Vertebral vein

Anatomy and course

The vertebral vein emerges within the suboccipital triangle, above the posterior arch of atlas (C1). It arises from the internal vertebral venous plexuses, a branch of the occipital vein and the veins that drain the suboccipital and prevertebral muscles. These veins anastomose with each other and form a venous plexus, which enters the transverse foramen of atlas and surrounds the vertebral artery. This plexus is sort of a predecessor of the vertebral vein and it traverses the transverse foramina of cervical vertebrae C1-C6. At the level of the C6 transverse foramen, the plexus unites into a single vessel - the vertebral vein.

The vertebral vein then courses inferiorly crossing the lateral sides of the cervical vertebrae, initially lying over the anterior aspect of the vertebral artery and then crossing over its anterolateral side. It passes over the anterior aspect of the first part of the subclavian artery, being posterior to the internal jugular vein. 

The vertebral vein terminates by emptying into the brachiocephalic vein via the orifice that usually features a two-leaved valve.

Tributaries

Along its course, the vertebral vein receives the following tributaries;

• Within the suboccipital triangle, it receives the communicating branches from the suboccipital venous plexus
• Communicating branches from the external venous plexuses at each intervertebral level from C1 to C6
• Anterior vertebral vein, which joins the vertebral vein just prior to its termination in the brachiocephalic vein
• Deep cervical vein, which empties into the vertebral vein once it passes onto the anterolateral surface of the vertebral artery

The vertebral vein often gives off a continuation at the level of the transverse foramen of C6; the accessory vertebral vein. This vessel passes through the transverse foramen of C7, takes a sharp anterior course and empties into the brachiocephalic vein.