Fetal Embolization Exhibits Early Success in High-Risk Vein of Galen Malformation: JAMA

The study, conducted at a single U.S. center between September 2022 and April 2025, enrolled seven fetuses diagnosed with high-risk VOGM. Eligibility required no major brain injury on fetal MRI and a falcine sinus width of at least 7 mm. Using ultrasound guidance, the team accessed the fetal brain through the uterus and skull, navigating a microcatheter to the malformed vein and deploying detachable coils to reduce abnormal blood flow.

The following were the key findings of the study:

• Successful embolization was achieved in 5 of 7 cases.
• Three infants survived beyond the newborn period and are currently aged 8–24 months, all without neurodevelopmental delay.
• Post-procedure imaging showed no clinically significant brain tissue injury.
• Fetal echocardiography demonstrated a mean 33% reduction in cardiac output, indicating potential relief from cardiac strain linked to severe VOGM.
• Five of the seven pregnancies ended in unscheduled deliveries, with three occurring prematurely, on average, just over three days post-procedure.
• Four of the seven infants, including two who had fetal embolization, required additional embolization after birth, indicating an ongoing need for specialized neonatal care.

The authors note that historically, fetuses with similar severity measurements have a mortality risk approaching 90%, with only about 9% achieving early developmental milestones under standard treatment. In the current study, overall mortality was 43%, and 43% of infants were on track at six months.

While the results are encouraging, the researchers stress that the findings are preliminary. The small sample size reflects the rarity of high-risk fetal VOGM, and the procedures were all performed in a high-volume tertiary care setting by specialists with significant experience in fetal and neurointerventional surgery. Longer-term follow-up will be essential to fully assess developmental outcomes, and broader multicenter studies will be required to determine if the approach can be replicated safely elsewhere.

"Still, this represents a landmark in fetal neurosurgery. As the research team notes, it is the first targeted effort to treat a congenital cerebrovascular anomaly before birth by directly altering fetal brain blood flow. The approach, while promising, must be weighed carefully against the increased risk of preterm delivery, with decisions guided by multidisciplinary expertise," the authors concluded.

Reference:

Orbach DB, Shamshirsaz AA, Wilkins-Haug L, et al. In Utero Embolization for Fetal Vein of Galen Malformation. JAMA. Published online August 11, 2025. doi:10.1001/jama.2025.12363