Transarterial embolization versus hemispherectomy in infants with hemimegalencephaly and drug-resistant epilepsy

Hemimegalencephaly is a severe congenital brain malformation characterized by early-onset, medically refractory seizures. The standard treatment, surgical hemipherectomy (SH), is constrained by age-related limitations. To address this gap, we developed a staged transarterial embolization (TAE) approach as a minimally invasive alternative for infants under 10-12 weeks. The comparative efficacy of TAE versus SH has not been systematically evaluated.

This single-center observational comparative effectiveness study evaluated seizure burden, neurodevelopmental outcomes, and perioperative hemodynamic stability in infants with hemimegalencephaly treated with TAE (n = 12) versus SH (n = 11). Hemodynamic metrics (blood pressure, fluid balance, serum metabolites) were analyzed using linear mixed models.

Six of eight (75%) patients receiving TAE as the primary treatment achieved seizure freedom. Neurodevelopmental outcomes in the TAE cohort were comparable to those in the SH cohort. Hemodynamic stability in the TAE group was supported by smooth transitions in blood transfusions and fluid administration, avoiding abrupt fluctuations and enabling blood pressure control equivalent to SH. Both cohorts maintained tight regulation of serum sodium, glucose, and potassium.

TAE provides hemodynamically stable seizure control in infants with hemimegalencephaly, minimizing cerebral edema and preserving contralateral perfusion. These findings position TAE as a feasible early alternative to SH for hemimegalencephaly.

Transarterial embolization (TAE) enables early seizure cessation in infants with hemimegalencephaly under 10-12 weeks of age, providing a novel therapeutic option for patients ineligible for surgical hemispherectomy. Infants treated with TAE maintain hemodynamic stability, supporting preserved perfusion in the contralateral hemisphere. This study establishes TAE as an effective early intervention that broadens the treatment landscape for hemimegalencephaly and may support improved neurodevelopmental trajectories. Findings underscore the feasibility of early, minimally invasive strategies for managing medically refractory epilepsy in the high-risk population of young infants with refractory epilepsy secondary to hemimegalencephaly.