Carotid-Cavernous Fistula (CCF)

Updated: May 24, 2019
  • Author: Ingrid U Scott, MD, MPH; Chief Editor: Hampton Roy, Sr, MD  more...
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Carotid-cavernous sinus fistula is an abnormal communication between the internal or external carotid arteries and the cavernous sinus. These lesions may be classified based on the following: etiology (traumatic vs spontaneous), velocity of blood flow (high vs low), and anatomy (direct vs dural, or internal carotid vs external carotid).



Carotid-cavernous sinus fistulae occur because of traumatic or spontaneous rents in the walls of the intracavernous internal carotid artery or its branches. This results in short-circuiting of the arterial blood into the venous system of the cavernous sinuses. [1]

Direct carotid-cavernous sinus fistulae, which represent 70-90% of all carotid-cavernous sinus fistulae in most series, are characterized by a direct connection between the intracavernous segment of the internal carotid artery and the cavernous sinus. These fistulae usually have high rates of arterial blood flow and most commonly are caused by a single traumatic tear in the arterial wall.

Dural carotid-cavernous sinus fistulae are characterized by a communication between the cavernous sinus and one or more meningeal branches of the internal carotid artery, external carotid artery, or both. These fistulae usually have low rates of arterial blood flow and almost always produce symptoms and signs spontaneously, without any antecedent trauma or manipulation. The lesions may represent congenital arteriovenous malformations, which develop spontaneously or in association with atherosclerosis, systemic hypertension, collagen vascular disease, pregnancy, and during or after childbirth.




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Carotid-cavernous fistula is rare.


Carotid-cavernous fistula is rare.


Nearly all patients with a direct carotid-cavernous sinus fistula experience progressive ocular complications if the fistula is left untreated. Increasing proptosis, conjunctival chemosis, and visual loss occur over months to years, with central retinal vein occlusion and secondary glaucoma representing the most severe ocular complications.

Several investigators have reported severe epistaxis and intracerebral hemorrhage, potentially fatal, in patients with traumatic carotid-cavernous sinus fistulae. Subarachnoid hemorrhage also may complicate the course of a traumatic carotid-cavernous sinus fistula. A 3% incidence of spontaneous intracerebral hemorrhage caused by carotid-cavernous sinus fistulae has been reported.

Visual loss, although less frequent than in patients with direct carotid-cavernous sinus fistulae, occurs in 20-30% of patients with dural carotid-cavernous sinus fistulae and may be due to secondary ischemic optic neuropathy, chorioretinal dysfunction, including central retinal vein occlusion, or uncontrolled glaucoma.


While direct carotid-cavernous sinus fistulae generally are associated with trauma or surgical manipulation, dural carotid-sinus fistulae occur more commonly in middle-aged to elderly women.


Traumatic carotid-cavernous sinus fistulae occur more commonly in young individuals.

Dural carotid-cavernous sinus fistulae usually occur in middle-aged to elderly women but may produce symptoms at any age, including infancy.



Although direct carotid-cavernous sinus fistulae rarely reopen after closure using a detachable balloon technique, it is not unusual for dural carotid-cavernous sinus fistulae to recanalize or form new abnormal vessels after embolization. The ocular pulse amplitude should be checked postoperatively in all patients, preferably using a pneumotonometer.

Once a fistula is closed, symptoms and signs usually begin to improve within hours to days. The rate and extent of improvement are associated with the severity of the signs and the length of time the fistula was present.

Preexisting ocular bruit, ocular pulsations, and thrill generally disappear immediately after the surgery.

Eyelid engorgement, conjunctival chemosis, dilated conjunctival vessels, stasis retinopathy, disc swelling, and elevated intraocular pressure generally return to normal within weeks to months.

Most patients with dural carotid-cavernous sinus fistulae are healthy within 6 months after treatment, but patients with direct carotid-cavernous sinus fistulae may not experience complete resolution of proptosis, ophthalmoparesis, and visual loss.