Direct carotid-cavernous fistula following carotid endarterectomy

A carotid-cavernous fistula is an aberrant communication between the internal or external carotid artery and the cavernous sinus.¹ This abnormality may be traumatic or spontaneous in origin. The two main types of carotid-cavernous fistula are direct and indirect. The direct type involves direct communication between the intracavernous portion of the internal carotid artery and the cavernous sinus, whereas the indirect type usually involves communication between the middle meningeal artery and the meningeal branches of the internal or external carotid artery and the cavernous sinus.² The clinical symptoms and signs of carotid-cavernous fistula include headache, ipsilateral or bilateral bruit over the orbit or temporal region, ptosis, periorbital edema and erythema, progressive exophthalmos, which may be pulsating, ophthalmoplegia, conjunctival chemosis or injection, retinal hemorrhages and, rarely, visual loss.³ Direct carotid- cavernous fistulae are usually due to injury^2-4 but may occur following iatrogenic damage to the internal carotid artery. Iatrogenic carotid-cavernous fistulae have been reported following transsphenoidal surgery,^5-6 ethmoid-sphenoid surgery,⁷ trigeminal ganglion procedures,^8-11 nasopharyngeal biopsy,¹² maxillary osteotomy,¹³ overinjection of contrast medium,¹⁴ balloon embolization^15,16 and carotid angioplasty.¹⁷ We report the case of a patient with an iatrogenic carotid-cavernous fistula related to a Fogarty catheter thrombectomy procedure and review the literature regarding this topic.