Combined unusual origin and course of the right vertebral artery and right inferior thyroid artery: a case report.

Abstract

An unusual unilateral origin and course of the prevertebral part of the right vertebral artery and anomalous course of the right inferior thyroid artery was observed during dissection of the neck of a cadaver. An accidental finding in the cadaver within the anatomical dissection was assessed. The right vertebral artery originated a nonstandard from brachiocephalic trunk and travelled in the anterior cervical region, along the longus colli muscle in front of the transverse processes from C7 to C4, and it entered the transverse foramen of C3. During its course, the position of the right inferior thyroid artery varied: it turned medially and passed posterior to the vertebral vessels and later curved inferomedially to its termination. Additionally, the left vertebral artery of the same cadaver arose directly from the subclavian artery and entered the transverse foramen at C6, and the left inferior thyroid artery passed anterior to the vertebral artery. Variation in the vertebral artery and inferior thyroid artery alone have been reported, but a combined variation is rare. The anatomical information from this study will be useful during dissection, angiography, endovascular surgery, thyroidectomy and non-invasive procedures in the cervical region.