Transvaginal Ultrasound and Laparoscopy-guided Microwave Ablation for Uterine Myoma and Adenomyosis: Preliminary Results

Twenty premenopausal women aged 30–45 years, diagnosed with symptomatic uterine fibroids (n = 13) or adenomyosis (n = 7), were prospectively enrolled between November 2021 and March 2022 at Kaohsiung Medical University Hospital. All participants underwent percutaneous MWA under combined transvaginal ultrasound and laparoscopic guidance using a 13-gauge antenna and the Emprint™ Ablation Generator with Thermosphere™ technology. Contrast-enhanced MRI was used to assess lesion volume at baseline and 3 months postprocedure. Symptom severity and quality of life (QOL) were evaluated using the Visual Analogue Scale (VAS) for pain, Pictorial Blood Assessment Chart (PBAC) for menstrual bleeding, and the Uterine Fibroid Symptom and Quality of Life (UFS-QOL) questionnaire at baseline and at 1, 3, and 6 months posttreatment.

Follow-up showed significant reductions in pain, bleeding, and symptom severity. VAS, PBAC, and UFS-QOL scores all improved significantly. Myoma volume decreased by 33.4%, whereas adenomyosis showed meaningful symptom improvement despite nonsignificant volume change. No major complications occurred.

Transvaginal ultrasound- and laparoscopy-guided MWA is a safe, effective, and minimally invasive treatment for uterine fibroids and adenomyosis, providing rapid symptom relief and improved QOL with uterine preservation.

Uterine fibroids are women’s most common benign pelvic tumor, reaching a lifetime incidence of up to 77%. Adenomyosis is a relatively common disease with a prevalence ranging from 8% to 27%.[1,2] Symptomatic patients often complain of dysmenorrhea, heavy menstrual bleeding, chronic pelvic pain, dyspareunia, and infertility, which highly impact the quality of daily life. The management options at present include medical, nonsurgical, and surgical treatment.[3,4] Medical management can be effective but is often transient in its symptom control. Surgical interventions such as hysterectomy or myomectomy offer definitive treatment and are commonly indicated for patients with severe or refractory symptoms. However, these approaches may not be suitable for women who wish to preserve their uterus or maintain fertility potential.[5-7] Therefore, some less invasive treatments have sprung up, such as high-intensity focused ultrasound (HIFU) ablation, image-guided radiofrequency ablation (RFA), and microwave ablation (MWA). HIFU is effective and noninvasive, but it is time-consuming.[8] The lesions’ location and vascularity limit their indication and effectiveness. In RFA and MWA, the electrode or antenna is directly inserted into the lesions and the generated heat acts straight on the target tissues.[9,10] In RFA, a high-frequency alternating electrical current is used to create ionic agitation producing frictional heat to achieve tissue necrosis.[10] MWA is one of the most recent and exciting technological advances in the thermo-ablative field, which uses electromagnetic energy to rotate adjacent polar water molecules and produce heat rapidly.[11] RFA and MWA are effective according to previous studies,[9] but there is a potential risk of thermal injury to nearby tissue and organs. Previous studies have primarily employed ultrasound-guided percutaneous MWA without laparoscopic assistance,[9,12] which may increase the risk of unintended thermal injury to adjacent structures. In contrast, our study integrates both transvaginal ultrasound and laparoscopic visualization, offering improved spatial orientation and enhanced procedural safety, particularly for deep-seated or posterior lesions.[13,14]

From November 2021 to March 2022, we prospectively enrolled 20 premenopausal women at Kaohsiung Medical University Hospital who met specific inclusion criteria and underwent transvaginal ultrasound- and laparoscopy-guided percutaneous MWA. Among them, 13 patients were diagnosed with symptomatic uterine fibroids and 7 with symptomatic adenomyosis, confirmed by imaging. The inclusion criteria were: Age between 30 and 45 years Premenopausal status Radiologic diagnosis of uterine fibroids or adenomyosis (via transvaginal or transabdominal ultrasound) Presence of moderate to severe symptoms, such as abnormal uterine bleeding, dysmenorrhea, or bulk-related discomfort impacting daily life. The exclusion criteria included: Current use of anticoagulant therapy or bleeding disorders (e.g., warfarin use, thrombocytopenia, hemophilia) Contraindications to general anesthesia (e.g., uncontrolled asthma, heart failure with reduced ejection fraction <35%) Contraindications to laparoscopic surgery or transvaginal sonography (e.g., extensive intra-abdominal adhesions, severe pelvic inflammatory disease, or patient refusal of transvaginal exams). Only patients who met all inclusion criteria and none of the exclusion criteria were invited to participate and signed informed consent prior to treatment. Importantly, only symptomatic patients were selected, and the data were collected prospectively as part of a structured treatment protocol. The study was conducted in accordance with the Declaration of Helsinki. The Ethics Committee of Kaohsiung University and Teaching Hospital approved the study protocol (approval number: KMU-HIRB-F(D-20210131). Informed consent was obtained from all participants before surgeries. Radiologic and outcome assessment The patient selection process is illustrated in Flowchart 1. All patients underwent contrast-enhanced MRI before and 3 months after the procedure. For myoma cases, the volume of the dominant fibroid was measured; for adenomyosis, the entire uterine volume was assessed. Volume calculation was performed using the prolate ellipsoid formula: Length × width × height × 0.523. A radiologist, blinded to treatment allocation, conducted all imaging measurements. Symptom severity and quality of life (QOL) were assessed using the Visual Analogue Scale (VAS) for pain, Pictorial Blood Assessment Chart (PBAC) for menstrual bleeding, and Uterine Fibroid Symptom Quality of Life (UFS-QOL) questionnaire. These evaluations were performed at baseline, and at 1, 3, and 6 months after treatment. Outcome assessments were conducted by clinical staff involved in patient care; blinding was not implemented, which represents a limitation of the study and may introduce potential observer bias. Microwave ablation procedure All procedures were performed under general anesthesia in the lithotomy position. We used an Emprint™ Ablation Generator with Thermosphere™ Technology (Medtronic, Minneapolis, USA) and a 13-gauge antenna operating at 2.45 GHz ± 50 MHz with an output power of 45–100 Watts. Ultrasound guidance was provided by LOGIQ™ 10 (GE Healthcare). To increase the safety margin, an artificial pneumoperitoneum was created to separate the uterus from surrounding organs. Wet gauze was placed in the cul-de-sac to protect adjacent structures. Any pelvic adhesions were treated laparoscopically before ablation. A 2 mm skin incision was made approximately 5 cm below the umbilicus for antenna insertion. Under combined real-time laparoscopic and transvaginal ultrasound guidance, the antenna was advanced into the target lesion. For uterine fibroids, the ablation was directed into the center of each myoma, whether located in the anterior or posterior wall. For diffuse adenomyosis, multiple overlapping ablation zones were systematically applied throughout the affected myometrium to maximize coverage while minimizing damage to healthy tissue. Ablation was performed segmentally, based on lesion size and location. Successful ablation was confirmed by changes in laparoscopic appearance (pink and moist to white and dry) and transvaginal ultrasound (hypoechoic to diffusely hyperechoic). Statistical analysis The primary outcomes were changes in UFS-QOL, PBAC, and VAS scores at 1, 3, and 6 months posttreatment. Differences between baseline and follow-up values were analyzed using the Mann–Whitney U-test. A P < 0.05 was considered statistically significant.

Participants in this study were premenopausal women aged 30–45 years, with a mean age of 39.33 ± 6.33 years. Their baseline demographic and clinical characteristics are summarized in Table 1. The mean body mass index was 22.20 ± 2.95 kg/m2. Among the 13 patients with uterine fibroids, 7 had anterior wall fibroids and 6 had posterior wall fibroids. All 7 adenomyosis cases were of the diffuse type. The mean uterine volume across all participants was 118.15 ± 104.14 ml. Demographic and clinical characteristics are given as mean±standard deviation or n (%) Table 2 demonstrates a significant and consistent improvement across all primary outcome measures. The VAS for pain decreased notably from a baseline of 6.40 ± 2.98–3.89 ± 2.90 at 1 month, continued to diminish to 2.70 ± 1.52 at 3 months, and reached 2.13 ± 2.20 at the 6-month evaluation, with the reductions gaining statistical strength over time (P = 0.0116 at 1 month, P < 0.0001 at 3 and 6 months). This trend was mirrored in the PBAC scores, which dropped from 64.10 ± 31.21 initially to 36.30 ± 22.21 at 1 month, slightly decreased further to 33.60 ± 29.46 at 3 months, and settled at 35.60 ± 24.90 at 6 months, with all-time points showing statistical significance (P = 0.0024, P = 0.0029, and P = 0.0028, respectively). Similarly, the (UFS-QOL) scores improved from 51.60 ± 18.93 at baseline to 39.13 ± 19.77 at 1 month, improved significantly to 28.85 ± 22.06 at 3 months, and to 27.08 ± 20.17 at 6 months, with each posttreatment score indicating a statistically significant enhancement in the QOL (P = 0.0487, P = 0.0012, and P = 0.0003 at 1, 3, and 6 months, respectively). In the subgroup analysis of patients with myomas [Table 3], the lesion volume significantly decreased from 102.0 ± 116.3 mL to 69.1 ± 93.6 mL at 3 months posttreatment (P < 0.01), with a mean regression rate of 33.4 ± 20.5%. UFS-QOL scores improved significantly at both 1 month (48.5 ± 18.9–40.5 ± 16.6, P = 0.02) and 3 months (28.9 ± 17.1, P = 0.03). VAS scores also showed a significant reduction at 3 months (6.1 ± 2.9–3.4 ± 2.5, P = 0.04). PBAC scores decreased from 46.0 ± 19.6–30.8 ± 20.3, reaching statistical significance at 3 months (P = 0.02). In the adenomyosis subgroup, the mean uterine volume decreased from 141.3 ± 102.5 mL to 82.8 ± 49.0 mL at 3 months, though this reduction did not reach statistical significance (P = 0.06). The regression rate was 36.0% ± 22.1%. UFS-QOL improved significantly at 1 month (57.3 ± 19.2–37.8 ± 26.9, P = 0.03), though the difference was not significant at 3 months (P = 0.07). PBAC scores improved significantly at 3 months (P = 0.05), whereas VAS scores did not show a statistically significant change.

The advancement of less invasive treatments, such as HIFU ablation, radiofrequency ablation (RFA), and particularly MWA, has been a significant stride in the management of gynecological disorders like adenomyosis and myomas.[11] These novel interventions, characterized by minimal to no wounds and negligible scarring, offer expedited recovery and reduced blood loss compared to traditional surgical approaches. This finding is consistent with previous reports comparing MWA and HIFU for uterine fibroid treatment.[15] Our study’s outcomes align with these benefits, demonstrating notable volume reductions in myomas and adenomyosis and improvements in both UFS-QOL and VAS scores. Such efficaciousness underscores MWA’s potential as a minimally invasive therapeutic option, offering symptom relief and enhancing the QOL.[16] However, there are still rare but severe complications, such as the high-energy outspreading and impact on the gastrointestinal or urology tracts. The imaging-guided MWA had complete attempts to exploit high-energy and avoid complications with real-time visual tools such as laparoscope and ultrasound.[17] A clinical study in 2011 by Zhang et al., using percutaneous MWA (PMWA) with ultrasound guided, revealed that the mean ablation time was 490 s, and the shrinkage rate of the fibroid could reach 93.1% at 12 months after ablation. However, women with fertility desires were excluded from the study.[18] Another prospective study from Liu et al. in 2019 enrolled 70 patients with symptomatic adenomyosis who underwent transvaginal ultrasound- and laparoscopy-guided PMWA and reported that symptom severity score and VAS had significantly improved 12 months postoperation.[13] Both studies reported no significant complications. Our study’s results are as satisfactory as previous published studies. The swift postoperative recovery observed within 1–3 months postoperation presents MWA as a favorable alternative to HIFU and other techniques. The potential of this new technology was observed. The treatment time of either the myoma or adenomyosis is comparably short to the traditional laparotomic or laparoscopic operation, which requires more time in suturing and hemostasis. The results from the adenomyosis subgroup reveal a complex but promising response to MWA therapy. Although the observed decrease in adenomyosis volume did not reach statistical significance, it should not detract from the potential of MWA to effectively target this condition. The inherent variability in treatment outcomes likely reflects the diffuse and infiltrative nature of adenomyosis, which presents unique challenges for any focal treatment. However, the significant and sustained improvement in PBAC scores 3 months posttreatment provides compelling evidence of MWA’s ability to substantially alleviate bleeding symptoms – a primary concern for patients with adenomyosis. Moreover, the initial improvements in UFS-QOL scores among patients with adenomyosis, though not consistently sustained over time, suggest that further optimization of technique – such as refining ablation field design, tailoring energy delivery, and enhancing real-time visualization – may contribute to more durable symptom relief. Recent studies have demonstrated that procedural refinements and increased operator experience with MWA are associated with improved clinical outcomes in adenomyosis management.[14,17] As our clinical volume continues to grow and is anticipated to exceed 100 procedures by the time of publication, we expect to gain deeper insight into the optimal application of this technique. Ongoing investigations into the procedural learning curve are likely to further enhance both precision and efficacy in future treatments. During our internal review and through a comprehensive examination of the current literature, it has become apparent that the proficiency in MWA techniques significantly influences patient outcomes. The steep learning curve associated with these procedures necessitates a high degree of technical skill and experience. As practitioners continue to refine their technique and accumulate expertise, it is anticipated that the outcomes for patients with adenomyosis will improve, mirroring the positive trends observed in the myoma subgroup. The contrast in treatment response between the myoma and adenomyosis cohorts could imply differential tissue responses to the ablation technique, a conjecture that aligns with the current medical understanding of these conditions. Specifically, adenomyosis, with its diffuse infiltration, may present challenges for focal treatments such as MWA, unlike the more circumscribed myomas. Our study’s limitations, including its small sample size, and brief follow-up duration, necessitate a cautious interpretation of these promising results. Future research should aim to extend the follow-up period and expand the participant pool to further validate the long-term efficacy of MWA and to refine patient selection criteria. Besides the limitation described, this new technique’s learning curve should be considered. With more knowledge and skill in controlling the ablation field design, the extent of tumor regression and patient satisfaction will be more excellent. All in all, our study is on the same page as the currently published literature. Among various surgical options, laparoscopic-guided MWA stands out, especially when managing complex cases of myoma or adenomyosis with adnexal lesions. This technique facilitates the simultaneous treatment of pelvic adhesions, reducing the need for multiple surgeries and enhancing patient acceptance. Research by G. Jonsdottir et al. highlighted that patients undergoing MWA experienced significantly shorter hospital stays and fewer sick days compared to those receiving uterine artery embolization.[19] Although further research with longer follow-ups and larger cohorts is needed, laparoscopic-guided MWA promises to be a safe, cost-effective treatment option for uterine conditions in the future.

Transvaginal ultrasound- and laparoscopy-guided MWA is an effective technique for treating uterine fibroids and adenomyosis, evidenced by significant short-term improvements in UFS-QOL, PBAC, and VAS scores. It notably reduces lesion volume, underscoring its efficacy in managing symptoms associated with these gynecological disorders. This minimally invasive method requires meticulous preoperative planning and a comprehensive understanding of its learning curve to achieve the best outcomes, highlighting the importance of expertise in its application. Author contributions C.Y. Long conceptualized and executed the study. C.Y. Chang and C.L. Yeh contributed to drafting and revising the manuscript. C.J. Jeng, Z.X. Loo, and K.L. Lin were responsible for data collection and analysis. All authors have read and approved the manuscript. They have met the criteria for authorship, and each author believes the manuscript represents honest work. Data availability statement The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request. Financial support and sponsorship Nil. Conflicts of interest Dr. Cheng-Yu Long, an editorial board member at Gynecologic Minimally Invasive Therapy, had no role in the peer review process of or decision to publish this article. All authors declared no conflicts of interest in writing this paper.

1. Khan AT, Shehmar M, Gupta JK. Uterine fibroids:Current perspectives. Int J Womens Health 2014;6:95–114. 5. Maheshwari A, Gurunath S, Fatima F, Bhattacharya S. Adenomyosis and subfertility:A systematic review of prevalence, diagnosis, treatment and fertility outcomes. Hum Reprod Update 2012;18:374–92. 8. Huang YF, Deng J, Wei XL, Sun X, Xue M, Zhu XG, et al. Acomparison of reproductive outcomes of patients with adenomyosis and infertility treated with high-intensity focused ultrasound and laparoscopic excision. Int J Hyperthermia 2020;37:301–7. 9. Lin XL, Hai N, Zhang J, Han ZY, Yu J, Liu FY, et al. Comparison between microwave ablation and radiofrequency ablation for treating symptomatic uterine adenomyosis. Int J Hyperthermia 2020;37:151–6. 10. Haider S, Parthasarathy S. Radiofrequency ablation in benign gynecologic disorders:Current status and future directions. Obstet Gynecol Surv 2020;75:635–47. 11. Athanasiou A, Fruscalzo A, Dedes I, Mueller MD, Londero AP, Marti C, et al. Advances in adenomyosis treatment:High-intensity focused ultrasound, percutaneous microwave therapy, and radiofrequency ablation. J Clin Med 2024;13:5828. 12. Zhang HL, Zhu JE, Deng EY, Li JX, Sun LP, Peng CZ, et al. Ultrasound-guided percutaneous microwave ablation for adenomyosis with abnormal uterine bleeding:Clinical outcome and associated factors. Int J Hyperthermia 2023;40:2249274. 13. Liu JX, Li JY, Zhao XY, Zhang QH, Cao Y, Huang XJ, et al. Transvaginal ultrasound- and laparoscopy-guided percutaneous microwave ablation for adenomyosis:Preliminary results. Int J Hyperthermia 2019;36:1233–8. 14. Shunshi Y, Li J, Li J, Huang L, Chen Y, Zhao X, et al. Transvaginal ultrasound- and laparoscopy-guided percutaneous microwave ablation for adenomyosis has short- and long-term benefits:A single-center study. Int J Hyperthermia 2023;40:2233713. 15. Zhao WP, Han ZY, Zhang J, Liang P. A retrospective comparison of microwave ablation and high intensity focused ultrasound for treating symptomatic uterine fibroids. Eur J Radiol 2015;84:413–7. 16. Liu H, Zhang J, Han ZY, Zhang BS, Zhang W, Qi CS, et al. Effectiveness of ultrasound-guided percutaneous microwave ablation for symptomatic uterine fibroids:A multicentre study in China. Int J Hyperthermia 2016;32:876–80. 17. Chen T, Ren Q, Ge Q, Wang F, Jin Y, Liu P, et al. Application of transabdominal ultrasound- and laparoscopy-guided percutaneous microwave ablation for treating uterine fibroids:24-month follow-up outcomes. Arch Gynecol Obstet 2024;309:1043–52. 19. Jonsdottir G, Beermann M, Lundgren Cronsioe A, Hasselrot K, Kopp Kallner H. Ultrasound guided microwave ablation compared to uterine artery embolization treatment for uterine fibroids –A randomized controlled trial. Int J Hyperthermia 2022;39:341–7.