From the Guidelines
The treatment for an arteriovenous malformation (AVM) of the brain typically involves surgical removal, endovascular embolization, stereotactic radiosurgery, or a combination of these approaches.
Treatment Options
The goal of treatment is to prevent hemorrhage, improve seizure control, and relieve headaches, with the choice of treatment depending on the AVM's size, location, drainage pattern, patient age, and overall health 1.
- Surgical resection (craniotomy) completely removes the AVM and provides immediate protection from bleeding but carries risks based on the AVM's location.
- Endovascular embolization uses catheters to deliver materials that block blood flow to the AVM, either as a standalone treatment for small AVMs or to reduce size before surgery.
- Stereotactic radiosurgery delivers focused radiation to gradually close off the abnormal vessels over 1-3 years, making it suitable for smaller AVMs in difficult-to-reach areas, with approximately 80% of patients achieving complete AVM obliteration within 2 to 3 years 1.
Considerations
For some patients with low-risk, asymptomatic AVMs, observation with regular imaging may be recommended, considering the risks and benefits of each treatment option, including associated mortality and morbidity 1. Preradiosurgical embolization may be used to decrease target size, eradicate angiographic predictors of hemorrhage, or reduce symptoms related to venous hypertension, with the choice of embolic material influencing the outcome 1.
Outcome
Treatment is necessary because AVMs can cause life-threatening hemorrhage, seizures, headaches, and neurological deficits due to their abnormal direct connections between arteries and veins that bypass normal capillary beds, creating high-pressure vessels prone to rupture. The best treatment approach should be individualized, taking into account the patient's specific condition and the potential risks and benefits of each treatment option, to optimize outcomes in terms of morbidity, mortality, and quality of life.
From the Research
Treatment Options for Arteriovenous Malformation (AVM) of the Brain
The treatment strategies for AVMs are challenging and variable, with the goal of complete nidal obliteration 2. The main treatment options include:
- Surgical resection: offers high rates of immediate obliteration but is invasive and carries a moderate risk of neurologic morbidity 2
- Embolization: is minimally invasive, but cure can only be achieved in a minority of lesions 2, 3
- Stereotactic radiosurgery (SRS): is also minimally invasive and has little immediate morbidity, but AVM obliteration occurs in a delayed fashion, so the patient remains at risk of hemorrhage during the latency period 2, 4
- Observation: may be considered for incidental AVMs, with the balance between the estimated cumulative lifetime hemorrhage risk vs the risk of intervention being the major determinant for treatment 2
Specific Treatment Approaches
Transvenous Embolization
Transvenous embolization is considered a salvage therapy in contemporary AVM management, with proposed indications including a small and compact AVM nidus, deep AVM location, hemorrhagic presentation, single draining vein, lack of an accessible arterial pedicle, exclusive arterial supply by perforators, and en passage feeding arteries 3.
Radiosurgery
SRS has been shown to have excellent treatment outcomes for patients with small- to moderate-sized AVM, with a complete obliteration rate of 80-90% achieved in 2-3 years 4. The role of pre-SRS embolization is permanent volume reduction of the nidus and treatment of high-risk lesions such as AVM-related aneurysms and high-flow arteriovenous shunts 4.
Combined Endovascular and Surgical Approaches
Combining maximal endovascular embolization and complete surgical resection in a single session has yielded a high cure rate and low morbidity, especially for low-grade lesions 5. This technique may make it possible to treat high-grade AVMs previously considered ineligible for surgery and reduce periprocedural morbidity.
Comparison of Treatment Outcomes
A propensity score matched study comparing stand-alone endovascular embolization versus SRS in the treatment of AVMs with Spetzler-Martin grades I-III found that SRS achieved significantly higher occlusion rates at last follow-up, with a higher tendency for fewer hemorrhagic complications and lower re-treatment rate 6.