Percutaneous microwave ablation for viable hepatic cystic echinococcosis: Real-world outcomes from a multicenter study

OBJECTIVES: Hepatic cystic echinococcosis (hepatic CE.) remains endemic in many regions, with severe complications and even death. Current treatments face limitations in efficacy and accessibility, while microwave ablation (MWA) represents a promising minimally invasive alternative, but real-world multicenter evidence is lacking. METHODS: This retrospective multicenter study included patients with imaging-confirmed viable hepatic CE (WHO-IWGE CE1-CE3) who underwent ultrasound-guided aspiration-assisted percutaneous MWA at three tertiary hospitals in China between 2016 and 2024. Primary outcomes were local lesion progression (LLP) and recurrence-free survival (RFS). Secondary outcomes included technical success and safety. Predictors of recurrence were identified using Firth-penalized Cox regression. Four hierarchical risk models (Full, Extended, Basic, Mini) were developed and evaluated using Harrell's C-index and Kaplan-Meier analysis. RESULTS: The study included 73 patients (56.2% female, mean age 51.4 ± 14.0 years) with 99 lesions. The mean lesion diameter was 7.5 ± 2.5 cm. MWA achieved 100% complete ablation with no major complications. During the median follow-up 34.0 months (IQR, 21.0-43.0), LLP occurred in 9.1% of lesions. The 1-, 2-, and 3-year RFS rates were 92.3%, 78.6%, and 64.2%, respectively. Three independent recurrence predictors were identified: age >55 years, cyst diameter ≥11 cm, and elevated bilirubin. Four hierarchical risk models were developed, with the Full model (8 predictors, C-index=0.928), followed by the Extended (6 predictors, C-index = 0.917), Basic (4 predictors, C-index = 0.859), and Mini (2 predictors, C-index = 0.788) models. All models stratified 3-year RFS (100% low-risk vs 51-59% high-risk, p < 0.001). CONCLUSIONS: MWA is a safe and effective minimally invasive option for hepatic CE, particularly in resource-limited settings. The hierarchical risk models enable precision treatment selection, enhancing clinical outcomes.