Dural Arteriovenous Fistula (DAVF)
A dural arteriovenous fistula is an abnormal direct connection between arteries in the brain's covering (dura) and venous sinuses or cortical veins. Its risk depends on the direction of venous drainage; types with reflux into cortical veins carry a higher hemorrhage risk.
Përditësimi i fundit: 2026-06-07
Definition
A dural arteriovenous fistula (DAVF) is an abnormal direct arteriovenous connection that bypasses the capillary bed, located between arteries within the dura and the venous sinuses (transverse, sigmoid, cavernous, superior sagittal sinus) or cortical veins. It represents a portion of intracranial vascular malformations and is usually seen in middle-aged to older adults. The transverse-sigmoid sinus region is the most common location.
Causes and Classification
Most DAVFs are acquired rather than congenital. Fistula formation in dural vessels follows venous hypertension that develops after venous sinus thrombosis, trauma, surgery or infection. Risk is determined by the venous drainage pattern and graded with the Borden and Cognard classifications: types draining anterograde into the sinus without reflux into cortical veins are benign, whereas those with cortical venous reflux carry a higher risk of hemorrhage and neurological decline.
Symptoms
In benign types the most common symptom is pulse-synchronous tinnitus (pulsatile tinnitus); chronic headache may accompany it, and some cases are asymptomatic. Aggressive types may present with intracranial hemorrhage, focal neurological deficits, seizures and cognitive decline from chronic venous hypertension. Cavernous sinus fistulas can cause eye protrusion (proptosis), red eye, double vision and visual loss, while spinal DAVFs may produce progressive leg weakness and gait disturbance.
Diagnosis
First-line assessment is brain MRI with MR venography, which may show dilated cortical veins, venous congestion and traces of prior hemorrhage. CT angiography evaluates feeding vessels and venous drainage. Digital subtraction angiography (DSA) is the gold standard; it defines the fistula site, feeding arteries and venous drainage pattern, enabling Borden/Cognard classification. The differential diagnosis includes AVM, cavernous malformation and venous sinus thrombosis.
Treatment
The treatment decision is based on the venous drainage pattern, symptoms and bleeding history. Benign, asymptomatic or mildly symptomatic cases may be followed with regular imaging. First-line active treatment is usually endovascular embolization (closing the fistula via an arterial or venous route). Surgical closure is used for complex cases not amenable to or failing endovascular treatment; stereotactic radiosurgery may be an option for selected small lesions.
Prognosis
Prognosis depends largely on the venous drainage type. Benign types without cortical venous reflux have a low annual hemorrhage risk and a generally favorable course. Aggressive types draining directly into cortical veins carry a markedly higher risk of hemorrhage and progressive neurological decline, so treatment is recommended. Recurrence can occur after treatment, requiring imaging follow-up. Outcomes vary by patient and cannot be guaranteed.
Burimet
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:1514-1520.
- Winn HR, ed. Youmans Neurological Surgery. 6th ed. Saunders; 2011:4016-4040.
- Spetzler RF, Kalani MYS, Nakaji P, eds. Neurovascular Surgery. 2nd ed. Thieme; 2015:833-841.
- Cognard C, et al. Cerebral Dural Arteriovenous Fistulas: Clinical and Angiographic Correlation. Radiology. 1995.
Ky artikull ka karakter të përgjithshëm informues dhe nuk zëvendëson vizitën mjekësore. Vendimet për diagnozën dhe trajtimin janë individuale.