In Utero Embolization for Fetal Vein of Galen Malformation.

IMPORTANCE

Vein of Galen malformation (VOGM) is the most common congenital cerebrovascular anomaly. Fetuses with VOGM and wide mediolateral falcine sinus diameters are at high risk for mortality, brain injury, and neurodevelopmental delay. In utero embolization may improve survival and outcomes.

OBJECTIVE

To report early results from this institutional review board-approved single-group intervention study of in utero embolization for VOGM.

DESIGN, SETTING, AND

PARTICIPANTS

Single-center, single-group intervention study in the US. First enrollment was on September 30, 2022; the most recent follow-up was on April 10, 2025. Eligible fetuses had VOGM, no major brain injury on fetal magnetic resonance imaging, and falcine sinus width of 7 mm or greater. Fetal embolization was ultrasound guided, using transuterine, transcranial needle access and microcatheterization of the prosencephalic venous varix with detachable coils.

INTERVENTION: In utero embolization of fetuses with VOGM.

MAIN OUTCOMES AND MEASURES: Neonatal mortality and neurodevelopmental outcomes. Pre- and postembolization fetal magnetic resonance imaging and echocardiography were performed.

RESULTS

Seven patients were enrolled; 5 underwent successful embolization. The mean maternal age was 32.4 years (range, 22-36); the mean fetal gestational age was 35 6/7 weeks (range, 33 6/7 to 37 1/7); and the sex ratio was 3:4 (female to male). The mean falcine diameter (10.3 mm) corresponded to 90% expected mortality and 9% likelihood of reaching 6-month milestones with standard postnatal care. Overall mortality was 43%, and 43% were meeting milestones at 6 months. Three embolized patients (aged 8, 18, and 24 months) survived, all without neurodevelopmental delay. Four of the 7 patients underwent additional neonatal embolization. Fetal echocardiography showed a mean 33.4% reduction (range, 16%-46%) in cardiac output. Five of 7 patients (71.4%) had unscheduled deliveries and 3 of these 5 were preterm, at a mean of 3.2 days after intervention.

CONCLUSIONS AND RELEVANCE: Early results demonstrate the feasibility of fetal embolization. Any potential reduction in mortality, brain injury, and neurodevelopmental delays must be weighed against an increased risk of unscheduled, preterm delivery.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04434729.