Variability in nerve patterns of the adductor muscle group supplied by the recurrent laryngeal nerve.
BACKGROUND
Accurate knowledge of the nerve supply of each individual muscle is needed to achieve a successful selective reinnervation of the larynx. The aim of the present work was to study the nerve supply of the adductor laryngeal muscles supplied by the recurrent laryngeal nerve.


METHODS
Morphologic study of human larynges.


METHODS
The muscular nerve supply was studied in a total sample of 75 human larynges obtained from necropsies (47 males and 28 females, age range from 41-95 years) and examined by careful dissection using a surgical microscope.


RESULTS
The arytenoid muscle received one branch from each recurrent nerve. In 88% of cases, this branch arose in a common trunk with the upper branch of the posterior cricoarytenoid muscle. In 8% of cases, the nerve for the arytenoid muscle also had a branch going to the lateral cricoarytenoid muscle. The arytenoid muscle also received from one to three pairs of branches from the posterior division of the internal laryngeal nerve; these were interconnected ipsi- and contralaterally and were also connected to the two branches coming from the recurrent laryngeal nerve. The lateral cricoarytenoid muscle received from one to six branches from the recurrent nerve, but in 5.8% of cases, it also received a twig from a connecting branch between the recurrent nerve and the external (5.6%) or the internal laryngeal nerves (0.2%). The thyroarytenoid muscle received from one to four branches from the recurrent nerve, but in 5.6% of cases, it also received a twig from a connecting branch between the recurrent nerve with the external (4.6%) or the internal (1%) laryngeal nerves.


CONCLUSIONS
No abductor or adductor division of the recurrent laryngeal nerve was found in the present study. In 88% of cases, the nerve supply to the arytenoid muscle (adductor) and the posterior cricoarytenoid muscle (abductor) arose from a common trunk, which in 8% of cases, also had a branch to the lateral cricoarytenoid muscle. Furthermore, the high incidence of branches innervating the adductor muscles from connections between the recurrent laryngeal nerve and the internal and external laryngeal nerves led us to reconsider the contribution of these nerves in the supply to this muscle group.
Maranillo
Eva
E
Department of Anatomy and Human Embryology, Faculty of Medicine, Complutense University of Madrid, Madrid 28040, Spain.
Leon
Xavier
X
Orus
Cesar
C
Quer
Miquel
M
Sanudo
Jose R
JR
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004210:Dissection; D005260:Female; D006801:Humans; D007821:Laryngeal Muscles / Q000294:innervation*; D008297:Male; D008875:Middle Aged; D012009:Recurrent Laryngeal Nerve / Q000033:anatomy & histology*