Dural arteriovenous fistulas.

Spontaneous dural arteriovenous fistulas (DAVFs) are abnormal arteriovenous shunts within the dura mater of the sinuses. The exact etiology remains uncertain. Arterial feeder derive from the meningeal branches in the region. The clinical symptoms are highly dependent on the venous drainage. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrate the epiphenomena rather than the DAVF itself. Angiography is the most important modality in evaluating a DAVF. Based on the patterns of venous drainage, a classification and a treatment strategy are possible. Therapeutic modalities include manual compression, transarterial embolization, transvenous embolization, and/or surgical resection. Recent technical advances concerning embolic material and microcatheter make endovascular treatment less dangerous and more effective.