Arteriovenous Fistulas
- Vein
of Galen malformation – neonate with cyanotic heart disease
- Presents
as hydrocephalus or SAH
- Type 1
(AVF) – congenital, anterior/posterior choroidal to median venous sac
(precursor of vein of galen)
- Type 2
(AVM) – older, parenchymal (in thalamus/midbrain), thalamoperforator
feeders, developmental delay/ocular symptoms
- Dural
AVF – 10%
of AVM, 30% of AVM in posterior fossa
- Presents
older than true AVM
- No
nidus; feeder in wall of dural sinus; feeders from ECA occipital or
meningeal, occasionally tentorial/dural ICA or vertebral
- Acquired
after dural thrombosis with revascularization
- Most
often in transverse or sigmoid; can be seen in SSS or straight sinus
- Rarely
hemorrhage as long as drain forward
- Carotid-Cavernous
Fistula (CCF) – traumatic has one feeder, spontaneous has multiple feeders
- Middle
age, F>M
- 50% of
low flow will spontaneously thrombose – observe if intraocular pressure
less than 25
- Present
with bruit, chemosis, headache, exophthalmos, declining vision, diplopia,
conjunctival/periorbital swelling
- Etiology:
- Traumatic
- High
flow lesions which may appear weeks after trauma
- Rupture
of intracavernous carotid aneurysm
- Spontaneous
- Low
flow lesions primarily seen in middle aged post-menopausal women
- Differential
dx:
- Cavernous
sinus thrombosis, orbital vascular malformation, retro-orbital tumor,
exophthalmos secondary to thyroid disease
- Diagnosis:
Angiography
- Treatment:
Angiographic embolization or balloon trapping
- Surgical
intervention includes carotid ligation, trapping
- 5-10%
of spontaneously occurring non-traumatic fistula resolve without
intervention