Corpus: Internal vertebral venous plexus

The internal vertebral venous plexus is a network of veins located in the epidural space of the vertebral canal.

The vessels of the internal vertebral venous plexus are thin-walled and lack valves. They are embedded in the epidural fat. The plexus receives blood from the ventral and dorsal radicular veins, which drain the spinal cord, and from the vertebral bodies via the basivertebral veins.

The ventral part of the plexus consists of two longitudinal veins that anastomose in a ladder-like pattern, extending from the basilar plexus. Similarly, the dorsal part of the plexus is formed by interconnected veins and connects to the confluence of sinuses via the occipital sinus.

Venous outflow from the internal vertebral venous plexus occurs through intervertebral veins, which pass through the intervertebral foramina and connect to the dorsal branches of the intercostal veins. The vertebral venous plexus provides a parallel route to the superior and inferior vena cava, forming a collateral circulation together with the azygos and hemiazygos veins.