Simultaneous Occurrence of Three Anatomical Variations: Anomalous Right Subclavian Artery, Non-Recurrent Inferior Laryngeal Nerve and Right Thoracic Duct

DOI : http://dx.doi.org/10.4067/S0717-95022013000400006
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Elizabeth Peña; Janneth Zúñiga & Gloria Baena

Summary

In one male cadaver of Colombian nationality, dissected by a group of medical students during a gross anatomy course at the Universidad del Valle in Cali, Colombia, three anatomical variations were found: an anomalous or aberrant right subclavian artery (ARSA), a non-recurrent inferior laryngeal nerve and a right thoracic duct. The aortic arch gave origin to four instead of three arteries, which, from right to left, were the right common carotid, the left common carotid, the left subclavian and the right subclavian arteries. The anatomical variation of the right subclavian artery is known also as lusoria artery, in which case the artery passes behind the esophagus and the trachea in its course towards the right side of the neck. The perimeters of the aortic arch and of the lusoria artery were measured in different sites; those of the lusoria artery gradually reduced during the course of the artery towards the right side of the neck. The non-recurrent inferior laryngeal nerve originated at a right angle from the right vagus nerve, at the level of the thyroid gland. The nerve described a horizontal course in its way towards the larynx, passing behind the right lobe of the gland, in close relation with the branches of the inferior thyroid artery. Of the three possible variations in the course of the non-recurrent inferior laryngeal nerve, the one found corresponds to the horizontal course or type II. The course of the thoracic duct in the thorax was normal, situated behind the esophagus, between the azygos vein and the thoracic aorta, but it gradually deviated towards the right side of the neck to end in the internal jugular vein. Out of the extensive databases that were consulted, only one report was found of these three simultaneous variations.

KEY WORDS: Aberrant right subclavian artery; Recurrent laryngeal nerve; Thoracic duct; Genetic variation.

How to cite this article

PEÑA, E.; ZÚÑIGA, J. & BAENA, G. Simultaneous occurrence of three anatomical variations: anomalous right subclavian artery, non- recurrent inferior laryngeal nerve and right thoracic duct. Int. J. Morphol., 31(4):1181-1184, 2013.