Carotid-cavernous fistula: a purpose of a case

We present a clinical case of an 18-year-old male with no history of interest, who went to the emergency department due to exophthalmos, conjunctival chemosis and loss of visual acuity in the right eye of several weeks of evolution. Corticoid treatment was prescribed for scleritis, with no improvement. CT angiography revealed right eye´s exophthalmos, an important dilation of the superior ophthalmic vein, and asymmetry in contrast enhancement in the arterial phase of the cavernous sinus with respect to the contralateral side. The arteriography showed the existence of a dural or indirect arteriovenous communication, fed by both right carotid arteries, the internal carotid artery and the external carotid artery. It was decided to perform endovascular treatment by embolization of the cavernous sinus.

Carotid-cavernous fistula (CCF) is an anomalous communication between the carotid arterial system and the cavernous sinus. Most often they are traumatic (70-90%) and unilateral. They are classified according to their vascular radiological anatomy, following the Barrow classification, dividing them into type A fistulas when there is a direct communication between the internal carotid artery to the sinus, type B and C when there is communication of the meningeal branches of the internal carotid artery (B) and external carotid artery (C) to the sinuses respectively and type D when there is simultaneous communication to the sinuses through the meningeal branches of the internal carotid artery and the external carotid artery. Patients may present diplopia, red eye, decreased vision, facial pain and a pathologic ophthalmologic examination with pulsatile exophthalmos. CT scan, MRI and orbital echography can be useful to confirm the diagnosis, but the definitive diagnostic test is cerebral arteriography. Prognosis of caroticocavernous fistulas are highly varied and treatment is similarly variable ranging from conservative management therapy to emergent endovascular or surgical treatment. CCF can be complicated by spontaneous hemorrhage (subarachnoid, intracranial or extracerebral hemorrhage) and patients may present ocular complications like loss of visual acuity.

Clinical suspicion is very important to make an early diagnosis that allows planning an endovascular treatment and avoid serious complications.

- Scott IU, Law SK, Roy H, Plager SD. Carotid-Cavernous Fistula (CCF). Medscape. Sep 05,2017.