Arteriovenous Malformations: Treatment and Management

Arteriovenous malformations (AVMs) are complex vascular lesions characterized by abnormal connections between arteries and veins forming a tangle of vessels, without an intervening capillary bed. The lack of resistance arterioles in AVMs allows for high-velocity shunting across the nidus and can lead to rupture and subsequent hemorrhage, which is the most common manifestation of an AVM. These lesions can remain asymptomatic until a precipitating event such as seizure or hemorrhage occurs, making epidemiological estimates difficult. However, the reported incidence of symptomatic AVMs is around 1 per 100, 000 person/years with a prevalence of 0.018% in the adult population and 0.02% in the pediatric population. AVMs carry an annual rupture risk between 2% and 4% across all age groups, though associated high-risk features can significantly increase this risk. Each lesion is unique and must be evaluated based on its own specific characteristics. Due to their complexity, AVMs often require a multimodal treatment approach with various combinations of endovascular, microsurgical, and radiosurgical techniques in order to safely achieve a cure. It is therefore essential to understand the various indications, limitations, and key principles for each treatment modality which are summarized in this chapter.