Malformações arteriovenosas encefálicas: caracterização morfológica e correlação clínica

Abstract

Brain arteriovenous malformations (BAVM) are morphological and neurovascular abnormalities characterized by direct communication between arteries and veins, without interposition of capillary bed, therefore without resistance to blood flow. OBJECTIVE: The purpose of this research was to characterize morphologically brain arteriovenous malformations aiming correlation with clinical presentation. CASUISTIC AND METHOD: A total of 170 patients with brain AVM, 78(46%) males and 92(54%) females, were studied from January 2001 to January 2007 at the Vascular and Endovascular Neurosurgery Unit of the Hospital de Base of São José do Rio Preto, SP. Univariate and multivariate analyses were conducted to test the associations among demographic (sex, age), clinical (hemorrhage, seizure, focal neurological deficit, and headache), and morphological features (anatomical localization; superficial, deep, infratentorial or supratentorial location; nidus size; number of feeding arteries, compartments, and draining veins; type of venous drainage; presence of stenosis, venous ectasias, and arterial aneurysms; Spetzler-Martin classification). RESULTS: The main clinical presentations at the moment of diagnosis included hemorrhage in 89 (52%) patients, headache in 79 (46%), focal neurological deficit in 54 (32%), and seizure in 52 (31%). According to the Spetzler-Martin classification, grade I was found in 15 (9%) patients, grade II in 49 (28%), grade III in 55 (33%), grade IV in 41 (24%), and grade V in 10 (6%) patients. There was a statistically significant association among hemorrhage and small nidus size (p = 0.002), single feeding artery (p = 0.007), single draining vein (p = 0.003), and single compartment (p = 0.040). Seizure was positively correlated with medium (3-6 cm) and large nidus size (>6cm), and negatively with small nidus size (<3cm) (p = 0.021). CONCLUSIONS: Brain AVM with small nidus size, Spetzler-Martin grade I, single feeding artery and draining vein are associated with hemorrhage. Spetzler-Martin grade V was negatively associated with hemorrhage. In the braim AVM there is no association between aneurysm and hemorrhage. On the other hand, seizure show positive correlation with large nidus size and negative with small nidus size.