Safety and Efficacy of Microwave Ablation Alone Versus Microwave Ablation Combined With Chemical Ablation in the Treatment of Uterine Fibroids: A Prospective, Multicenter Study

Uterine fibroids are the most common benign tumors in women of reproductive age, with a prevalence of 20%-50%, often causing menorrhagia, anemia, pelvic pain, and pressure symptoms that markedly impair quality of life. Current treatments include pharmacological therapy (GnRH-a, mifepristone) - effective temporarily but with high recurrence after discontinuation; surgical myomectomy or hysterectomy - definitive yet invasive, with prolonged recovery and potential fertility compromise; and minimally invasive therapies such as uterine artery embolization (UAE), high-intensity focused ultrasound (HIFU), and microwave ablation (MWA), which are increasingly favored for their minimal invasiveness and rapid recovery.

MWA delivers thermal energy via a percutaneously inserted antenna under ultrasound guidance, inducing coagulative necrosis of fibroid tissue through temperatures exceeding 60°C. Advantages include minimal trauma (\~2 mm puncture), rapid recovery (discharge within 1-2 days), uterine preservation, and negligible ovarian impact. However, a key limitation is the heat sink effect: in hypervascular fibroids, flowing blood dissipates thermal energy, resulting in incomplete ablation, prolonged procedural time, and higher energy requirements - particularly challenging for fibroids >5 cm in diameter.

Chemical ablation involves intralesional injection of a sclerosing agent (e.g., lauromacrogol), which damages vascular endothelial cells, causing vascular occlusion, thrombosis, ischemic necrosis, and direct membrane disruption that accelerates apoptosis. Theoretically, pre-ablation chemical sclerotherapy may occlude feeding vessels, attenuate the heat sink effect, and enhance subsequent thermal ablation efficiency. Supporting this concept, an ex vivo bovine liver study demonstrated that pre-injection of 5 mL of 99.5% ethanol around the electrode prior to radiofrequency ablation produced a significantly larger ablation zone at equivalent energy levels compared with ablation alone. Small-sample clinical studies, including a prospective cohort from Shanghai Tenth People's Hospital, have preliminarily explored combined chemical ablation plus MWA for uterine fibroids, suggesting improved ablation rates and shorter procedural times, though findings require validation through high-quality randomized controlled trials.

Therefore, the investigators conducted this multicenter, prospective, randomized controlled trial to rigorously compare the safety (incidence and severity of adverse events) and efficacy (fibroid volume reduction rate, symptom improvement, quality-of-life outcomes) of MWA alone versus MWA combined with chemical ablation. This study aims to clarify the clinical value of the combined approach and provide high-quality, evidence-based data to guide the optimal selection of minimally invasive treatment strategies for uterine fibroids.