Syntopy of vagus nerve in the carotid sheath: A dissectional study of 50 cadavers

BACKGROUND: Vagus nerve anatomical position inside the carotid sheath is not clear in the literature. Nevertheless, monitoring laryngeal nerves during thyroid surgeries may damage big vessels in the carotid sheath (jugular vein; carotid artery). This gap led to an unprecedent cross sectional study of vagus syntopy using the carotid artery as anatomical mark. METHODS: Fifty cadavers less than 24 hours postmortem were studied. The vagus nerve was spotted, reproducing the patterns performed in thyroidectomies. RESULTS: On the right side, vagus nerve was posterior to the common carotid artery in 64% of the cases. On the left side, it was anterior, in 68% of the dissections. Comparing both sides, there was no symmetry in this syntopy. No influence of ethnic or anthropometric characteristics was observed. CONCLUSION: The vagus nerve is more frequently posterior to the common carotid artery on the right side and, anterior, on the left side. LEVEL OF EVIDENCE: 4