A giant spontaneous dural arteriovenous fistula of the spheno-parietal sinus clinically masquerading as carotico-cavernous fistula: A case report

Dural arteriovenous fistulas (DAVF) are abnormal connections between the feeding arteries and veins within the dural leaflets and constitute 10%–15% of all intracranial arteriovenous malformations. DAVF draining into sphenoparietal sinus is a rare pathologic entity that is fed by the middle meningeal artery and is associated with a history of prior trauma. We report a unique case of DAVF of sphenoparietal sinus that had developed spontaneously. Being giant in morphology, it had eroded into the orbit and presented with proptosis, chemosis and restriction of eye movement. Although the clinical findings pointed towards caroticocavernous fistula, the real pathomorphology was unveiled by the six-vessel catheter angiography with selective catheterisation of smaller feeding vessels. All the feeding vessels were meticulously mapped out, and the fistulous connection was vividly identified and subsequently obliterated using detachable coils and n-butyl cyanoacrylate.