Carotid Cavernous Fistula

A carotid-cavernous fistula (CCF) results from an abnormal communication between the arterial and venous systems within the skull's cavernous sinus. A narrow passage or duct known as a "fistula" can form as a result of this abnormal communication, which may initially be caused by trauma, surgery or an aneurysm.
 
With a carotid-cavernous fistula, arterial blood under high pressure enters the cavernous sinus, but the normal venous return out of the sinus is impeded. This causes an engorgement of the draining veins. The most dramatic manifestation of a CCF is a sudden engorgement and redness of the eye on the same side.

Carotid-cavernous fistulas may form following head trauma, surgical damage, rupture of an intracavernous aneurysm or in association with connective tissue disorders or vascular diseases and fistulas in the dura, which is the outermost of the membranes covering the brain and spinal cord.

For more information about carotid-cavernous fistula, call the Neuroscience Institute at (206) 314-1900.