A rare variation of radial nerve coexisting with the intercalated ectopic muscle from latissimus dorsi muscle / Una rara variación del nervio radial que coexiste con el músculo ectópico intercalado del músculo latísimo del dorso

SUMMARY: The axilla is the main communication channel connecting the upper limbs, the neck and chest. Stabilization of the internal structure is essential for upper limb and shoulder mobility. In this case, we observed and recorded the characteristics of the variation of the radial nerve as well as the intercalated ectopic muscle from latissimus dorsi muscle. The position relationship between both, was also particularly noted by us. In view of the presence of the variation we reported, related clinical research, surgery and disease diagnosis are expected to take this case into account.

La axila es el principal canal de comunicación que conecta los miembros superiores, el cuello y el tórax. La estabilización de la estructura interna es fundamental para la movilidad del miembro superior y del hombro. En este caso observamos y registramos las características de la variación del nervio radial así como del músculo ectópico intercalado del músculo latísimo del dorso. La relación de posición entre ambas también fue significativa en este estudio. En vista de la presencia de la variación que informamos, se espera que la investigación clínica relacionada con la cirugía y el diagnóstico de la enfermedad tengan en cuenta este caso.

Nerve root transfer from C4 to C5 in brachial plexus injuries. Anatomical study and description of the surgical technique / Transferência nervosa da raiz de C4 para C5 em lesões do plexo braquial. Estudo anatômico e descrição de técnica cirúrgica

Abstract Objective This is an anatomical study of C4 and C5 roots for nerve transfers in upper brachial plexus injuries, with surgical technique demonstration. Methods Fifteen brachial plexuses from both male and female cadavers were dissected. Morphological features of C4 and C5 roots were recorded and analyzed, followed by a neurotization simulation. Results In all dissections, C4 and C5 roots morphological features allowed their mobilization and neurotization with no need for a nerve graft. The surgical technique spared important regional nerve branches. Conclusion Based on these data, we conclude that C4-C5 nerve transfers are feasible and result in no additional neurological deficit in upper brachial plexus injuries.

Resumo Objetivo Estudo anatômico das raízes usadas na transferência nervosa de C4 para C5 nas lesões altas do plexo braquial, com demonstração da técnica cirúrgica. Métodos Dissecção de 15 plexos braquiais de cadáveres de ambos os sexos, registro e análise das características morfológicas das raízes de C4 e C5 e simulação de neurotização. Resultados As características morfológicas encontradas nas raízes de C4 e C5 em todas as dissecções permitiram a mobilização das mesmas e a realização de uma neurotização sem a necessidade de usar enxerto nervoso. A técnica cirúrgica permitiu preservar ramos nervosos importantes na região abordada. Conclusão Com base nos dados encontrados no presente estudo, podemos concluir que é possível realizar a transferência entre C4 e C5 sem provocar déficit neurológico adicional nas lesões altas de plexo braquial.

Anatomorphometry of the brachial plexus under high-definition system: an experimental study in rats

Purpose: To study the anatomorphometry of the plexus brachialis (PB) of rats under a high-definition video system. Methods: Ten male Wistar rats discarded from other research that did not interfere in the morphology of the animal, respecting the principle of reduction, were used. All animals were submitted to the same protocol. Initially, the cervical region was shaved. The animals were placed in a dorsal position. A single elbow-to-elbow incision was performed and dissection started at the deltopectoral sulcus. The procedures were performed under a video system. To measure the structures, the Image J software was used. Results: All the PB evaluated originated from the C5-T1 spinal nerves. C5 and C6 converged to form the truncus superior, the root of C7 originated the truncus medius, and the confluence of C8 and T1 originated the truncus inferior. It was found the union of C7, C8, and T1 to form truncus inferomedialis instead of separate medial and inferior truncus. C8 (1.31 mm) was the thickest root, the truncus inferior (1.80 mm) and the nerve radialis (1.02 mm), were the thickest. Conclusions: The anatomy of the PB is comparable to humans, admitting variations. The videomagnification system is useful to perform microsurgical dissection.

Two cases of variations of musculocutaneous nerve communication with the median nerve / Dos casos de variaciones de la comunicación del nervio musculocutáneo con el nervio mediano

SUMMARY: To know the nerve variations of brachial plexus and its branches is very important in the management of upper limb nerve injuries. Variations of the brachial plexus are not uncommon, but types of variations are diverse. The unusual communication branches between the musculocutaneous nerve (MCN) and the median nerve (MN) in course were found during routine dissection on the two different left arms of formalin fixed male cadavers. Depending on the position related to the coracobrachial muscle (CBM), one MCN pierced the CBM, the other did not in the two cases. The branches of MCN emerged interior to the coracoid process to innervate the CBM. The present case reports of anatomical variations of nerves can help to manage nerve injuries and plan surgical approaches during surgical procedures.

RESUMEN: Conocer las variaciones nerviosas del plexo braquial y sus ramas es muy importante en el tratamiento de las lesiones nerviosas de los miembros superiores. Las variaciones del plexo braquial no son infrecuentes, sin embargo los tipos de variaciones son diversos. Los ramos inusuales de comunicación entre el nervio musculocutáneo (NMC) y el nervio mediano (NM) en curso fueron descubiertos durante la disección de rutina en dos miembros superiores izquierdos de dos cadáveres de sexo masculino fijados con formalina. Un NMC atravesó el MCB, otro no lo hizo en los dos casos. Los ramos de NMC emergieron a nivel del proceso coracoideo para inervar el MCB. Los presentes informes de casos de variaciones anatómicas de los nervios pueden ayudar a tratar las lesiones nerviosas y planificar los abordajes quirúrgicos durante los procedimientos quirúrgicos.

Description of brachial plexus of sloth (Bradypus variegatus) / Descrição do plexo braquial do bicho-preguiça (Bradypus variegatus)

The species Bradypus variegatus is known as the common sloth, an endemic mammal from neotropical regions, which has been suffering from devastating anthropogenic activities. Our study aimed to describe the brachial plexus of B. variegates, regarding the origin and distribution of nerves, through the sampling of 10 adult females. Analyses were carried out at the Anatomy Section, "Departamento de Morfologia e Fisiologia Animal", "Universidade Federal Rural de Pernambuco", under license no. 034/2015 of the Ethics Committee on the Use of Animals. The results determined that the brachial plexus of the common sloth starts from the fifth cervical spine segment until the second thoracic segment. This area contains the long and suprascapular thoracic nerves, which originate immediately from the medullary segment 5 and 6, respectively, and from the pectoral, subscapular, axillary, radial, musculocutaneous, medial, forearm and ulnar medial cutaneous nerves, arising from a trunk comprised of cervical spine nerves (C) 7, C8, C9, and thoracic (T) 1 and T2. Regarding other wild and domestic animals, different suggestions were observed about the origin of the plexus in B. variegatus, however, the constituent nerves and their innervation areas did not demonstrate any discrepancies.(AU)

A espécie Bradypus variegatus é conhecida como preguiça-comum. Trata-se de um mamífero endêmico de regiões neotropicais que vem sofrendo com a ação antrópica devastadora. Esses Bradipodídeos possuem três dedos nos membros torácicos e pélvicos, são arborícolas consagrados e descem ao solo apenas para excretar e trocar de árvore. O estudo teve como objetivo descrever o plexo braquial de B. variegatus em relação à origem e distribuição dos nervos. Para tal, utilizou-se 10 fêmeas adultas. As análises foram realizadas no Pavilhão de Anatomia do Departamento de Morfologia e Fisiologia Animal da Universidade Federal Rural de Pernambuco, sob a licença nº 034/2015 do Comitê de Ética no Uso de Animais. Os cadáveres foram obtidos após morte natural, fixados em formaldeído a 20%, conservados em solução salina a 30% em tanques e dissecados para a visualização dos nervos destinados a inervar os membros e músculos torácicos. Uma vez feito, constatou-se que o plexo braquial da preguiça-comum se origina do quinto segmento espinal cervical, se estendendo até o segundo segmento torácico. Sendo formado pelos nervos torácico longo e supraescapular, de origem imediatamente do segmento medular 5 e 6, respectivamente, e pelos nervos peitorais, subescapulares, axilar, radial, musculocutâneo, mediano, cutâneo medial do antebraço e ulnar, decorrentes de um tronco formado a partir de nervos espinais cervicais (C) 7, C8, C9, e torácicos (T) 1 e T2. Em comparação a outros animais silvestres e domésticos foram observadas diferentes disposições em relação à origem do plexo de B. variegatus, todavia, os nervos constituintes e suas áreas de inervação não apresentaram discrepâncias.(AU)

Positional anomaly between the brachial plexus and the scalene muscles, concomitant with an anomalous path of the musculocutaneous nerve: case report and clinical implication / Anomalía posicional entre el plexo braquial y el músculo escaleno anterior, concomitante con un trayecto anómalo del nervio musculocutáneo: reporte de un caso e implicancia clínica

Anatomical variations of the scalene muscles are frequent, as are those of the brachial plexus and its terminal nerves. Nonetheless, these variations are reported separately in the literature. The aim of this work is to present a variation of scalene muscles, concomitant with an abnormal path of the musculocutaneous nerve. During a routine dissection of the cervical region, axilla and right anterior brachial region in an adult male cadaver, a supernumerary muscle fascicle was located in the anterior scalene muscle, altering the anatomical relations of C5 and C6 ventral branches of the brachial plexus. This variation was related to an anomalous path of the musculocutaneous nerve that did not cross the coracobrachialis muscle. It passed through the brachial canal along with the median nerve. It then sent off muscular branches to the anterior brachial region and likewise, communicating branches to the median nerve. The concomitant variations of the brachial plexus and scalene muscles they are not described frequently. Knowledge of these variations improves diagnosis, enhancing therapeutic and surgical approaches by reducing the possibility of iatrogenesis during cervical, axillary and brachial region interventions.

Las variaciones anatómicas de los músculos escalenos son frecuentes, así como también las del plexo braquial y sus nervios terminales. Sin embargo la literatura científica las presenta por separado. El propósito de este trabajo es presentar una variación de los músculos escalenos concomitante con un trayecto anómalo del nervio musculocutáneo. Disección de rutina de región cervical, axila y región braquial anterior derechas realizada en un cadáver adulto de sexo masculino. Se encontró un fascículo muscular supernumerario para el músculo escaleno anterior que alteraba las relaciones anatómicas de los ramos ventrales C5 y C6 del plexo braquial. Esta variación estaba acompañada por un trayecto anómalo del nervio musculocutáneo, el cual no atravesaba al músculo coracobraquial y transitaba por el conducto braquial acompañando al nervio mediano. Desde allí enviaba a la región braquial anterior ramos musculares y al nervio mediano ramos comunicantes. Las variaciones conjuntas del plexo braquial y los músculos escalenos no se presentan con frecuencia. Conocerlas enriquece la capacidad diagnóstica, terapéutica y quirúrgica. Reduciendo la posibilidad de iatrogenia al intervenir en las regiones cervical, axilar y braquial.

Origen del nervio subescapular inferior, patrones de ramificación y su contribución a la inervación del músculo subescapular / Origin of the inferior subscapular nerve, branching patterns and its contribution to the subscapular muscle innervation

El nervio subescapular inferior (NSI) inerva parcialmente al músculo subescapular (MSe) e inerva también al músculo redondo mayor (MRM). Diversas publicaciones determinan amplia variación en su origen en el Plexo Braquial (PB), pero existe poca evidencia de estas variaciones y del patrón de inervación del MSe y MRM en individuos latinoamericanos. El propósito de este estudio fue describir el origen del NSI en el PB, determinar número de ramos que le entrega al MSe y los patrones de ramificación. Se utilizaron 30 miembros superiores de individuos adultos, Brasileños; 13 del lado derecho y 17 del izquierdo, fijados en formaldehido al 10 %. Se disecaron las regiones axilares para exponer el fascículo posterior del plexo braquial (FPPB) y sus ramos. Se determinó si el origen del NSI era individual o procedía de un tronco común. Se cuantificó el número de ramos para el MSe, estableciendo patrones de ramificación. El NSI y sus ramos se agruparon según su origen y ramificación. En 3 de los casos (10 %) el NSI procedía de un tronco común con el nervio toracodorsal (NTD), 2 del lado izquierdo (6,6 %) y 1 del derecho (3,3 %); en 27 casos (90 %) procedía del nervio axilar (NAx), 15 del lado izquierdo (50 %) y 12 del derecho (40 %). En ningún caso, el origen fue directo del FPPB. Además, se cuantificó el número de ramos que aportaba a la inervación del MSe, observándose un promedio de 4 ramos (de 1 a 8 ramos) para el MSe. Se identificaron 4 patrones de ramificación del NSI hacia el MSe y el MRM. Tanto el origen como la distribución del NSI presentaron variaciones. Los datos aportados complementarán los conocimientos para la correcta enseñanza, el oportuno diagnóstico y la buena práctica quirúrgica de la zona axilar.

The inferior subscapular nerve (ISN) partially innervates the subscapular muscle (SbM) and also innervates the teres major muscle (TMM). Several publications determine wide variation in their origin from Brachial Plexus (BP), but there is little evidence of these variations and the innervation pattern of SbM and TMMin Latin American individuals. The purpose of this study was to describe the origin of the ISN from PB, to determine the number of branches that it gives to the SbM and the branching patterns. 30 upper limbs of cadavers of the Brazilian adult individuals were used; 13 on the right side and 17 on the left, fixed in 10 % formaldehyde. The axillary regions were dissected to expose the posterior fascicle of the brachial plexus (PFBP) and its branches. It was determined whether the origin of the NSI was individual or came from a common trunk. The number of branches for the SbM was quantified, establishing branching patterns. The ISN and its branches were grouped according to their origin and branching. In 3 of the cases (10 %) the ISN came from a common trunk with the thoracodorsal nerve (TDN), 2 from the left side (6.6 %) and 1 from the right side (3.3 %); in 27 cases (90 %) it came from the axillary nerve (AxN), 15 from the left side (50 %) and 12 from the right side (40 %). In no case, the origin was direct from the PFBP. In addition, the number of branches that contributed to the innervation of the SbM was quantified, with an average of 4 branches (from 1 to 8 branches) being observed for the SbM. Four branching patterns of the ISN towards the SbM and the TMM were identified. Both the origin and the distribution of the ISN presented many variations. The data provided will complement the knowledge for proper teaching, timely diagnosis and good surgical practice of the axillary area.

The need for supplemental blocks in single versus triple injections in infraclavicular brachial plexus blocks with a medial approach: a clinical and anatomic study / Bloqueio complementar de nervos no bloqueio de plexo braquial infraclavicular com técnica medial de injeção única versus tripla: estudo anátomo-clínico

Abstract Background and objectives: To evaluate the single-injection and triple-injection techniques in infraclavicular blocks with an ultrasound-guided medial approach in terms of block success and the need for supplementary blocks. Methods: This study comprised 139 patients who were scheduled for elective or emergency upper-limb surgery. Patients who received an infraclavicular blocks with a triple-injection technique were included in Group T (n = 68). Patients who received an infraclavicular blocks with a single-injection technique were included in Group S (n = 71). The number of patients who required supplementary blocks or had complete failure, the recovery time of sensory blocks and early and late complications were noted. Results: The block success rate was 84.5% in Group S, and 94.1% in Group T without any need for supplementary nerve blocks. The blocks were supplemented with distal peripheral nerve blocks in 8 patients in Group S and in 3 patients in Group T. Following supplementation, the block success rate was 95.8% in Group S and 98.5% in Group T. These results were not statistically significant. A septum preventing the proper distribution of local anesthetic was clearly visualized in 4 patients. The discomfort rate during the block was significantly higher in Group T (p < 0.05). Conclusion: In ultrasound-guided medial-approach infraclavicular blocks, single-injection and triple-injection techniques did not differ in terms of block success rates. The need for supplementary blocks was higher in single injections than with triple injections. The presence of a fascial layer could be the reason for improper distribution of local anesthetics around the cords.

Resumo Justificativa e objetivos: Avaliar as técnicas de injeção única e tripla no bloqueio infraclavicular, empregando-se acesso medial guiado por ultrassonografia, comparando-se o sucesso do bloqueio e a necessidade de bloqueios complementares. Método: O estudo incluiu 139 pacientes com indicação de cirurgia de membro superior eletiva ou de emergência. O Grupo T (n = 68 pacientes) recebeu bloqueio infraclavicular com técnica de injeção tripla e o Grupo S (n = 71), bloqueio infraclavicular com injeção única. Registrou-se o número de pacientes que necessitaram bloqueio complementar de nervo ou que apresentaram falha completa do bloqueio, o tempo de recuperação do bloqueio sensorial e as complicações precoces e tardias. Resultados: A taxa de sucesso do bloqueio infraclavicular, sem necessidade de bloqueio complementar de nervo, foi 84,5% e 94,1% para os Grupos S e T, respectivamente. No bloqueio infraclavicular foi necessário bloqueio de nervos periféricos distais em 8 e 3 pacientes dos Grupos S e T, respectivamente. Após a complementação, a taxa de sucesso do bloqueio foi 95,8% e 98,5% para os Grupos S e T, respectivamente. Os resultados não foram estatisticamente significantes. Imagem de septo impedindo a distribuição adequada do anestésico local foi claramente visualizada em quatro pacientes. A taxa de desconforto durante a realização do bloqueio foi estatatisticamente mais alta no Grupo T (p< 0,05). Conclusões: As técnicas de injeção única e tripla em bloqueio infraclavicular guiado por ultrasonografia com acesso medial não diferiram quanto à taxa de sucesso. A necessidade de bloqueio complementar foi maior com a técnica de injeção simples. A ocorrência de invólucro de fascia poderia justificar a distribuição inadequada do anestésico local ao redor dos fascículos do plexo.

Anatomical study of the brachial plexus in human fetuses and its relation with neonatal upper limb paralysis / Estudo anatômico do plexo braquial de fetos humanos e sua relação com paralisias neonatais do membro superior

ABSTRACT Objective To study the anatomy of the brachial plexus in fetuses and to evaluate differences in morphology during evolution, or to find anatomical situations that can be identified as the cause of obstetric paralysis. Methods Nine fetuses (12 to 30 weeks of gestation) stored in formalin were used. The supraclavicular and infraclavicular parts of the brachial plexus were dissected. Results In its early course, the brachial plexus had a cord-like shape when it passed through the scalene hiatus. Origin of the phrenic nerve in the brachial plexus was observed in only one fetus. In the deep infraclavicular and retropectoralis minor spaces, the nerve fibers of the brachial plexus were distributed in the axilla and medial bicipital groove, where they formed the nerve endings. Conclusion The brachial plexus of human fetuses presents variations and relations with anatomical structures that must be considered during clinical and surgical procedures for neonatal paralysis of the upper limbs.

RESUMO Objetivo Estudar a anatomia do plexo braquial em fetos e avaliar diferenças de morfologia durante a evolução, ou encontrar situações anatômicas que possam ser apontadas como causa de paralisias obstétricas. Métodos Foram utilizados nove fetos formolizados entre 12 a 30 semanas de gestação e submetidos à dissecação supra e infraclavicular do plexo braquial. Resultados O plexo braquial inicialmente tem formato de cordão durante sua passagem pelo hiato dos escalenos e em apenas um feto foi observada a origem do nervo frênico por meio do plexo braquial. Na região infraclavicular profunda e retropeitoral menor, os fascículos do plexo braquial se distribuíam na axila e sulco bicipital medial para a formação dos nervos terminais. Conclusão O plexo braquial de fetos humanos apresenta variações e relações com estruturas anatômicas que devem ser consideradas durante os procedimentos clínicos e cirúrgicos das paralisias neonatais do membro superior.

Características morfométricas de las raíces del plexo braquial en el hombre / Morphometric characteristics of brachial plexus roots in man

El plexo braquial se forma a partir de cinco raíces espinales: C5, C6, C7, C8 y T1, proporcionando inervación al miembro superior. Se ha demostrado que el análisis morfométrico de las fibras nerviosas es de gran valor para detectar anormalidades, como el tamaño de los haces nerviosos, el número o tamaño de los axones y el área de mielina. El presente estudio fue realizado en muestras de 10 plexos braquiales (5 derechos, 5 izquierdos), obtenidos de 5 cadáveres frescos, de sexo masculino, con un promedio de edad entre 24 ± 3,14 (rango, 20-30 años), y 73 ± 5,52 años (rango, 60-90 años), sin antecedentes de neoplasia maligna y patología neuropsiquiátrica. Las muestras fueron fijadas en formalina 10 % y teñidas con hematoxilina-eosina. Los datos obtenidos de los 10 plexos braquiales se agruparon en dos rangos de edades, siendo estos jóvenes y adultos. En el grupo de jóvenes el número de fascículos en C5, 4,00 ± 1,22; C6, 9,25 ± 3,83; C7, 15,20 ±7,57;C8, 8,60 ± 5,39; T1, 4,80 ± 3,19 en adultos el diámetro de la raíz fue C5, 4,77 ± 1,31; C6, 5,39 ± 0,76; C7, 5,91 ± 1,63; C8, 5,19 ± 0,94; T1, 4,86 ± 1,40. Existen diferencias entre las raíces nerviosas del plexo braquial humano, de individuos jóvenes y adultos chilenos, así el área de la raíz de individuos jóvenes es menor, el número de fascículos decrece en los individuos adultos y sus diámetros siempre son mayores en estos últimos.

The brachial plexus is formed from five spinal roots: C5, C6, C7, C8 and T1, providing innervation to the upper limb. It has been shown that the morphometric analysis of nerve fibers is of great value in detecting abnormalities, such as the size of nerve bundles, the number or size of axons and the area of myelin. The present study was performed on samples of 10 brachial plexuses (5 right, 5 left), obtained from 5 fresh cadavers, male, with an average age between 24 ± 3.14 (range, 20-30 years), and 73 ± 5.52 years (range, 60-90 years), with no history of malignancy and neuropsychiatric pathology. The samples were fixed in 10% formalin and stained with hematoxylineosin. The data obtained from the 10 brachial plexuses were grouped into two age ranges, these being young and adult. In the group of young people the number of fascicles in C5, 4.00 ± 1.22; C6, 9.25 ± 3.83; C7, 15.20 ± 7.57; C8, 8.60 ± 5.39; T1, 4.80 ± 3.19 in adults the diameter of the root was C5, 4.77 ± 1.31; C6, 5.39 ± 0.76; C7, 5.91 ± 1.63; C8, 5.19 ± 0.94; T1, 4.86 ± 1.40. There are differences between the nerve roots of the human brachial plexus, young individuals and Chilean adults, so the root area of young individuals is smaller, the number of fascicles decreases in adult individuals and their diameters are always higher in the latter.

Anatomic variations in relation to the origin of the musculocutaneous nerve: absence and non-perforation of the coracobrachialis muscle: anatomical study and clinical significance / Variaciones anatómicas en relación al origen del nervio musculocutáneo: ausencia y no perforación del músculo coracobraquial: estudio anatómico y significado clínico

The most frequent anatomic variations of the musculocutaneous nerve could be divided in two main groups: communicating branches with the median nerve and variations in relation to the origin, which in turn can be subdivided into absence of the nerve and non-perforation of the coracobrachialis muscle. Unusual clinical symptoms and/or unusual physical examination in patients with motor disorders, could be explained by anatomic variations of the musculocutaneous nerve. A total of 106 arms were evaluated, corresponding to 53 fresh male cadavers who were undergoing necropsy. The presence or absence of the musculocutaneous nerve was evaluated and whether it pierced the coracobrachialis muscle or not. The lengths of the motor branches and the distances from its origins to the coracoid process were measured. In 10 cases (9.5 %) an unusual origin pattern was observed, of which six (5.7 %) correspond to non-perforation of the coracobrachialis muscle and four (3.8 %) correspond to absence of the nerve. The length of the branch for the brachialis muscle was 37.7±15.4 mm and for the short and long heads of the biceps 27.6±11.7 mm and 33.2±10.1 mm respectively. The study showed that our population has similar prevalence of absence of the musculocutaneous nerve and non-perforation of the coracobrachialis muscle compared to previous reports in different populations. Moreover, there was no statistical correlation between the sides and the evaluated variables.

Las variaciones anatómicas más frecuentes del nervio musculocutáneo se pueden dividir en dos grupos principales: Ramas comunicantes con el nervio mediano y variaciones en relación al origen, que a su vez se pueden subdividir en la ausencia del nervio y la no perforación del músculo coracobraquial. Los síntomas clínicos inusuales y / o el examen físico inusual en pacientes con trastornos motores podrían explicarse por variaciones anatómicas del nervio musculocutáneo. Se evaluaron un total de 106 brazos, que corresponden a 53 cadáveres de machos frescos sometidos a necropsia. Se evaluó la presencia o ausencia del nervio musculocutáneo y si atravesó o no el músculo coracobraquial. Se midieron las longitudes de las ramas motoras y las distancias desde sus orígenes hasta el proceso coracoides. En 10 casos (9,5 %) se observó un patrón de origen inusual, de los cuales seis (5,7 %) corresponden a la no perforación del músculo coracobraquial y cuatro (3,8 %) corresponden a la ausencia del nervio. La longitud de la rama para el músculo braquial fue de 37,7 ± 15,4 mm y para las cabezas cortas y largas del bíceps 27,6 ± 11,7 mm y 33,2 ± 10,1 mm, respectivamente. El estudio mostró que nuestra población tiene una prevalencia similar de ausencia del nervio musculocutáneo y la no perforación del músculo coracobraquial comparado con informes previos en diferentes poblaciones. Además, no hubo una correlación estadística entre los lados y las variables evaluadas.

Origem dos nervos do plexo braquial de sagui-de-tufos-brancos (Callithrix jacchus Linnaeus, 1758) / Origin of brachial plexus nerves for common marmoset (Callithrix jacchus Linnaeus, 1758)

O sagui-de-tufos-brancos (Callithrix jacchus) é um pequeno primata que habita florestas arbustivas da Caatinga e a Mata Atlântica do Nordeste brasileiro. Essa espécie de sagui é muito comum e de fácil adaptação ao cativeiro, aspecto que estimula a captura clandestina desses animais, os quais são vítimas de maus tratos que causam lesões. A falta de conhecimento da anatomia de saguis e outros animais silvestres dificulta a aplicação segura de procedimentos clínicos, cirúrgicos e terapêuticos. O plexo braquial tem sido descrito em algumas espécies animais, porém até o momento não existia descrição em saguis-de-tufos-brancos (Callithrix jacchus). Para estudar o plexo branquial desses animais foram dissecados dez cadáveres de saguis-de-tufos-brancos (Callithrix jacchus) adultos sendo cinco machos e cinco fêmeas. Em todos os animais o plexo braquial originou- se dos nervos espinhais C5, C6, C7, C8 e T1, com poucas variações na origem e nas contribuições dos nervos, em ambos os antímeros, formando três troncos: cranial (C5 e C6), médio (C7) e caudal (C8 e T1).(AU)

The common marmoset (Callithrix jacchus) is a small primate that inhabits shrub forests of the Caatinga and the Atlantic Forest in Brazilian Northeast. This species of marmoset is very common and easy to adaptation in captivity, aspect that encourages illegal capture of these animals that are victims of mistreatments, causing injuries. The lack of knowledge in anatomy in marmosets and other wildlife hinders the safe application of clinical, surgical and therapeutic procedures. The brachial plexus has been described in some species of animals, but so far, there is no description for common marmoset (Callithrix jacchus). To study the brachial plexus of these animals were dissected ten corpses of common marmosets (Callithrix jacchus) adults, being five males and five females. In all animals, the brachial plexus was originated from spinal nerves C5, C6, C7, C8 and T1, with few variations in origin and the contributions of the nerves in both antimeres, forming three trunks: the cranial (C5 and C6), medium (C7) and caudal (C8 and T1).(AU)

Origins of plexus brachial in Iguana iguana iguana / Origens do plexo braquial da Iguana iguana iguana

This paper aims to describe the origin of the brachial plexus of 12 iguanas, male and female, which were donated already dead by the Wild Animal Screening Center and Independent Company of Highway and Environmental Police of the Araguaína, Tocantins State, to Veterinary Anatomy Laboratory of Federal University of Tocantins, Araguaína campus These animals were fixed by intramuscular injections of aqueous 10% formalin. It was made a parallel incision to dorsal midline from the skull to the caudal ribs. It was pulled all the epiaxial muscles eight ribs, the periosteum, exposing and individualizing the ventral rami of spinal nerves that make up the brachial plexus. The ventral rami of spinal nerves C6, C7, C8, T1 and T2 form the brachial plexus in 12 iguanas. In 41.6% of cases, the branches involved were C6, C7, C8 and T1; in 33.4%, the branches C6, C7, C8, T1 and T2; 16.6% the branches C7, C8, T1 and T2 and in 8.4%, the branches C7, C8 and T1. The branches ventral C7, C8 and T1 formed three trunks and C6 and T2, when present, consisted of nervous fillet. There was variation in number of vertebrae in Iguana iguana iguana which caused oscillations in anastomoses, that constitute the nerves of brachial plexus. The axillary, subscapular, cutaneous, pectoral, coracobrachialis, radial, median, ulnar, thoracodorsal nerves are the main nerves that constitute the brachial plexus in iguanas.

Esse trabalho tem como objetivo descrever a origem do plexo braquial de 12 iguanas, machos e fêmeas, doados mortos pelo Centro de Triagem de Animais Silvestres e Companhia Independente de Polícia Rodoviária e Ambiental ­ Araguaína ­ Tocantins, ao Laboratório de Anatomia da Universidade Federal do Tocantins, campus de Araguaína. Fixou-se os animais com injeções intramusculares de solução aquosa de formalina a 10%. Realizou-se uma incisão paralela a linha mediana dorsal desde o crânio até a região caudal das costelas. Retirou toda a musculatura epiaxial, oito costelas, o periósteo, expondo e individualizando os ramos ventrais dos nervos espinhais que compõem o plexo braquial. Os ramos ventrais dos nervos espinhais C6, C7, C8, T1 e T2 formam o plexo braquial nas 12 iguanas. Em 41,6% dos casos, os ramos envolvidos foram C6, C7, C8 e T1; em 33,4%, os ramos C6, C7, C8, T1 e T2; em 16,6 % os ramos C7, C8, T1 e T2 e em 8,4%, os ramos C7, C8 e T1. Dos ramos ventrais C7, C8 e T1 formavam três troncos e C6 e T2, quando presentes, consistiam de filetes nervosos. Houve variação no número de vértebras na Iguana iguana iguana, que provocaram oscilações nas anastomoses que constituem os nervos do plexo braquial nas iguanas. Os nervos axillar, subscapular, cutâneo, peitoral, coracobraquial, radial, mediano, ulnar e toracodorsal são os principais nervos que constituem o plexo braquial nas iguanas.

Descrição anatômica do plexo braquial de Callithrix jacchus e Callithrix penicillata / Anatomic description of brachial plexus of Callithrix jacchus and Callithrix penicillata

Callithrix jacchus e Callithrix penicillata são primatas de pequeno porte cuja utilização como modelo anatômico tem se mostrado cada vez mais frequente, não somente pela praticidade no manuseio como facilidade no trato em criatório e sua taxa de reprodução. Este estudo teve como objetivo descrever os componentes dos plexos braquial em Callithrix jacchus e penicillata. Para tanto, três espécimes com aproximadamente 8 anos e 240 g foram fixados em solução de formaldeído a 10%, e posteriormente dissecados e fotodocumentados. O plexo braquial do Callithrix jacchus e penicillata originou-se dos nervos espinhais C5 a T1 constituindo os troncos cranial, médio e caudal. A composição do plexo braquial destes animais se assemelha ao de outros primatas, bem como a outros mamíferos.(AU)

Callithrix jacchus and Callithrix penicillata are small primates used as anatomic model, not only for convenience in handling as ease in regard to breeding and reproductive rate. The aim of this study was to describe the components of the brachial plexus in Callithrix jacchus and C. penicillata. Three specimens about 8 years old and weighing 240g were fixed in 10% formaldehyde and subsequently dissected and photodocumented. The brachial plexus of Callithrix jacchus and C. penicillata originates from the spinal nerves C5 to T1 in continuation of the cranial, medium and flow trunk. The composition of the brachial plexus of these animals is similar to the one of other primates ands other mammals.(AU)

Ultrasound and gross anatomy of the brachial plexus and major nerves of the forelimb. An anesthetic approach using the domestic rabbit (Oyctolagus cuniculus) as an experimental model1

PURPOSE: To update the gross and sonographic anatomy and propose landmarks to perform ultrasound-guided (US-guided) axillary brachial plexus block (BPB) in rabbits. METHODS: Forty New Zeeland's rabbit (NZR) cadavers were dissected and the nerves were trimmed, identified, measured, and photographed. Additionally, in twenty NZRs, sonographic images of brachial plexus (BP) were performed through a simple-resolution ultrasound device. The US-guided block was achieved through a minimum volume of lidocaine necessary to surround the BP roots. The effectiveness of the brachial plexus block was assessed on sensitivity and motor functions. RESULTS: The BP resulted from connections between the ventral branches of the last four cervical spinal nerves and the first thoracic spinal nerve. In the axillary sonoanatomy, the BP appeared as an agglomerate of small, round hypoechoic structures surrounded by a thin hyperechoic ring. The amount of time and the minimum volume required to perform was 4.3 ± 2.3 min and 0.8 ± 0.3ml, respectively. CONCLUSIONS: The gross and sonographic anatomy of the BP showed uncommon morphological variations. Moreover, from sonographic landmarks, we showed complete reproducibility of the axillary US-guided brachial plexus block with simple resolution equipment and small volume of anesthetics required.

Connection between radial and ulnar nerves at humeral level and its clinical significance: a cadaveric case report / Conexión entre los nervios radial y ulnar a nivel humeral y su importancia clínica: reporte de caso en un cadáver

Variations of the terminal branches of the brachial plexus in the upper limb are abundant and frequently have been reported. But connection between its radial and ulnar nerves at humeral level is very rare. During routine dissection of the right arm of a 75-year-old male cadaver in the Department of Anatomy of Birjand University of Medical Sciences (BUMS), in Iran, we observed a connection between radial and ulnar nerves, and from the literature reviewed, we found only two cases that had been reported previously, one of them was unilateral and the other bilateral. Awareness of such variations are very important for surgeons and diminish the possible complication of regional anesthesia and surgical procedures, hence, we decided to report it.

Las variaciones de los ramos terminales del plexo braquial en el miembro superior son abundantes y reportadas con frecuencia. Sin embargo, la conexión entre los nervios radial y ulnar a nivel humeral es muy rara. Durante la disección rutinaria de un brazo derecho en un cadáver de sexo masculino de 75 años, en el Departamento de Anatomía de la Birjand University of Medical Sciences (BUMS) en Irán, se observó una relación entre los nervios radial y ulnar. En la literatura, encontramos sólo dos casos que habían sido reportados previamente, uno bilateral y otro unilateral. Conocer estas variaciones es de importancia para los cirujanos, así como para disminuir posibles complicaciones en la colocación de anestesia regional y procedimientos quirúrgicos.

Origens e ramificações do plexo braquial no cachorro-do-mato Cerdocyon thous (Linnaeus, 1766) / Origins and ramifications of brachial plexus in the crab-eating-fox Cerdocyon thous (Linnaeus, 1766)

Este estudo teve o objetivo de descrever a origem e ramificação dos nervos de vinte plexos braquiais de cachorro-do-mato (Cerdocyon thous). Dez animais da espécie, obtidos post mortem por atropelamento em rodovias, foram utilizados para o estudo, de acordo com a autorização do IBAMA/SISBIO nº33667-1. Depois de coletados, os cadáveres foram fixados em solução de formaldeído a 50% e conservados por pelo menos 14 dias em solução de formaldeído a 10% antes das dissecções. Após remoção da pele, incisões na musculatura peitoral e afastamento dos membros, acessou-se o espaço axilar e os nervos do plexo tiveram seu trajeto dissecados individualmente até sua inserção muscular. Para melhorar a visualização dos ramos ventrais cervicais e torácicos que originavam cada nervo, removeram-se a musculatura que encobria os forames intervertebrais, os processos transversos e os corpos vertebrais ventralmente, expondo inclusive a medula espinhal. Registros fotográficos e desenhos esquemáticos documentaram a origem e ramificação dos nervos. Os vinte plexos braquiais foram resultantes das conexões entre os ramos ventrais dos três últimos nervos espinhais cervicais (C6, C7 e C8) e do primeiro torácico (T1). Estes ramos derivaram os nervos supra-escapular, subescapular, axilar, musculocutâneo, radial, mediano, ulnar para a musculatura intrínseca e os nervos braquiocefálico, toracodorsal, torácico lateral, torácico longo, peitoral cranial e peitoral caudal para a musculatura extrínseca do membro torácico. Constatou-se que os ramos ventrais de C7 foram os que mais contribuíram na formação de nervos (61,5%), seguido de C8 (55,4%), de T1 (41,2%) e de C6 (30,8%). O teste t de comparação entre as médias, ao nível de significância de 5%, não demonstrou diferenças na origem do plexo quando comparados os antímeros e os sexos. Do total dos 260 nervos dissecados, 68,8% foram originados pela combinação de dois ou três ramos, enquanto apenas 31,2% tiveram formação por um único ramo. A combinação entre C8 e T1 foi a que mais formou nervos para o plexo (23,8%) nesta espécie. Quando comparadas a origem, ramificação e área de inervação do plexo braquial do C. thous com outras espécies domésticas e silvestres, verificou-se maior semelhança com o cão doméstico. Os resultados deste estudo podem embasar o diagnóstico de disfunções neuromusculares, as técnicas de bloqueios anestésicos e análises morfofuncionais comparativas envolvendo esta espécie.

This study aimed to describe the origin and branching of nerves from twenty brachial plexuses of crab-eating foxes (Cerdocyon thous). Ten animals of the species, obtained post mortem from being run over on highways, were used for the study, in accordance with the authorization from IBAMA / SISBIO No. 33667-1. Once collected, the cadavers were fixed in 50% formaldehyde and kept for at least 14 days in a solution of 10% formaldehyde before dissections. After removal of skin, incisions in breast muscles and reflection of thoracic limbs allowed access to axillary space and the nerves could have trajects dissected individually to each muscle insertion. To improve visualization of the cervical and thoracic ventral roots that originated every single nerve, muscles that covered the intervertebral foramina, transverse processes and vertebral bodies were removed ventrally and the spinal cord exposed. Schematic drawings and photographic records documented the origin and branching of nerves. The twenty plexuses were resulted from connections between the ventral branches of the last three cervical spinal nerves (C6, C7 and C8) and first thoracic (T1). These branches derived the nerves suprascapular, subscapular, axillary, musculocutaneous, radial, median and ulnar to the intrinsic muscles and brachiocephalic, thoracodorsal, lateral thoracic, long thoracic, cranial and caudal pectoral nerves to the extrinsic muscles of the thoracic limb. It was found that the ventral rami of C7 were the main contributors in the formation of nerves (61.5%), followed by C8 (55.4%), T1 (41.2%) and C6 (30.8%). The t-test comparison between means at a significance level of 5% showed no differences in the origin of plexus when compared antimeres and sexes. Of the total of 260 dissected nerves, 68.8% originated by the combination of two or three roots, while only 31.2% were formed by a single root. The combination between C8 and T1 was the most frequent origin of nerves to the plexus (23.8%) in this species. Comparing the origin, branching and innervation area of the brachial plexus in C. thous with other domestic and wild species, there was a greater similarity with the domestic dog. These results may give the anatomical basis to diagnosis of neuromuscular disorders, anesthetic blocks techniques and comparative morphofunctional analyzes involving this species.

A cadaveric study to determine the minimum volume of methylene blue to completely color the nerves of brachial plexus in cats. An update in forelimb and shoulder surgeries

PURPOSE: To determine the minimum volume of methylene blue (MB) to completely color the brachial plexus (BP) nerves, simulating an effective anesthetic block in cats. METHODS: Fifteen adult male cat cadavers were injected through subscapular approach with volumes of 2, 3, 4, 5 and 6 ml in both forelimbs, for a total of 30 brachial plexus blocks (BPB). After infusions, the specimens were carefully dissected preserving each nervous branch. The measurement of the effective area was indicated by the impregnation of MB. Nerves were divided into four segments from the origin at the spinal level until the insertion into the thoracic limb muscles. The blocks were considered effective only when all the nerves were strongly or totally colored. RESULTS: Volumes of 2, 3 and 4 ml were considered insufficient suggesting a failed block, however, volumes of 5 and 6 ml were associated with a successful block. CONCLUSIONS: The injection of methylene blue, in a volume of 6 ml, completely colored the brachial plexus. At volumes of 5 and 6 ml the brachial plexus blocks were considered a successful regional block, however, volumes of 2, 3 and 4 ml were considered a failed regional block. .