basivertebral veins basivertebral veins the basivertebral veins are veins of the trabecular bone of vertebral bodies that drain to the internal and external vertebral venous plexuses. they emerge from the vertebral bodies horizontally through foramina in the bone. anteriorly, they drain into the external vertebral venous plexuses; posteriorly, they drain into the anterior internal vertebral venous plexus by way of transverse vessels that bridge the two vertical anterior internal vertebral plexus vessels across the midline. basivertebral veinstransverse section of a thoracic vertebra, showing the vertebral venous plexuses (basivertebral veins labeled as vena basi-verteb at bottom center)median sagittal section of two thoracic vertebrae, showing the vertebral venous plexuses (basivertebral veins labeled as vena basi-vert at bottom right)detailsidentifierslatinvenae basivertebralesta98a12.3.07.022ta24948fma70891anatomical terminology it is unclear whether basivertebral veins contain functional venous valves; blood flow through basivertebral 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). anatomy they are contained in large, tortuous channels in the bony substance of the vertebral bodies akin to those in the diploë of the cranial bones. anteriorly and laterally, they emerge through small foramina upon the vertebral bodies to drain into the external vertebral plexus, whereas posteriorly, they converge into a single canal (which is sometimes doubled distally) before emptying into the internal vertebral plexus. the basivertebral veins become enlarged in advanced age.