Endometrial receptivity

Abbreviations: MRg: Magnetic Resonance Imaging Guided; HIFU: High-Intensity Focused Ultrasound