92 - Mapping the Common Carotid Artery Bifurcation: A Geospatial Analysis of Its Position Relative to Neck Landmarks Using Human Donors

Poster Board Number: 92
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Odd poster #s – first hour
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Co-authors:

Sampath Kumar - Lewis Katz School of Medicine at Temple University; Elena Milin - Lewis Katz School of Medicine at Temple University; Rebeccah Overton - Lewis Katz School of Medicine at Temple University; Eve Gibson - Lewis Katz School of Medicine at Temple University; Nicole Griffin - Lewis Katz School of Medicine at Temple University; Steven Popoff - Lewis Katz School of Medicine at Temple University

Abstract Body : Introduction: Endarterectomy is a common operation used to treat patients with carotid artery disease. Previous studies have shown that hypoglossal nerve injuries occur in patients with a high CCB. This study first mapped the precise location of the CCB in human donors with reference to several axial planes established by palpable landmarks in the neck. Secondly, it tested for a direct correlation between the location of the CCB and its proximity to the hypoglossal nerve.

Materials and Methods: Formalin-fixed male (n=21) and female (n=21) human donors were selected based on their suitability for comprehensive anterior neck dissections. Careful dissection exposed the hyoid bone, angle of the mandible, hypoglossal nerve, common carotid bifurcation, and the laryngeal prominence. These structures were then pinned on both left and right sides and used to construct axial planes. The plane in which the CCB was located was recorded and vertical measurements were taken from the CCB to the lowest part of the hypoglossal nerve and from the CCB to the angle of the mandible on both the left and right sides.

Results: Bilateral mapping of the precise location of the CCB in 42 human donors demonstrated considerable variation in location ranging from the thyroid cartilage below the laryngeal prominence to above the hyoid bone. The highest percentage of CCBs occurred at the level of the body of the hyoid bone (n=28, 34.6%). There was greater variation in location in which the CCB on the right and left sides were not in the same plane among female donors (60%) as compared to male donors (43%). There were also twice as many female donors in which the left CCB was lower than the right CCB (40%) compared to the left CCB being higher than the right CCB (20%). Quantitative measurements from the CCB to the hypoglossal nerve demonstrated a strong linear correlation (R² = .976) in which the more superior the bifurcation was located, the closer it was to the hypoglossal nerve. Measurements made from the CCB to the angle of the mandible demonstrated greater variability and less robust correlation (R² = .753) with the location of the CCB.

Conclusion: This study demonstrates that despite there being considerable variability in the precise location of the CCB, there is a strong linear correlation between the height of the CCB and the proximity to the hypoglossal nerve.

Significance/Implication: This study demonstrates that identification of the location of the CCB using easily identifiable anterior neck landmarks can help assess the risk associated with potential injury of the hypoglossal nerve during carotid endarterectomy. A simple pre-operative evaluation of patients undergoing the procedure using point of care ultrasound could help the surgeon anticipate potential complications that may be encountered during this procedure.