How to handle tangled blood vessels in brain?

An MRI exam for a head injury in 2003 was how Gary Johnson discovered he had tangled blood vessels in his brain that could cause serious, potentially fatal, internal bleeding.
Johnson, 56, of Elkhart, Ind., has a condition called arteriovenous malformation, or AVM. It's an abnormal connection of the arteries and veins that interrupts normal blood flow between them.
Most of the estimated 300,000 Americans who have the condition, which is usually present from birth, never experience symptoms. But every year about 2 to 4 percent of AVMs rupture, researchers estimate.
Because the risk of a life-threatening rupture is small, there's debate over whether it's better for patients to undergo surgery to remove the tangle before it becomes unstable or take a more conservative wait-and-see approach.
A large clinical trial being conducted at medical centers around the world, including two Chicago-area hospitals, aims to answer that question.
The study will randomly assign 800 people with an arteriovenous malformation that hasn't bled to receive preventive treatment to fix the problem or careful monitoring. Patients will be followed for at least five years to see which approach yields better results -- taking into account the likelihood of death or stroke, rates of complications and the cost.
The research is especially relevant now that more of these malformations are being discovered ''accidentally'' because of expanded use of brain imaging, said Dr. Michael Chen, a neurointerventionalist at Rush University Medical Center who is recruiting patients for the study. Loyola University Medical Center in Maywood is another of the research sites.
''We're trying to figure out what's the best approach for how to risk-stratify patients, in terms of which ones should undergo the risk of treatments,'' Chen said. ''We do not really know how likely it is that an unruptured AVM will bleed, or if it ever will.''
Malformations are treated three ways: surgery to remove them, radiation therapy or the use of a glue-like substance to block blood flow to the abnormal vessels.
But these treatments can injure brain tissue and cause a stroke, Chen said.
The multicenter study, being funded by the National Institutes of Health, will be the first randomized trial to examine whether taking a hands-off approach to the condition is as good, if not better, than aggressive treatment.
Johnson, a participant in the study, was assigned to the group that will get regular checkups but no preventive treatment. He acknowledged that some in his situation would feel as if they had a ticking time bomb in their head, but he said it doesn't bother him to leave his condition untreated.
''When I first learned about it, I was very concerned,'' he said. ''But the more knowledge I gained, the less I worried.''
Johnson said he hopes his participation in the study will give others with his condition similar peace of mind.