Factors Contributing to Major Neurological Complications From Vein of Galen Malformation Embolization

This cohort study assesses the rate of major periprocedural neurological complications in Canadian children following vein of Galen malformation embolization with major procedural and strategic contributors. Importance Major neurological complications from the embolization of vein of Galen malformations (VOGMs) are poorly understood. We provide a detailed analysis of contributors to periprocedural neurological complications and lessons learned. Objective To assess the rate of major periprocedural neurological complications following VOGM embolization with major procedural and strategic contributors. Design, Setting, and Participants This retrospective cohort study was conducted at a quarternary referral pediatric hospital (Hospital for Sick Children; Toronto, Ontario, Canada) from January 1999 to December 2018 with a mean clinical follow-up of 44.7 months; all children with VOGM diagnosed and/or treated were eligible (n = 48). Thirty-three patients who underwent endovascular treatment were included. Interventions Endovascular staged transarterial embolization performed in 33 patients over 91 sessions. Main Outcomes and Measures The primary outcome was the rate of periprocedural neurological complications (occurring within 1 week of embolization). The secondary outcomes were mortality, long-term neurological outcomes, and contributing anatomical and management factors to neurological complications. Results Of 33 patients who underwent embolization (31 boys [64.6%]; 17 girls [35.4%]; median age at first embolization, 4 months [range, 0-29 months]), 10 patients (30.3%) developed major periprocedural neurological complications. Five of these patients died. Univariate logistic regression analyses identified internal cerebral vein drainage to the main venous sac of the VOGM and use of a microcatheter with a distal outer diameter of more than 2.0F as significant predictors of poor neurological outcomes. Lessons learned from our experience include the need to assess the internal cerebral vein drainage pattern on preprocedural magnetic resonance venography, avoidance of excessive embolization into the venous sac, treatment of more distal fistulae before proximal fistulae to avoid a sump effect, and preferably use of smaller (<2.0F outer diameter) microcatheters in neonatal embolization procedures. Conclusions and Relevance In this cohort, 10 patients with VOGM treated with embolization (30.3%) experienced major periprocedural neurological complications, half of whom died. While these outcomes are superior to historic conservative and surgical treatment results, ongoing improvements in treatment and pretreatment diagnostic approaches are needed. Awareness of the lessons learned from our experience can help to avoid similar complications in the future for this vulnerable population. Question What are the contributors to major periprocedural neurological complications from endovascular treatment of vein of Galen malformations (VOGMs)? Findings In this cohort study of 48 children with VOGM, of whom 33 underwent endovascular treatment, 10 of 33 (30%) experienced a major periprocedural neurological complication, half of whom died as a result. The major contributing factors were presence of normal deep venous drainage into the venous sac of the VOGM, excessive embolization of the venous outflow, treatment of more proximal fistulae before treating distal fistulae, and the use of larger microcatheters in neonates. Meaning Pretreatment detailed diagnostic assessment of deep venous outflow, staged transarterial embolization, and initial targeting of distal fistulae should be undertaken to avoid major periprocedural neurological complications in children with VOGM.