(A545) Examination of Anatomical Variations of the Recurrent Laryngeal Nerve Relative to the Inferior Thyroid Artery

Introduction: This study examines the anatomical variations of the recurrent laryngeal nerve (RLN) relative to the inferior thyroid artery (ITA) within cadavers.

Methods: Cadavers from the anatomy lab of Texas Tech El Paso from November 2024 - January 2025 were used to dissect the RLN and surrounding structures (thyroid gland and ITA). In total, 13 cadavers and 25 nerves were examined and no interventions were implemented. Results were documented marking the anatomic variation, laterality, gender, and bilateral combination. Results were analyzed using Fisher’s Exact tests; p-values < 0.05 indicated statistical significance.

Results: Twenty-five RLNs were studied on 13 cadavers; 1 nerve was severed and unable to be classified. Overall, 18 nerves traveled posterior, 7 traveled anterior, and 0 traveled between the ITA branches. On the right side, 7 traveled posterior, 5 traveled anterior, and 0 traveled between the ITA branches. Contralaterally, 11 traveled posterior, 2 traveled anterior, and 0 were noted to travel between the ITA branches. No significant difference in anatomical variation was found between right and left RLNs (p = 0.202).
Based on gender, right and left RLNs were not significantly different, suggesting gender does not affect anatomical variation (p = 0.293 and 1.0). When comparing the anatomical position of the RLN on both sides of the neck, 61.5% of cadavers had both RLNs posterior or anterior to the ITA branches. The most common RLN combination observed was posterior-posterior (53.8%). However, no significant difference was found among RLN combinations, suggesting no prevalent combination (p = 0.417).

Conclusions: This study highlights the anatomical variability of the RLN relative to the ITA, providing valuable insights to reduce the risk of nerve injury during surgical procedures and dissections.