Treatments for AVM
The goal of treatment is to prevent complications by controlling bleeding and seizures and, if possible, to remove the AVM. It is important to complete a thorough diagnostic workup to ensure an accurate evaluation. For example, an MRI may allow the surgeon to determine if an AVM is near critical brain areas.
A treatment plan is then developed for each patient, based on a number of factors, including:
- The size of the AVM
- Its location and the blood vessels involved
- A person's age and medical history
The neurosurgeons and endovascular surgeons at the Swedish Cerebrovascular Center use state-of-the-art technology to perform a number of different treatments including microsurgery, embolization, and radiosurgery to treat AVMs.
Following treatment, imaging tests are repeated to see if the AVM was completely removed, or if additional treatment is needed. Patients are monitored closely for completion of the treatment plan with ongoing visits and additional imaging testing if needed.
Microsurgery involves special techniques to close off the blood vessels that are feeding the AVM and remove the AVM, which in turns removes the risk of future bleeding. The image below is an example of the area of the brain the neurosurgeon accesses in order to remove an AVM.
Illustration: External view of AVM
Illustration: Cross-section view of an AVM
This view shows the arteries and veins that are feeding the tangled mass of blood vessels.
Illustration: Closing off arteries that feed the AVM
Illustration: Removal of AVM
Embolization, also known as selective vessel AVM embolization, is an interventional radiology procedure in which a special surgical “glue” is inserted into the AVM to block the blood flow. Under X-ray guidance, a very thin tube called a catheter is inserted into the femoral artery and threaded up into the brain. This surgical "glue" is then delivered to a specific area in the brain in order to block the blood flow to the AVM.
This procedure may be done as one procedure, or as part of a more complex surgical procedure. Embolization is performed by an endovascular surgeon.
Radiosurgery involves delivering of a high dose of radiation directly to an AVM. This causes the blood flow to slowly close off over a period of time until it eventually stops. This treatment is often selected if AVMs are in deep locations in the brain, making surgery difficult.
Illustration: How Radiosurgery Works
Radiosurgery is also used when the AVM is too close to regions of the brain that are critical to everyday living including speech, motor and visual areas. The team at the Swedish Radiosurgery Center utilizes the Perfexion™ Gamma Knife — which is the most proven and versatile radiosurgery equipment available for AVM treatment. Below is an illustrated example of how an AVM shrinks over time after radiosurgery.
Illustration: AVM After Radiosurgery