Intervertebral_vein
The intervertebral veins accompany the spinal nerves through the intervertebral foramina to drain the internal vertebral venous plexuses into the external vertebral venous plexuses.[1] They drain (in craniocaudal sequence) into vertebral vein, intercostal veins, lumbar veins, and lateral sacral veins. Upper posterior intercostal veins may additionally drain via brachiocephalic vens. They may drain to ascending lumbar veins. They may drain into the inferior vena cava directly, reaching it by winding around the surface of the vertebral body.[2]
 | This article or section appears to contradict itself on Last's Anatomy states: "The internal vertebral plexus sends its efferent veins (the intervertebral veins) [...] to drain into the external vertebral venous plexus and thence into the segmental veins." This seems to contradict the content referencing Gray's Anatomy.. (August 2023) |
It is unclear whether intervertebral veins contain functional venous valves; blood flow through intervertebral veins may be reversible, suggesting a possible mechanism for metastatic spread of e.g. prostatic cancer to the spine during temporary blood flow reversals (e.g. during periods of elevated intra-abdominal pressure or during postural alterations).[2]
