Costocervical trunk

Definition
The costocervical trunk is a short arterial branch that arises from the subclavian artery (or, less commonly, directly from the aortic arch) and supplies the deep structures of the neck and the upper thoracic wall.

Overview

• Origin: On the right side, the trunk typically originates from the posterior surface of the right subclavian artery shortly after the artery passes the anterior scalene muscle. On the left, it usually arises from the first part of the left subclavian artery.
• Course: After its origin, the trunk descends posteriorly, passing behind the scalenus medius muscle and in front of the first rib.
• Branches: It divides into two principal branches:
  1. Deep cervical artery – ascends to supply the deep neck musculature and the vertebral column.
  2. Supreme (or highest) intercostal artery – descends to give rise to the first (and occasionally the second) posterior intercostal arteries.
• Variations: Anatomical variations are reported in up to 10 % of specimens, including differences in the level of origin, the presence of a common trunk with the vertebral artery, or the absence of one of its branches.

Etymology / Origin
The term combines the Latin roots costo‑ (relating to the ribs) and cervical (pertaining to the neck), reflecting the artery’s dual supply to rib‑related (intercostal) and neck structures.

Characteristics

• Size: Generally a short, robust vessel, roughly 1–2 cm in length before bifurcation.
• Relations: Lies posterior to the brachial plexus roots and anterior to the first rib; in close proximity to the sympathetic trunk and the thoracic duct on the left.
• Clinical significance: Injury or iatrogenic damage during cervical or thoracic surgical procedures can lead to hemorrhage or ischemia of the supplied regions. Its location is also relevant in the evaluation of thoracic outlet syndrome and in the interpretation of imaging studies of the neck and upper thorax.
• Embryology: Develops from the seventh cervical intersegmental artery and the dorsal aorta during the fourth to fifth week of gestation; its formation reflects the complex remodeling of the aortic arches.

Related Topics

• Subclavian artery
• Vertebral artery
• Deep cervical artery
• Supreme (highest) intercostal artery
• Posterior intercostal arteries
• Thoracic outlet syndrome
• Cervical sympathetic trunk
• Aortic arch and its branches

This entry follows the structure: Definition → Overview → Etymology/Origin → Characteristics → Related Topics.