UGC NET Paper 1 Mathematical Reasoning & Aptitude.pdf
cc fistula
1. Carotid Cavernous Fistula
Laura S Gilmore, MD
Department of Ophthalmology
TTUHSC
February 13, 2004
Discussant: Kenn Freedman, MD
2. Case Presentation
• 26yo AAM s/p MVA
• CHI, L zygoma fracture
• Consulted for proptotic, red OS
• CT: proptosis OS. No basilar skull
fracture. no retrobulbar hematoma, no
superior ophthalmic vein enlargement,
no ocular muscle enlargement
8. Carotid Cavernous Fistula
• Abnormal communication between
previously normal carotid artery
and cavernous sinus
• Characterized as:
-Direct vs. Indirect
-High vs. Low Flow
-Traumatic vs. Spontaneous
11. 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
12. Signs of Direct CCSF
• Ptosis
• Very red, chemotic conj
• Increased IOP from increased episcleral
venous pressure
• Anterior segment ischemia in 20%
– Corneal edema, cell/flare, iris atrophy,
rubeosis, cataract
• Proptosis is pulsatile
• Bruit and thrill
• Muscle palsies
• Visual loss
13. Etiologies of Direct CCSF
• From trauma in 75% of all cases
– Basal skull fracture tears ICA within
cavernous sinus
– Traumatic fistulae-high flow rates, sudden
and dramatic onset of symptoms
• Spontaneous rupture of aneurysm or
atherosclerotic artery in 25%
– Post-menopausal, hypertensive females
– Lower flow rates, less severe symptoms
14. Mechanisms of Traumatic CCSF
• direct injury from basilar skull fracture
• injury from torsion or stretching of the
carotid siphon upon impact
• impingement of the vessel on bony
prominences
15. 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
• Lesions may fluctuate, and may resolve
spontaneously
16. Clinical Presentation of CCSF
• Ophthalmic consequences of CCSF are
caused by compression and ischemia
related to increased venous pressure
and reduced arterial pressure
– flow reversal leads to engorged ophthalmic
veins causing proptosis, conjunctival
injection, chemosis.
– Patients complain of retro-orbital
headache, or a bruit. Facial pain with V1
and V2 involvement
17.
18.
19. Clinical Presentation of CCSF
• Other manifestations:
– congestion of the opposite orbit
– diplopia
– ptosis, mydriasis
– corneal ulceration
– loss of visual acuity
– transient neurological deficits
– subarachnoid hemorrhage
20. Radiological Evaluation of CCSF
• 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
21.
22. Treatment of CCSF
• Most are not life-threatening
– Only involved eye is at risk typically
• Main indicators for treatment
– Glaucoma
– Diplopia
– Intolerable bruit or HA
– Severe proptosis causing exposure
keratopathy
– Spontaneous closure from thrombosis of
cavernous sinus is unlikely (as in trauma,
high-flow)
23. Treatment of CCS Fistulas
• 99% of treatment is done by
interventional neuroradiologists
– Intravascular approach-placement of
thrombogenic materials, eg coils
• Other therapies include:
– carotid artery ligation
– surgical exposure with clipping of the
fistula
24. Summary
• Direct CCSF usually results from
trauma
• Patients typically present with proptosis,
conjunctival injection, and a bruit
• Angiography when pt stable
• Transarterial embolization
Hinweis der Redaktion
To aid in DD. Pt holds breath n keeps eyes still, listen 10-15s for whoosh, synch with heartbeat. Bruit is decreased by comp of ipsi carotid in neck. Unilateral bruits may be from CCF, AV malformations, ipsi ICA thrombosis. Atherosclerosis or mech narrowing of ICA. B bruits-anemia, hyperthytoidism. Carotid bruit can be transmittted, so listen at neck.
Proptosis, no enlarged SO vein/enlarged EOM
MRI-No fx. New engorgement of L orbit. Signal flow void of L cavernous CA, suggestive of fistula or aneurysm. No vein engorgement of arteries/veins of L orbit, as expected with CCF, but cannot be excluded MRA-abnl signal of L Carotid artery n sphenoid sinus-CCSF vs aneurysm
Lateral views of selective injection of LCA, with early filling of CS and SO vein proving CCSF. Early appearance of veing on arteriography proves fistula, b/c blood has bypassed the capillaries
2 to trauma or degeneration. Basal skull fx-most common trauma prod AV fistulas. Spont usually occur as degenerative process in elderly with HTN n atherosclerosis. Most common venous sttructure involved-cav sinus. Arterial-ICA
Direct high flow-trauma; indirect low flow-congenital or idiopathic, B, in F.
blunt head injury, fracture through the skull base, or penetrating trauma
Especially at risk are hypertensives with atherosclerosis, esp post-menopausal women
Arterialization of normally low-pressure CS causes reversal of flow within SO vein and consequent venous congestion and increased venous pressure
Tortuous epibulbar vessels, bruit audible to examiner, pt, or both. Pulsating proptosis.ischemic ocular damage 2o to diversion of arterialized blood into venous system. High pressure in cavernous sinus can compromise CN 6 and cause LR palsy-abducens dysfunction 2o to dilatation of inferior petrosal sinus, which travels with CN6.
Ophthalmoplegia v common 2o EOM nerve damage. 6 th CN in 50%, with variable 3 n 4. Engorgement of EOMs contributes. FE-venous engorgement n tortuosity, occ CRVO. Dec VA common n may be perm.
Nec for eval n tx. See retrograde opacification of CS and orbital venous system
Detachable balloon embolization is TOC for post-traumatic, high flow shunts. Intravascular embolization is TOC for high flow spontaneous shunts-less successful. Goal of therapy is twofold : complete fistula closure. preservation of parent artery
