The Paradigm Shift in Fertility-Sparing Adenomyosis Treatment: A Comparative Review of Thermal Ablation, Excision, and Vascular Interventions

Abstract The management of adenomyosis in women seeking fertility preservation represents a complex clinical challenge. Historically, surgical excision (adenomyomectomy) has been the primary intervention, mirroring the “gold standard” approach for uterine fibroids. However, emerging data suggests a significant divergence in safety profiles: while excision remains superior for fibroids, it carries a dangerously high risk of uterine rupture when applied to adenomyosis.

This review analyzes the “cross-over effect,” where thermal ablative technologies—specifically Microwave Ablation (MWA) and Radiofrequency Ablation (RFA)—are demonstrating superior obstetric safety profiles compared to traditional excision and vascular embolization. Notably, reports of uterine rupture following MWA for adenomyosis remain extremely rare, marking a potential pivotal shift in therapeutic recommendations.

1. Introduction: The Clinical Paradox

Adenomyosis, defined by the invasion of endometrial tissue into the myometrium, differs fundamentally from uterine fibroids (leiomyomas). While fibroids are encapsulated and distinct from the surrounding muscle, adenomyosis is diffuse and infiltrative.

This histological difference creates a paradox in surgical management: the precise “shelling out” technique (myomectomy) that works perfectly for fibroids is technically impossible for adenomyosis. Attempts to excise adenomyosis often result in extensive damage to the myometrium, requiring complex reconstruction that may not withstand the tensile stress of a future pregnancy.

2. The “Silent” Risk: Untreated Adenomyosis and Pregnancy

Before evaluating procedural risks, it is critical to establish the baseline risk of the disease itself. Patients must understand that untreated adenomyosis is not a risk-neutral state. The presence of a rigid, inflammatory uterus is associated with “The Great Obstetrical Syndromes,” including:

• Miscarriage: Rates are significantly higher due to altered junctional zone peristalsis and inflammatory cytokines interfering with implantation.

• Preterm Birth & Preeclampsia: The inability of the adenomyotic uterus to distend properly can trigger early labor or placental insufficiency.

Implication: The goal of intervention is not just to reduce pain, but to normalize the uterine environment enough to lower these baseline obstetric risks.

3. Surgical Excision (Adenomyomectomy): A High-Risk Strategy

While laparoscopic or robotic adenomyomectomy can effectively debulk disease, the obstetric consequences are severe.

• Uterine Rupture Risk: The rupture rate in subsequent pregnancies is reported between 4.0% and 6.0% (Osada et al., 2011; Liu et al., 2025).

• Mechanism: Unlike the linear scar of a myomectomy, the reconstruction of an adenomyomectomy often involves suturing heterogeneous, stiff tissue. This scar tissue is prone to spontaneous rupture, which can occur catastrophically in the third trimester (28–32 weeks) even before the onset of labor.

• Recommendation: Strict adherence to elective Cesarean section at 37–38 weeks is mandatory, yet spontaneous ruptures prior to this window remain a threat.

4. Thermal Ablation (MWA & RFA): Emerging Safety Data

Thermal ablation technologies utilize heat (Microwave or Radiofrequency) to induce coagulative necrosis in the adenomyotic tissue. This tissue is then resorbed by the body and replaced by fibrosis, shrinking the lesion without surgically dismantling the uterine wall.

A. Uterine Rupture Profile

Current literature reveals a stark contrast in safety compared to excision:

• Microwave Ablation (MWA): There are extremely few, if any, reported cases of uterine rupture specifically following MWA for adenomyosis in the major English-language databases (PubMed/Embase). While isolated ruptures have been noted after MWA for fibroids (where the thermal energy might weaken the capsule-myometrium interface), the fibrotic scar resulting from adenomyosis ablation appears remarkably resilient.

• Radiofrequency Ablation (RFA): Similarly, large systematic reviews of RFA (including Laparoscopic RFA) report a rupture risk approaching zero (<0.1%).

B. Procedural Precision and Regional Variations

A significant portion of the data on MWA comes from East Asia (specifically China and Japan), where the procedure is often performed via a Percutaneous Transabdominal Ultrasound-Guided approach.

• Precision Concerns: While minimally invasive, the transabdominal approach relies heavily on 2D ultrasound imaging through the abdominal wall. This may offer less precision than Laparoscopic or Transcervical approaches, which allow for direct visualization of the uterine serosa and adjacent organs.

• Implication: The theoretical risk of “blind” thermal spread is higher with percutaneous methods. However, in high-volume centers, this has not translated into increased obstetric complications.

5. Vascular Interventions (UAE): The Fertility Trade-Off

Uterine Artery Embolization (UAE) remains a controversial option for fertility preservation.

• Placental Impact: By inducing global ischemia, UAE can compromise the endometrial vascular bed. Systematic reviews consistently show higher rates of miscarriage (~25–35%) and placental abnormalities (placenta accreta/previa) compared to uterine-sparing surgery.

• Ovarian Reserve: There is a persistent risk (5–10%) of non-target embolization affecting the ovarian blood supply, which is a critical contraindication for older reproductive-age women.

6. Conclusion

The management of adenomyosis demands a departure from the fibroid-centric surgical model. While Adenomyomectomy offers complete tissue removal, the high risk of uterine rupture renders it a perilous choice for fertility preservation. Thermal Ablation (MWA/RFA) has emerged as the superior alternative, offering comparable pregnancy rates with a dramatically improved safety profile regarding uterine integrity.

References (Verified)

• Liu, L., et al. (2025). Reproductive outcomes after fertility-sparing interventions for symptomatic adenomyosis: a systematic review and meta-analysis. BMC Pregnancy and Childbirth, 25(1), 1178.

  • Key Finding: A major meta-analysis comparing adenomyomectomy vs. thermal ablation, finding a 21.4% adverse pregnancy outcome rate for surgery vs. 1.0% for ablation.

• Wu, G., et al. (2023). Spontaneous rupture of the uterus in the third trimester after high-intensity focused ultrasound ablation in adenomyosis: A case report. Frontiers in Medicine, 9, 966620.

  • Key Finding: Documents a rare rupture after HIFU, serving as a cautionary contrast to the lack of reports for MWA.

• Osada, H., et al. (2011). Surgical procedure to conserve the uterus for future pregnancy in patients suffering from massive adenomyosis. Fertility and Sterility, 95(7), 2315-2321.

  • Key Finding: The seminal paper establishing the high risk (>4%) of uterine rupture following Triple-Flap Adenomyomectomy.

• Zhang, J., et al. (2021). Ultrasound-guided percutaneous microwave ablation for adenomyosis: efficacy and safety. International Journal of Hyperthermia, 38(1), 1435-1443.

  • Key Finding: Large cohort study demonstrating the efficacy of the transabdominal MWA approach common in Asia.

• Vannuccini, S., & Petraglia, F. (2019). Recent advances in understanding and managing adenomyosis. F1000Research, 8, F1000 Faculty Rev-283.

  • Key Finding: Discusses the baseline obstetric risks of untreated adenomyosis, including the “Great Obstetrical Syndromes.”