M VOORMOLEN, MD PhD

Interventional Neuroradiology

Antwerp University Hospital, Belgium

Antwerp, May 15th 2015

ESNR SPINE COURSE Spinal vascular malformations: classification, diagnosis and treatment

Introduction

Spinal vascular diseases:

• Vascular occlusions:

• thrombo-embolic

• aortic dissection

• embolisation from intervertebral disc

• iatrogenous

• compression (tumor)

• decompression illness

• Vascular pathologic lesions

• vascular neoplasm

• aneurysm

• arterioveneous malformation

Spinal vascular lesions

• Neoplasm:

• Haemangioblastoma

• Cavernous haemangioma

• Aneurysm

• Malformation:

• Dural arteriovenous fistula (sDAVF)

• Arteriovenous malformation (sAVM)

(Spetzler et al 2002)

haemangioblastoma

Vascularisation spinal cord

• intercostal arteries:

• thoracolumbar spine

• sidebranches vertebral arteries:

• cervical spine

• high thoracic spine

• radicular arteries:

• nerve roots

• most end in pia mater

• anterior spinal artery (anterior 2/3 cord):

• 0 – 6 cervical region

• 2 – 4 thoracic region

• 1 – 2 lumbar region

• largest: arteria radicalis magna (Adamkiewicz)

Arteria spinalis anterior (ASA)

• Adamkiewicz

• Th 10 – L2

• Li > Re

Arteria spinalis posterior (ASP)

• cervical:

• sidebranches a vertebrales (intracranial)

• posterior radicular arteries:

• cervical – thoracic - lumbar

• more collateral circulation

compared to anterior spinal arteries

• posterior 1/3 part spinal cord

Spinal vasculature

• Arterial:

• spinal artery

• radicular artery

• anterior

• posterior

• Venous:

• spinal vein

• anterior

• posterior

• radicular vein

• internal vertebral venous plexus

(epidural)

Spinal venous drainage

• venous plexus

• anterior

• posterior

• intervertebral veins

• ascending lumbar vein

• segmental vein

• inferior vena cava

• (hemi-) azygos vein

Vascular spinal diseases

• Ischemia by arterial occlusion

• spontaneous (≈ acute CVA ; usually ASA)

• abdominal aortic surgery (Adamkievicz)

• decompression illness (air embolus; 2 x frequent than brain)

• disc embolus (young persons; degeneration analus fibrosus)

• Ischemia by venous occlusion:

• spinal dural AV fistula (sDAVF)

• Spinal subarachnoid hemorrhage

• spinal aneurysm (rare)

• spinal aneurysm associated with spinal AVM

Spinal subarachnoid haemorrhage

• very rare

• sudden, knife-like pain

• level pain = level lesion

• 50% rebleeding

• < 10% symptom free recovery

• after treatment 60% DLA independent (Shepard, 1992)

• spinal intradural AVM most frequent cause

• aneurysm associated with sAVM

• some cases of arterial aneurysm (Massand et al, 2005)

Imaging

• CT scan:

• limited information, except CT angio (pigtail in aorta)

• MRI scan:

• first choice

• extramedullar and intramedullar lesions

• MR angiography

• Angiography:

• risk (2-3%) permanent neurological deficit (Forbes et al. 1988)

• focused at vascular lesion (and ASA)

• embolisation

Spinal angiography

Classification

1. single shunts caused by a genetic disorder, for

example arteriovenous lesions associated with

hereditary haemorrhagic telangiectasia (Rendu–Osler–

Weber disease)

2. multiple spinal cord vascular lesions that are not

genetically determined but share metameric links

(involvement with cord, bone, paraspinal, subcutaneous and

skin tissues)

3. single lesions, which are either AVMs or AVF

Berenstein A, Lasjaunias P, Ter Brugge KG. Surgical neuroangiography 2.2. Berlin: Springer; 2004

Classification (based on topographic and anatomic criteria)

• sAVM (nidus; fed by arteries normally supplying the neural tissue):

• Intramedullary

• Pial

• Epidural

• Intra- and extramedular (Juvenile)

• sAVF (direct AV shunt; fed by radiculomeningeal arteries):

• Dural

• Pial (small, large, giant)

• Epidural

Spetzler RF, et al. Modified classification of spinal cord vascular lesions. J Neurosurg 2002; 96: 145–56

Frequency spinal vascular lesions

1. sDAVF 70%

2. sAVM 20-30%

3. pial sAVF rare

4. epidural sAVF very rare

5. juvenile sAVM extreme rare

Spinal dural arteriovenous fistula (sDAVF)

• middle aged male

• late diagnosis (weeks/months/years) due to gradual onset

• starts with sensory or motor deficit feet / lower legs

• later:

• sensory / motor deficits lower body

• micturation / defecation disorder

• acquired

• unknown etiology (venous thrombosis?)

sDAVF

• abnormal connection radiculomeningeal artery /

radicular vein (along nerve root) in dura mater of

intervertebral foramen (McCutcheon et al;1996)

• usually thoracic or lumbar level (Jellema et al; 2003)

• common venous drainage radicular vein and spinal cord

• high pressure on spinal cord veins/capillaries (valveless)

• venous congestion

• disfunction and necrosis (edema and loss of blood-cord barrier)

• first gray matter, later white matter (Hurst et al; 1995)

sDAVF - symptoms

• starts at medullary conus (independent of level sDAVF)

1. sensory deficits feet ascending to buttock (sacral

segments)

2. motor deficits:

1. periferal (gray matter cord)

2. spasticity and pathologic reflexes (white matter)

3. mictural disorders (periferal nature)

4. erectile disorders

5. defecation disorder

Spinal haemorrhage very rare (only in some cervical sDAVF)

sDAVF - imaging

• MRI scan

• venous congestion

• spinal cord edema (T2 hyperintens)

• tortuous veins dorsal to spinal cord

• Angiography:

• indentification level of sDAVF

• identification ASA (Adamkievicz)

sDAVF - treatment

• Surgery:

• Clipping / cauterisation of fistula (laminectomy)

• Endovascular embolisation:

• First choice option

• Glue (Histo-Acryl) or Onyx embolisation of fistula

• Venous part needs to be reached

• Presurgical marking of vertebral level with coil

Male, 80 years; sDAVF L2

Spinal angiography with 3D reconstructions

Endovascular treatment with Histo-acryl glue (arrows)

sDAVF left L1: surgical clipping

sAVM

• 20-30% of all sAV lesions

• high-flow

• location:

• spinal cord surface, intramedullary or both

• arterial supply: pial and perforating arteries (ASA/PSA)

• venous drainage: intrinsic or pial veins

• nidus, single or multiple fistulae

• association with arterial aneurysm or venous pouches

• even distribution along spinal cord

sAVM

• childhood or early adulthood

• sudden onset of symptoms due to hemorrhage or

compression-induced myelopathy:

• motor and/or sensory deficits

• bladder and bowel disturbances

• pain

• progressive deterioration of spinal cord function with

each new event

Male, 29 years; sAVM L1 (Adamkievicz Th10)

Right Th10 Left L1

Endovascular occlusion with Onyx®

Characteristics sDAVF and sAVM

dural AVF intradural AVM

Age first symptoms 95% after 4th decade 85% before 4th decade

Gender 80% male male = female

Spinal SAH rare 60%

Pial sAVF

• single or few intradural direct arteriovenous shunts

without intervening nidus

• location: pial surface of the cord

• arterial supply: ≥1 arterial feeder (ASA or PSA)

• venous drainage: spinal cord veins

• classification (shunt size and flow):

• small (type I)

• large (type II)

• giant (type III)

Small pial sAVF (type I)

• present later in life

• progressive neurologic deficits (venous hypertension)

• SAH is rare

• single slow-flow shunt: nondilated ASA - slightly dilated

spinal vein

• location: anterior aspect conus medullaris/filum terminale

easily confused with DAVFs

Large pial sAVF (type II)

• single or few shunts

• greater flow than small sAVF

• many arterial feeders (ASA or PSA) that converge to 1 or

few shunts

• ampullary dilation draining vein

• location: posterolateral aspect conus medullaris

Giant pial sAVF (type III)

• single or few high-flow shunts with ≥1 dilated arterial

feeder from ASA and PSA converging to single shunt

draining into massively dilated arterialized draining veins

• more prevalent in conus medullaris region

• associated with complex vascular malformation

syndromes

Symptoms large and giant pial sAVF

• usually childhood and adolescence

• variety of clinical scenarios:

• secondary to SAH (venous rupture): acute onset of symptoms

• secondary to vascular steal, venous hypertension, or mass

effect on the spinal cord and/or nerve roots from dilated veins:

progressive motor and sensory deterioration and sphincter

disturbance

• mass effect on the cord or nerve roots from dilated veins

explains the sometimes asymmetric nature of deficits

A, Angiogram of the left T10 intercostal artery shows a pial AVF supplied by the artery of

Adamkiewicz (arrow).

Patsalides A et al. AJNR Am J Neuroradiol 2011;32:798-808

©2011 by American Society of Neuroradiology

Epidural sAVF

• rare lesion associated with significant neurologic

morbidity

• abnormal shunt artery and epidural vein/venous plexus

• cervical spine: most common location

• neurologic symptoms occur by

• mass effect on spinal cord and/or nerve roots from enlarged

draining veins

• arterial steal

• venous hypertension

A, A 69-year-old man with progressive bilateral lower extremity weakness.

Patsalides A et al. AJNR Am J Neuroradiol 2011;32:798-808

©2011 by American Society of Neuroradiology

Juvenile sAVM = intra- and extramedular sAVM

• least frequent; children and young adults

• large malformations with both fistulous and glomerular

compartments

• involving spinal cord and neighboring tissues such as dura,

vertebral body, paravertebral musculature and cutis

• multiple feeders over several vertebral levels are common

• metameric angiomatosis (Rendu-Osler-Weber) or Cobb’s

syndrome: association of (in the same metamere)

• vertebral hemangioma,

• cutaneous lesion

• spinal cord AVM

• symptoms: pain and progressive myelopathy

Boy, 3 years; Rendu Osler Weber; spinal macrofistula

Multiple arterial feeders

Right L1 Left Th12

Left Th9

Coil and Onyx embolisation aneurysm and main feeder

Treatment

• postoperative function is highly related to preoperative

presentation

• maximum functional results are obtained in patients

treated early before advanced deterioration

• partial results can still be obtained in patients with

severe neurologic impairment

• clearly define vascular anatomy before any attempt at

embolization (risk for spinal cord ischemia)

• check the levels above and below for anastomoses that

would supply the ASA territory

Treatment

• too proximal occlusion of arterial feeder to an

arteriovenous shunt is ineffective:

• other arterial anastomoses are recruited to supply the shunt

• increased arterial steal (blood will be diverted to the shunt)

• diminished access shunt for further embolization

• occlusion of venous drainage of large arteriovenous

shunts also has increased risks:

• sAVM: increased nidal pressure and subsequent hemorrhage

• sAVF: increased venous hypertension

• Aim treatment:

• occlusion of nidus in AVM

• occlusion of fistula in AVF

Treatment

• Surgery

• Endovascular

• Combination

• Surgery:

• high intraprocedural risk of neurologic injury, especially in

lesions located in the anterior cord

• superficial or (posterior) filum terminale lesions

• Endovascular:

• n-BCA (glue) or Onyx® (EV3, Covidien)

• Microparticles

• Microcoils (aneurysm / large vessels)

Summary

type etiology feeding

artery

draining vein pathofysiology age of

onset

(years)

therapy

DAVF acquired radiculo-

meningeal

radicular vein ->

perimedularry vein

(retrograde)

chronic venous

congestion

40-60 surgery

and/or glue

embolisation

AVM glomerular

(nidus) inborn radiculo-

medullary

Intramedular and

superficial spinal cord

veins -> epidural

venous plexus

(orthograde)

hemorraghe,

chronic venous

congestion,

space

occupation

< 20 particle or

glue

embolisation

Pial

DAVF

perimedullar

fistula

(type I –III)

20 – 40 surgery

and/or

embolisation

AVM juvenile < 15 surgery

and/or

embolisation

Table adapted afterT Krings et al; Spinal vascular malformations; Eur Radiol (2005) 15:267–278

literature

• Krings T, Geibprasert S. Spinal dural arteriovenous fistulas. AJNR Am J

Neuroradiol 2009; 30: 639–48

• Krings T, et al. Spinal vascular malformations. Eur Radiol 2005; 15: 267–78

• Spetzler RF, et al. Modified classification of spinal cord vascular lesions. J

Neurosurg 2002; 96: 145–56

• Berenstein A, Lasjaunias P, Ter Brugge KG. Surgical neuroangiography 2.2.

Berlin: Springer; 2004.

• Houdart E, et al. A proposed angiographic classification of intracranial

arteriovenous fistulae and malformations. Neuroradiology 1993; 35: 381–

85

• A. Patsalides, et al. Endovascular Treatment of Spinal Arteriovenous

Lesions: Beyond the Dural Fistula .AJNR Am J Neuroradiol 2011 32: 798-808

THANK YOU

• The intracranial DAVF with perimedullary and spinal venous drainage (Fig 6)—

classified as type V in the Djindjian-Merland classification28—represents a

distinct category of intracranial lesions with spinal cord symptoms. These lesions

receive arterial supply from meningeal branches of the internal carotid, external

carotid, and the vertebral arteries, with venous drainage around the brain stem

and into the pial veins in the anterior and posterior surface of the spinal cord.

They are usually seen in men in their third-to-seventh decades of life, and

because of the venous drainage pattern, they may cause venous hypertension of

the spinal cord. The typical clinical findings include ascending myelopathy,

sphincter disturbances, bulbar signs like difficulty swallowing, and autonomic

dysfunction.29 These lesions highlight the importance of complete and

meticulous angiographic evaluation from the cranium to the sacrum in cases of

venous hypertension of the spinal cord.