Dorsal Branches of the Posterior Intercostal Arteries, Posterior View

Description

Running segmentally from the thoracic aorta, the posterior intercostal arteries send dorsal branches medially and posteriorly toward the vertebral column, then into the deep musculature flanking the spinous processes. A posterior view like this places the dorsal branches deep to the trapezius and latissimus dorsi, coursing over the rib angles and between slips of the erector spinae (iliocostalis, longissimus, spinalis) as they distribute along each intercostal space. Scapular-region landmarks such as the infraspinatus, teres minor, and teres major sit laterally, while the vertebral midline remains the reference axis for the arteries’ repeated, paired pattern. Segmentation is the story. Clinically, these dorsal branches matter because they feed the posterior thoracic wall and contribute to perfusion around the vertebral canal via spinal branches, a point that comes up in thoracic spine surgery and in discussions of spinal cord blood supply. Their course also explains why posterior approaches, including thoracotomy extensions, costotransversectomy, or deep paraspinal dissection, can encounter brisk bleeding near the rib head and transverse process junction if the intercostal neurovascular bundle is not respected. Surgeons and trainees often focus on the intercostal arteries in the intercostal space, but the dorsal branch is the vessel you meet as you work back toward the spine. Small caliber, high consequence. Suitable for gross anatomy teaching of the posterior thoracic wall, surgical anatomy modules on posterior spinal exposure, and publisher figures illustrating the relationship of paraspinal muscle layers to the posterior intercostal vessels in an adult male. It also supports clinical education on sources of paraspinal hematoma and operative bleeding control along the costovertebral region. Anatomical accuracy verified by SciePro's Medical Advisory Board.