Dural Arteriovenous Fistula Could Be Due to Hemodynamic Disturbance in Dural Physiological Shunts? Histopathological Study and a Case Report

Abstract

Histopathologic studies of dural arteriovenous fistulas (dAVFs) are important for clarifying the pathogenesis. We present a case of Cognard type IV dAVF with detailed histopathologic studies in correlation with radiologic and intraoperative findings. An otherwise asymptomatic 53-year-old man presented with chronic headache. Neurologic examination revealed no abnormalities. Neuroimaging and cerebral catheter angiographic studies disclosed a left frontoparietal dAVF close to the middle third of the superior sagittal sinus, fed by the left superficial temporal and bilateral middle meningeal arteries and draining into ectatic cortical and dural veins. No evidence of superior sagittal sinus thrombosis or occlusion was seen. Intraoperatively, the parietal branch of the left superficial temporal artery penetrated the skull vault to feed the fistula; arterialized cortical and draining dural veins were also noted. Complete obliteration of the dAVF with removal of the affected dura mater was achieved safely. Histopathologic studies in serial sections documented a shunt point between the dural artery and the dural vein within the dura mater and a draining point between the dural and cortical veins. On the basis of clinical, angiographic, intraoperative, and histologic findings in our case, we strongly excluded acquired etiologies.