Surgical approaches and nuances for supratentorial arteriovenous malformations

An arteriovenous malformations (AVM) is an abnormal collection of blood vessels consisting of direct fistulous connections between arteries and veins without a normal intervening capillary bed or functional neural tissue. They are generally believed to be congenital lesions developing during the fourth and eighth weeks of gestation. Although the incidence and prevalence of cerebral AVMs is not known with certainty, autopsy data suggest that their frequency of detection is approximately 4.3% [1,2]. Cerebral AVMs are most commonly discovered in the third or fourth decade of life. Intracerebral hemorrhage remains the most common presentation and can be seen in more than 70% of patients [3,4]. They account for 2% of all strokes and 38% of intracerebral hemorrhages in patients between 15 and 45 years of age [5-7]. The other common presentations include seizures (25-50% of patients), progressive neurological deficit from mass effect or steal, and chronic headaches. A thorough understanding of the natural history of cerebral AVMs is paramount to forming a proper treatment plan. A number of series have evaluated the natural history of AVMs with regard to the risk of hemorrhage (Table 11.1) [3,4,8–13]. Although a detailed discussion of these studies is beyond the scope of this chapter, it has been shown that in the majority of these series the overall annual risk of rupture is approximately 2–4%. Furthermore, several factors have been suggested to influence the rate of rupture, including hemorrhagic presentation, AVM size, and location.