Cerebral Arteriovenous Malformation (AVM) Treatment
Cerebral arteriovenous malformation (AVM) is a malformed collection of blood vessels within the brain, characterized by tangle(s) of veins and arteries. While an arteriovenous malformation can occur elsewhere in the body, this article discusses malformations found in the brain.
The treatment in the case of sudden bleeding is focused on restoration of vital function. Anticonvulsant medications such as phenytoin are often used to control seizure; medications or procedures may be employed to relieve intracranial pressure. Eventually, curative treatment may be required to prevent recurrent hemorrhage. However, any type of intervention may also carry a risk of creating a neurological deficit.
In the U.S., surgical removal of the blood vessels involved (craniotomy) is the preferred curative treatment for most types of AVM. While this surgery results in an immediate, complete removal of the AVM, risks exist depending on the size and the location of the malformation.
Radiation treatment (radiosurgery) has been widely used on smaller AVMs with considerable success. The Gamma Knife, developed by Swedish physician Lars Leksell, is one apparatus used in radiosurgery to precisely apply a controlled radiation dosage to the volume of the brain occupied by the AVM. While this treatment is non-invasive, two to three years may pass before the complete effects are known. Complete occlusion of the AVM may or may not occur, and 8%-10% of patients develop long term neurological symptoms after radiation.
Embolization, that is, occlusion of blood vessels with coils or particles or glue introduced by a radiographically guided catheter, is frequently used as an adjunct to either surgery or radiation treatment. However, embolization alone is rarely successful in completely blocking blood flow through the AVM.
The benefit of invasive treatment for unruptured AVMs has never been proven, as the risk of intervention may be as high as the spontaneous bleeding risk. An international study is currently under way to determine the best therapy for patients with unruptured AVMs (ARUBA—A Randomized Trial of Unruptured Brain AVMs).[1]
References
[1] Hartmann A, Mast H, Choi JH, Stapf C, Mohr JP (2007). “Treatment of arteriovenous malformations of the brain”. Current neurology and neuroscience reports 7 (1): 28–34. doi:10.1007/s11910-007-0018-2. PMID 17217851.