Race and Hemorrhage in Cerebral Arteriovenous Malformations

Abstract

he ability to determine the rupture risk of an arteriovenous malformation (AVM) (either initial or subseT quent rupture) is a key factor for the clinician who counsels these patients and makes treatment recommendations. The low prevalence of AVMs in the general population, estimated at 0.01%, has made natural history studies of these lesions challenging and limited. The majority of important natural history studies have either evaluated a homogenous, intransient patient population or a patient cohort referred to a regional tertiary referral center with the inherent biases of both these approaches. Despite heterogeneous results when comparing individual studies, what we have gathered from these studies is that the annual rupture risk of most AVMs is likely between 2% and 4%, with previous rupture likely increasing this risk. Further evidence is suggestive, but not conclusive, that deep-seated AVMs, deep venous drainage, and the presence of associated aneurysms may also increase risk of bleed (4). Relatively few studies have elucidated a strong association between AVM hemorrhage and patient demographic factors.