[Classification and diagnosis of intracranial dural arteriovenous fistulas].

Intracranial dural arteriovenous fistulas (DAVFs) are abnormal connections between the dural arteries and dural veins in the cranial dura mater. These fistulas involve the cavernous sinus, transverse-sigmoid sinus, superior sagittal sinus, inferior/superior petrosal sinus, sphenoparietal sinus, anterior cranial base, tentorium, craniocervical junction, and anterior condylar confluence. Presently, there are several classifications according to the venous restrictive condition. These classifications are useful in both determining the hemodynamic status of the patient and in formulating treatment strategies. The clinical signs and symptoms of these fistulas essentially result from hypertensive venopathy with or without venous hemorrhages. Patients with aggressive course are characterized by retrograde leptomeningeal venous drainage and veneous restrictive lesions. Besides location specific symptoms, intracranial venous hypertension is a key mechanism mimicking benign intracranial hypertension. Angiographic evaluation of the impairment in cerebral venous drainage is important as well as evaluating the angioanatomical features of the feeding and draining vessels and of the fistula sites. The characteristic findings of modern diagnostic tools such as CT scan, MRI, and conventional angiography are also described in this study.