Patient after Brain Arteriovenous malformation surgery;What is a brain AVM?Normally, arteries carry blood containing oxygen from the heart to the brain, and veins carry blood with less oxygen away from the brain and back to the heart. When an arteriovenous malformation (AVM) occurs, a tangle of blood vessels in the brain or on its surface bypasses normal brain tissue and directly diverts blood from the arteries to the veins.How common are brain AVMs?Brain AVMs occur in less than 1 percent of the general population. It’s estimated that about one in 200–500 people may have an AVM. AVMs are more common in males than in females.