[Cranial dural arteriovenous fistulas--current status of therapy]

Spontaneous dural arteriovenous fistulas (DAVF) are abnormal arteriovenous shunts with a nidus within the dura mater. The exact etiology of the spontaneous DAVFs remains uncertain. Arterial inflow is from the meningeal branches in the region, which can be from an extracranial or an intracranial source. The venous drainage is through the dural sinuses, although cortical or deep venous drainage may be recruited. The critical symptoms are highly dependent on the venous drainage. Computed tomography and/or magnetic resonance imaging demonstrates the epiphenomena rather than the DAVF itself. Angiography is the most important modality in evaluating a DAVF. Based on the patterns of the venous drainage, a classification of the DAVF is possible. This classification enables decision-making about the appropriate therapy. Also the risk of each DAVF may be determined.