63-year-old male presented with a two-month history of left eye swelling
Associated with pain and horizontal diplopia
Also reports decreased vision for the past few months
VAcc: 20/25-1; 20/50+1
Pupils: Round and Reactive OU, no RAPD
IOP: 10; 26
EOM: Full OD; -3 abduction OS otherwise full EOM in all other directions OS
Cavernous sinus thrombosis
Cavernous sinus tumors
Idiopathic Orbital Inflammation
A CT/CTA of the patient’s brain was performed, given high suspicion for a cavernous sinus lesion (Note: MRI was not performed since patient has a pacemaker).
Cerebral angiogram was performed and showed a left carotid cavernous fistula fed by branches of the left external carotid artery and, to a lesser degree, the right external carotid artery and left internal carotid artery.
Dural carotid cavernous fistula
Direct carotid cavernous fistula – Arise most commonly secondary to a traumatic tear of internal carotid artery within the cavernous sinus. It can also rarely arise secondary to a spontaneous aneurysm rupture.
Dural carotid cavernous fistula – Arise from connections between dural branches of the internal or external carotid arteries and the cavernous sinus. Pathophysiology is somewhat unknown. Two major hypotheses:
Associated with occlusion of adjacent draining venous dural sinuses. This results in arterialization of venous blood flow and subsequent formation of an arteriovenous shunt.
Arise from congenital arteriovenous shunts that are normal variants. Often in the setting of hypertension / atherosclerotic disease, these congenital shunts proliferate into a carotid cavernous fistula.
The patient was started on Cosopt (dorzolamide hydrochloride-timolol maleate)for the elevated IOP in the left eye
Neurosurgery was consulted for angiography and embolization of the left carotid cavernous fistula
Prognosis and Future Directions
The overall prognosis for dural CCF is very good. There is very minimal increase in mortality rates and generally 20 to 50 percent of cases spontaneously resolve.
Patients with mild ocular symptoms can be closely monitored with regular ophthalmology exams (checking visual acuity, IOP, EOM and dilated fundus exam).
Patients with mild exposure keratopathy can be treated with aggressive lubrication.
Patients experiencing diplopia can be treated with prism or occlusion therapy and IOP-lowering medications can be started if IOP is substantially elevated.
The main indications for intervention with angiography are: visual deterioration, intolerable diplopia, elevated IOP despite maximal medical therapy, proliferative retinopathy, proptosis with untreatable corneal exposure and patients with cortical venous drainage.
Transvenous embolization is typically used when intervention is necessary. In difficult cases, retrograde cannulation of superior or inferior ophthalmic vein can be performed to access the CCF for coiling.
Successful closure is reported to occur in 80 to 100 percent of cases following embolization.
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