Spinal angiography Anatomy Blood Supply of Spinal Cord

Spinal angiography

Anatomy

Blood Supply of Spinal Cord

The spinal cord is supplied by 1. Anterior spinal artery 2. Posterior spinal artery 3. Spinal branch from the 1 st intercostal artery 4. Spinal branch from the 11 th intercostal artery • Branches of the vertebral, deep cervical, intercostal, and lumbar arteries contribute to three arteries that run the length of the spinal cord; the anterior spinal and the two posterior spinal arteries. Anterior spinal artery • • The anterior spinal artery is the larger It is a midline artery – lies on the anterior median fissure It is formed at the foramen magnum by union of two arteries one from each vertebral artery Supplies the spinal cord anterior part namely the lateral columns and the anterior grey and white columns The posterior spinal arteries • • One or two on each side – derived from the vertebral artery (or from inferior cerebellar artery) at the level of foramen magnum Both the anterior and the posterior spinal arteries descend from the level of the foramen magnum

21 pairs of segmental radicular arteries supply the nerve roots and about half of them contribute to the spinal arteries.

The arteries of Adamkiewicz Spinal branches (segmental radicular arteries) from the 1 st and 11 th intercostal arteries are large (T 1 & T 11) They pass along the nerve roots to the spinal cord and reinforce the anterior and posterior spinal arteries supplies the lower thoracic and upper lumbar parts of the cord. Spinal artery at T 1 (Adamkiewicz) supplies the cord only downwards Spinal artery at T 11 (Adamkiewicz) supplies the cord both above and below (radicularis magna)

Abnormal situation e. g. high take off – the iliac artery branch supplies the lower thoracolumbar region of the cord entering through intervertebral foramen of L 4 -5

Spinal Veins Spinal veins form plexuses anteriorly and posteriorly On each side the spinal veins are double, straddling the posterior nerve roots All of them drain into vertebral veins in the neck, azygos veins in the thorax, lumbar veins in the lumbar region, lateral sacral veins in the sacral region through intervertebral foramina

Horizontal distribution

Generally the proportion of flow is greatest from the raducularis magna “feeder” artery to the thracolumbar region. In abnormal situations ( e. g. high take-off) the iliac artery branch may supply the lower thoracolumbar region of the cord entering by way of the intervertebral foramen in the vicinity of L 4 -5