Relationship between the Branches of the Recurrent Laryngeal Nerve and the Inferior Thyroid Artery

Abstract

Objectives: The relationship between the recurrent laryngeal nerve (RLN) and the inferior thyroid artery (ITA) is an important and helpful landmark for isolating the RLN and its branches during surgery. In the present study, we aimed to define and classify in detail all of the possible relationships between the two anatomic structures and their branches. Methods: We examined 100 specimens (200 sides) from cadavers of 76 men and 24 women who were between 16 and 90 years of age at the time of death. After anatomic dissection was performed, the relationship between the RLN and the ITA was noted for each side and documented in the form of high-resolution photographs. Results: The relationships of both structures and their branches were classified into 6 types. Details were verified regarding the relationships between the main trunks, between the trunks and branches, and between the branches, as follows: Type A (ITA trunk to RLN trunk); type B (ITA branches to RLN trunk); type C (ITA trunk to RLN branches); type D (ITA branches to RLN trunk and RLN branches); type E (ITA branches to RLN branches); and type F (others). Conclusions: Despite the various anatomic and surgical studies already performed, in the present study we tried to demonstrate all types of relationships between the RLN and the ITA and their branches and devise a new, detailed classification of the possible relationships between the two structures.