Vein of Galen Malformation Thrombosis by Single-Stage, 2-Coil Embolization

Advances in endovascular embolization have improved morbidity and mortality among patients with vein of Galen malformations (VoGMs). The patient presented at 3 months of age with increased head circumference and a bruit over his anterior fontanelle. Diagnostic cerebral angiography confirmed the presence of a large mural-type VoGM. The decision was made to undergo a staged arterial embolization at 4 years of age after developing worsening right-sided hemiparesis. An attempt was made to occlude the posterior choroidal feeding vessel with a large 25 mm × 50 cm coil, followed by a 6 mm × 20 cm coil; however, the high flow of the lesion displaced both coils into the wall of the aneurysmal venous sac. Interval magnetic resonance imaging and angiography revealed partial occlusion of the VoGM at 7 months and complete thrombosis at 24 months post procedure, precluding a need for additional coiling. This case illustrates that a minimal change in intramural flow dynamics of VoGMs could lead to progressive thrombosis.