Carotid Cavernous Fistula

Excerpt

Carotid cavernous fistula (CCFs) is an abnormal shunt from the carotid artery to the cavernous sinus. The symptomatology of CCFs depends on the involvement of the important neural and vascular structures in the cavernous sinus. These structures include cranial nerves III (oculomotor nerve), IV (trochlear nerve), V1 (ophthalmic nerve), V2 (maxillary nerve), and VI (abducens nerve). CCFs can be classified based on the hemodynamic properties, the etiology, or the anatomy of the shunt.

Hemodynamically, the fistulas can be classified as:

1. Low flow fistulas, and

2. High flow fistulas.

Etiologically, they are classified as:

1. Occurring following trauma, and

2. Occurring spontaneously.

Anatomical classification is most commonly used. The Barrow classification divides CCFs into:

1. Type A fistulas are direct connections between the internal carotid artery (ICA) and the cavernous sinus

2. Type B fistula results from dural branches of the ICA

3. Type C results from dural branches from the external carotid artery (ECA)

4. Type D result from dural branches from ICA and ECA

The flow velocity of the CCF, the venous anatomy, and the progression of symptoms of the patient dictates the intervention used to treat the CCF.