Vessel
Posterior intercostal arteries
Segmental arteries supplying the posterior chest wall
High-yield
In the main costal-groove bundle the vein is superior, artery intermediate and nerve inferior; collateral branches create additional vessels elsewhere in the space.
Overview
The first two posterior intercostal pairs usually come from the highest intercostal artery; the remaining nine arise from the thoracic aorta. Each artery travels into an intercostal space and gives dorsal and collateral branches. The major neurovascular bundle runs between the internal and innermost muscle layers.
Reference facts
- Origin
- Usually highest intercostal artery for spaces one and two, descending thoracic aorta for spaces three through eleven
- Course
- Around the chest wall toward the costal groove, between internal and innermost intercostals
- Branches
- Dorsal, spinal, collateral and cutaneous branches
- Supplies
- Chest-wall tissues and, through selected spinal branches, vertebral and spinal-cord structures
- Drains to
- Posterior intercostal veins return blood mainly through azygos-system channels, with upper-level exceptions
Clinical correlation
Chest-wall injury or procedures can damage these arteries. Segmental branches may also contribute to spinal-cord blood supply, so their importance extends beyond the intercostal muscles.
Frequently asked questions
Where do the posterior intercostal arteries originate?
Usually highest intercostal artery for spaces one and two, descending thoracic aorta for spaces three through eleven.
What do the posterior intercostal arteries supply?
The posterior intercostal arteries supply the chest-wall tissues and, through selected spinal branches, vertebral and spinal-cord structures.
Where do the posterior intercostal arteries drain to?
Posterior intercostal veins return blood mainly through azygos-system channels, with upper-level exceptions.
What are the branches of the posterior intercostal arteries?
Branches of the posterior intercostal arteries include the dorsal, spinal, collateral and cutaneous branches.