Mapping the Common Carotid Artery Bifurcation Utilizing Anterior Neck Landmarks

Area of Science:

• Anatomy
• Surgical Anatomy
• Vascular Anatomy

Background:

• High common carotid artery bifurcation (CCAB) is an anatomical variant associated with increased cranial nerve injury risk during carotid endarterectomy.
• Specifically, hypoglossal nerve injury is a significant concern in cases of high CCAB.
• This study aimed to categorize CCAB location using anterior neck landmarks to assess proximity to critical surgical structures.

Purpose of the Study:

• To analyze the location of the common carotid artery bifurcation (CCAB) relative to superficial anterior neck landmarks.
• To establish a method for categorizing CCAB height and its proximity to the hypoglossal nerve and mandible.
• To improve preoperative risk assessment for carotid endarterectomy by defining high CCAB more precisely.

Main Methods:

• Dissection of 159 common carotid artery bifurcations (CCABs) from 81 formalin-fixed donors.
• Classification of CCAB height using six transverse anterior neck planes and superficial landmarks.
• Measurement of distances from CCAB to the hypoglossal nerve and mandibular angle, and recording of superior thyroid artery origin.

Main Results:

• CCAB height varied significantly between and within donors, with most located near the hyoid bone.
• Higher CCABs demonstrated a strong linear relationship with increased proximity to the hypoglossal nerve and mandibular angle.
• The hypoglossal nerve looped inferior to the CCAB in 11 instances, and superior thyroid artery origin varied with CCAB height.

Conclusions:

• Classifying common carotid artery bifurcation (CCAB) height using anterior neck landmarks provides a precise definition of high CCAB.
• This classification allows for reliable estimation of hypoglossal nerve proximity.
• The proposed method can enhance preoperative risk assessment, guide surgical decisions, and potentially reduce surgical complications.