[Anatomy of the external laryngeal nerve: surgical implications. Report of 30 dissections].
OBJECTIVE
This anatomic study aimed to detail the anatomy of the external laryngeal nerve and to determine the possible variations of nerves at risk.


METHODS
Fifteen cadavers (30 nerves) were dissected. The peri pharyngo laryngeal route, the anatomic rapports, the branches of division and the distal penetration point of the external laryngeal nerve were noted.


RESULTS
The external laryngeal nerve gave branches to the inferior pharyngeal constrictor muscle in 90% of cases and to the thyroid gland in 70% of cases. There was an adherence between the nerve and the trunk of the superior thyroid artery in 13.33% of cases. The nerve had a distal superficial route even on the cricothyroid muscle in 6.67% of cases. In one case the nerve was situated close to the medial face of the superior thyroid lobe.


CONCLUSIONS
The external laryngeal nerve has numerous anatomic variations. The anatomic variations at risk during thyroid surgery are: an adherence between the nerve and the thyroid artery (or a course of the nerve between the branches of the superior thyroid artery); a superficial distal route; a distal situation close to the medial face of the thyroid lobe. In this study, 7 nerves were considered at risk (23.33% of cases).
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Laboratoire d'Anatomie et d'Organogenèse à la Faculté de Médecine et Service d'ORL et de Chirurgie Cervico-Faciale, C.H.U. Amiens, Hôpital Nord, Place Victor Pauchet, 80054 Amiens Cedex 1. Cyril.Page@caramail.com
Laude
M
M
Peltier
J
J
Charlet
L
L
Ayache
S
S
Strunski
V
V
D006801:Humans; D007823:Laryngeal Nerves / Q000033:anatomy & histology* / Q000502:physiology / Q000601:surgery*