Spinal branch of subcostal artery

Spinal branch of the subcostal artery is a small arterial branch that arises from the subcostal artery (the artery running beneath the 12th rib) and enters the vertebral canal through the intervertebral foramen to supply the spinal cord, its meninges, and the vertebral bodies at the corresponding level.

The subcostal artery is the last paired branch arising from the thoracic aorta, coursing along the inferior border of the 12th rib. Like the posterior intercostal arteries above it, the subcostal artery gives off a dorsal branch, which in turn divides into a medial (spinal) branch and a lateral branch.

The spinal branch follows a consistent pattern seen throughout the segmental arteries of the thorax and abdomen:

• It enters the intervertebral foramen at the level of T12L1.

• Once inside the vertebral canal, it divides into smaller branches that supply:

  • The vertebral body and periosteum

  • The spinal meninges (dura mater and arachnoid)

  • The spinal cord itself, via radicular or radiculomedullary arteries

• In some individuals, the spinal branch at this level may contribute a radiculomedullary artery (such as the artery of Adamkiewicz), which is a major feeder of the anterior spinal artery and is of critical surgical importance.

Clinical Significance

This vessel is particularly relevant in:

• Aortic surgery and interventional procedures, where inadvertent compromise of segmental spinal branches (including the subcostal level) can lead to spinal cord ischemia and paraplegia.

• Vertebral body fractures or tumors at the thoracolumbar junction, where embolization or surgical ligation may be required.

• Spinal angiography, where identification of the spinal branch is essential for mapping the blood supply to the spinal cord before surgical or endovascular interventions.