Do Asians have Higher Carotid Bifurcation? A Computed Tomographic Angiogram Study of the Common Carotid Artery Bifurcation and External Carotid Artery Branching Patterns

INTRODUCTION: Carotid endarterectomy is a major treatment modality for high-grade carotid stenosis. Preoperative identification of the level of the carotid bifurcation and its branching pattern is important in planning for adequate exposure and cross-clamping to achieve hemostasis during the procedure. Most of the previous studies on carotid arteries were performed in cadavers. METHODS: We studied levels of carotid bifurcation compared relatively with the level of the vertebral body and ipsilateral angle of the mandible and its branching pattern using computed tomographic angiogram (CTA) carotid with multiplanar reconstruction and three-dimensional imaging in 100 CTA studies. RESULTS: Most of the carotid bifurcations were located at the level of C3–C4 vertebral body and 12% were considered to be high bifurcation. Carotid bifurcations were located below the angle of the mandible in 83.5%. The superior thyroid, facial, and lingual arteries arose from separate branches of external carotid arteries in 67.7% of samples. Facial arteries arose in common trunk with lingual arteries in 29.2%, much more common than previous cadaveric studies. The lingual arteries arose with superior thyroid arteries in 2%, while occipital arteries had high variations in their branching patterns. CONCLUSIONS: CTA is an effective and reliable modality for preoperative evaluation of the carotid system in patients undergoing carotid endarterectomy and other carotid procedures. Higher percentage of high carotid bifurcation was found in our study, concordant with other Asian cadaveric studies. We assumed that carotid bifurcation of Asian tends to be located slightly higher than those of the Caucasian population.