Vascular Malformations of the Spine and Spinal Cord*

Abstract

Spinal vascular malformations are rare diseases with a wide variety of neurologic presentations. Their classification depends on the differentiation of shunting versus nonshunting lesions, the latter being the spinal cord cavernomas. In the shunting lesions, the next step in the proposed classification scheme is related to the feeding artery which can subdivide the dural vascular shunts from the pial vascular malformations: while those shunts that are fed by radiculomeningeal arteries (i.e., the counterparts of meningeal arteries in the brain) constitute the dural arteriovenous fistulas, the shunts that are fed by arteries that would normally supply the spinal cord (i.e., the radiculomedullary and radiculopial arteries) are the pial cord arteriovenous malformations (AVMs; whose cranial counterparts are the brain AVMs). Depending on the type of transition between artery and vein, the latter pial AVMs can be further subdivided into glomerular (plexiform or nidus-type) AVMs with a network of intervening vessels in between the artery and vein and the fistulous pial AVMs. The last step in the classification then describes whether the type of fistula has a high or a low shunting volume which will differentiate the "macro-" from the "micro"fistulas. The proposed classification is therefore based on a stepwise analysis of the shunt including its arterial anatomy, its nidus architecture and its flow-volume evaluation. The major advantage of this approach is that it leads to a subclassification with direct implications on the choice of treatment, thereby constituting a simple and practical approach to evaluate these rare diseases.

Comparison of 3 Different Types of Spinal Arteriovenous Shunts below the Conus in Clinical Presentation, Radiologic Findings, and Outcomes

“…pinal arteriovenous lesions are rare and complex neurovascular diseases that can be categorized according to embryologic considerations, 1 anatomic and imaging features, 2 or their locations. 3 Among the spinal vascular malformations, arteriovenous shunts below the conus medullaris include some particular groups of lesions and are sometimes misdiagnosed due to similar clinical and radiologic presentations, which are worth addressing and differentiating separately.…”

Clinical Features and Outcomes of Spinal Cord Arteriovenous Malformations

“…1,2 The Bicetre group suggested a classification based on genetic and hereditary perspectives that divided conditions into 3 main groups: genetic hereditary lesions, genetic nonhereditary lesions, and single lesions that may reflect an incomplete expression of a genetic condition. 3,4 The vast majority of spinal vascular malformations fall into this third group.…”

Transmedullary Venous Anastomoses: Anatomy and Angiographic Visualization Using Flat Panel Catheter Angiotomography

“…TMVAs have been documented by contrast-enhanced MRA and by DSA, 6,7,17 while centrodorsolateral TMVAs have, to our knowledge, not been imaged clinically until now, probably because of their smaller size. 15 New imaging methods such as spinal SWI also require a sound understanding of the spinal venous system anatomy and its variants, for example, to differentiate TMVAs from small intraparenchymal hemorrhages.…”

“…[3][4][5] This retrospective review of 8 clinical cases describes the morphology and angiographic appearance of several types of transmedullary venous anastomoses (TMVAs), including some previously undocumented configurations observed during routine spinal DSA. TMVAs, rarely observed in living subjects, [6][7][8] were until now essentially known through the study of postmortem material.…”