Spinal cord blood supply

The spinal cord blood supply is formed by many different vessels with an extensive collateral supply and drainage.

Arterial supply

The spinal cord is supplied by three longitudinal arteries:

• single anterior spinal artery: supplies the anterior two-thirds of the spinal cord
• paired posterior spinal arteries: supply the posterior one-third of the spinal cord
• anastomoses between the spinal arteries, called arterial vasocorona, supply the peripheral lateral aspect of the spinal cord (lateral columns)
  • cruciate anastomosis of the conus medullaris connects these arteries at the distal cord⁴.

These have their origin at or near the cervico-occipital junction and are small calibre, often appearing discontinuous. Thus they require reinforcement by numerous segmental (radicular) arteries, which from superior to inferior are branches of the:

• ascending cervical arteries
• deep cervical arteries
• posterior intercostal arteries
• lumbar arteries
• lateral sacral arteries

These arteries pass through the intervertebral foramina and divide into anterior and posterior radicular arteries and have variable anastomoses with the spinal arteries.

The dominant segmental artery is called the artery of Adamkiewicz, which can have a variable origin and side. Damage to this vessel can cause paralysis from spinal cord infarction. 

In the event of arterial supply being interrupted from the aorta (e.g. surgery, trauma) collateral arterial flow can come from the internal thoracic and lateral thoracic arteries, which anastomose with the posterior intercostal arteries. 

Venous drainage

Venous drainage largely follows arterial supply. That is, there are anterior and posterior spinal veins and anterior and posterior radicular veins, which freely communicate with the internal vertebral plexus in the epidural space. This is in turn drains to the cerebral dural venous sinuses and cerebral veins as well as the external vertebral plexus. The veins of the spinal cord and vertebral column are valveless.

Related pathology

• acute spinal cord ischaemia syndrome