Surgical management of an unruptured dural arteriovenous fistula of the anterior cranial fossa: natural history for 7 years.

BACKGROUND

Anterior cranial fossa dural arteriovenous fistulas (DAVFs), unlike those in other locations, form a distinct subgroup because of a high incidence of intracerebral hemorrhage and their unique anatomy. We surgically obliterated an unruptured anterior cranial fossa DAVF because the venous aneurysm in the DAVF increased in size during the follow-up period and we present the clinical symptoms, the natural history for a 7-year period before operation, the radiologic findings, and surgical management. This is the first case report in which the growth of a preexisting venous aneurysm in an anterior fossa DAVF was identified. The possible pathogeneses of the rupture of anterior cranial DAVFs are discussed.

CASE DESCRIPTION

A 68-year-old man presented with diplopia, retro-orbital headache, and loss of consciousness. Cerebral angiography revealed an anterior cranial fossa DAVF. The primary source of arterial supply was from the ipsilateral anterior ethmoidal artery in combination with the contralateral anterior ethmoidal artery and other less prominent feeding vessels from the external carotid artery (ECA). Venous drainage was through the superior sagittal sinus via dilated pial veins. In addition, a subfrontal pial vein drained toward the region of the sphenoparietal and cavernous sinuses. The detection of the growth of a venous aneurysm 7 years after the initial evaluation prompted an aggressive therapeutic decision on considering a future catastrophic rupture risk. The vascular malformation was approached via a low-frontal craniotomy. A venous aneurysm with a dural feeder was encountered near the site of the anastomosis. The vascular connection between the dura of the cribriform plate and the pial vessels was completely occluded. Postoperative angiography confirmed the complete obliteration of the DAVF.

CONCLUSION

In this case, we confirmed an increase in the size of a venous aneurysm of an anterior cranial fossa DAVF. Our findings support the belief that the catastrophic intracranial hemorrhage in an anterior cranial fossa DVAF may occur in the setting of increased hemodynamic pressure of its draining venous channel.