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​Carotid Cavernous Fistula (Cavernous Sinus Fistulas)

What is a Carotid Cavernous Fistula?

Carotid cavernous fistulas (CCFs) are abnormal connections between the blood vessels that take blood to and from the brain:

  • Internal carotid artery
  • External carotid artery
  • Cavernous sinus or its dura (the thin membrane that covers the cavernous sinus)

The integrity of the cavernous sinus and its dura are particularly important because blood is toxic to a number of nearby sensitive neural tissues.

CCFs are classified as either indirect (type A, or dural) or direct (type B, C, and D).

Indirect CCFs are usually spontaneous and have no known cause.

Direct CCFs may result from:

  • Trauma
  • Rupture of a cavernous carotid aneurysm
  • A tear in the wall of a weak cavernous internal carotid artery caused by congenital collagen vascular disease.

Symptoms of carotid cavernous fistulas may include:

  • Bulging eyes
  • Deteriorating vision
  • Ringing in the ears

UPMC neurosurgeons may recommend a combination of surgical and non-surgical approaches to treat CCFs. Surgical treatment depends on the type of CCF.

Treatment options may include:

Diagnosing Carotid Cavernous Fistula

Symptoms of Carotid Cavernous Fistula

Your physician will also ask you about your symptoms. These may include:

  • Bulging eyes
  • Swelling of the membranes that cover the outside of the eyes and line the eyelids
  • Forward displacement of the eyeballs
  • Deteriorating vision
  • Cranial nerve palsies
  • Nosebleed
  • Headache
  • Bruit (a blowing sound in the vessel that can be heard with a stethoscope)
  • Tinnitus (ringing in the ears)

Image and radiology testing for carotid cavernous fistula

Carotid cavernous fistulas can be diagnosed by imaging studies such as:

  • CT scan
  • MRI scan
  • Angiogram

Carotid Cavernous Fistula Treatment Options

Carotid cavernous fistula treatments vary depending on the type of CCF. Surgical treatment depends on the type of CCF.

Treatment options may include:


Embolization is a minimally invasive procedure that involves the threading of a small catheter or tube through a blood vessel in the groin, which is then navigated to blood vessels in the brain to create an emboli or block blood flow.

During embolization, small coils or detachable silicon balloons are guided through the arteries to stop the abnormal blood flow to the CCF.

Gamma Knife® radiosurgery

Gamma Knife radiosurgery is a painless treatment that uses hundreds of highly focused radiation beams to target tumors and lesions within the brain, with no surgical incision.

As the nation's leading provider of Gamma Knife procedures, UPMC has treated more than 12,000 patients with tumors, vascular malformations, pain, and other functional problems.