Traumatic Carotid Cavernous Fistula

KEY FACTS

TERMINOLOGY

• Direct carotid cavernous fistula (CCF), high-flow CCF

• Single-hole tear/transection of cavernous internal carotid

artery (ICA) with arteriovenous shunt into cavernous sinus

(CS)

IMAGING

• General features

○ Proptosis, dilated superior ophthalmic vein (SOV) and CS,

extraocular muscle enlargement

○ Skull base fracture involving sphenoid bone/carotid canal

↑ likelihood of ICA injury

• MRA: ↑ flow-related signal in CS and SOV

• CT/CTA may be suggestive; should proceed to DSA to

confirm and treat

• DSA is definitive

○ Early filling of CS + outflow pathways including

retrograde filling of SOV, angular + facial veins

○ Reduced or absent antegrade flow in ICA beyond fistula,

depending on size of ICA tear

TOP DIFFERENTIAL DIAGNOSES

• Indirect CCF

○ Low-flow CCF

○ CS dural arteriovenous fistula

○ Often older patient without history of trauma

CLINICAL ISSUES

• Bruit, pulsating exophthalmos, orbital edema/erythema, ↓

vision, glaucoma, headache

• Hemispheric ischemia if ↓ flow in ICA beyond CCF

• Focal deficits → cranial nerves 3-6 (ptosis)

• Endovascular treatment options include

○ Transarterial-transfistula balloon embolization

○ Transvenous embolization

○ Pipeline/covered stent placement

○ ICA sacrifice

(Left) Coronal graphic depicts

a carotid cavernous fistula

(CCF). The right cavernous

sinus ﬊ is enlarged. Note

numerous dilated arterial and

venous channels st within the

laterally bulging cavernous

sinus. (Right) Clinical

photograph depicts findings in

posttraumatic right carotid

cavernous fistula. Pulsatile

exophthalmos ﬉ with 3, 4,

and 6 nerve palsies including

ptosis ﬈ was present.

(Left) CECT scan in a patient

with posttraumatic pulsatile

exophthalmos shows that the

right cavernous sinus ﬇ is

enlarged. The ipsilateral

superior ophthalmic vein ſt is

more than 4x the size of the

left superior ophthalmic vein

st. (Right) DSA in the same

case shows opacification of

the cavernous sinus ﬇ in the

arterial phase. Also outlined

are many of the venous

outflow pathways of the

cavernous sinus, including the

superior ophthalmic vein ﬈,

superior and inferior petrosal

sinuses ﬊, and pterygoid and

pharyngeal venous plexi ﬉.

Trauma, and Stroke

Brain: Pathology-Based Diagnoses: Malformations,

53