Spinal branch of posterior intercostal artery

The spinal branch of the posterior intercostal artery is a branch arising from the dorsal branch of a posterior intercostal artery that enters the vertebral canal through the intervertebral foramen to supply the spinal cord, meninges, and vertebral structures.

The posterior intercostal arteries (arising mainly from the thoracic aorta) run within the intercostal spaces. Each gives off a dorsal branch near the vertebral column. The dorsal branch divides into:

• A spinal branch that enters the intervertebral foramen and further divides into:

  • radicular branches (supplying spinal nerve roots)

  • meningeal branches (supplying meninges)

  • may contribute to segmental medullary arteries that reinforce the spinal cord blood supply

• Some cutaneous branches, including:

  • the medial dorsal cutaneous branch

  • the lateral dorsal cutaneous branch

Territory supplied by the spinal branch

• Spinal cord (via segmental contributions)

• Spinal nerve roots

• Meninges (especially dura mater)

• Vertebrae and ligaments within the vertebral canal