Lateral-bilateral costal branch (R. costalis lateralis): a clinically relevant anatomical variation / Rama costal lateral bilateral (R. costalis lateralis): una variación anatómica clínicamente relevante

SUMMARY: The lateral costal branch (LCB) is a variation present in 15-30 % of the population. This blood vessel runs parallel and laterally to the internal thoracic artery from which it originates. Knowledge about the LCB is relevant for thoracic surgeons. In this study we present the findings from the dissection in a practical teaching exercise of the cadaver of a 62-year-old male. The thoracic contents were accessed by raising the anterolateral thoracic wall, the pulmonary pedicles were dissected and both lungs were removed. We observed bilaterally the trajectory of the LCB at the level of the medial axillary line parallel to the internal thoracic artery. On the right side, the LCB originates from the internal thoracic artery at the level of the first rib and extends to the eighth intercostal space, with a length of 26 cm and a caliber of 1.95 mm, communicating with the anterior and posterior intercostal arteries. The left branch originates from the internal thoracic close to their origin artery and extends until the sixth intercostal space, with a length of 14 cm and a caliber of 1.55 mm. it connects with the anterior and posterior intercostal arteries. On both sides the arteries were accompanied by a pair of satellite veins. The lateral costal arteries form part of the circulation of the thoracic wall, constituting an accessory arterial system with a trajectory parallel to the internal thorax and the aorta. Knowledge of it is relevant for invasive procedures, and myocardial revascularization procedure.

RESUMEN: La rama costal lateral es una variación presente en el 15-30 % de los casos, y sigue paralelo y lateral a la arteria torácica interna, de la cual se origina, siendo su conocimiento relevante para los cirujanos de tórax. Se presenta un hallazgo durante una disección en una actividad práctica docente, en un cadáver de sexo masculino de 62 años. Se accedió al contenido torácico levantando la pared esternocostal, procedimiento que comenzó con disección de la piel y musculatura hasta exponer ambas clavículas, se realizó un corte transversal de éstas en su tercio lateral para posteriormente realizar sección bilateral desde la primera hasta la octava costilla siguiendo la línea axilar anterior. Una vez revertida la pared esternocostal, se seccionaron los pedículos pulmonares, y se retiraron ambos pulmones. Se observó bilateralmente en la pared torácica el trayecto de un paquete vascular a nivel de la línea axilar media paralela a la arteria torácica interna. En el lado derecho se originaba a 2 cm del trayecto de la arteria torácica interna y se extendía hasta el octavo espacio intercostal con una longitud de 26 cm y un calibre de 1,95 mm, estableciendo comunicaciones con las arterias intercostales anteriores y posteriores, agotándose en ellas. La rama izquierda se originaba a 1,5 cm del trayecto iniciado por la arteria torácica interna extendiéndose hasta el sexto espacio intercostal; presentó un calibre de 1,55 mm y una de longitud de 14 cm, estableciendo comunicaciones con las arterias intercostales anteriores y posteriores, agotándose en ellas. En ambos lados las arterias eran acompañadas por un par de venas satélites. Las arterias costales laterales forman parte de la circulación de la pared torácica, constituyendo un sistema arterial accesorio al de la arteria torácica interna y la aorta. Su conocimiento es relevante en procedimientos invasivos, además de tener un alto valor docente y formativo.

Ramos colaterais do Arco aórtico do preá (Galea spixii Wagler, 1831) / Collateral branches of the aortic arch of galea (Galea spixii Wagler, 1831)

O preá é um roedor típico da caatinga pertencente à família Caviidae. Considerando a inexistência de dados sobre o arco aórtico do preá, foi realizado este estudo tendo como objetivo descrever os ramos colaterais do arco aórtico neste cavídeo, e dessa forma, contribuir com dados para biologia da espécie. Foram utilizados vinte preás machos provenientes de estudos anteriores e encontravam-se armazenados em freezer no Centro de Multiplicação de Animais Silvestres (CEMAS/UFERSA). Os animais foram descongelados, a cavidade torácica foi aberta, a aorta canulada e o sistema vascular lavado com solução salina e em seguida, injetado látex Neoprene corado com pigmento vermelho, amarelo ou branco. Posteriormente, os animais foram fixados em formol e depois de 72 horas, dissecados e analisados, sendo obtidos desenhos esquemáticos e os exemplares mais representativos fotografados. O arco aórtico do preá emitiu como ramos colaterais, o tronco braquiocefálico e a artéria subclávia esquerda. O tronco braquiocefálico originou na maioria das peças estudadas, a artéria carótida comum esquerda e o tronco braquiocarotídeo, do qual surgem as artérias subclávia direita e carótida comum direita. As artérias subclávias direita e esquerda em todos os animais estudados emitiram a artéria vertebral, a artéria torácica interna, a artéria cervical superficial, o tronco costocervical e a artéria axilar. O padrão da formação do arco aórtico do preá assemelhou-se ao observado em outros roedores, tais como no mocó, no porquinho-da-índia e na chinchila...

Galea spixii is a typical rodent of the caatinga belonging to the Caviidae family. Considering the lack of data on the aortic arch of the galea, this study aimed to describe the collateral branches of the aortic arch in this specie and to contributes to knowledge of its biology. Twenty males from previous studies were used which had been stored in a freezer at Multiplication Center of Wild Animals (CEMAS/UFERSA). The animals were thawed, the thoracic cavity was opened and the aorta cannulated vasculature was washed with saline and then injected with Neoprene latex colored with red pigment, yellow or white. Subsequently, the animals were fixed in formalin and after 72 hours dissected and analyzed, to obtain schematic drawings and the most representative samples were photographed. The cavy aortic arch issued as collateral branches, the brachiocephalic trunk and the left subclavian artery. The brachiocephalic trunk afforded in most of the specimens the left common carotid artery and the brachiocarotid trunk, where the right subclavian and right common carotid arteries arise. The right and left subclavian arteries in all animals studied issued the vertebral artery, internal thoracic artery, superficial cervical artery costocervical trunk and axillary artery. The pattern of formation of the aortic arch of galea was similar to that observed in other rodents, such as the kerodon, the guinea pig and chinchilla....

Ramos colaterais do Arco aórtico do preá (Galea spixii Wagler, 1831) / Collateral branches of the aortic arch of galea (Galea spixii Wagler, 1831)

O preá é um roedor típico da caatinga pertencente à família Caviidae. Considerando a inexistência de dados sobre o arco aórtico do preá, foi realizado este estudo tendo como objetivo descrever os ramos colaterais do arco aórtico neste cavídeo, e dessa forma, contribuir com dados para biologia da espécie. Foram utilizados vinte preás machos provenientes de estudos anteriores e encontravam-se armazenados em freezer no Centro de Multiplicação de Animais Silvestres (CEMAS/UFERSA). Os animais foram descongelados, a cavidade torácica foi aberta, a aorta canulada e o sistema vascular lavado com solução salina e em seguida, injetado látex Neoprene corado com pigmento vermelho, amarelo ou branco. Posteriormente, os animais foram fixados em formol e depois de 72 horas, dissecados e analisados, sendo obtidos desenhos esquemáticos e os exemplares mais representativos fotografados. O arco aórtico do preá emitiu como ramos colaterais, o tronco braquiocefálico e a artéria subclávia esquerda. O tronco braquiocefálico originou na maioria das peças estudadas, a artéria carótida comum esquerda e o tronco braquiocarotídeo, do qual surgem as artérias subclávia direita e carótida comum direita. As artérias subclávias direita e esquerda em todos os animais estudados emitiram a artéria vertebral, a artéria torácica interna, a artéria cervical superficial, o tronco costocervical e a artéria axilar. O padrão da formação do arco aórtico do preá assemelhou-se ao observado em outros roedores, tais como no mocó, no porquinho-da-índia e na chinchila.(AU)

Galea spixii is a typical rodent of the caatinga belonging to the Caviidae family. Considering the lack of data on the aortic arch of the galea, this study aimed to describe the collateral branches of the aortic arch in this specie and to contributes to knowledge of its biology. Twenty males from previous studies were used which had been stored in a freezer at Multiplication Center of Wild Animals (CEMAS/UFERSA). The animals were thawed, the thoracic cavity was opened and the aorta cannulated vasculature was washed with saline and then injected with Neoprene latex colored with red pigment, yellow or white. Subsequently, the animals were fixed in formalin and after 72 hours dissected and analyzed, to obtain schematic drawings and the most representative samples were photographed. The cavy aortic arch issued as collateral branches, the brachiocephalic trunk and the left subclavian artery. The brachiocephalic trunk afforded in most of the specimens the left common carotid artery and the brachiocarotid trunk, where the right subclavian and right common carotid arteries arise. The right and left subclavian arteries in all animals studied issued the vertebral artery, internal thoracic artery, superficial cervical artery costocervical trunk and axillary artery. The pattern of formation of the aortic arch of galea was similar to that observed in other rodents, such as the kerodon, the guinea pig and chinchilla.(AU)

[Histomorphometric differences between the left and right internal thoracic arteries in humans]. / Diferenças histomorfométricas entre as artérias torácicas internas esquerda e direita em humanos.

OBJECTIVE: The use of the left internal thoracic artery in coronary artery bypass surgery is currently recognized as the best option, providing lesser incidence of cardiovascular events and superior long-term survival. As a result, great expansion of bilateral internal thoracic artery (ITAs) grafts has been observed, with additional demonstration of improved long-term survival. Therefore the aim of this study was to examine and compare the histomorphometric structure among different segments of the left and right ITA. METHOD: Specimens of ITAs harvested from 18 cadavers were divided in nine proportional segments. Cuts of each segment had been stained with hematoxylin-eosin and Verhoeff-Van Gieson technique. The following parameters had been analyzed: perimeter of the arterial lumen, thickness of the intima, thickness of the media layer and amount of elastic fiber in the media layer. RESULTS: The perimeter of both ATIs decreases downstream its course, the proximal segments of the right ITA exhibit perimeter significantly greater than left ITA The analysis of the intima thickness revealed no significant difference between left and right ITA, except in the segment 9. The thickness of media layer showed no statistical difference between them, except in the segment 1. The number of elastic layers in the distal left ITA segments is significantly higher than right ITA. CONCLUSION: Data analyses from this study suggest structural differences between the left and right internal thoracic arteries.

Diferenças histomorfométricas entre as artérias torácicas internas esquerda e direita em humanos / Histomorphometric differences between the left and right internal thoracic arteries in humans

OBJETIVO: O uso do enxerto de artéria torácica interna esquerda (ATIE) é atualmente reconhecido como a melhor opção na cirurgia de revascularização miocárdica, proporcionando menor incidência tardia de eventos cardiovasculares e maior sobrevida. Conseqüentemente, houve grande incremento nas últimas décadas do uso bilateral das artérias torácicas internas (ATIs), com demonstração de melhora adicional de sobrevida em longo-termo. O objetivo desse trabalho foi estudar a estrutura histológica das ATIs esquerda e direita (ATID), com a análise histomorfométrica seqüencial e comparativa entre os segmentos das duas artérias. MÉTODOS: Foram estudados espécimes de ATIs retirados de 18 cadáveres, divididos em nove segmentos proporcionais. Cortes de cada segmento foram corados com técnica de hematoxilina-eosina e Verhoeff-Van Gieson. Foram analisados os seguintes parâmetros: perímetro da luz arterial, espessura da íntima, espessura da camada média e quantidade de fibras elásticas da camada média. RESULTADOS: O perímetro interno de ambas as ATIs diminuiu ao longo do percurso, dos segmentos mais proximais para os mais distais. Os segmentos proximais da ATID apresentaram perímetro significativamente maiores do que os da ATIE. A análise da espessura da íntima revelou não existir diferença significativa entre ATIE e ATID, exceto no segmento 1. A espessura da camada média diminuiu ao longo da extensão das ATIs, não havendo diferença estatística entre elas, exceto no segmento 9. O número de lâminas elásticas nos segmentos distais da ATIE foi estatisticamente superior ao da ATID. CONCLUSÃO: Portanto, os dados do presente estudo sugerem haver diferenças estruturais entre as ATIs direita e esquerda.

OBJECTIVE: The use of the left internal thoracic artery in coronary artery bypass surgery is currently recognized as the best option, providing lesser incidence of cardiovascular events and superior long-term survival. As a result, great expansion of bilateral internal thoracic artery (ITAs) grafts has been observed, with additional demonstration of improved long-term survival. Therefore the aim of this study was to examine and compare the histomorphometric structure among different segments of the left and right ITA. METHOD: Specimens of ITAs harvested from 18 cadavers were divided in nine proportional segments. Cuts of each segment had been stained with hematoxylin-eosin and Verhoeff-Van Gieson technique. The following parameters had been analyzed: perimeter of the arterial lumen, thickness of the intima, thickness of the media layer and amount of elastic fiber in the media layer. RESULTS: The perimeter of both ATIs decreases downstream its course, the proximal segments of the right ITA exhibit perimeter significantly greater than left ITA The analysis of the intima thickness revealed no significant difference between left and right ITA, except in the segment 9. The thickness of media layer showed no statistical difference between them, except in the segment 1. The number of elastic layers in the distal left ITA segments is significantly higher than right ITA. CONCLUSION: Data analyses from this study suggest structural differences between the left and right internal thoracic arteries.

[Internal mammary lymph nodes identification from isolated sternum of human cadaver]. / Identificação de linfonodos da cadeia mamária interna em esternos isolados de cadáver humano.

PURPOSE: To identify the lymph nodes positioned along the internal mammary vessels in isolated sternum of human cadaver and to standardize the surgical approach to those nodes, in order to establish anatomical landmarks to be used with the current techniques of mammary gland sentinel lymph node detection. METHODS: Ten sternum plates removed from unclaimed cadavers were used in this study. Sternal plates were removed using bilateral incisions of the ribs at the midclavicular lines. The characterization of the internal mammary vessels and the anatomical integrity of the parietal pleura were indispensable requirements during the procedure. RESULTS: A total of 29 lymph nodes were removed from the 2nd (13) and the 3rd (16) intercostals spaces. Almost 50% of all nodes collected were located medially to the vessels. CONCLUSION: The approach used is a reliable surgical technique for removing lymph node from sternal plates. The model is therefore valuable for breast surgeons training in sentinel node biopsy, an important procedure for breast cancer patients.

Estudo histomorfométrico seqüencial da artéria torácica interna esquerda / Sequential histomorphometric study of the left internal thoracic artery

OBJETIVO: O uso de enxertos de artéria torácica interna esquerda (ATIE) é atualmente reconhecido como a melhor opção na cirurgia de revascularização miocárdica, proporcionando menor incidência de eventos cardiovasculares e maior sobrevida. Entretanto, com a expansão do uso dos enxertos arteriais, faz se necessário melhor entendimento da estrutura histológica da ATIE. Portanto, o objetivo deste trabalho foi estudar a estrutura histológica da ATIE e a análise histomorfométrica seqüencial e comparativa entre os diferentes segmentos. MÉTODO: Foram estudados espécimes de ATIE retirados de 18 cadáveres, divididos em nove segmentos proporcionais. Cortes de cada segmento foram corados com técnica de Verhoeff-Van Gieson. Foram analisados os seguintes parâmetros: perímetro da luz arterial, espessura da íntima, espessura da camada média, número de fibras elásticas da camada média e a densidade de fibras elásticas. RESULTADOS: Os dados obtidos mostraram que perímetro da ATIE mostra tendência a diminuir ao longo de sua extensão, a espessura da íntima é aumentada nos segmentos proximais, a espessura da camada média diminui ao longo de sua extensão, o número de lâminas elásticas se concentra nos segmentos intermediários, a densidade de lâminas elásticas é diminuída nos segmentos proximais e distais. CONCLUSÃO: Portanto, os achados do presente estudo confirmam a heterogeneidade da estrutura histológica seqüencial da ATIE.

OBJECTIVE: The use of left internal thoracic artery (LITA) in coronary artery bypass surgery is currently recognized as the best option, providing lower incidences of cardiovascular events and superior long-term survival. Now, incremental utilization of these grafts makes a reassessment of its histological structure necessary. Therefore, the purpose of this study was to examine and compare the sequential histological structure of LITA. METHOD: Specimens of LITA harvested from 18 cadavers, divided into nine proportional segments, were studied. Cuts of each segment were stained by the Verhoeff-Van Gieson technique. The following parameters were analyzed: perimeter of the arterial lumen, thickness of the intima, thickness of the media layer, amount of elastic fiber in the media layer and the elastic fiber density. RESULTS: The collected data showed that perimeter of the LITA decreases downstream on its course, the thickness of the intima is increased in the proximal segments, the thickness of the media layer diminishes throughout its extension, the number of elastic fibers is concentrated in the intermediate segments and the density of elastic fibers is reduced in the proximal and distal segments. CONCLUSION: Therefore, the findings of the present study validate the heterogeneity of the LITA sequential histological structure.

[Comparative analysis of the flows of left internal thoracic artery grafts dissected in the pedicled versus skeletonized manner for myocardial revascularization surgery]. / Análise comparativa dos fluxos da artéria torácica interna esquerda dissecada na forma pediculada versus a forma esqueletizada em cirurgia de revascularização do miocárdio.

OBJECTIVE: To compare the free blood flow, caliber, and length of the left internal thoracic artery (LITA), dissected in the pedicled (P) and skeletonized (S) manners, during surgery before and after topical vasodilator (TV) application. METHODS: A randomized, blind, clinical trial was carried out with 50 patients undergoing elective myocardial revascularization to assess the use of the LITA in situ in its pedicled or skeletonized form. The 25 patients in the pedicled group (GP) had NYHA class II or III angina, ejection fraction (EF) of 50.8+/-9.2%, and 16 were of the male sex. The patients in the skeletonized group (SG) had NYHA class II angina, EF of 46.8+/-9.3%, and 19 were of the male sex. The measurements were performed before extracorporeal circulation and divided into 2 phases: phase 1 (before topical papaverine application) and phase 2 (15 min after topical application of papaverine, 2.5 mg/mL, at 37 degrees C). During the measurements, mean blood pressure, central venous pressure, and heart rate were monitored. RESULTS: The phase 1 and 2 results are as follows: 1) PG: blood flow, 46+/-16 and 77+/-28 mL/min; caliber, 1.4+/-0.1 and 1.7+/-0.1 mm, respectively; 2) SG: blood flow, 57+/-27 and 97+/-35 mL/min; and caliber, 1.4+/-0.1 and 1.8+/-0.2 mm, respectively. No significant differences were observed in length. CONCLUSION: The LITA in SG had a significant increase in blood flow and caliber after the use of TV compared with blood flow and caliber in PG (P=0.03 and P=0.01, respectively).

Análise comparativa dos fluxos da artéria torácica interna esquerda dissecada na forma pediculada versus a forma esqueletizada em cirurgia de revascularização do miocárdio / Comparative analysis of the flows of left internal thoracic artery grafts dissected in the pedicled versus skeletonized manner for myocardial revascularization surgery

OBJETIVO: Comparar os fluxos livres, os calibres e os comprimentos da artéria torácica interna esquerda (ATIE) pediculada (P) e esqueletizada (E) no transoperatório antes e depois da aplicação do vasodilatador tópico (VT). MÉTODOS: Em ensaio clínico randomizado e cego foram estudados 50 pacientes submetidos a cirurgia de revascularização miocárdica eletivas quanto ao emprego da ATIE in situ nas formas P ou E. Dos 25 pacientes no grupo pediculada (GP), 16 eram do sexo masculino, apresentando angina classe II e III (NYHA) e fração de ejeção (FE) de 50,8 ± 9,2 por cento. No grupo esqueletizada (GE), 19 pacientes eram do sexo masculino, possuindo angina classe II e FE de 46,8 ± 9,3 por cento. As medidas foram realizadas pré-circulação extracorpórea e divididas em duas fases: fase 1 (antes) e fase 2 (após 15 min da aplicação da papaverina tópica a 2,5 mg/ml a 37ºC). Durante as aferições, eram monitoradas a pressão arterial média, pressão venosa central e freqüência cardíaca. RESULTADOS: O GP apresentou fluxo de 46±16 e 77±28 ml/min e calibre de 1,4±0,1 e 1,7±0,1 mm nas fases 1 e 2, e o GE, 57±27 e 97±35 ml/min de fluxo e 1,4±0,1 e 1,8±0,2 mm de calibre, respectivamente, não havendo diferenças significativas no desfecho comprimento. CONCLUSAO: ATIE E demonstrou um aumento significativo no fluxo e calibre, após o uso de VT com p=0,03 e p=0,01 respectivamente, comparados com a ATIE P.

Perforator flap breast reconstruction using internal mammary perforator branches as a recipient site: an anatomical and clinical analysis.

A variety of useful recipient sites exist for breast reconstruction with free flaps, and correct selection remains a significant decision for the surgeon. Among the main pedicles, the disadvantages of the internal mammary vessels are the necessity of costal cartilage resection and the impairment of future cardiac bypass. This study was designed to reduce morbidity and to seek alternative recipient vessels. In the anatomical part of the study, 32 parasternal regions from 16 fresh cadavers were used. The locations and components of internal mammary perforator branches were measured and a histomorphometric analysis was performed. In the clinical part of the study, 36 patients underwent 38 deep inferior epigastric perforator (DIEP) flap and two superior gluteal artery perforator flap breast reconstructions (31 immediate and four bilateral). The recipient vessels were evaluated. In the anatomical study, there were 22 perforating vessels, with 14 (63.6 percent) on the second intercostal space and 11 (50 percent) with one artery and vein. The average (+/-SD) internal and external perforator artery diameters were 598.48 +/- 176.68 microm and 848.97 +/- 276.68 microm, respectively. In the clinical study, 13 successful anastomoses (32.5 percent) were performed at the internal mammary perforator branches (second and third intercostal spaces) with 12 DIEP flaps and one superior gluteal artery perforator flap (all performed as immediate reconstructions). One case of intraoperative vein thrombosis and one case of pedicle avulsion during flap molding were observed. The anatomic and clinical studies demonstrated that the internal mammary perforator branch as a recipient site is a further refinement to free flap breast reconstruction. However, it is neither a reproducible technique nor potentially applicable in all patients. Preoperative planning between the general surgeon and the plastic surgeon is crucial to preserve the main perforator branches during mastectomy. The procedure was not demonstrable in late reconstructions. The main advantages of internal mammary perforator branches used as recipient sites are sparing of the internal mammary vessels for a possible future cardiac surgery, prevention of thoracic deformities, and reduction of the operative time by limited dissection. Despite this, limited surgical exposure, caliber incompatibility, and technical difficulties have to be considered as the main restrictions.

Size of the collateral intercostal artery in adults: anatomical considerations in relation to thoracocentesis and thoracoscopy.

No detailed descriptions exist of the collateral intercostal artery which can provide an accurate anatomical basis for ensuring a low rate of vascular complications during thoracocentesis and thoracoscopy. Consequently the present study was undertaken to provide information on the origin, size and topographic relationships of the collateral intercostal artery. Ninety cadaveric adult intercostal spaces were dissected using standard procedures. The collateral intercostal arteries were exposed throughout their full length and measured at the points within the intercostal spaces considered to be the most important for clinical purposes. The posterior intercostal arteries and their collateral branches were observed to decrease in size from posterior to anterior; however, no significant differences were present in their size in the first four intercostal spaces. Based on these findings the usual thoracocentesis or thoracoscopy technique, in which it is recommended that puncture is done as close as possible to the superior margin of the inferior rib, may lead to collateral intercostal artery laceration and considerable bleeding. A subtle, but important, modification to this technique is suggested aimed at achieving safer access to the intercostal space. In the modified technique, the puncture should be made in the middle of the intercostal space, thereby reducing the possibility of laceration of the collateral intercostal artery.

Aspectos morfo-funcionales de arterias y venas mamarias usadas en revascularización cardíaca / Morphologic and functional aspects of mammary arteries and veins used for myocardial revascularization surgery

Los vasos sanguíneos están inervados por el sistema nervioso simpático autonómico. La fisiología y neuroquímica de los nervios perivasculares humanos ha sido poco estudiada. Con el propósito de contribuir a las investigaciones sobre la fisiología de la co-transmisión simpática humana, esta investigación se concentró en: i) estudiar el contenido de los neurotransmisores simpáticos, noradrenalina (NA) y neuropéptido y (NPY) en vasos de arteria y vena mamaria interna humana; ii) detectar mediante técnicas inmunohistoquímicas la presencia de los nervios simpáticos perivasculares de estos vasos; iii) caracterizar la reactividad vascular de la arteria mamaria interna, como un modelo usado en implantes de revascularización cardíaca. Se estudió además, la vena mamaria derivada de la misma biopsia. La arteria y vena mamaria contienen 50 veces más NA que NPY, el contenido de NA y NPY en la arteria y en la vena es muy similar. La detección inmunohistoquímica de los nervios simpáticos demuestra que éstos se localizan entre las capas musculares de los vasos. La estimulación de los filetes nerviosos perivasculares produce respuestas vasomotoras sensibles a tetrodotoxina y guanetidina, lo que es consistente con la naturaleza simpática de la respuesta, confirmando que parte de los nervios perivasculares son simpáticos. Los músculos lisos se estimulan por NA y por ATP, que sólo no contrae, facilita las respuestas vasomotoras de la NA. Estos resultados permiten concluir que en la arteria y la vena mamaria interna humana NA, ATP y NPY cooperan en la respuesta vasomotora, evidenciando la co-transmisión simpática en humanos

Variaciones del tronco braquicefálico común en equinos / Variation of common brachiocephalic trunk in equine

Los orígenes de la arteria intercostal superior apartir de la arteria axilar o bien de la arteria cervucal profunda (ACP) descriras por CHAVEAU & ARLONG (1905 por ciento) como anomalías, no fueron observados en nuestra experiencia. El desplazamiento de la arteria escapular dorsal hacia el 3º espacio intercostal y de la arteria cervical profunda hacia el 2º espacio intercostal descritos por este autor, fueron observados en los casos examinados. A su vez, el origen en común de la arteria cervical superficial y arteria torácica externa no fue observado. Si bien la ATE puede originarse de la arteria torácica interna como describe CHAVEAU & ARLOING, en nuestras diseccionesfue observado como colateral de la arteria torácica interna. El comportamiento de la arteria costocervical y arteria cervical profunda cuanto a su origen, a partir de un tronco común, Coincide con las variaciones descritas por GETTY, (1982). Las aseveraciones efectuadas por BOSSI et al., (1903) sobre el mayor porcentaje de variaciones en la arteria costocervical y arteria torácica externa, no coinciden con nuestras descripciones. Existe coincidencia con BOSSI et al. En cuanto al uso del término <> y no el de arteria subclavia en perisodáctilos domésticos, ya que no existe una clavícula perfectamente desarrollada que justifique tal denominación. Los datos obtenidos del matrial procesado, indican variaciones a nivel de las colaterales intatóracicas, entre las que merecen especial mención las arterias costo cervical y cervical profunda, en las cuales fue observado el mayor número de variaciones, en su origen, trayecto y terminación. El conocimiento de sus variaciones es importante tanto en el campo de la Anatomía como el de la Cirugía , ya que permite evitar errores, a veces insalvables, durante el acto quirúrgico de patologías de la región torácica

Surgical anatomy of the internal thoracic artery.

BACKGROUND: The internal thoracic artery (ITA) has become increasingly important in coronary artery bypass grafting due to the excellent long-term results. This study reviews its anatomic characteristics. METHODS: The ITAs of 100 cadavers were examined and their origin, relation to the phrenic nerve, presence of lateral costal branch; origin of pericardiacophrenic arteries, length, level and type of ITA termination, relation with the transverse muscle of thorax, collateral parietal branches, and distance between the ITA and sternal margins were studied. RESULTS: The ITA was present in all cases, originating directly from the subclavian artery or from a common trunk with other arteries. Its length was 20.4 cm on average, and the most frequent level of termination was at the sixth intercostal space, existing as a bifurcation in 93% and as a trifurcation in 7%. The pericardiacophrenic artery originated from the ITA in 89%. The lateral costal branch was present in 15% of the cases. The ITA was covered by the transverse muscle of the thorax for 7.5 cm (average) and was crossed anteriorly by the phrenic nerve in 70.0%. CONCLUSIONS: Information provided by this study may contribute to knowledge of its anatomic characteristics and in turn help prevent complications in ITA dissections.