From the Guidelines
The recommended workup for an arteriovenous (AV) malformation includes a comprehensive neuroimaging evaluation starting with contrast-enhanced CT or MRI scans to identify the lesion's location, size, and characteristics, as well as digital subtraction angiography (DSA) for detailed assessment of the AV malformation's angioarchitecture, feeding arteries, draining veins, and presence of aneurysms 1.
Key Components of the Workup
- Contrast-enhanced CT or MRI scans to identify the lesion's location, size, and characteristics
- Digital subtraction angiography (DSA) for detailed assessment of the AV malformation's angioarchitecture, feeding arteries, draining veins, and presence of aneurysms
- Additional imaging may include CT angiography (CTA) or MR angiography (MRA) for complementary information
- Functional MRI and tractography to evaluate the relationship between the AV malformation and eloquent brain areas
Importance of Grading Scales
The Spetzler-Martin grading scale is a widely used system for risk stratification, taking into account the size, location, and venous drainage of the AV malformation 1. This scale helps determine the optimal treatment approach among surgical resection, endovascular embolization, stereotactic radiosurgery, or conservative management.
Additional Evaluations
A complete neurological examination should be performed to establish baseline function and detect any deficits. Laboratory tests including complete blood count, coagulation profile, and renal function tests are important before contrast administration or potential interventions. For patients with seizures, electroencephalography (EEG) may be indicated.
Treatment Approach
The treatment approach should be individualized based on the patient's clinical presentation, AV malformation characteristics, and risk of hemorrhage, with consideration of the Spetzler-Martin grading scale and other relevant factors 1.
From the Research
Recommended Workup for Arteriovenous (AV) Malformation
The workup for an arteriovenous (AV) malformation typically involves a combination of imaging studies to diagnose and evaluate the malformation. The following are some of the recommended steps:
- Clinical exam: A thorough clinical exam is essential to evaluate the patient's symptoms and overall health 2.
- Imaging studies:
- Magnetic Resonance Imaging (MRI): MRI is superior to Computed Tomography (CT) in detecting and recognizing AV malformations, especially in the presence of fresh or older hematoma 3.
- CT-angiography: Although CT-angiography may reveal an underlying AV malformation, it is not as sensitive as MRI or digital subtraction angiography 4.
- Digital subtraction angiography: This remains the gold standard for evaluating AV malformations, providing detailed information about the vascular anatomy 4, 3.
- MR angiography: This non-invasive technique provides useful information and can be performed using several techniques, including time of flight, phase contrast, and 3D gradient echo acquisition 5, 6.
- Additional tests:
Evaluation and Treatment
The evaluation and treatment of AV malformations depend on the size, location, and vascular anatomy of the malformation. The following are some of the key considerations:
- Treatment options:
- Microsurgical resection: This is the optimal treatment option for AV malformations, especially for those that are symptomatic or have a high risk of bleeding 4.
- Endovascular embolization: This may be used as an adjunct to microsurgery or as a standalone treatment for AV malformations that are not amenable to surgical resection 4, 2.
- Stereotactic radiosurgery: This may be used as a viable treatment alternative for inoperable AV malformations or those that are not amenable to endovascular treatment 4.