What is a dural arteriovenous fistula (Dural AVF)?
Dural arteriovenous fistulas (Dural AVFs) are abnormal connections (fistulas) between arteries (arteries) and veins (veins) on the surface of the brain, called the dura. It is accompanied by irregular abnormal veins in the form of balls in places. They are also called dural arteriovenous malformations.
What complaints and findings do dural arteriovenous fistulas (Dural AVF) cause?
Dural AVFs are clinically highly variable. They may show a clinical course ranging from spontaneous cure to fatal bleeding. Pulsatile tinnitus, trill, cranial nerve palsies, ocular symptoms, headache, nausea-vomiting, epileptic seizures, focal neurologic findings and intracranial hemorrhage can be seen in association with increased intracranial pressure. Hydrocephalus (enlargement of the brain cavities) may be seen in high-flow fistulas in children.
Can dural arteriovenous fistulas (Dural AVF) be treated and what are the treatment options?
Treatment options include no treatment, conservative approach, palliative (partial and for complaints) or full endovascular (intravenous) treatment, surgery, endovascular, surgical and radiotherapy combination. The natural course of DAVFs shows a wide spectrum ranging from complete spontaneous regression to fatal hemorrhages. Therefore, a complete angiographic evaluation is required in terms of prognosis and treatment. Regardless of the type, if there is an increase in intracranial pressure, definitive treatment is required.
What is the conservative treatment in dural arteriovenous fistulas (Dural AVF)?
In conservative treatment, manual compression is performed and ocular symptoms, if present, are treated medically. The rate of fistula closure with manual compression is approximately 30%. In general, asymptomatic patients can be followed up and manual compressions can be performed in patients with ocular symptoms and tinnitus that are considered benign.
How is endovascular (intravenous) treatment performed in dural arteriovenous fistulas (Dural AVF)?
The goal of endovascular therapy may be complete treatment of the lesion, rendering a high-risk fistula low-risk, or relieving symptoms. Complete and permanent treatment can only be achieved by occlusion of all feeding arteries or venous drainage with embolic (occlusive) material.
In cavernous sinus fistulas (indirect), embolization can be performed by catheterizing the inferior petrosal sinus on the same side, if not on the opposite side. The complication rate due to embolization varies between 2-10%.