125 Vein Number and Drainage Pattern Predicts Hemorrhage Risk and Outcome in Pediatric Arteriovenous Malformations

Abstract

INTRODUCTION: The significance of draining vein anatomy is poorly defined in pediatric arteriovenous malformations. In adult cohorts, venous characteristics have been shown to lead to an increased rate of hemorrhage, but this phenomenon has not been well studied in pediatric AVMs. This report analyzes the impact of draining vein anatomy on presentation and outcome in a large series of pediatric AVMs. METHODS: Eighty-one pediatric patients with AVMs were treated at the Columbia University Medical Center between 1991 and 2012. Charts were retrospectively reviewed for patient characteristics, clinical course, outcome, and AVM angioarchitectural features. Univariate analyses were performed and multivariate analysis was performed using logistic regression for variables with P < .2. RESULTS: Twenty-seven patients had 2 or 3 draining veins and 20 patients presented with exclusive deep venous drainage. Patients presenting with 2 or greater draining veins were less likely to present with hemorrhage than patients with a single draining vein (OR: 5.16; P = .044). Patients with exclusively deep drainage were more likely to present with hemorrhage (OR: 8.22; P = .024). Patients with a single draining vein were less likely to have impairments causing disability (OR: 0.18; P = .049) on long term follow up, but not on discharge (P = .1). Exclusively deep drainage was found to predict discharge outcome (OR: 4.68; P = .04) but not long term outcome (P = .3). CONCLUSION: This study suggests that the influence of draining veins in pediatric arteriovenous malformations is significant. A single draining vein or an exclusively deep drainage system seems to increase a patient's risk of hemorrhage. This effect could potentially be due to an increased degree of venous impedance. The short term effect on outcome due to drainage pattern may be due to increased surgical morbidity, whereas a negative effect on long term outcome when multiple veins were present may be due to a greater disruption of the cerebral venous drainage patterns.