Efficacy and safety of percutaneous microwave ablation for adenomyosis in the posterior uterine wall

Ultrasound-Guided Percutaneous Microwave Coagulation Studies on VX2 Rabbit Models for Breast Cancer Treatment and Ultrasound Imaging Assessment

Background

The study aimed to explore the tissue morphology and hemodynamics of rabbit VX2 breast carcinoma by high-frequency ultrasound (US) and the effectiveness and safety of US-guided percutaneous microwave coagulation (PMC) therapy on rabbit VX2 breast tumors.

Methods

Twenty VX2 tumor-bearing rabbits were assessed using color Doppler ultrasound for tumor growth characteristics including echo, size, blood supply and hemodynamic parameters once a week for six weeks. Subsequently, US-guided PMC was performed in randomly assigned ten VX2 tumor-bearing rabbits (the other ten as controls). US images after ablation were obtained and analyzed. Three rabbits with double VX2 tumors were used as pathological observation at weeks 0, 1, and 4 of ablation. The therapeutic efficacy was evaluated by tumor growth, physical examinations, survival time, survival rate and metastasis of tumors and histopathology.

Results

Ultrasound monitoring indicated that the tumor growth rate was 463.09% at the 2nd to 3rd weeks, and PMC was performed during this period under real-time US guidance. After microwave ablation, some tumors were greatly reduced or undetectable at week 8. Moreover, no flow signals were detected by US. The survival rates at 2 and 3 months in the treatment group and control group were 100%, 70% and 10%, 0%, respectively, while the metastatic rates were 10%, 30% and 90%, 100%, respectively (P<0.05).

Conclusion

The proliferation and metastasis of rabbit VX2 breast carcinoma were monitored by US imaging, and US-guided percutaneous microwave ablation was proven to be a safe, effective and minimally invasive therapeutic option for treating breast cancer in rabbits, showing potential clinical applicability.

Risk factors for symptom recurrence after microwave ablation of adenomyosis: a preliminary retrospective study

INTRODUCTION

Microwave ablation (MWA) effectively treats adenomyosis, yet symptom recurrence remains challenging. Thus, our study aims to explore the independent risk factors related to symptom recurrence after MWA of symptomatic adenomyosis.

MATERIAL AND METHODS

Patients with symptomatic adenomyosis who received MWA treatment at our institute from June 2020 to June 2023 were retrospectively included. Preoperative and intraoperative clinical data were retrospectively collected, and symptom relief following MWA was systematically monitored. Independent risk factors for symptom recurrence after MWA of adenomyosis were explored through Cox regression analysis. Kaplan-Meier (K-M) curves were plotted to estimate recurrence-free survival, and differences between groups were analyzed using the Log-Rank test.

RESULT

In total, 38 patients with adenomyosis were included, with a median follow-up duration of 15 months (interquartile range: 10-23 months). Among them, 81.58% (31/38) of patients experienced significant symptom relief, while 18.42% (7/38) reported partial relief, culminating in a clinical success rate of 100%. The symptom recurrence rate was 21.05% (8/38). Multivariate COX proportional hazards regression indicated that the fertility requirement, the absence of artificial ascites during the MWA procedure, and inadequate EPV (<524 J/cm3) were independent risk factors for symptom recurrence after MWA of adenomyosis.

CONCLUSION

MWA is an effective treatment for relieving symptoms of adenomyosis. While fertility requirements, without artificial ascites assistance, and lower EPV were independent risk factors for symptom recurrence after MWA of adenomyosis.

An Updated Review of Thermal Ablation Technology for Uterine Fibroids and Adenomyosis: Focusing on Protecting Fertility

There is a growing trend towards minimally invasive or noninvasive alternatives for gynecological disorders due to their rapid alleviation of symptom, expedited recovery, and minimal risks of postoperative complications. Thermal ablation technology has been commonly advocated as a minimally invasive therapeutic methods in recent years, including microwave ablation, radiofrequency ablation, and high-intensity focused ultrasound. The increasing application scenarios require updated and systematic research, and more evidence to promote their appropriate use. The objective of this review is to summarize the latest views of ablation from a prospective of fertility protection, endeavor to clarify the clinical value of thermal ablation technology in protecting fertility by assessing parameters such as ablation rates, alleviation of disease symptoms, re-intervention rates and post-treatment pregnancy rates. We review the clinical studies of ablation for uterine fibroids and adenomyosis treatment in the past 10 years, summarize the limitation and the prospects of its development in the treatment process, so as to provide clinicians with advice on the best practice. In the management of uterine fibroids and adenomyosis, thermal ablation technology offers improved fertility preservation and minimizes normal tissue injury compared to traditional surgical approaches for patients pursuing reproductive goals. In the future, thermal ablation technology will play a significantly enhanced role in preserving fertility for individuals requiring treatment for uterine fibroids and adenomyosis, guided by indications. But further research is still needed in the form of more extensive randomized prospective trials to provide stronger evidence supporting this perspective.

Intrauterine chilled saline instillation reduces endometrial impairment on MRI after ultrasound-guided percutaneous microwave ablation of uterine adenomyosis

OBJECTIVE

To investigate whether intrauterine chilled saline can reduce endometrial impairment during US-guided percutaneous microwave ablation (PMWA) of adenomyosis.

METHODS

An open-label, randomized trial was conducted with sixty symptomatic adenomyosis patients who were randomly assigned (1:1) to receive PMWA treatment assisted by intrauterine saline instillation (study group) or traditional PMWA treatment alone (control group). The primary endpoint was endometrial perfusion impairment grade on post-ablation contrast-enhanced MRI. The secondary endpoints were endometrial dehydration grade, ablation rate, and intra-ablation discomfort.

RESULTS

The baseline characteristics of the two groups were similar. The incidence rates of endometrial perfusion impairment on MRI in the study and control groups were 6.7% (2/30) and 46.7% (14/30), respectively (p < 0.001). There were 28 (93.3%), 2 (6.7%), 0, and 0 patients in the study group and 16 (53.3%), 7 (23.3%), 5 (16.7%), and 2 (6.7%) in the control group (p < 0.001) who had grade 0, 1, 2, and 3 perfusion impairment, respectively. Additionally, there were 27 (90%), 3 (10%), and 0 patients in the study group and 19 (63.3%), 10 (33.3%), and 1 (3.3%) in the control group who had grade 0, 1, and 2 endometrial dehydration (p = 0.01). The ablation rates achieved in the study and control groups were 93.3 ± 17% (range: 69.2-139.6%) and 99.7 ± 15.7% (range: 71.5-129.8%), and they were not significantly different (p = 0.14). No significant difference was found in the intra-ablation discomfort.

CONCLUSION

Intrauterine chilled saline can effectively reduce endometrial impairment after PMWA treatment for adenomyosis.

CRITICAL RELEVANCE STATEMENT

This trial demonstrated that the instillation of intrauterine chilled saline reduced endometrial impairment on MRI during PMWA of adenomyosis. This approach allows more precise and safe ablation in clinical practice.

KEY POINTS

Endometrial impairment occurs in the PMWA treatment of adenomyosis. Intrauterine chilled saline can reduce endometrial impairment during PMWA for adenomyosis. An intrauterine catheter is a practical endometrial protecting method during thermal ablation.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2100053582. Registered 24 November 2021, www.chictr.org.cn/showproj.html?proj=141090 .

Value of contrast-enhanced ultrasonography in microwave ablation treatment of symptomatic focal uterine adenomyosis

PURPOSE

This study evaluated the value of contrast-enhanced ultrasonography (CEUS) in the ultrasound-guided microwave ablation (MWA) treatment of symptomatic focal uterine adenomyosis.

METHODS

This retrospective study was conducted between March 2020 and January 2023, enrolling 52 patients with symptomatic focal uterine adenomyosis who had undergone MWA. All patients were examined with CEUS before and after MWA. The non-perfused volume (NPV) was compared between CEUS and dynamic contrast-enhanced magnetic resonance imaging (DCEMRI) following ablation. Therapeutic efficacy and safety were evaluated at 3-, 6-, and 12-month follow-ups. Additionally, this study explored the correlations between pre-treatment CEUS features and a volume reduction ratio indicating sufficient ablation, defined as 50% or more at the 3-month follow-up.

RESULTS

No significant differences in NPV were noted between CEUS and DCE-MRI immediately after MWA and during follow-up (all P>0.05). At the 3-month follow-up, the median VRRs for the uterus and adenomyosis were 33.2% and 63.9%, respectively. Sufficient ablation was achieved in 69.2% (36/52) of adenomyosis cases, while partial ablation was observed in the remaining 30.8% (16/52). The identification of non-enhancing areas on pre-treatment CEUS was associated with sufficient ablation (P=0.016). At the 12-month follow-up, significant decreases were observed in both the uterine and adenomyosis volumes (all P<0.001). Dysmenorrhea and menorrhagia were significantly alleviated at 12 months, and no major complications were encountered.

CONCLUSION

CEUS can be used to evaluate the ablation zone of focal adenomyosis that has been treated with MWA, similarly to DCE-MRI. The identification of non-enhancing areas on pretreatment CEUS indicates satisfactory treatment outcomes.

Ultrasound-guided percutaneous microwave ablation for adenomyosis with abnormal uterine bleeding: clinical outcome and associated factors

OBJECTIVE

To investigate the factors affecting the efficacy of ultrasound (US)-guided percutaneous microwave ablation (PMWA) for adenomyosis with abnormal uterine bleeding (AUB-A).

METHODS

Baseline data of patients with AUB-A who underwent US-guided PMWA treatment between October 2020 and October 2021, including demography characteristics, laboratory and imaging examination results were retrospectively analyzed. 3D reconstruction of magnetic resonance imaging (MRI) was applied to quantitatively assess the local treatment responses, including ratio of non-perfusion volume to adenomyosis volume (NPVr), ablation rate of the endometrial-myometrial junction (EMJ), and surface area (SA) of the ablated part of the EMJ. Patients were followed up at 3, 6, and 12 months after treatment, and divided into two groups: group with complete relief (CR), and group with partial relief (PR) or no relief (NR). Data were compared between them.

RESULTS

Thirty-one patients were analyzed with a mean age of 38.7 ± 6.8 years (range: 24-48): 48.4% (15/31), 63.3% (19/30), and 65.5% (19/29) achieved CR at 3, 6, and 12 months, respectively. In univariate analysis, compared with the PR/NR group, serum CA125 levels were significantly lower in CR group at 3 months, while ablation rates of EMJ and SA of the ablated part of the EMJ were significantly higher at the three time points. Other baseline characteristics and NPVr did not differ between the two groups.

CONCLUSION

Baseline CA125 and ablation rate of the EMJ and SA of the ablated part of the EMJ are associated with the outcome of AUB-A patients after US-guided PMWA treatment.