Relation of the External Laryngeal Nerve to Superior Thyroid Artery in an African Population

The external laryngeal nerve runs parallel to superior thyroid artery and later crossing the artery either above or below the upper pole of the thyroid gland. This relatively high anatomic variability demonstrates interpopulation differences. However, datum among the Kenyan population is lacking. Knowledge of normal and variant anatomy of these structures is important in surgical procedures within the neck. This study therefore aimed at describing the variant anatomical relations of the superior thyroid artery and external laryngeal nerve for the Kenyan population. Twenty formalin fixed cadavers obtained from the Department of Human Anatomy, University of Nairobi were dissected to expose the thyroid gland, superior thyroid artery and external laryngeal nerve. The relation of the superior thyroid artery to the external laryngeal nerve was noted. The external laryngeal nerve crossed the superior thyroid artery within 1cm above the upper pole of the thyroid gland in 25% of cases and more than 1 cm in 75% of cases. The level at which the external laryngeal nerve crosses the superior thyroid artery displays variations among Kenyans warranting care during surgical procedures of the thyroid gland.