The Transdural Course of Radicular Spinal Cord Veins—A Microangiographical and Microscopical Study

Abstract

Reflux from the epidural plexus to radicular veins is not reliably stopped at the dural level and possibly physiological. Different arrangements of the transdural course of the veins appear to be at least appropriate to modulate flow. The purpose for two different types of radicular vein exit is unclear. The clinical impact of disturbed reflux-control is uncertain, which is in stark contrast to the severe consequences resulting from dural arteriovenous shunts. The functional role of the probably predominant epidural venous plexus for the spinal cord blood circulation remains poorly understood.

Concomitant conus medullaris arteriovenous shunts and sacral dural arteriovenous fistulas: pathophysiological links related to the venous drainage of the lesions in a series of five cases

“…The dural sac was found to be significantly thinner at the lumbar level and in younger people. Thron et al 25 also described a difference between the transdural course of the radicular veins at different spinal levels, in particular with a higher occurrence of blind ending fibrotic radicular veins among the posterior thoracic veins which might be explained by individual poor development of the posterior internal vertebral venous plexus. Similar anatomic venous variations at the sacral level have not been specifically described, to the best of our knowledge, but this deserves further studies.…”

Transdural Segment of the Radicular Vein in Spinal Dural Arteriovenous Fistula

“…Two structurally distinct arrangements of the transdural segment of the radicular vein could be identified: A slit type was seen in 60% of the veins studied and a bulge- or nodular type was seen in 35% of the veins [7]. Different arrangements of the transdural course of the veins appear to be at least appropriate to modulate flow.…”

“…Different arrangements of the transdural course of the veins appear to be at least appropriate to modulate flow. The caliber of the vessel decreases at its transdural course [7]. The normal composition of the vessel wall gradually gets lost and is replaced by dural tissue and a layer of arachnoid.…”

“…The normal composition of the vessel wall gradually gets lost and is replaced by dural tissue and a layer of arachnoid. There was no venous valve except anti-backflow system within the transdural course of the radicular vein, resulting from narrowing and zigzagging of the vein while crossing the dura [78]. …”

Imaging Findings of Benign Enhancing Foramen Magnum Lesions

“…While this could suggest a neural or perineural origin, we likewise referenced the findings of prior anatomic studies, in which small bridging veins approximate nerve roots as they course to and through the surrounding dura. [2][3][4] Thus, the spatial relationship between the lesion and the upper cervical nerve roots does not preclude a venous etiology of the process. Last, our patient had a large developmental venous anomaly in the left cerebellum ( Fig 1F), superior to the foramen magnum finding, but we suspect this may be coincidental in nature.…”