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1、Spinal Vascular Malformations Typical and Atypical Findings,Contents,Introduction,Spinal vascular malformations are rare and still under-diagnosed entities which, if not treated properly, can lead to considerable morbidity with progressive spinal cord symptoms and myelopathy.Initial symptoms: acute
2、onset of symptoms: intramedullary or subarachnoidal hemorrhages unspecific initial neurological symptoms: venous congestion with chronic myelopathy. Render an early diagnosis difficult.,Introduction,potential therapeutic approaches,“ classical ” spinal vascular malformations,some atypical findings,r
3、emind both the neuroradiologist and the referring physician that the diagnosis and subsequent treatment of these treatable causes of severe and otherwise progressive neurological deficits still remains challenging.,Classification & Vessel Anatomy,In this article we use a classification that is simil
4、ar to the one employed for vascular malformations of the brain.inborn lesions:arteriovenous malformations (AVM) cavernomas acquired lesions: dural arteriovenous (AV) fistulaeSince the classification outlined above relies heavily on vessel anatomy, we will briefly describe the salient features of the
5、 spine and spinal cord vascular supply.,Classification & Vessel Anatomy,Like their cerebral counterparts, malformations that are fed by arteries normally supplying the neural tissue.,sulcal arteries: supplying mainly the grey matter and the central parts, originate from the anterior spinal artery (A
6、SA)perforating pial arteries: derived from the vasocorona that supply the periphery of the spinal cord, i.e. mainly the white matter, that are fed by the dorsolateral arteries and small branches from the ASA (a)&(b) constitute a superficial longitudinal anastomosing system,Classification & Vessel An
7、atomy,ASA: typically originates from the two vertebral Arteries, travels along the anterior sulcus Posterolateral spinal arteries (paired): originate from the preatlantal part of the vertebral artery or from the postero-inferior cerebellar artery (PICA).These three arteries are not capable of feedin
8、g the entire spinal cord. Instead, they are reinforced at various (and unpredictable!) segmental levels by anterior (radiculomedullary) and posterolateral (radiculopial) arteries, the most well known of them being the arteria radiculomedullaris magna or Adamkiewicz artery .,Classification & Vessel A
9、natomy,Hairpin curve: Radiculomedullary arteries branch in a very typical way once they have reached the midline of the spinal cord into an ascending branch and a descending branch, the latter being the larger one at the thoracolumbar levels and forms a hairpin curve as soon as it reaches the midlin
10、e at the entrance of the anterior fissure. In the adult patient, not all lumbar or intercostal segmental arteries have a radiculomedullary feeder; however, they all have a limited territory related to the radiculomeningeal artery. All radiculomedullary arteries enter the spinal canal via the nerve r
11、oots .,Classification & Vessel Anatomy,Dural Arteriovenous Fistulae,easily be misdiagnosed.degenerative disease, polyneuropathy, neoplasms, or infections. Only a careful analysis of non-invasive imaging studies will result in the correct diagnosis.,Most in thoracolumbar region The arteriovenous shun
12、t: the dura mater of a proximal root sleeve, pedicle (radiculomeningeal artery enters a radicular vein).,Hypo-/paresthesias, progressive paraparesis, back pain that can irradiate to the lower legs, impotence, and sphincter disturbances. Usually, the deficits are slowly progressive; however, an acute
13、 onset of disease and a progressive development interrupted by intermediate remissions is also possible. Without therapy, this lesion results in irreversible para- or even tetraplegia.,Spinal dural arteriovenous fistulae (SDAVF) are the most often encountered spinal vascular malformations and accoun
14、t for approximately 70 % of all AV shunts of the spine.,Dural Arteriovenous Fistulae,The characteristic findings on MRI: Cord edema + Perimedullary dilated vessels Cord edema: centromedullary, On T2, not well delineated hyperintensity over multiple segments, often accompanied by a hypointense rim. C
15、ontrast enhancement chronic venous congestion. Perimedullary dilated vessels: typically seen on the T2 as flow voids. However, small volume shunt may only be seen after contrast enhancement. Contrast-enhanced time-resolved MRA might be helpful in locating the fistula before performing a selective sp
16、inal angiography. Spinal angiography Verify the exact height of the fistula and to rule out the fistulous type of low flow perimedullary arteriovenous malformations.,Dural Arteriovenous Fistulae,Treatment of SDAVF: 2 options Microsurgical treatment: is a fast, simple and definitive method with excep
17、tion of sacral fistulae and should aim at occluding the feeding arterial network and the proximal portion of the radicular vein. Success rates: above 95%. Endovascular therapy employing glue after superselective catheterization of the feeding radiculomeningeal artery must reach the same goal. Success rates: 25-75%.,
