Comparison of Dose and Effectiveness of a Single-Session Ultrasound-Guided High-Intensity Focused Ultrasound Ablation of Uterine Fibroids With Different Sizes

Comparing the effect of FUAS and myomectomy on the elasticity of myometrium around targeted uterine fibroid

BACKGROUND

Focused ultrasound ablation surgery (FUAS) has been widely employed to treat patients with uterine fibroid (UF). This study aimed to estimate myometrial stiffness changes in patients who received FUAS for UFs or myomectomy (ME) and compare the recovery of surrounding myometrium between FUAS and ME groups. Our results may provide more evidence for guiding the proper conception timing in patients with UF.

METHODS

This study enrolled 173 patients from May 2022 to August 2023. Shear wave elastography (SWE) was used to dynamically monitor myometrial elasticity changes in patients before and after surgery. Moreover, our study monitored and analyzed the stiffness changes in the targeted fibroid after FUAS, as well as in the myometrium around after FUAS or ME.

RESULTS

The stiffness of the myometrium around the resected fibroid was significantly higher than at the preoperative level until 6 months. Conversely, the stiffness of the surrounding myometrium was only temporarily increased 1 day after FUAS. The comparison between FUAS and ME groups regarding the stiffness of the surrounding myometrium showed that nonsignificant differences were detected between the two groups before the treatment. The stiffness of the surrounding myometrium in the ME group was statistically significantly higher than that of the FUAS group 1 day as well as 1, 3, and 6 months after the treatment, respectively.

CONCLUSION

The FUAS had less impact on the surrounding myometrium than the ME, which may be more conducive to the recovery of myometrial elasticity in patients with UF.

Prediction of high-intensity focused ultrasound (HIFU)-induced lesion size using the echo amplitude from the focus in tissue

In the realm of high-intensity focused ultrasound (HIFU) therapy, the precise prediction of lesion size during treatment planning remains a challenge, primarily due to the difficulty in quantitatively assessing energy deposition at the target site and the acoustic properties of the tissue through which the ultrasound wave propagates. This study investigates the hypothesis that the echo amplitude originating from the focus is indicative of acoustic attenuation and is directly related to the resultant lesion size. Echoes from multi-layered tissues, specifically porcine tenderloin and bovine livers, with varying fat thickness from 0 mm to 35 mm were collected using a focused ultrasound (FUS) transducer operated at a low power output and short duration. Subsequent to HIFU treatment under clinical conditions, the resulting lesion areas in the ex vivo tissues were meticulously quantified. A novel treatment strategy that prioritizes treatment spots based on descending echo amplitudes was proposed and compared with the conventional raster scan approach. Our findings reveal a consistent trend of decreasing echo amplitudes and HIFU-induced lesion areas with the increasing fat thickness. For porcine tenderloin, the values decreased from 2541.7 ± 641.9 mV and 94.4 ± 17.9 mm2 to 385(342.5) mV and 24.9 ± 18.7 mm2, and for bovine liver, from 1406(1202.5) mV and 94.4 ± 17.9 mm2 to 502.1 ± 225.7 mV and 9.4 ± 6.3 mm2, respectively, as the fat thickness increases from 0 mm to 35 mm. Significant correlations were identified between preoperative echo amplitudes and the HIFU-induced lesion areas (R = 0.833 and 0.784 for the porcine tenderloin and bovine liver, respectively). These correlations underscore the potential for an accurate and dependable prediction of treatment outcomes. Employing the proposed treatment strategy, the ex vivo experiment yielded larger lesion areas in bovine liver at a penetration depth of 8 cm compared to the conventional approach (58.84 ± 17.16 mm2 vs. 44.28 ± 15.37 mm2, p < 0.05). The preoperative echo amplitude from the FUS transducer is shown to be a reflective measure of acoustic attenuation within the wave propagation window and is closely correlated with the induced lesion areas. The proposed treatment strategy demonstrated enhanced efficiency in ex vivo settings, affirming the feasibility and accuracy of predicting HIFU-induced lesion size based on echo amplitude.

Effectiveness and Safety of Ultrasound-guided Percutaneous Microwave Ablation for a Single Uterine Fibroid Greater than 300 cm3

STUDY OBJECTIVE

To evaluate the effectiveness and safety of ultrasound-guided percutaneous microwave ablation (MWA) for a single uterine fibroid greater than 300 cm³.

DESIGN

Retrospective observational study.

SETTING

China-Japan Union Hospital of Jilin University, China.

PATIENTS

Thirty-seven patients each with a single fibroid greater than 300 cm³ diagnosed by ultrasound and core needle biopsy.

INTERVENTIONS

Ultrasound-guided percutaneous MWA.

MEASUREMENTS AND MAIN RESULTS

All patients were followed up for 12 months postoperatively to assess the postoperative lesion volume reduction rate, degree of symptomatic relief, improvements in quality of life, and occurrence of adverse events. All 37 patients met the criteria for complete ablation, and the lesion volume significantly decreased from 334.28 cm³ (95% confidence interval [CI] 326.75-366.73) preoperatively to 52.01 cm³ (95% CI, 46.95-74.69) at the 12-month follow-up (difference: 280.15 cm³; 95% CI, 267.92-294.65; p <.001). The lesion volume reduction rates at 1, 3, 6, and 12 months postoperatively were 27.30% (95% CI, 24.12-31.45), 52.90% (95% CI, 47.95-55.80), 67.90% (95% CI, 63.03-70.77), and 84.00% (95% CI, 80.22-85.94), respectively. The differences in the preoperative and postoperative Uterine Fibroid Symptom and Health-Related Quality of Life Questionnaire scores were significant (p <.01). The hemoglobin levels of the anemic patients were significantly elevated after the procedure (p <.001). Of the 37 patients in this study, 29 patients (78.38%) had a highly significant treatment effect, and 8 patients (21.62%) had a significant treatment effect. Seventeen patients (45.95%) had Society of Interventional Radiology grade A to B adverse effects that required no clinical intervention or only simple clinical intervention.

CONCLUSION

Ultrasound-guided percutaneous MWA has good clinical efficacy and high safety in the treatment of a single uterine fibroid greater than 300 cm³.

Treatment of Placenta Increta With High-Intensity Focused Ultrasound Ablation and Leaving the Placenta in situ: A Multicenter Comparative Study

Objective

To explore the feasibility of simple high-intensity focused ultrasound (HIFU) ablation for placenta increta.

Methods

Ninety-five patients after a vaginal delivery were enrolled in this retrospective cohort study, 53 patients were treated with simple HIFU ablation, and 42 patients were treated with HIFU followed by uterine curettage.

Results

All 95 patients were successfully treated with a single-session HIFU procedure, and in the control group, the necrotic placental tissue was removed with curettage. Vaginal hemorrhage did not occur in either group. The duration of bloody lochia was 25.9 ± 8.6 days in the sHIFU group and 24.2 ± 8.8 days in the control group (P > 0.05). The median serum human chorionic gonadotropin (HCG) level was 3,222 mIU/mL and 2,838 mIU/mL in the sHIFU and control groups, respectively, which decreased and returned to normal within 30 days, and the differences were not significantly on comparing the blood HCG level in the two groups at 7, 15, and 30 days after HIFU (all P > 0.05). Decreased menstrual volume occurred in 85.71% of patients in the control group, which was higher than that in the sHIFU group (23.08%) (χ² = 6.839, P < 0.001). During 2–8 years of follow-up, six pregnancies occurred in the sHIFU group without any recurrence of placenta increta, three pregnancies occurred in the control group, and one patient developed a repeat placenta increta.

Conclusion

Simple HIFU treatment is safe and effective for postpartum placenta increta and leaving the placenta in situ. It is a promising option for patients who wish to preserve their fertility and conceive.