The four pairs of lumbar arteries arise from the posterior surface of the abdominal aorta at each lumbar vertebral level and encircle the vertebral bodies to reach the posterior abdominal wall. Each gives a dorsal branch that divides into a muscular branch to the paraspinal muscles and a spinal branch entering the intervertebral foramen to supply the spinal cord, cauda equina, and vertebral canal contents.
The spinal branches of the lumbar arteries contribute to the anterior and posterior spinal artery supply of the lower thoracic and lumbar cord. In aortic aneurysm repair, deliberate or inadvertent sacrifice of lumbar arteries may reduce spinal cord perfusion, particularly when the artery of Adamkiewicz arises from a lumbar level rather than the more typical lower thoracic level. Lumbar artery bleeding after spinal surgery or vertebral body fracture is managed by selective embolisation. Posterior retroperitoneal approaches must control lumbar arteries to expose the anterior lumbar spine.
Burst fractures of lumbar vertebrae can lacerate the adjacent lumbar artery, producing a retroperitoneal haematoma that tracks into the psoas fascia and can cause haemodynamic instability requiring selective angiographic embolisation.
Anterior lumbar interbody fusion requires mobilisation of the great vessels off the anterior spine, with lumbar arteries and veins at risk during this dissection; avulsion of a lumbar vessel from the aorta causes brisk haemorrhage requiring immediate vascular repair.
