Does treatment with N-butyl cyanoacrylate embolization protect against hemorrhage in cerebral arteriovenous malformations?

OBJECTIVE To assess the role of this procedure to prevent hemorrhage in cerebral arteriovenous malformations (cAVM). METHOD Between 1992 and 2000, we studied 104 patients submitted to embolization as the main treatment. Patients were followed until hemorrhage or death. RESULTS Follow-up ranged from 1.6 months to 8 years. The most frequent presentations were hemorrhage (50%) and seizures (38%). In addition, 40% were small (<30 mm); 56% were medium (30-60 mm). Obliteration was < or =1/3 in 11% of the cases; from 1/3 to < or = 2/3 in 49%; >2/3 in 36%; complete in 5%. The risk of death was 1%/year, and of bleeding, 5.4%/year. Presentation with hemorrhage and low obliteration rate were the main factors associated with hemorrhage. CONCLUSION cAVM embolization provides limited protection against hemorrhage with obliteration rates below 2/3. Presentation with hemorrhage is the main factor for predicting hemorrhage.