A DVA is a radial arrangement of veins usually draining into one slightly enlarged, main or central vein. Sometimes you will hear the descriptive term “caput medusae” (Latin for “head of Medusa”) used to describe this feature, since the vein pattern resembles the snakes of hair from the Medusa character of Greek mythology. DVAs have the highest prevalence rate (over 60%) of all intracranial vascular malformations. They may appear anywhere in the body. Like CCMs, multiple DVAs may exist within the same individual. It is thought that one person in fifty has at least one DVA.
The brain’s venous network acts as a conduit to drain blood from the brain so that this blood can be re-oxygenated by the lungs. Even though DVAs are anomalous structures, they are fully integrated with the body’s venous system and provide the brain with normal blood drainage function.
Diagnosis is either via an incidental finding during imaging of other lesions, or during autopsy. Conventional computed tomograms (CTs) may not always document DVAs sufficiently, although newer high resolution CT scans with thin cuts and contract enhancement, and CT angiogram (CTA) reconstructions can image these lesions, as well as MRI/MRA and conventional angiograms. With these non-invasive modalities, the vast majority of suspected DVAs should not be subjected to the risk of catheter angiography, except in rare instances where a true AVM may be suspected clinically
The generally passive nature of DVAs requires an expectant course of management. Because these anomalies provide a useful and important blood draining function, in no case should they be excised or radiated. Doing so during surgery, either by accident or intent, has resulted in venous infarction and patient death. This includes those instances of CCM resection in association with a DVA. While the CCM can be safely removed, the DVA must remain undisturbed. Both clinical and radiographic information must be integrated when considering diagnosis and treatment of mixed vascular malformation such as DVA-CCM.