Relation of external branch of superior laryngeal nerve to superior thyroid artery and Cernea classification

Vinaya Chandra P H

Volume : VI, Issue : IV, April - 2017

Relation of external branch of superior laryngeal nerve to superior thyroid artery and Cernea classification

Vinaya Chandra P H

Abstract :

Background and Objectives: External anch of superior laryngeal nerve (EBSLN) is at risk of injury while ligating superior thyroid vessels during thyroid surgeries. The relation between nerve and artery varies. The aim of the study was to study the relation of EBSLN and superior thyroid artery (STA). The anches of EBSLN and STA were also studied.

Methodology: In a descriptive cadaveric study, 28 head and neck specimens of 14 cadavers were studied (12 males and 2 females).

Results: Type 1 Cernea variant is seen in sixteen specimens (57.4%). The mean distance between the crossing point of EBSLN and STA from the upper pole in type 1 specimens was 1.52 (� 0.31) cm. Type 2a variations was found in seven specimens (25%) with mean distance being 0.37 (�0.3) cm. Type 2b variation was found in two specimens. In four specimens, had EBSLN running almost parallel to STA was found. Only in twelve preparations, EBSLN was single trunk as far as cricothyroid muscle. In twenty one specimens, STA was arising from external carotid artery. In seven specimens, origin was very close to bifurcation of common carotid artery. In all 28 specimens, superior laryngeal artery was identified. Infrahyoid artery was noted in 18 specimens.

Conclusion: For routine identification of EBSLN during thyroid surgeries, the normal anatomical variation has to be considered. Cernea type 1 is the commonest scheme of relation between EBSLN and STA. In cases of non–localization of EBSLN, possibility of type 2b variation considered.