Internal vertebral venous plexuses

Anatomical structure of the vertebral venous system

Internal vertebral venous plexuses

Diagram of the vertebral venous system
Latin	Plexus venosus vertebralis internus
System	Circulatory system

The internal vertebral venous plexuses are a network of veins located within the vertebral column. They are part of the vertebral venous system, which plays a crucial role in the drainage of blood from the spinal cord and surrounding structures.

Anatomy

The internal vertebral venous plexuses are situated within the vertebral canal, lying in the epidural space between the dura mater and the vertebrae. They are divided into anterior and posterior components:

• Anterior internal vertebral venous plexus: Located anterior to the spinal cord, this plexus runs along the posterior surfaces of the vertebral bodies.
• Posterior internal vertebral venous plexus: Situated posterior to the spinal cord, this plexus is found along the anterior surfaces of the vertebral arches.

These plexuses are valveless, allowing for bidirectional blood flow, which is important for maintaining venous drainage under varying physiological conditions.

Function

The internal vertebral venous plexuses serve several important functions:

• Venous drainage: They collect blood from the spinal cord, meninges, and vertebrae, and communicate with the external vertebral venous plexuses and the basivertebral veins.
• Thermoregulation: The plexuses help in regulating the temperature of the spinal cord by facilitating heat exchange.
• Pressure regulation: They act as a cushion to absorb pressure changes within the vertebral canal, protecting the spinal cord from mechanical stress.

Clinical significance

The internal vertebral venous plexuses are clinically significant for several reasons:

• Pathway for metastasis: Due to their valveless nature, these plexuses can serve as a route for the spread of cancer cells, particularly from the pelvis and abdomen to the spine and brain.
• Epidural anesthesia: Understanding the anatomy of these plexuses is crucial for the safe administration of epidural anesthesia, as inadvertent puncture can lead to complications such as hematoma.
• Spinal cord compression: Conditions such as vertebral hemangiomas or epidural abscesses can compress these plexuses, leading to venous congestion and potential spinal cord compression.

Also see

• Vertebral venous system
• Spinal cord
• Epidural space
• Basivertebral veins