The costocervical trunk is a short arterial vessel that usually arises from the distal segment of the subclavian artery. After a short course in the anterior portion of the neck, it provides two terminal branches: deep cervical and supreme (highest) intercostal arteries.
The deep cervical branch provides supply for the last cervical and first thoracic vertebrae, posterior neck muscles and a segment of the spinal cord. The supreme intercostal supplies the muscles, parietal pleura and skin of the first two or three posterior intercostal spaces.
This article will discuss the anatomy and function of the costocervical trunk.
|Branches||Superior intercostal artery, deep cervical artery|
|Supply||Cervical and thoracic vertebrae (C7 and T1), posterior muscles of the neck, muscles, skin and the parietal pleura within the first two or three intercostal spaces|
Origin and course
The costocervical trunk is a short artery that usually stems from the upper portion of the distal segment of the subclavian artery, distal to the thyrocervical trunk. The origin of the costocervical trunk is located at the level of the lower pole of the inferior (cervicothoracic/stellate) ganglion.
It courses posteriorly, over the apex of the lung, where it divides into two terminal branches; supreme intercostal and deep cervical arteries.
Branches and supply
After a short course in the neck, the costocervical trunk terminates by dividing into two terminal branches: the supreme intercostal artery and the deep cervical artery.
- The supreme intercostal artery (also known as the superior intercostal artery) arches posteroinferiorly, between the parietal pleura and neck of the first rib. It passes lateral to the stellate ganglion and medial to the ventral rami of spinal nerve T1. Descending down the inner aspect of the thoracic cage, it provides the first two posterior intercostal arteries for the first two intercostal spaces. The artery terminates by anastomosing with the third posterior intercostal artery. Here, it provides the blood supply for the muscles, skin and parietal pleura of the corresponding intercostal spaces.
- The deep cervical artery courses in a posterosuperior direction passing over the neck of the first rib. It then runs upwards, parallel to the cervical spine and over the posterior neck muscles. It terminates at the level of the second cervical vertebra where it forms an anastomosis with the descending branch of the occipital artery. At the proximal segment, the artery provides a spinal branch that enters the cervical spinal canal between the last cervical and first thoracic vertebrae. Distally, it gives off several muscular branches that supply the posterior muscles of the neck.
Learn more about the ventral neck vessels and nerves with our articles, videos, labeled diagrams and quizzes.
- In about 40% of cases, the costocervical trunk arises more proximally, at the second segment of the subclavian artery.
- In approximately 25% of cases there is an additional accessory deep cervical artery, more often on the left side.
- The superior intercostal artery is not constant, it can be absent and replaced by a direct branch from the descending aorta. This branch can also arise from other arteries such as the thyrocervical trunk, the deep cervical, inferior thyroid, second intercostal, or axillary arteries.