The neurosurgeons and interventional neuroradiologists at Houston Methodist Hospital Neurological Institute Cerebrovascular Center diagnose and treat many kinds of cerebrovascular conditions, including carotid cavernous fistulas.
A carotid cavernous fistula (CCF) is an abnormal connection between a carotid artery (the arteries that run up your neck) and the cavernous sinus located behind your eyes. If one these arteries tears or develops a hole near the veins in the cavernous sinus area, a fistula (channel or shunt) develops, which lets blood flow from the artery to the vein. Carotid cavernous fistulas are typed either as direct or indirect.
Direct CCFs usually result from a torn carotid artery—often resulting from head trauma. Between 70% and 90% of direct CCFs are caused by basal skull fractures.
Indirect CCFs happen spontaneously. This can be caused by a connective tissue disorder.. CCFs caused by ruptured aneurysms or atherosclerotic (hardened) arteries are less common, but tend to occur in postmenopausal women who have high blood pressure.
A CCF can raise the pressure in the cavernous sinus and affect nearby nerves. These nerves control eye movements and some sensations in parts of your head and face. It can also affect the veins that drain the eyes. CCFs are one of the causes of “red eye” and other visual problems—including vision loss—if not found and treated. Many people who have carotid cavernous fistulas see their eye doctors first because of eye or vision symptoms.
Symptoms of a carotid cavernous fistula include:
Diagnosing a carotid cavernous fistula begins with a thorough exam, including an eye exam. Your neurologist may order imaging scans to get a look at your eye, nearby blood vessels and cavernous sinus area. These may include:
Rarely, a direct carotid cavernous fistula can heal on its own without any treatment. When a CCF causes severe symptoms, or symptoms get worse over time, it may need to be treated with surgery.
An endovascular embolization is the most common treatment for CCF. In this procedure, a neurosurgeon or interventional neuroradiologist inserts a tiny catheter into an artery in your groin, then guides it up to the fistula to block the blood flow between the artery and vein. Platinum coils or other materials may be used to block the blood flow.
No drug can cure a CCF, but if it causes eye symptoms, drugs may be prescribed to lubricate the eye or lower eye pressure.
Most direct CCF treatment is permanent. Many people who are treated for CCFs notice an improvement in their symptoms quickly—within a few hours or a few days. Most people are recovered within six months. However, not everyone recovers completely. Sometimes indirect CCFs can recur and may need to be treated again.