Left brachiocephalic vein

At a glance

English

Left brachiocephalic vein

Latin (TA2)

Vena brachiocephalica sinistra

System

Vein

Region

Trunk

Side

Single, on the midline

About the left brachiocephalic vein

The left brachiocephalic vein, also called the left innominate vein, carries blood from the left side of the head, neck and upper limb, together with parts of the upper chest wall, to the superior vena cava. It forms behind the left sternoclavicular joint, where the left internal jugular vein and the left subclavian vein unite. It is roughly twice as long as the right vein, about six centimetres, because it must cross the midline to reach the right side.

From its origin it runs obliquely downwards and to the right across the upper part of the superior mediastinum. It passes behind the manubrium of the sternum, with the remnant of the thymus and loose fat in front of it, and in front of the three great branches of the aortic arch: the left subclavian artery, the left common carotid artery and the brachiocephalic trunk. The trachea and the left vagus and phrenic nerves also lie behind it. Behind the lower border of the right first costal cartilage, close to the right edge of the sternum, it meets the right brachiocephalic vein, and the superior vena cava begins.

Besides its two roots it receives the left vertebral vein, the left internal thoracic vein on its lower border, the left inferior thyroid veins on its upper border and the left superior intercostal vein, which drains the upper left intercostal spaces. The thoracic duct usually opens near its origin, at the angle between the internal jugular and subclavian veins. In development the vein arises as a cross-link joining the two anterior cardinal veins, after part of the left cardinal vein regresses.

Its position just behind the manubrium matters clinically. In young children the vein may rise above the jugular notch and is at risk during tracheostomy. A persistent left superior vena cava may exist alongside a small or absent left brachiocephalic vein. The vein is also a common route for central lines and pacing leads inserted from the left side.

Course and drainage

Begins at

Formed behind the left sternoclavicular joint by the union of the left internal jugular and left subclavian veins.

Drains into

Crosses obliquely behind the manubrium to join the right brachiocephalic vein behind the right first costal cartilage, forming the superior vena cava.

Drains

Drains the left side of the head and neck, the left upper limb and the upper left chest wall, receiving the left vertebral, internal thoracic, inferior thyroid and superior intercostal veins.