1280 Rupture-Associated Angioarchitectural Features in Pediatric Brain Arteriovenous Malformations

INTRODUCTION: Brain arteriovenous malformations (AVMs) are the leading cause of spontaneous intracranial hemorrhage in children, and AVM rupture can lead to significant morbidity and mortality. Understanding the angioarchitectural features associated with AVM rupture is critical to guide management strategies and improve outcomes. METHODS: We retrospectively reviewed the records of 63 pediatric patients who underwent surgical resection for AVMs at our institution between 1998 to 2023. Demographic factors, clinical presentation, and angioarchitecture details including nidus size, location, venous drainage, flow aneurysm, presence of en-passage vessel, and perforator vessel supply were collected. Clinical presentation and angioarchitecture were compared between the unruptured and ruptured cases. RESULTS: Of the 63 patients included in this study, 60% presented after rupture. In the ruptured cohort, 76.7% presented with focal deficits compared to 23.3% in the unruptured group. Smaller nidus (38.61 vs 23.16mm, p<0.001) and exclusively deep venous drainage (38.61 vs 23.16mm, p<0.001) were associated with ruptured AVMs. While these did not reach significance, there was a trend towards higher prevalence of major vascular supply (68.4% vs 31.5%, p=.520), flow aneurysm (75% vs 25%, p=.416), en-passage vessel (66.7% vs 33.3%, p=.348), supratentorial location (61.4% vs 38.6%, p=.273), and perforator supply (66.7% vs 33.3%, p=.406) in the ruptured group. Good clinical outcomes (mRS =2) at last follow up were similar between groups (77.8% vs 85.7%, p=.485). Multivariable logistic regression analysis showed smaller nidus diameter (OR 0.90, p<0.021, 95% CI .823-.983) as a predictor of hemorrhagic presentation. CONCLUSIONS: Smaller AVM nidus size was identified as a specific angioarchitectural characteristic associated with hemorrhagic presentation in children with AVMs. Further studies evaluating a larger cohort are necessary to draw definitive conclusion regarding rupture risk related to specific angioarchitectural features.