Anatomy & Physiology: Current Research
Open Access

Abstract

Observations on the Superior Thyroid Artery and its Relationship with the External Laryngeal Nerve

Raed Eid Alzahrani, Abduelmenem Alashkham and Roger Soames

Due to the close association between the superior thyroid arteries (STA) and external laryngeal nerve (ELN) one potential complication of thyroidectomy is trauma to the ELN. The aim of the current study was to evaluate variations in the origin of the STA and its relation to the ELN in 44 hemisections from 22 Thiel embalmed cadavers (9 male, 13 female: mean age 79 years). The STA arose from the external carotid artery in 31/44 (71%) specimens, the common carotid artery in 12/44 (27%) and was absent in 1/44 (2%) specimens. The ELN crossed the STA within 10 mm superior to the superior pole of the thyroid gland in 21/44 (48%) specimens, between 10 and 15 mm superiorly in 10/44 (23%) and more than 15 mm superiorly in 7/44 (16%) in 6/44 (13%) specimens the ELN did not cross the STA. A modified classification of the relationship between the STA and ELN is proposed in which a crossing point between 10 and 15 mm superior to the superior pole of the thyroid gland in introduced.