P 32 Anatomical evaluation of the common carotid artery bifurcation and the branching pattern: A preliminary study.

Abstract

Bifurcation of the common carotid artery (CCA) and the branching pattern of the carotid arteries in the neck show great anatomical variations. Better knowledge of these variations is clinically important for surgical procedures and radiological investigations. Variant Anatomy of carotid arteries has been reported but there is no data in Sri Lankan population. This study aimed to evaluate the variations in the level of bifurcation of the CCA; the origin of the external carotid artery (ECA) in relation to the internal carotid artery (ICA) and the variations in the origin of the superior thyroid artery (STA). Twenty eight common carotid arteries of 14 cadavers were used for the study. CCA bifurcation was classified into three groups, with reference to the level of the upper border of the thyroid cartilage (TC). They were standard bifurcation, high bifurcation and low bifurcation. Standard bifurcation was observed in 5 (17.9%), high bifurcation in 19 (67.9%) and low bifurcation in 4 (14.3%). The origin of ECA was anterior to the ICA in 16 (57.1 %), and anteromedial in 6 (21.4 %). While 19 (67.9%) of STA originated from ECA at the level of carotid bifurcation or just above the carotid bifurcation 7 (25%) of STA arose from CCA. In one cadaver there was no STA in both sides. In conclusion, the level of bifurcation CCA varied from above the level of hyoid bone to the lower border of the TC. Bifurcation above the upper border of the TC was the most frequent bifurcation level of the CCA. The ECA most commonly originated anterior to the ICA. The knowledge of these anatomical variations is useful in surgical and clinical investigation procedures. Therefore further studies to evaluate anatomical variations of carotid arteries is paramount important.