AVM and Dural Fistulas

Dural arteriovenous fistulas (dAVFs) are rare vascular anomalies accounting for 10-15% of intracranial vascular malformations, where arteries connect directly to veins within the dura mater. Unlike brain AVMs, they lack a nidus and are often acquired, with symptoms like pulsatile tinnitus, headaches, or hemorrhage.

Radiopaedia

Radiopaedia

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Key Aspects of Dural Fistulas (dAVFs)

Definition & Location: Abnormal connections between meningeal arteries and dural sinuses/veins, most commonly at the transverse-sigmoid sinus junction.

Causes: Often acquired, frequently following thrombosis, trauma, or surgery.

Symptoms: Commonly include pulsatile tinnitus (rushing noise in ear), vision changes (red eyes/proptosis), and headaches.

Diagnosis: Digital subtraction angiography is the gold standard, though CT/MRI can suggest the diagnosis.

Treatment: Endovascular embolization (glue/onyx), surgical resection, or radio-surgery.

National Center for Biotechnology Information (.gov)

National Center for Biotechnology Information (.gov)

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Dural Fistula vs. Brain AVM

Location: dAVFs are in the dura (outer covering); AVMs are within the brain parenchyma (brain tissue).

Structure: dAVFs have direct connections; AVMs have a tangled “nidus”.

Flow: dAVFs often cause higher venous pressure leading to venous congestion.