Right superior intercostal vein

At a glance

English

Right superior intercostal vein

Latin (TA2)

Vena intercostalis superior dextra

System

Vein

Region

Trunk

Side

Single, on the midline

About the right superior intercostal vein

On the right side the posterior intercostal veins of the second and third spaces, and frequently the fourth, join to form a single right superior intercostal vein. It lies on the necks of the upper ribs and the sides of the upper thoracic vertebrae, behind the parietal pleura.

The vein runs downwards to meet the azygos vein where that vessel begins to arch forwards over the root of the right lung, and it ends in the azygos at or just below the arch. Through the azygos its blood reaches the superior vena cava.

The first right posterior intercostal vein does not usually join it. That highest vein, draining the first space, passes up over the neck of the first rib to end in the right brachiocephalic vein or the vertebral vein. The lower right posterior intercostal veins, from the fifth space downwards, open separately into the azygos as it ascends.

The arrangement differs from the left side, where the corresponding vein has to cross the aortic arch to reach the left brachiocephalic vein. On the right the short course to the azygos is simple. The vein and the azygos arch lie near the oesophagus and trachea, so they come into view in thoracoscopic operations on the upper oesophagus and on the sympathetic trunk, which runs over the rib heads close to the vein. Enlargement may occur when the superior vena cava is obstructed below the azygos and collateral flow passes through the intercostal veins.

Course and drainage

Begins at

Formed by the right posterior intercostal veins of the second, third and often fourth spaces.

Drains into

Ends in the azygos vein at or near its arch over the root of the right lung.

Drains

Drains the upper right intercostal spaces into the azygos system.