Spinal Arteriovenous Fistula

Abstract

A 53-year-old man presented with urinary retention,
bilateral lower extremity weakness, and numbness after
a L2–L5 lumbar laminectomy 6 weeks prior. MRI of the
lumbar region revealed spinal cord edema and dilated
peri-medullary vessels on T2 images. Digital subtraction
angiography revealed early venous filling arising from
the segmental T12 artery supplying the spinal cord, confirming the diagnosis.
Spinal dural arteriovenous fistulas (AVFs) are the most
common vascular malformation of the spine. It is presumed that spinal AVFs are an acquired disease although
their exact etiology is unclear. The diagnosis is suspected when patients present with symptoms of spinal cord
venous congestion [1]. Spinal cord edema may be at a
distant location from the arteriovenous shunt.
Connective tissue diseases such as fibromuscular dysplasia, neurofibromatosis type 1, Marfan syndrome, and
Ehlers–Danlos syndrome are often seen with AVFs [2].
Arteriovenous fistula may be associated with RASA1
gene mutations as part of a capillary malformation-arteriovenous malformation (CM-AVM) syndrome or
Parkes Weber Syndrome [3]. CM-AVM and Parkes
Weber syndromes are characterized by multiple small
capillary malformations and arteriovenous fistula. Capillary malformation along the involved dermatome in
association with AVF should raise suspicion for Cobb’s
syndrome.

Currently, no serum or genetic testing is routinely indicated in patients with arteriovenous fistulas. In patients
with an associated syndrome, genetic testing for RASA1
gene mutations may be offered, although other unidentified genes are also likely involved in all of the above
mentioned syndromes. Treatment of spinal arteriovenous
fistulas is by endovascular embolization or surgical
occlusion of the intra-dural vein [4].