Transcript 20070111_cc_fistula

Journal Reading
VS孫銘希 / PGY R1 呂威揚
2007 / 01 / 11
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Carotid-cavernous Fistula
• Overview
• Traumatic Carotid-Cavernous Fistula:
Pathophysiology and Treatment
(THE JOURNAL OF CRANIOFACIAL SURGERY / VOLUME 14, NUMBER 2 March 2003)
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• Specific type of dural arteriovenous fistula
characterized by abnormal arteriovenous
shunting within the cavernous sinus
• Abnormal communication between
previously normal carotid artery and
cavernous sinus
• High-pressure arterial blood entering the
low-pressure venous cavernous sinus
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Direct Carotid Cavernous
Fistula
• Arterial blood passes directly through a defect
in the wall of intracavernous portion of ICA
• Blood in vein becomes arterialized
• Venous pressure increases
• Arterial pressure and perfusion decreases
• From trauma in 75% of all cases, spontaneous
rupture of aneurysm or atherosclerotic artery in
25%
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Clinical features
• Symptoms develop suddenly
• Pulsating tinnitus as a “noise” inside the
head. Pain may follow.
• Ocular manifestations: ophthalmic
venous hypertension and orbital venous
congestion, proptosis, corneal exposure,
chemosis and arterialization of episcleral
veins.
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Indirect Carotid Cavernous
Fistula
• Fistulous connection is within the wall of the
cavernous sinus
• Tend to be low-flow
• Small meningeal arteries supplying dural wall
of cavernous sinus can rupture spontaneously,
while ICA itself remains intact
• Insidious onset, mild orbital congestion,
proptosis, low or no bruit
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Radiological Evaluation of
C-C Fistula
• Angiography is the definitive diagnostic
examination
• CT and MRI may show
– Enlarged superior ophthalmic vein
– Enlarged muscles
– Enlarged cavernous sinus with a convex
shape to the lateral wall
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Treatment of C-C Fistula
• Spontaneous closure occurs in up to 60%
• Most are not life-threatening
• Main indicators for treatment
– Glaucoma
– Diplopia
– Intolerable bruit
– Severe proptosis causing exposure keratopathy
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Traumatic Carotid-Cavernous
Fistula:
Pathophysiology and Treatment
(THE JOURNAL OF CRANIOFACIAL SURGERY / VOLUME 14,
NUMBER 2 March 2003)
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Right and left cavernous
sinuses
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• The cavernous sinus essentially
functions as a dural venous structure,
receiving blood supply from the superior
and inferior ophthalmic veins as well
as from the sphenoparietal sinuses.
• The venous architecture of the cavernous
sinus is maintained by multiple
communicating sinusoids, allowing the
venous blood flow to be quite slow and of
low pressure.
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• CN III, IV, V1 and V2 are located on the
lateral aspect of the sinus. CN VI,
however, lies medially in the sinus and
thus is not protected by the same dural
influences.
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Classification and Incidence
• The universally adopted classification
system in the CCF literature is the
schema developed by Barrow in 1985
based on angiographic studies.
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• Type A (direct): shunt between the ICA and cavernous
sinus ; usually associated with trauma (TCCF) and produce
early signs and symptoms
• Type B (indirect): shunt between the meningeal branches of
the ICA and cavernous sinus
• Type C (indirect): shunt between the meningeal branches of
the ECA and cavernous sinus
• Type D (indirect): shunt between the meningeal branches of
the ICA, ECA, and cavernous sinus
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• Direct CCF (Type A or TCCF) are high-flow
shunts, which occurs three times as often as the
indirect types.
• Type A shunts are not only frequently associated
with trauma, but they also predominantly occur in
men.
• Indirect or dural CCF (Type B,C, and D) are
low-flow shunts and usually occur spontaneously.
These indirect lesions are more common in the
elderly and women, with an increased peak in
incidence during pregnancy.
• Most CCF are unilateral; bilateral cases account
for 12% to 15% of the cases and are usually of
the indirect variety.
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Clinical Presentation
• The majority of the signs and symptoms of CCF
are the result of shunting of blood between a highflow and low-flow system.
• 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.
• Onset of symptoms may occur within hours after
injury (direct) or may be delayed for months
(indirect).
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• Patients often complain of a swollen red eye,
orbital pain, loud buzzing and swishing sounds,
diplopia, headache and progressive vision loss.
• Common signs of CCF include proptosis,
temporal / orbital bruit, chemosis, extraocular
palsy (especially of CN VI, which is often the
first CN to be affected), pulsating
exophthalmos, ptosis, elevated IOP, anterior
segment ischemia, papilledema, and optic
nerve atrophy.
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Diagnosis and Evaluation
• In addition to the common clinical symptoms,
the only relevant clinical test confirming the
diagnosis of CCF is that the bruit should
cease with digital compression of the
ipsilateral carotid artery in the neck.
• Four-vessel digital subtraction cerebral
angiography is the current gold standard in
the diagnosis of CCF.
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Unilateral
CCF
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• CT with contrast is also quite useful
because it can depict any bony fractures /
spicules around the cavernous sinus as well
as outlining engorged superior ophthalmic
veins, a common radiographic finding in
CCF.
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Treatment
• The spectrum of treatment modalities traditionally
included ligation or trapping of the carotid artery,
and balloon embolization combined with carotid
artery ligation.
• Endovascular detachable balloon occlusion of
CCF introduced through a transfemoral access
allows preservation of the distal aspect of the ICA,
thereby reducing morbidity.
 current standard therapy !!
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• Some clinicians believe that unless urgent
treatment is indicated (i.e., rapid loss of vision,
progressive hemiplegia, herniation of cavernous
sinus into the sphenoid sinus), a 6-week delay
and a repeat angiogram may be prudent before
intervention.
• Successful embolization of CCF will result in
immediate resolution of proptosis, chemosis, and
bruits. Ophthalmoplegia and optic nerve
dysfunction may take up to 4 months for resolution.
• The overall mortality of CCF is low, with major ICH
occurring in only 3% of the cases.
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Summary
• A carotid cavernous fistula is a rare but
potentially lethal condition.
• Direct CCF usually results from trauma.
• Patients typically present with proptosis,
chemosis, and a bruit.
• Angiography when p’t stable
• Transarterial embolization
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