RESUMO
BACKGROUND: When it comes to autogenous nerve grafting, the sural and great auricular nerve (GAN) are the 2 nerves predominately used for trigeminal and facial nerve repair. Arising from the second and third cervical ventral rami, the GAN emerges from the posterior border of the sternocleidomastoid coursing superiorly and anteriorly toward the ear. METHODS: Eleven sides from 5 Caucasian and 1 Asian cadaveric heads (all fresh-frozen) were used. One man and 5 women were used with an age at death ranging from 57 to 91 years, with a mean of 80.3 years. Measurements were made from the inferior border of the ear to the GAN, the GAN to the external jugular vein, and the inferior border of the mastoid process to the GAN; the proximal, medial, and distal diameters of the GAN and the length of the GAN that was obtained from this exposure were also measured. RESULTS: The mean distance from the inferior border of the mastoid process to the GAN, inferior border of the ear to the GAN, and GAN to the external jugular vein was 27.71, 31.03, and 13.28 mm, respectively. The mean length of the GAN was 74.86 mm. The mean diameter of its distal, middle, and proximal portions was 1.51, 1.38, and 1.58 mm, respectively. CONCLUSIONS: The GAN is an excellent option for use in nerve grafting for repair of, for example, facial dysfunction. In this study, we review our measurements, techniques for identification, and dissecting techniques for the GAN. The proximity to the operative area and minimal complications associated with GAN grafting might contribute to improved patient satisfaction and better outcomes regarding functional restoration.
Assuntos
Plexo Cervical/anatomia & histologia , Nervo Facial/anatomia & histologia , Pescoço/anatomia & histologia , Procedimentos Neurocirúrgicos , Idoso , Idoso de 80 Anos ou mais , Pontos de Referência Anatômicos/inervação , Cadáver , Dissecação/métodos , Feminino , Cabeça/anatomia & histologia , Cabeça/inervação , Humanos , Masculino , Pessoa de Meia-Idade , Pescoço/inervação , Músculos do Pescoço/anatomia & histologia , Músculos do Pescoço/inervaçãoRESUMO
The communications between the branches of cervical plexus and cervical branch of facial nerve are common and are well known. However, this communication usually occurs between the transverse cervical nerve and cervical branch of facial nerve. During routine dissection classes for the Medical undergraduate students, we came across an anatomical variant of anterior division of great auricular nerve. This variation was found in a 60-year-old male cadaver of South Indian origin and it was unilateral. The great auricular nerve arose from the loop of ventral rami of C2 and C3 spinal nerves and divided into anterior and posterior branches. The anterior branch ran obliquely upwards and forwards on the surface of the sternocleidomastoid muscle along with the external jugular vein towards the apex of parotid gland and divided into many branches. One of these branches gave a communicating branch to cervical branch of facial nerve outside the parotid gland. Nerve endings of the remaining branches were found to penetrate the interlobular septa and a few of them were seen deep in the gland along the ducts and near the vessels. The functional significance of anatomic variations of nerve endings in relation to ducts, thin vessels deep in the parotid gland, observed in the present case are yet to be evaluated...
Las comunicaciones entre los ramos del plexo cervical y ramo cervical del nervio facial son comunes y bien conocidos. Sin embargo, esta comunicación por lo general ocurre entre el nervio cervical transverso y el ramo cervical del nervio facial. Durante las clases de disección de rutina para los estudiantes de pregrado de medicina, nos encontramos con una variante anatómica de la división anterior del nervio auricular mayor, unilateral, en un cadáver de sexo masculino de 60 años, del Sur de la India. El nervio auricular mayor se originó desde el bucle de los ramos ventrales de los nervios espinales C2 y C3, y dividió en ramos anterior y posterior. El ramo anterior se dirigió oblicuamente hacia arriba y adelante sobre la superficie del músculo esternocleidomastoideo junto con la vena yugular externa hacia el ápice de la glándula parótida y se dividió en numerosos ramos terminales. Uno de estos ramos dió un ramo comunicante al ramo cervical del nervio facial fuera de la glándula parótida. Las terminaciones nerviosas de los ramos restantes penetraron en los septos interlobulares. Algunos de éstos se observaron profundos en la glándula a lo largo de los conductos y cerca de los vasos. La importancia funcional de las variaciones anatómicas de las terminaciones nerviosas en relación a los conductos y vasos finos profundos en la glándula parótida aquí observados aún no se han evaluado...
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Glândula Parótida/inervação , Nervo Facial/anatomia & histologia , Plexo Cervical/anatomia & histologia , Cadáver , Pavilhão Auricular/inervaçãoRESUMO
The great auricular nerve (GAN) is the largest branch of the superficial cervical plexus that winds around the posterior border of the sternocleidomastoid muscle, accompanied by the external jugular vein. Forty fetuses (right side: 40/80; left: 40/80) with gestational ages between 15 to 28 weeks were microdissected to document the anatomy of the GAN. The results obtained were classified as: i) Incidence and morphometry: GAN was present in 100 percent of the fetal specimens with average length on the right and left sides recorded as 12.65 +/- 2.14 mm and 12.55 +/- 2.82 mm respectively. ii) Course: GAN was located parallel to the transverse cervical nerve and the external jugular vein. Duplicate external jugular veins were observed in 5 percent (4/80) with GAN located anterior to one of the tributaries; iii) Branching Pattern: 16 percent (13/80) of specimens depicted a single branch. Duplicate branches in 67 percent (54/80) (referred to as Type I: anterior and posterior branches and 33 percent (26/80) referred to as Type II: anterior and posterior branches; iv) Variation: the transverse cervical nerve formed a communication with GAN, inferior to the parotid gland in 1 percent. The anatomical knowledge of the course, bifurcation pattern and variations of GAN may prevent complications during surgical procedures such as parotidectomies.
El nervio auricular mayor (NAM) es el ramo más grande del plexo cervical superficial que gira alrededor del margen posterior del músculo esternocleidomastoideo, acompañado de la vena yugular externa. Cuarenta fetos (lado derecho: 40/80; izquierdo: 40/80), con edades gestacionales de 15 a 28 semanas fueron microdisecados para describir la anatomía del NAM. Los resultados obtenidos se clasificaron en: i) Incidencia y morfometría: NAM estaba presente en el 100 por ciento de las muestras fetales con una longitud media de los lados derecho e izquierdo de 12,65+/-2,14mm y 12,55+/-2,82mm, respectivamente. ii) Curso: NAM se encuentra paralelo al nervio cervical transverso y la vena yugular externa. Duplicación de las venas yugulares externas se observaron en el 5 por ciento (4/80) con el NAM situado por delante de uno de los afluentes, iii) Patrón de ramificación: 16 por ciento (13/80) de las muestras presentaba una solo ramo. Ramos duplicados en el 67 por ciento (54/80) de Tipo I, ramos anterior y posterior y, el 33 por ciento (26/80) Tipo II, ramos anterior y posterior, y iv) Variación: el nervio cervical transverso formando una comunicación con NAM, inferior a la glándula parótida en el 1 por ciento. El conocimiento anatómico del curso, patrón de bifurcación y variaciones del NAM pueden prevenir las complicaciones durante los procedimientos quirúrgicos como la parotidectomía.