Vein of Galen Malformation with Pial Arteriovenous Fistula in a 12-month-old Child

Pial arteriovenous fistulas are extremely rare vascular malformations of the brain (accounting for approximately 1.6% of vascular malformations of the brain) and are classified as Galenic and non-Galenic pial fistulas. We present a rare association of a mural-type vein of Galen malformation with a pial fistula involving the precentral branch of the right middle cerebral artery (MCA) in a 12-month-old infant. A 12-month-old preterm male infant, born vaginally with a delayed cry (birth weight 1.2 kg), presented with progressive macrocephaly, recurrent upper respiratory tract infections, developmental delay, and a history of seizures. Neurologically, the child was intact with no focal deficits. He was the firstborn child of a non-consanguineous marriage; maternal antenatal history was notable for polyhydramnios and fetal cardiomegaly detected on antenatal ultrasound. Antenatal scans at 26 and 28 weeks revealed aneurysmal dilation of the vein of Galen. Postnatal transfontanelle ultrasound showed enlarged lateral and third ventricles with a midline cystic lesion exhibiting turbulent flow, suggestive of a high-flow arteriovenous shunt. At 12 months of age, multidetector computed tomography (MDCT)) identified a 37 × 15 mm lobulated soft tissue density in the perimesencephalic/suprasellar region with ventriculomegaly. MRI of the brain confirmed a 35 × 19 × 21 mm flow void in the region of the vein of Galen associated with hydrocephalus, periventricular ooze, and cerebral atrophy. Digital subtraction angiography revealed a mural-type vein of Galen malformation fed by the right posterior choroidal artery, draining into the torcula. Additionally, a separate pial arteriovenous fistula was identified, supplied by the precentral branch of the right MCA, with cortical venous drainage into the superior sagittal sinus. Left sigmoid sinus hypoplasia with redirected venous outflow into the left superior petrosal sinus and cavernous system was noted. Mural-type vein of Galen malformation with concurrent pial arteriovenous fistula. The child was taken up for endovascular embolization. The vein of Galen malformation was embolized using 70% N N-butyl cyanoacrylate (NBCA). Subsequently, transarterial embolization of the right MCA pial fistula was done using coils and Onyx liquid embolic agent in the same sitting. Post-embolization, complete closure of both fistulas was noted. Post-treatment, CT revealed closure of fistulas with no fresh parenchymal abnormality. The child was discharged on postoperative day 6 without any focal deficit. At 3-month follow-up, the patient remained neurologically stable without new deficits, and follow-up MRI was planned.