superior intercostal vein
n.
A tributary of the azygos vein, formed by union of the right second, third, and fourth posterior intercostal veins; right superior intercostal vein.
A vein that is formed by the union of the left second, third and fourth intercostal veins, passes across the arch of the aorta, empties into the left brachiocephalic vein, and frequently communicates with the accessory hemiazygos vein; left superior intercostal vein.