Le nerf laryngé inférieur: considérations anatomiques et chirurgicales à propos de 60 thyroïdectomies

Thyroid surgery requires a thorough knowledge of cervical anatomy and anatomical variations, in particular of the lower laryngeal nerve, in order to avoid iatrogenic lesions. The objective of our study was to analyze the relationships of the lower laryngeal nerve, the existence of branches of nerve division and a subjective appreciation of the size of the nerve. This is a prospective study of 1 year including 60 patients who underwent thyroidectomy. Sixty patients underwent surgery on the thyroid gland between February 2014 and January 2015 by the same principal operator (10 men and 50 women). The average age of our patients was 51 years. For men were performed 6 total thyroidectomies, 2 left lobo-isthmectomies and 2 right lobo-isthmectomies. For women were performed 33 total thyroidectomies, 8 left lobo-isthmectomies and 9 right lobo-isthmectomies. On the right, the nerve was superficial relative to the artery in 71.6% of cases; it was divided in 33.3% of cases and was abnormally thin in 16.6% of cases. On the left, the nerve was deep in relation to the artery in 83.3% of cases; it was divided in 15% of cases and was abnormally thin in 11.6% of cases. Knowledge of the anatomical variations of the lower laryngeal nerve is essential in thyroid surgery, the risk is particularly important on the right side given the sometimes very small caliber and the existence of branches of division more frequent than on the left side.