Quick Facts
Origin: Fifth intercostal space.
Course: Posteriorly within the intercostal space.
Tributaries: Dorsal branch and intervertebral veins.
Drainage: Intercostal space, back, and skin.
Related parts of the anatomy
Origin
The posterior intercostal veins form within their corresponding intercostal space and are accompanied by the posterior intercostal artery and the anterior rami of the thoracic nerves. The vein is usually found superiorly in this arrangement.
Course
The fourth to eleventh posterior intercostal veins course through their corresponding intercostal spaces. They drain the blood posteriorly, ending at the azygos vein on the right and the hemiazygos or accessory hemiazygos on the left. However, the azygos veins are subject to variation, and therefore, the drainage pattern of the posterior intercostal veins may vary.
Tributaries
The posterior intercostal veins follow branches of the posterior intercostal arteries, thus draining the same territory the artery supplies. They receive dorsal tributaries accompanying the dorsal branches of the posterior intercostal arteries and the intervertebral veins which accompany the spinal nerves. The posterior intercostal veins also form an anastomosis with the anterior intercostal veins.
Structures Drained
The posterior intercostal veins drain the muscles of the intercostal space, muscle of the back, vertebral column, and overlying skin.
