Arteriovenous malformations (AVMs) are vascular abnormalities which most commonly occur in the brain. They are believed to be congenital in nature, with all evidence suggesting that people are born with the AVM. Symptoms experienced by the patient depend on the location and size of the arteriovenous malformation. Treatment options are available to manage the condition if it becomes a problem.
In someone with an arteriovenous malformation, an abnormal connection is made between the arteries and the veins in the blood supply. This bypasses the distribution system which is designed to move blood through the area affected by the malformation. As a result, the patient experiences lack of oxygen because the arteries are not able to deliver it to end destinations. The malformation looks like a tangled web of blood vessels, and it grows over time.
Several risks are associated with arteriovenous malformations. In the case of a brain AVM, the first is damage to the brain caused by oxygen deprivation, which can lead to stroke-like symptoms and other signs of neurological damage including seizures, headaches, and back pain. Additionally, there is a risk that the AVM could rupture, causing bleeding in the brain and a neurological emergency is the growth is large enough. Low-level bleeding can also cause minor damage which may not be immediately connected with an arteriovenous malformation unless the growth has been recognized and diagnosed. Arteriovenous malformations elsewhere in the body can lead to a variety of complications.
Symptoms of arteriovenous malformations can set in around the 30s, if at all. Medical imaging studies, including angiograms to look at the blood vessels, can be used to diagnose an AVM. In many patients, however, the growth is discovered as an incidental finding when doctors are looking for or treating something else. In some cases, AVMs are only identified after death, when a pathologist notes during an autopsy that the patient had an arteriovenous malformation and lived with it for life without realizing it.
When arteriovenous malformations are diagnosed, treatments can include radiation and embolization to address the malformed blood vessels. A doctor may also determine that a wait and see approach is the best treatment, in which case the growth will be monitored for changes or signs of instability. If problems occur, treatment will be offered. This helps patients avoid unnecessary medical procedures which might be used to treat an AVM which actually requires no treatment or further action.