Obstructive hydrocephalus due to high-volume liquid embolic agent embolization for management of pediatric arteriovenous malformations: illustrative case

Introduction: As embolization techniques for the management of vein of Galen malformations (VOGM) continue to evolve, aggressive embolization for complete obliteration is increasingly favored. Transvenous embolization with the retrograde pressure cooker technique, involving high volumes of liquid embolic agent (LEA), has gained popularity to achieve complete obliteration. Though clinical outcomes have improved, there is limited discussion regarding the impact of high-volume embolization on the juvenile brain. Case: A 2-year-old boy without previous history of hydrocephalus presented with tri-ventricular hydrocephalus and signs of clinical deterioration 6 days after complete cure of his VOGM by transvenous embolization with Onyx, n-BCA, and coils. The patient was emergently taken for endoscopic third ventriculostomy (ETV), which was successful. On long-term follow-up, the patient did not experience any permanent neurologic deficits and continued to demonstrate progression in milestones. Conclusions: Though embolization is viewed as the appropriate strategy for management of VOGM-related hydrocephalus, patients receiving high-volume LEA embolization may be at increased risk for obstructive hydrocephalus secondary to mass effect even without previous history of hydrocephalus. As guidelines continue to favor aggressive embolization for cure, neurosurgeons should maintain a high degree of suspicion for signs of new-onset hydrocephalus when following VOGM patients after high-volume embolization.