Mapping the Common Carotid Artery Bifurcation Utilizing Anterior Neck Landmarks

Background/Objectives: High common carotid artery bifurcation (CCAB) is an anatomic variant relevant to carotid endarterectomy that is associated with an increased risk of cranial nerve injury, particularly hypoglossal nerve injury. This study analyzed CCAB location relative to anterior neck landmarks as a method for categorizing its proximity to critical surgical structures. Methods: Eighty-one formalin-fixed donors were dissected, yielding 159 CCABs. CCAB height was classified relative to six transverse anterior neck planes using superficial anatomic landmarks. Distances from the CCAB to the hypoglossal nerve and angle of the mandible were measured. Superior thyroid (ST) artery origin was also recorded. Results: A majority of CCABs occurred near the hyoid bone, but locations varied between and within donors. CCAB height did not differ significantly by sex or by which side of the neck they were from. Higher CCABs were closer to the hypoglossal nerve and angle of the mandible. When using anterior neck landmarks, there was a strong linear relationship between the height of the CCAB and both the hypoglossal nerve and the angle of the mandible. The hypoglossal nerve looped inferior to the CCAB in 11 cases. ST artery origin varied, with higher CCABs originating from the common carotid artery more often. Conclusions: By using anterior neck landmarks to classify CCAB height, clinicians may establish a more precise definition of high CCAB that incorporates reliable estimates of hypoglossal nerve proximity. This approach may improve preoperative risk assessment, guide surgical selection, and reduce complications.