While an arteriovenous malformation can develop anywhere in the body, it is most commonly found in the brain or spinal cord. An arteriovenous brain malformation (AVM) is a tangle of abnormal blood vessels in the brain where arteries connect directly to veins. This creates an artificial shunt where blood does not pass through smaller vessels called capillaries in order to oxygenate the brain.
WHEN IS THIS TYPE OF SURGERY NECESSARY?
This is an area of very complex decision making and many factors need to be taken into account such history of the AVM bleeding, the location, the size, patient age and many other factors. Decision making is individualised based on the configuration of the AVM. In circumstances where there is significant bleeding, surgery for AVM’s will need to be done on an urgent basis.
WHAT ARE THE OPTIONS FOR AVM TREATMENT?
Depending on the size and location of the AVM in your brain, as well as your overall health, treatment options may vary. Often the decision may be to wait and hold off any treatment. However, where treatment is recommended, there are several treatment options, which might be used alone or as a combination.
AVM Surgery – Dr Profyris and his team, in Johannesburg, South Africa may choose surgery for AVM’s that have already bled, or for AVMs that are accessible and operable. AVM surgery would be done through a craniotomy with an incision made on the scalp and an opening made in the bone. Brain mapping and other visualisation techniques will be used to guide the operation. Once the tangled blood vessels or AVM is located, the abnormal blood vessels are sealed off with clips and then carefully removed in order to prevent future bleeding. The skull bone is replaced, and the incision in the scalp is closed with stitches.
Endovascular Treatment - This procedure may be used as an alternative to surgery to reduce the risk of bleeding in the AVM or as a complementary procedure. During endovascular treatment, a long, thin tube known as a catheter is inserted into a main artery, usually in the groin. Using X-ray imaging the catheter is directed to the brain and the AVM. A special type of embolizing agent, like a glue, is injected into the catheter all the way to the tangled blood vessels in the brain to treat the AVM and its risk of bleeding.
Stereotactic Radiosurgery - This is not surgery in the literal sense, but it is a treatment option for smaller AVMs and AVMs that may be inoperable. Radiation treatment in the form of Gamma Knife can be tailored to the lesion in order to decrease the AVMs risk of rupturing.