Left vertebral artery origin from the thyrocervical trunk: a unique vascular variant

Abstract

The vertebral artery normally arises from the subclavian artery, and variations in its origin have been described. We describe a unique case of the left vertebral artery arising from the thyrocervical trunk.

Fig 1.

A, Oblique, volume-rendered CT angiogram projection. Note the left vertebral artery arising directly from the thyrocervical trunk and extending cephalad outside of the transverse foramina of the vertebral bodies (arrows). The suprascapular artery is noted arising directly from this vessel in the lower neck (arrowhead). B, Posterior, volume-rendered CT angiogram projection. There has been a decompressive occipital craniectomy, and resection of the posterior arch of C1. The left vertebral artery is well seen continuing intracranially (arrows).

Fig 2.

A, Axial image of the cervical spine at C4 in bone algorithm. Note the absence of the foramen transversarium on the left (arrow). B, Axial image of the cervical spine at C4 in soft tissue algorithm showing the course of the left vertebral artery (arrow).