Arteriovenous malformations (AVMs) are abnormal tangles of blood vessels in the brain that are under high pressure and high flow. In these malformations, arteries and veins are unusually tangled. This usually happens during development before birth or shortly after. Most people with AVMs will never have any problems. If symptoms have not appeared by the time a person is 50, they probably will never appear. Women sometimes have symptoms as a result of the burden that pregnancy places on the blood vessels. Nearly 12 percent of people with AVMs do have some symptoms, however.
AVMs can eventually rupture and cause bleeding in the brain. In some patients, AVMs can reduce the amount of oxygen getting to the brain and spinal cord, put pressure on surrounding tissues, or can cause seizures.
A team of specialists at Brigham and Women’s Hospital, including neurosurgeons, endovascular surgeons, neurologists, and radiation oncologists, collaborate to determine the best treatment for each AVM. The optimal treatment depends on the AVM’s location and anatomical features. Many can be treated with a combination of embolization and surgery. Embolization involves injecting a material into the blood vessels that serves to block blood flow to the AVM. Surgery can then be used to remove the AVM. Some AVMs are best treated with radiosurgery, which directs highly focused beams at the AVM. It can take up to three years for the AVM to completely disappear after radiosurgery.