Intercostal Arteries, Posterior View

Description

Centered on the posterior thoracic wall, the descending thoracic aorta runs along the left anterolateral aspect of the vertebral bodies and gives rise to paired posterior intercostal arteries that course laterally within each intercostal space. Each vessel tracks inferior to its corresponding rib in the costal groove, traveling with the intercostal vein and nerve in the neurovascular plane between the internal intercostal and innermost intercostal muscles. Posteriorly, the arteries pass near the heads and necks of the ribs adjacent to the sympathetic trunk, with dorsal branches turning medially toward the vertebral canal and deep back musculature. Clear segmental anatomy. For teaching and clinical correlation, a posterior angle emphasizes where intercostal arteries are most clinically encountered, close to the vertebral column and rib heads, and why aortic pathology can present with posterior thoracic pain. Segmental posterior intercostal branches also contribute to the anterior spinal artery supply via radiculomedullary arteries, so thoracic aortic repair, endovascular stenting, or cross clamping carries a recognized risk of spinal cord ischemia when key feeders are compromised. The relationship of the artery to the inferior margin of the rib also reinforces safe technique for pleural procedures, since needle or tube placement along the superior border of a rib reduces the chance of lacerating the intercostal artery and precipitating a hemothorax. Ideal use includes gross anatomy lab manuals, cardiothoracic surgery and vascular surgery teaching files, and radiology or anesthesiology materials that explain posterior thoracic interventions, thoracotomy approaches, and complications of intercostal bleeding. It also fits problem based learning cases on aortic aneurysm, coarctation collateral pathways, and intercostal nerve blocks in the male thorax. Anatomical accuracy verified by SciePro's Medical Advisory Board.