Eva Maranillo

An anatomical study of anastomoses between the laryngeal nerves

Objective: To systematize the anatomy of the connecting branches between laryngeal nerves. Methods: Microdissection of 90 larynges obtained from necropsies (57 men and 33 women; age range, 41–95 y). Results: Anastomoses between the internal and recurrent nerves appeared in four different patterns: 1) Galens anastomosis, as the connection between the dorsal branches of both nerves (100%); 2) arytenoid plexus, as the connection between the arytenoid branches of both nerves, in relation with the arytenoid muscle, and divided in a deep part (100%) and a superficial part (86%); 3) cricoid anastomosis, previously only described in cows, located in the front of the cricoid lamina (6/10 cases); and 4) thyroarytenoid anastomosis, as the connection of a descending branch of the internal laryngeal nerve and an ascending branch of the recurrent nerve (14%). Anastomosis between the internal laryngeal and the external laryngeal nerves appeared as a connecting branch throughout the foramen thyroideum (21%). Anastomosis between the external laryngeal and recurrent nerves appeared as a connecting branch throughout the cricothyroid muscle (68%). Conclusion: At least two anastomoses (Galens anastomosis and arytenoid plexus) appeared in 21% of hemilarynges, and 79% of cases had three or more anastomoses between the laryngeal nerves. The different prevalence of this complex anastomotic pattern suggests functional differences in the sensory and motor innervation of individual subjects. Key Words: Larynx, innervation, anastomosis, nerves.

Variability in Nerve Patterns of the Adductor Muscle Group Supplied by the Recurrent Laryngeal Nerve

Introduction: 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.

Is the external laryngeal nerve an exclusively motor nerve? The cricothyroid connection branch

Objectives To obtain an accurate morphological description of the nerve that provides communication between the external laryngeal nerve and the recurrent laryngeal nerve in a large sample of human larynges.

Anatomical variations of the superior thyroid and superior laryngeal arteries.

There are known to be variations in the origins of the superior thyroid artery (STA), an important surgical landmark, and 1 of its branches, the superior laryngeal artery (SLA).

Variability of the Nerve Supply Patterns of the Human Posterior Cricoarytenoid Muscle

Objectives/Hypothesis To achieve a successful selective reinnervation of the larynx, an accurate knowledge of the nerve supply of each individual muscle is required. The posterior cricoarytenoid muscle, the only abductor or respiratory muscle of the larynx, plays a vital role in cases of recurrent palsy and orthotopic transplantation. Descriptions of the posterior cricoarytenoid muscle nerve supply pattern vary considerably. The goal of the present study was to establish an accurate morphological description of the posterior cricoarytenoid muscle nerve supply in a large sample of human larynges.

Recurrent laryngeal nerve landmarks revisited

The aim of this work was to evaluate, to prove their reliability, the different surgical landmarks previously proposed as a mean to locate the recurrent laryngeal nerve (RLN).

The central projections of the laryngeal nerves in the rat.

The larynx serves respiratory, protective, and phonatory functions. The motor and sensory innervation to the larynx controlling these functions is provided by the superior laryngeal nerve (SLN) and the recurrent laryngeal nerve (RLN). Classical studies state that the SLN innervates the cricothyroid muscle and provides sensory innervation to the supraglottic cavity, whereas the RLN supplies motor innervation to the remaining intrinsic laryngeal muscles and sensory innervation to the infraglottic cavity, but recent data suggest a more complex anatomical and functional organisation. The current neuroanatomical tracing study was undertaken to provide a comprehensive description of the central brainstem connections of the axons within the SLN and the RLN, including those neurons that innervate the larynx. The study has been carried out in 41 adult male Sprague–Dawley rats. The central projections of the laryngeal nerves were labelled following application of biotinylated dextran amines onto the SLN, the RLN or both. The most remarkable result of the study is that in the rat the RLN does not contain any afferent axons from the larynx, in contrast to the pattern observed in many other species including man. The RLN supplied only special visceromotor innervation to the intrinsic muscles of the larynx from motoneurons in the nucleus ambiguus (Amb). All the afferent axons innervating the larynx are contained within the SLN, and reach the nucleus of the solitary tract. The SLN also contained secretomotor efferents originating from motoneurons in the dorsal motor nucleus of the vagus, and special visceral efferent fibres from the Amb. In conclusion, the present study shows that in the rat the innervation of the larynx differs in significant ways from that described in other species.

Inmovilidad glótica: estudio retrospectivo de 229 casos

Resumen Se ha llevado a cabo un estudio retrospectivo de los casos de inmovilidad glotica uni o bilateral diagnosticados en nuestro centro entre los anos 1985 y 1998. De los 229 casos analizados, 58 (25%) correspondian a una inmovilidad glotica bilateral, 60 (26%) a una inmovilidad unilateral derecha y 111 (49%) a una inmovilidad unilateral izquierda. Las etiologias mas frecuentes responsables en los casos bilaterales fueron la cirugia tiroidea (38%) y la intubacion prolongada (31%), en los casos unilaterales derechos las formas idiopaticas (32%) y la cirugia tiroidea (23%), y en los casos unilaterales izquierdos las formas idiopaticas (28%) y los tumores extralaringeos (22%). Tras una paralisis unilateral se consiguio una compensacion clinica en mas del 85% de las ocasiones cuando la etiologia era idiopatica o una lesion quirurgica de los nervios recurrente o vago, del 70% en el caso de intubacion prolongada, del 56% ante patologia neurologica y del 38% en caso de tumor extralaringeo. De los pacientes afectos de inmovilidad glotica bilateral un 14% no requirieron tratamiento, un 34% requirieron una traqueostomia permanente, y un 52% recuperaron una ventilacion oro-nasal adecuada tras cirugia (traqueostomia transitoria en 12 casos y aritenoidectomia en 18 casos).

Functional role of human laryngeal nerve connections.

Current knowledge of the functional role of human laryngeal nerves is based on traditional laryngeal neuroanatomic descriptions or contradictory electromyographic studies. The aim of this study was to clarify the functional role of neural connections between laryngeal nerves by correlating the different electromyographic patterns observed after laryngeal stimulation and the existence of different neural connections.

Potential Structures That Could Be Confused With a Nonrecurrent Inferior Laryngeal Nerve: An Anatomic Study

Objectives: Study and detailed description of the large connections between the normally recurrent inferior laryngeal nerve (RILN) and the sympathetic trunk (ST) because these may be mistaken for a nonrecurrent inferior laryngeal nerve (NRILN).