Three anatomical variations in the arterial system of the neck of a female donor body: a case study

Abstract

The common carotid artery (CCA) bifurcates into the external carotid artery (ECA) and internal carotid artery (ICA) at the level of the intervertebral disc between third and fourth cervical vertebra. After the bifurcation, the ICA normally lies posterolateral to the ECA. While ICA does not give off any branches in the neck, superior thyroid (STA), lingual (LA), facial artery, ascending pharyngeal, and occipital arteries arise from the ECA within the carotid triangle of the neck. During a routine dissection to demonstrate the neurovasculature of the neck, three anatomical variations in the arterial system were noted on the left side of a female donor body (Race: Caucasian, Age: 51 years). First, the CCA bifurcated into ECA and ICA below the level of the cricoid cartilage, approximately between the sixth and seventh cervical vertebra, at a distance of 5.7 cm from the arch of the aorta. Second, after the bifurcation, the ICA laid posteromedial to the ECA. Finally, despite the low bifurcation of CCA, STA and LA arose from a common thyrolingual trunk off the ECA (7.7 cm from the carotid bifurcation), between the second and third cervical vertebra. As a result, STA was 6 cm in length from its origin to its termination on the superior aspect of the thyroid gland. While each of these anatomical variations have been reported in the literature, to our knowledge, this is the first description of a ‘triple’ variation in the arterial network of the neck. Clinically, the knowledge of these anatomical variations may be important during surgical procedures involving the neck and its arterial network.