Spinal Vascular Malformations Overview¶

Classification¶

Spinal vascular malformations are classified by their angioarchitecture and location:

Type I — Dural Arteriovenous Fistula (dAVF) The most common spinal vascular malformation (60–80%). An abnormal arterial-venous connection within the dural sleeve of a nerve root, causing venous congestion of the cord. Typically affects older men.

Type II — Intramedullary AVM (Glomus type) A true AVM nidus within the cord parenchyma. Compact nidus with high flow. Most common in young adults.

Type III — Intramedullary AVM (Juvenile type) A large, diffuse AVM involving the cord, often with extramedullary and even extraspinal components. Rare and aggressive.

Type IV — Perimedullary (Intradural Extramedullary) AVF A direct arterial-venous fistula on the surface of the cord (pial surface), without a nidus. Three subtypes based on size and flow.

Cavernous Malformation Low-flow lesion within the cord parenchyma, not visible on angiography.

Imaging Approach¶

MRI¶

T2-weighted — Flow voids on the cord surface (dilated perimedullary veins) are the hallmark of dAVFs and high-flow AVMs
Cord edema — Diffuse T2 hyperintensity within the cord from venous congestion (dAVF) or ischemia
Cord expansion — Variable
Contrast — Enhancing serpiginous vessels on the cord surface; cord enhancement from congestion/ischemia

Spinal Angiography (Gold Standard)¶

Identifies the feeding artery, fistula point, draining veins, and nidus
Essential for treatment planning (endovascular embolization vs surgical disconnection)

MR Angiography¶

Non-invasive screening; can localize the fistula level to guide catheter angiography

Clinical Pearl

Serpiginous flow voids on the dorsal cord surface on T2-weighted MRI in a patient with progressive myelopathy should immediately raise suspicion for a spinal dural AVF. This is a treatable cause of progressive paraplegia — early diagnosis and treatment can prevent irreversible cord damage.

Key Points¶

Dural AVF (Type I) is the most common spinal vascular malformation
Flow voids on the cord surface on T2 MRI are the hallmark
Spinal angiography is the gold standard for diagnosis and treatment planning
Early diagnosis is critical — venous congestion myelopathy from dAVF is reversible if treated early
Classification is based on angioarchitecture: dural AVF, intramedullary AVM, perimedullary AVF, cavernous malformation

References¶

Spetzler RF, Detwiler PW, Riina HA, Porter RW. Modified classification of spinal cord vascular lesions. J Neurosurg. 2002;96(2 Suppl):145-156. https://pubmed.ncbi.nlm.nih.gov/12450276/
Kim LJ, Spetzler RF. Classification and surgical management of spinal arteriovenous lesions: arteriovenous fistulae and arteriovenous malformations. Neurosurgery. 2006;59(5 Suppl 3):S195-201; discussion S3-13. https://pubmed.ncbi.nlm.nih.gov/17053603/
McCarty J, Chung C, Samant R, et al. Vascular pathologic conditions in and around the spinal cord. RadioGraphics. 2024;44(9):e240055. https://pubmed.ncbi.nlm.nih.gov/39207926/
Kona MP, Buch K, Singh J, Rohatgi S. Spinal vascular shunts: a patterned approach. AJNR Am J Neuroradiol. 2021;42(12):2110-2118. https://pubmed.ncbi.nlm.nih.gov/34649916/
Alkhaibary A, Alharbi A, Alnefaie N, et al. Spinal dural arteriovenous fistula: a comprehensive review of the history, classification systems, management, and prognosis. Chin Neurosurg J. 2024;10:2. https://pmc.ncbi.nlm.nih.gov/articles/PMC10775532/
Eddleman CS, Jeong H, Cashen TA, et al. Advanced noninvasive imaging of spinal vascular malformations. Neurosurg Focus. 2009;26(1):E9. https://pmc.ncbi.nlm.nih.gov/articles/PMC2843400/
Spinal vascular malformations. Radiopaedia.org. https://radiopaedia.org/articles/spinal-vascular-malformations