Carotid-cavernous fistula

Carotid-cavernous fistula
Classification and external resources
Oblique section through the cavernous sinus.
DiseasesDB	2152
eMedicine	oph/204 radio/134
MeSH	D020216

A carotid-cavernous fistula (CCF) results from an abnormal communication between the arterial and venous systems within the cavernous sinus in the skull. It is a type of arteriovenous fistula. As arterial blood under high pressure enters the cavernous sinus, the normal venous return to the cavernous sinus is impeded and this causes engorgement of the draining veins, manifesting most dramatically as a sudden engorgement and redness of the eye of the same side.

Causes

Carotid cavernous fistulae may form following closed or penetrating head trauma, surgical damage, rupture of an intracavernous aneurysm etc. or in association with connective tissue disorders, vascular diseases and dural fistulas.

Classification

Many types of classification have been proposed for CCF, based on the anatomy, pathophysiology and aetiology. They may be divided into low-flow or high-flow, traumatic or spontaneous and direct or indirect. One of the most popular classifications divides CCF into four varieties depending on the type of arterial supply.

Type	Description
A	Fistulous supply from the internal carotid artery
B	Supply from the dural branches of internal carotid artery
C	Supply from the dural branches of external carotid artery
D	Combined forms

Symptoms and presentation

While CCF is not a lethal disease, its symptoms can be disabling and include bruit (a humming sound within the skull due to high blood flow through the arteriovenous fistula), progressive visual loss, and pulsatile proptosis or progressive bulging of the eye due to dilatation of the veins draining the eye. Pain is the symptoms that patients often find the most difficult to tolerate.

Patients usually present with sudden or insidious onset of redness in one eye, associated with progressive proptosis or bulging.

They may have a history of similar episodes in the past.

Diagnosis

This is based on MRI scan with MRA/MRV, CT angiogram and a cerebral DSA.

Treatment

The mainstay of treatment for CCF is endovascular therapy. This may be transarterial (mostly in the case of direct CCF) or transvenous (most commonly in indirect CCF). Occasionally, more direct approaches, such as direct transorbital puncture of the cavernous sinus or cannulation of the draining superior orbital vein are used when conventional approaches are not possible. Spontaneous resolution of indirect fistulae has been reported but is uncommon. Staged manual compression of the ipsilateral carotid has been reporteed to assist with spontaneous closure in selected cases.

Direct CCF may be treated by occlusion of the affected cavernous sinus (coils, balloon, liquid agents), or by reconstruction of the damaged internal carotid artery (stent(s) +/- coils, liquid agents.

Indirect CCF may be treated by occlusion of the affected cavernous sinus with coils, liquid agents or a combination of both.

External links

• Carotid Cavernous Fistula Radiology Images from MedPix
• Ong, CK; Wang, LL; Parkinson, RJ; Wenderoth, JD (2009). "Onyx embolisation of cavernous sinus dural arteriovenous fistula via direct percutaneous transorbital puncture". Journal of Medical Imaging and Radiation Oncology 53 (3): 291–5. doi:10.1111/j.1754-9485.2009.02086.x. PMID 19624295. 
• Bhatia, Kartik D; Wang, Lily; Parkinson, Richard J; Wenderoth, Jason D (2009). "Successful Treatment of Six Cases of Indirect Carotid-Cavernous Fistula with Ethylene Vinyl Alcohol Copolymer (Onyx) Transvenous Embolization". Journal of Neuro-Ophthalmology 29 (1): 3–8. doi:10.1097/WNO.0b013e318199c85c. PMID 19458567. 
• Nadarajah, M.; Power, M.; Barry, B.; Wenderoth, J. (2011). "Treatment of a traumatic carotid-cavernous fistula by the sole use of a flow diverting stent". Journal of NeuroInterventional Surgery. doi:10.1136/neurintsurg-2011-010000. PMID 21990483.