Cerebral Arteriovenous Malformation Flow Is Associated With Venous Intimal Hyperplasia

Background and Purpose-The pathogenesis of venous intimal hyperplasia and venous outflow stenosis associated with cerebral arteriovenous malformation (AVM) draining veins is poorly understood. We sought to determine the relationship between maximum vein wall thickness and AVM flow. Methods-Patients who underwent AVM surgical resection and had flow measured before treatment using quantitative magnetic resonance angiography were retrospectively reviewed. Specimens were mounted on slides and stained with elastin special stain. Perinidal veins were identified, and maximum wall thickness was measured from digitized images. Relationship between maximum vein wall thickness and AVM flow was assessed. Results-Twenty-eight patients were included. Spearman correlation revealed a statistically significant relationship between maximum vein wall thickness and total AVM flow(P=+ 0.51; P=0.006), AVM flow per draining vein (P=+ 0.41; P=0.03), and mean intranidal vessel diameter (P=+ 0.39; P=0.04). Conclusions-Maximum vein wall thickness increases with higher total AVM flow and AVM flow per draining vein. This finding implicates chronically high AVM inflow in venous intimal hyperplasia.