Lesiones del nervio torácico largo de Bell. Revisión de conceptos terapéuticos / Long thoracic nerve of Bell. Review of therapeutic management

Las lesiones del nervio torácico producen parálisis del serrato anterior y originan una deformidad característica (escápula alata), que genera debilidad y alteraciones importantes en la movilidad del hombro. En esta revisión, se analizan conceptos sobre anatomía, etiología, presentación clínica y alternativas terapéuticas.

The long thoracic nerve injuries are manifested by a characteristic deformity called scapula alata, causing weakness, and impaired shoulder mobility. In this review current concepts of the anatomy, etiology, clinical presentation and therapeutic management are analyzed.

The existence of axillary arch in human fetus and applied importance and clinical implications in the axillary brachial plexus blocks / La existencia de arco axilar en el feto humano y la importancia aplicadae implicancias clínicas en los bloques de plexo braquial

Axillary arch is the most common muscle variation of axillary fossa that gains importance for regional interventional procedures, screening methods and physical examination. In order to avoid malpractice the variations must be borne in mind. This study has been planned to research the frequency and the features of the axillary arch in human fetus, to mention the potential clinical and functional significance of axillary arch while applying axillary brachial plexus block and reflect on possible complications. Axillary fossa was examined with a stereomicroscope in 20 upper extremities of ten human fetuses. The gestation ages ranged from 16 to 36 weeks. Axillary arch was determined in 2/20 specimen unilaterally. In both specimen, muscular slip detached from latissimus dorsi, passed anterior neurovascular bundle and ended posterior pectoralis major tendon and lateral border of intertubercular groove. In one specimen axillary arch was innervated with medial pectoral nerve whereas the other one did not have a particular innervating nerve branch. The possible effects of axillary arch in the axillary brachial plexus block applications are discussed. Arcus axillaris may have a potential clinical and functional significance with regard the axillary brachial plexus block applications and may have possible effects on failure rate and acute complications. Also, we think that this fetus study which the pure structure of the muscles without any usage effect can be observed will be beneficial regarding this topic.

El arco axilar es la variación muscular más común de la fosa axilar, siendo de importancia para la región en los procedimientos de intervención, los métodos de selección y el examen físico. Con el fin de evitar las negligencias se debe tener en cuenta las variaciones. El objetivo de este estudio fue determinar la frecuencia y las características del arco axilar en el feto humano. Es necesario mencionar la importancia del potencial clínico y funcional del arco axilar en la aplicación de bloqueo axilar del plexo braquial y sus posibles complicaciones. La fosa axilar fue examinada bajo microscopio estereoscópico en 20 miembros superiores de diez fetos humanos. La edad de gestación varió de 16 a 36 semanas. El arco axilar se observó unilateralmente en 2/20 especímenes. En ambos especímenes el músculo cruzó anteriormente el paquete neurovascular y terminó en el tendón del músculo pectoral mayor y en el margen lateral del surco intertubercular. En un especimen el arco axilar se encontraba inervado por el nervio pectoral medial, mientras que en el otro no existía una determinado ramo del nervio. Se discuten los posibles efectos del arco axilar en las aplicaciones de bloqueo axilar del plexo braquial. Puede tener un significado potencial clínico y funcional, en lo que se refiere a la aplicación de bloqueo axilar del plexo braquial y aademás producir efectos de complicaciones agudas.

Back to the debate: sternalis muscle / Volver al debate: músculo esternal

The sternalis muscle (SM) is an anatomical variant found in the anterior thoracic wall. While the attachment sites of SM are generally agreed upon, the innervation and function of this muscle are not well established. Cadaveric and surgical explorations to date report that SM is innervated by either the pectoral nerves or the anterior branches of the intercostal nerves, or a combination of both. Knowledge of SM is relevant to health care providers specialising in imaging and/or surgery of the anterior thoracic wall. This paper aims to raise awareness in the medical community of the clinical relevance of SM through two case reports and a brief literature review.

El músculo esternal (ME) es una variante anatómica en la pared torácica anterior. Mientras que los sitios de fijación del ME estan acordados, la inervación y la función de este músculo no están bien establecida. Exploraciones cadavéricas y quirúrgicas han informado que el ME está inervado por los nervios pectorales o ramos anteriores de los nervios intercostales, o una combinación de ambos. El conocimiento del SE es relevante para los proveedores de atención de salud especializada de imágenes y/o cirugía de la pared torácica anterior. Este documento tiene como objetivo crear conciencia en la comunidad médica de la relevancia clínica de ME a través de dos reportes de caso y una breve revisión bibliográfica.

Análise comparativa da origem do plexo branquial de catetos (Tayassu tajacu) / Comparative analysis of the origin of the brachial plexus of the collared peccary (Tayassu tajacu)

O cateto (Tayassu tajacu) pertence à familia Tayassui-dae e é caracterizado por "colar" de pêlos brancos ao redor do pescoço que se estende bilateralmente cranialmente aos ombros. Pode ser encontrado do sudoeste dos Estados Unidos da América até a Argentina. Na literatura verificou-se a falta de dados a respeito da anatomia funcional do cateto especialmente trabalhos que envolvem a anatomia do plexo braquial. Visando elucidar o comportamento do plexo braquial do cateto e com a finalidade de contribuir para o desenvolvimento da anatomia comparada, realizou-se esta pesquisa. Utilizou-se 30 animais de idades diferentes (13 fêmeas e 17 machos) provenientes do Centro de Multiplicação de Animais Silvestres, Universidade Federal Rural do Semi-árido, Mossoró, Rio Grande do Norte. Após o abate, realizou-se a dissecação bilateral dos plexos braquiais e registraram-se os resultados através de desenhos esquemáticos e as disposições agrupadas em tabelas para subseqüente análise estatística e obtidas as freqüências percentuais. Observou-se que o plexo braquial de catetos é resultado das comunicações estabelecidas, principalmente, entre os ramos ventrais dos três últimos nervos espinhais cervicais (C6, C7 e C8) e dos dois primeiros nervos espinhais torácicos (T1 e T2), tendo uma contribuição do quarto e quinto nervos cervicais em 16,67 por cento e 50,00 por cento dos casos, respectivamente. Em 40,00 por cento das dissecações a formação do plexo, mais freqüente, foi do tipo C6, C7, C8, T1 e T2. Os principais nervos derivados do plexo braquial dos catetos e suas respectivas origens foram: nervo supraescapular (C6 e C7), nervo subscapular (C5, C6 e C7 ou C6 e C7), nervo axilar (C6 e C7), nervo músculocutâneo (C7 e C8), nervo mediano (C7, C8, T1 e T2), nervo ulnar (C8, T1 e T2), nervo radial (C8, T1 e T2), nervos peitorais craniais (C7) e caudais (C7 e C8), nervo toracodorsal (C6, C7 e C8), nervo torácico longo (C7 e C8) e nervo torácico lateral (C8, T1 e T2).

Collared peccary (Tayassu tajacu) belongs to the Tayassuidae family, characterized by a "collar" of white hairs that cross behind the neck and extend bilaterally in front of the shoulders. It can be found from south-western United States to Argentina. In the literature a shortage of data is verified regarding the functional anatomy of the collared peccaries, especially of studies that involve the anatomy of the brachial plexus. To elucidate the behavior of this plexus of collared peccaries and with the purpose to contribute for the development of compared anatomy, this study was accomplished. Thirty animals of different ages were used (17 males and 13 females) coming from the Wild Animal Multiplication Center of the "Universidade Federal Rural do Semiárido" Mossoró, Rio Grande do Norte, Brazil. After slaughter bilateral dissection of the brachial plexuses took place, and the results were registered in schematic drawings and the dispositions grouped in tables for subsequent statistical analysis based on the percentile frequency. It was found that the Plexus brachialis of collared peccaries is the result of established communications, mainly among the Rami ventrales of the last three cervical nerves and of the first two thoracic nerves, having a contribution of the fourth and fifth cervical nerves in 16.67 percent and 50.00 percent of the cases, respectively. In 40.00 percent of the dissections the most frequent plexus was of the type C6, C7, C8, T1 and T2. The main nerves derived from brachial plexus of the collared peccaries and its respective origins had been: Nervus suprascapularis (C6, C7), Nn. subscapulares (C5, C6 e C7 or C6 e C7), N. axillaris (C6, C7), N. musculocutaneus (C7, C8), N. medianus (C7, C8, T1, T2), N. radialis (C8, T1, T2), N. ulnaris (C8, T1, T2), cranialis (C7), and caudalis (C7, C8) Nn. pectorales , N. thoracodorsalis (C6, C7, C8), N. thoracicus longus (C7, C8), and N. thoracicus lateralis (C8, T1, T2).

Análise comparativa da origem do plexo branquial de catetos (Tayassu tajacu) / Comparative analysis of the origin of the brachial plexus of the collared peccary (Tayassu tajacu)

O cateto (Tayassu tajacu) pertence à familia Tayassui-dae e é caracterizado por "colar" de pêlos brancos ao redor do pescoço que se estende bilateralmente cranialmente aos ombros. Pode ser encontrado do sudoeste dos Estados Unidos da América até a Argentina. Na literatura verificou-se a falta de dados a respeito da anatomia funcional do cateto especialmente trabalhos que envolvem a anatomia do plexo braquial. Visando elucidar o comportamento do plexo braquial do cateto e com a finalidade de contribuir para o desenvolvimento da anatomia comparada, realizou-se esta pesquisa. Utilizou-se 30 animais de idades diferentes (13 fêmeas e 17 machos) provenientes do Centro de Multiplicação de Animais Silvestres, Universidade Federal Rural do Semi-árido, Mossoró, Rio Grande do Norte. Após o abate, realizou-se a dissecação bilateral dos plexos braquiais e registraram-se os resultados através de desenhos esquemáticos e as disposições agrupadas em tabelas para subseqüente análise estatística e obtidas as freqüências percentuais. Observou-se que o plexo braquial de catetos é resultado das comunicações estabelecidas, principalmente, entre os ramos ventrais dos três últimos nervos espinhais cervicais (C6, C7 e C8) e dos dois primeiros nervos espinhais torácicos (T1 e T2), tendo uma contribuição do quarto e quinto nervos cervicais em 16,67 por cento e 50,00 por cento dos casos, respectivamente. Em 40,00 por cento das dissecações a formação do plexo, mais freqüente, foi do tipo C6, C7, C8, T1 e T2. Os principais nervos derivados do plexo braquial dos catetos e suas respectivas origens foram: nervo supraescapular (C6 e C7), nervo subscapular (C5, C6 e C7 ou C6 e C7), nervo axilar (C6 e C7), nervo músculocutâneo (C7 e C8), nervo mediano (C7, C8, T1 e T2), nervo ulnar (C8, T1 e T2), nervo radial (C8, T1 e T2), nervos peitorais craniais (C7) e caudais (C7 e C8), nervo toracodorsal (C6, C7 e C8), nervo torácico longo (C7 e C8) e nervo torácico lateral (C8, T1 e T2).

Collared peccary (Tayassu tajacu) belongs to the Tayassuidae family, characterized by a "collar" of white hairs that cross behind the neck and extend bilaterally in front of the shoulders. It can be found from south-western United States to Argentina. In the literature a shortage of data is verified regarding the functional anatomy of the collared peccaries, especially of studies that involve the anatomy of the brachial plexus. To elucidate the behavior of this plexus of collared peccaries and with the purpose to contribute for the development of compared anatomy, this study was accomplished. Thirty animals of different ages were used (17 males and 13 females) coming from the Wild Animal Multiplication Center of the "Universidade Federal Rural do Semiárido" Mossoró, Rio Grande do Norte, Brazil. After slaughter bilateral dissection of the brachial plexuses took place, and the results were registered in schematic drawings and the dispositions grouped in tables for subsequent statistical analysis based on the percentile frequency. It was found that the Plexus brachialis of collared peccaries is the result of established communications, mainly among the Rami ventrales of the last three cervical nerves and of the first two thoracic nerves, having a contribution of the fourth and fifth cervical nerves in 16.67 percent and 50.00 percent of the cases, respectively. In 40.00 percent of the dissections the most frequent plexus was of the type C6, C7, C8, T1 and T2. The main nerves derived from brachial plexus of the collared peccaries and its respective origins had been: Nervus suprascapularis (C6, C7), Nn. subscapulares (C5, C6 e C7 or C6 e C7), N. axillaris (C6, C7), N. musculocutaneus (C7, C8), N. medianus (C7, C8, T1, T2), N. radialis (C8, T1, T2), N. ulnaris (C8, T1, T2), cranialis (C7), and caudalis (C7, C8) Nn. pectorales , N. thoracodorsalis (C6, C7, C8), N. thoracicus longus (C7, C8), and N. thoracicus lateralis (C8, T1, T2).

Sistematização dos territórios nervosos do plexo braquial em chinchila (Chinchilla lanigera) / The nervous territories of the brachial plexus in Chinchilla lanigera

Para a realização do estudo referente ao plexo braquial (PB) e territórios nervosos do membro torácico de chinchila (Chinchilla lanigera) foram utilizados 10 animais de sete a 11 meses de idade. Tendo a pele sido retirada, procedeu-se a identificação da musculatura do membro torácico, região peitoral e parede torácica e abdominal. Subseqüentemente, foram aplicadas compressas de solução de ácido acético glacial 3% nas referidas regiões, com o intuito de melhorar a visualização dos nervos. Nos animais analisados notou-se a emergência do PB a partir do sexto nervo cervical até o primeiro torácico. Destas quatro raízes se formam os troncos dos nervos cujos ramos ventrais constituirão seu arranjo e distribuição territorial. Destes quatro troncos surgem os 12 nervos que constituem o PB, estes podem ser formados por apenas um segmento medular: unissegmentar (supraescapular, peitoral cranial e toracodorsal) ou por mais de dois segmentos: plurissegmentar (subescapular, axilar, músculo-cutâneo, torácico lateral, peitoral caudal, torácico longo, mediano, ulnar e radial). Com isso se observou constância na origem, inervação da musculatura, articulações e ossos do membro torácico, podendo-se afirmar a existência de um padrão claramente definido na delimitação dos territórios nervosos.

For the study concerning the Brachial Plexus (BP) and nervous territories of chinchillas (Chinchilla lanigera) 10 animals were used. After the removal of the skin, the indetification of the thoracic limb, pectoral area and thoracic and abdominal walls was made. Then, compresses of glacial acetic acid at 3% were applied to these areas, in order to improve the observation of the nerves. In the studied animals, the emergence of the BP was observed to be from the sixth cervical nerve to the first thoracic nerve. These four roots make the trunks of the nerves whose ventral branches constitute their arrange and territorial distribution. From these four trunks arise the 12 nerves that constitute the BP. These nerves may be formed by a single medullary segment - monosegmentar (suprascapular, cranial pectoral, thoracodorsal), or by two ou more segments, plurisegmentar (subscapular, axillary, musculocutaneous, lateral thoracic, caudal pectoral, long thoracic, median, ulnar and radial). Therefore, constancy in origin, muscle, joint and bone innervation was observed, and can confirm the existence of a clearly defined pattern of the delimitation of nervous territories.

Variations of the ventral rami of the brachial plexus

We studied the variations in the ventral rami of 152 brachial plexuses in 77 Korean adults. Brachial plexus were composed mostly of the fifth, sixth, seventh and eighth cervical nerves and the first thoracic nerve (77.0%). In 21.7% of the cases examined, the fourth, fifth, sixth, seventh and eighth cervical and the first thoracic nerves contributed to the plexus. A plexus composed of the fourth, fifth, sixth, seventh and eighth cervical and the first and second thoracic nerves, and a plexus composed of the fifth, sixth, seventh eighth cervical nerves were also observed. The plexuses were classified into three groups according to cephalic limitation, and the plexus of group 2 in which the whole fifth cervical nerve enters the plexus, were observed the most frequent. The average diameter of the sixth and the seventh cervical ventral rami of the plexus was greatest and that of the fifth cervical was smallest. The largest nerve entering the plexus was the sixth or the seventh cervical nerve in about 79% of cases. The dorsal scapular nerve originated from the fifth cervical ventral ramus in 110 cases (75.8%). The long thoracic nerve was formed by joining of roots from the fifth, sixth, and seventh cervical nerves in 76.0% of cases. Also, a branch to the phrenic nerve, the suprascapular nerve, a nerve to the pectoralis major muscle and a nerve to the subscapular muscle arising from the ventral rami of the plexus were observed.