A 49-year-old man was transferred to the University of New Mexico Health
Sciences Center after a helmeted motorcycle crash. He suffered a skull base
fracture, multiple facial fractures including bilateral medial and inferior
orbital wall fractures, bilateral orbital roof fractures and a left lateral
orbital wall fracture. He presented with multiple brain hemorrhages. He was
intubated and admitted to the neurosurgical intensive care unit. Ophthalmology
was consulted for the orbital fractures.
On examination, the patient’s vision could not be elicited due to
intubation. His pupils were equally round and reactive to light. There was no
relative afferent pupillary defect. Severe periorbital ecchymosis and edema
were present in both eyes. Extraocular movements were limited due to soft
tissue swelling. Mild proptosis and lid lag were present in both eyes, and the
findings were more pronounced in the right eye. There was no resistance to
retropulsion. The IOP was soft by palpation. Slit lamp exam showed bilateral
conjunctival chemosis and exposure keratopathy in both eyes. The anterior
chambers were deep, and there was no hyphema. The lens was clear in both eyes.
Dilated fundus examination was deferred due to hourly neuro checks. Given the
proptosis and corneal exposure, intensive lubrication and corneal protection
During his hospital course, the patient developed severe prolapsing
conjunctival chemosis with conjunctival and episcleral venous congestion. He
also developed worsening proptosis of the right eye (Figure 1). The right pupil
became dilated and nonreactive to light with a reverse afferent pupillary
defect. IOP was 45 mm Hg in the right eye and 18 mm Hg in the left eye. Visual
acuity decreased to no light perception in the right eye. The cornea of the
right eye showed a central epithelial defect and subepithelial fibrosis
inferiorly. No fundus details could be appreciated due to the exposure
1. Proptosis, chemosis and episcleral venous congestion of the right eye.
Images: Semela LB, Boisvert C
What is your diagnosis?
Proptosis, chemosis, episcleral venous congestion
Given that trauma is the etiology of the patient’s signs and
symptoms, the differential diagnosis becomes quite narrow. In trauma associated
with craniofacial fractures, a carotid cavernous sinus fistula, retrobulbar
hematoma, superior orbital fissure syndrome and orbital apex syndrome have to
be considered. Given the patient’s clinical presentation of prolapsing
chemosis and episcleral injection with worsening proptosis in the setting of
head trauma, a traumatic carotid-cavernous sinus fistula (CCF) was suspected. A
cavernous sinus thrombosis can present with the same signs but is most commonly
caused by bacterial infection of the cavernous sinus.
The patient underwent neuroimaging, and the studies were reviewed. A CT
angiography study demonstrated enlargement of the right superior ophthalmic
vein, enlarged extraocular muscles and enhancement of the right cavernous sinus
consistent with a carotid cavernous sinus fistula (Figure 2). The patient
underwent an emergent transarterial coiling procedure by interventional
neuroradiology to embolize the fistula.
|Figure 2. CT angiography scan showing proptosis and superior
ophthalmic vein enlargement of the right eye. |
|Figure 3. Angiography, lateral view, demonstrating right
high-flow CCF (red arrow) causing enlargement of the superior ophthalmic vein
4. After embolization of the carotid cavernous sinus fistula. Regressing
proptosis, chemosis and episcleral venous congestion.
Traumatic carotid cavernous sinus fistulas are rare but potentially
lethal vascular anomalies in the skull base seen after craniomaxillofacial
trauma. They represent an abnormal communication between the carotid artery and
the cavernous sinus. The fistulas were angiographically classified by Barrow
and colleagues. Direct fistulas have an abnormal communication between the
internal carotid artery and the cavernous sinus (Barrow type A fistulas).
Indirect fistulas have communications between the small meningeal branches of
the internal, external, or both internal and external carotid artery and the
cavernous sinus (Barrow type B, C and D fistulas), which are also called
cavernous sinus-dural fistulas. The direct fistulas are mainly high-flow
shunts, which usually have a traumatic origin, and only a few resolve without
therapy. The majority of dural shunts are idiopathic and appear spontaneously.
The incidence of a CCF as a result of craniomaxillofacial trauma is less than
0.2%, although CCF is the most common posttraumatic intracranial vascular
The majority of the signs and symptoms, as well as possible sequelae, of
CCF are the result of shunting of blood between a high-flow and low-flow
system. The venous congestion occurring within and around the cavernous sinuses
causes a state of hypertension in the surrounding vascular tree. The orbits,
whose venous drainage travels to the cavernous sinuses through the superior and
inferior ophthalmic veins, are the first structures to manifest the symptoms of
this reversed blood flow. Common signs of CCF include proptosis,
temporal/orbital bruit, chemosis, extraocular palsy, pulsating exophthalmos,
elevated IOP, anterior segment ischemia, papilledema, optic nerve atrophy and
trigeminal nerve involvement. The classic triad of the more commonly occurring
anterior CCF consists of proptosis, bruit and chemosis. The most common cause
for visual loss is secondary glaucoma due to elevated episcleral venous
pressure, as was the case in our patient. Other causes include choroidal
detachment, diplopia, proptosis with corneal exposure, macular edema, venous
stasis retinopathy, or retinal or optic nerve ischemia.
The diagnosis of carotid cavernous sinus fistula is based on clinical
findings and must be confirmed by CT scan or angiography. Angiography can
reveal the precise location and size of a CCF. CT with contrast is also useful
because it can depict any bony fractures or spicules around the cavernous sinus
as well as outline engorged superior ophthalmic veins, a common radiographic
finding in CCF. MRI and MRA have been used in demonstrating reversal of blood
flow with the cavernous sinus and superior ophthalmic veins. Angiographic
studies in our patient showed a high-flow CCF caused by the skull base fracture
through the right petrous internal carotid artery canal (Figure 3).
Treatment of direct cavernous sinus fistulas consists of embolization of
the fistula. Different modalities such as detachable balloon or coiling methods
are available. This procedure is usually performed by an interventional
neuroradiologist via transarterial or transvenous access of the fistula. Our
patient underwent coiling embolization of the CCF via a transfemoral access.
After successful coiling embolization of the cavernous sinus fistula,
IOP normalized immediately in the affected eye. The chemosis, conjunctival and
episcleral vessel dilation regressed slowly. The patient’s vision,
however, did not recover (Figure 4).
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- Linda Brenner Semela, MD, and Chantal Boisvert, MD, can be reached
at New England Eye Center, Tufts University School of Medicine, 750 Washington
St., Box 450, Boston, MA 02111; 617-636-4219; fax: 617-636-4866; website:
- Edited by Priti Batta, MD, and Namrata Nandakumar, MD. Drs. Batta
and Nandakumar can be reached at New England Eye Center, Tufts University
School of Medicine, 750 Washington St., Box 450, Boston, MA 02111;
617-636-4219; fax: 617-636-4866; website: