Anatomy of the lymphatic drainage of the upper limb and breast and its role in lymphedema prevention after breast cancer treatment / Anatomía del drenaje linfático del miembro superior y de la mama y su papel en la prevención del linfedema después del tratamiento del cáncer de mama

The surgical treatment of breast cancer has been enhanced throughout the years in order to offer oncologically safer and more effective results with lower esthetic impact and fewer sequelae. The lymphedema of the upper limb is still an iatrogenic result of great incidence and morbidity after this treatment. A possible existence of independent breast and upper limb lymphatic pathways has become the issue of many researchers willing to minimize its occurrence. This review aims to compare the lymphatic pathways in the axilla described by traditional anatomy books and recently published articles about Axillary Reverse Mapping (ARM). With this purpose, a comparative table was made with the descriptions found in books and articles, a statistic table of the data collected, a flowchart of anastomoses among nodes and an analytical drawing of the most statistically mentioned drained areas. It was observed that there is great variability in the descriptions of drainage and anastomoses among the lymph nodes in the references used, so there should be a consensus of a universal description which also assembles possible anatomical variations. Furthermore, the findings brought about by recent studies show possible anastomoses among pathways and lymph nodes, however they have not been taken into consideration when ARM was initially proposed. Therefore, the axillary resection with the preservation of the posterior and lateral axillary lymph nodes is theoretically possible to avoid lymphedema of the upper limb, but the development of an updated universal description that involves all possible anatomical variations will provide a safer and more effective treatment.

El tratamiento quirúrgico del cáncer de mama ha mejorado a lo largo de los años con el fin de ofrecer resultados oncológicamente más seguros y eficaces con menor impacto estético y menos secuelas. El linfedema del miembro superior es todavía un resultado iatrogénico de gran incidencia y morbilidad después de este tratamiento. La posible existencia de vías linfáticas de mama y de los miembros superiores independientes se ha convertido en un tema central de muchas investigaciones para lograr minimizar su ocurrencia. Esta revisión tiene como objetivo comparar las vías linfáticas en la axila descritas en los libros de anatomía tradicionales con artículos recientemente publicados sobre Mapeo Reverso Axilar (MRA). Con este fin, se realizó un cuadro comparativo con las descripciones y un diagrama de flujo de las anastomosis entre los nodos, además de un dibujo analítico de las áreas drenadas estadísticamente más mencionadas. Se observó que existe una gran variabilidad en las descripciones sobre el drenaje y las anastomosis entre los nodos linfáticos, por lo que la descripción universal no debería ser considerada un consenso debido a que también presenta posibles variaciones anatómicas. Por otra parte, los resultados producidos por los estudios recientes muestran posibles anastomosis entre las vías y los nodos linfáticos, sin embargo, no se han tomado en consideración cuando se propuso inicialmente el MRA. Por lo tanto, la resección axilar con la preservación de la parte posterior y los nodos linfáticos axilares laterales es teóricamente posible para evitar el linfedema del miembro superior, pero el desarrollo de una descripción universal actualizada, que incluya todas las posibles variaciones anatómicas, proporcionará un tratamiento más seguro y eficaz.

Unusual relationship between the piriform muscle and sciatic, inferior gluteal and posterior femoral cutaneous nerves / Relación inusual entre el músculo piriforme y los nervios isquiático, glúteo inferior y cutâneo femoral posterior

Piriformis muscle syndrome has been increasingly recognized as a cause of leg pain. Overuse, strain, or anatomical variations of the relationship between the nerve and the piriformis muscle are thought to be the underlying causes of the entrapment of the sciatic nerve. We report a variation not previously described which was found during a routine dissection. During routine dissection of the left gluteal region of an adult male cadaver we observed a high division of the sciatic nerve and the presence of an accessory piriformis muscle. The sciatic nerve divided beneath the piriformis muscle and the common fibular nerve passed over the accessory piriformis muscle, whereas the tibial nerve reflected anteriorly to pass between the accessory piriformis and the superior gemellus muscle. Additionally, both nerves communicated with a side branch under the inferior border of the accessory piriformis muscle and the inferior gluteal nerve originated from the fibular nerve. Anatomical variations in the relationship between the piriformis muscle and the sciatic nerve may be present in up to 17% of the population. Six different variations have been described and none of them is similar to our description. Though complete understanding of the physiopathology of the piriformis muscle syndrome remains to be elucidated, knowledge of the possible anatomical variations may be useful for its adequate diagnosis and treatment.

El síndrome del músculo piriforme se ha reconocido cada vez más como una causa de dolor en los miembros inferiores. Tensión excesiva o variaciones anatómicas del nervio y del músculo piriforme se cree son las causas subyacentes de pinzamiento del nervio isquiático. Se presenta una variación no descrita anteriormente. Durante una disección de rutina en un cadáver de sexo masculino, se observó una división más alta del nervio isquiático y la presencia de un músculo piriforme accesorio. El nervio isquiático se dividía bajo el músculo piriforme y el nervio fibular común pasaba sobre el músculo piriforme accesorio. Por otra parte, el nervio tibial cruzaba entre los músculos piriforme accesorio y gemelo superior. Además, ambos nervios se comunicaban con un ramo lateral bajo el margen inferior del músculo piriforme accesorio y el nervio glúteo inferior se originaba desde el nervio fibular. Variaciones anatómicas y relaciones entre el músculo piriforme y nervio isquiático pueden estar presentes hasta en el 17% de la población. Seis variaciones diferentes se han descrito en este artículo y ninguna es similar a nuestra descripción. A pesar del completo entendimiento de la fisiopatología del síndrome del músculo piriforme, aún queda por esclarecer y conocer las posibles variaciones anatómicas que pueden ser útiles tanto para su diagnóstico como para el tratamiento adecuado.

A rare pattern of brachial artery variation: case report / Un patrón de variación raro de la arteria braquial: reporte de caso

Unlike the venous system, variations in arterial anatomy are less frequent and most of them affect visceral arteries. In limbs, variations of the brachial artery are the most reported and at least six different patterns have been described so far. The commonest is the superficial brachial artery which lies superficially to the median nerve. Much less prevalent are the high origin of the radial artery (brachioradial artery) or the existence of a doubled brachial artery (accessory brachial artery). We present a previously undescribed pattern of brachial artery variation. During dissection of the right upper limb of a 60 year-old male embalmed cadaver, we found the bifurcation of the brachial artery in the proximal portion of the middle third of the arm. Its medial branch reaches the medial aspect of the arm, posterior to the median nerve. Afterwards, this medial branch redirects laterally and crosses again the median nerve, this time lying anterior to the nerve until it reaches the lateral aspect of the arm. At the elbow level, the medial branch originates the radial artery. The lateral branch of the brachial artery remains lateral to the median nerve and continues as ulnar artery and originates the interosseus artery.

A diferencia del sistema venoso, las variaciones en la anatomía arterial son menos frecuentes y la mayoría afecta a las arterias viscerales. En los miembros, las variaciones de la arteria braquial son las más informadas y por lo menos seis diferentes patrones han sido descritos. La variación más común es de la arteria braquial superficial que está superficialmente al nervio mediano. Mucho menos frecuente es el origen alto de la arteria braquial radial (la arteria braquiorradial) o la existencia de una arteria braquial doble (arteria braquial accesoria). Presentamos un patrón de variación no descrito de la arteria braquial observado durante la disección del miembro superior derecho de un cadáver en un hombre de 60 años de edad. Encontramos la bifurcación de la arteria braquial en la porción medial del brazo, pasando posterior al nervio mediano. Luego, esta rama medial se redirecciona lateralmente y cruza nuevamente al nervio mediano, esta vez, anterior a él, hasta alcanzar la región lateral del brazo. A nivel de la flexura del codo, la rama medial origina la arteria radial. La rama lateral de la arteria braquial se mantiene lateral al nervio mediano y continúa como arteria ulnar y origina la arteria interósea común.

Brachial artery variation: a rare pattern

Unlike venous system, variations in arterial anatomy are less frequent and most of them affect visceral arteries.In limbs, variations of the brachial artery are the most reported and at least six different patterns have beendescribed so far. The commonest is the superficial brachial artery, which lies superficially to the median nerve.Much less prevalent are the high origin of the radial artery (brachioradial artery) or the existence of a doubledbrachial artery (accessory brachial artery). We present a previously undescribed pattern of brachial arteryvariation. During dissection of the right upper limb of a 60-year-old male embalmed cadaver, we found thebifurcation of the brachial artery in the proximal portion of the middle third of the arm. Its medial branchreaches the medial aspect of the arm, posterior to the median nerve. Afterwards, this medial branch redirectslaterally and crosses again the median nerve, this time lying anterior to the nerve until it reaches the lateralaspect of the arm. At the elbow level, the medial branch originates the radial artery. The lateral branch of thebrachial artery remains lateral to the median nerve, continues as ulnar artery, and originates the interosseusartery.

Pharyngeal lymphatic ring: anatomical review

The tonsils form part of a circular band of adenoid tissue which guards the opening into the digestive andrespiratory tubes, known as Waldeyer’s ring. The anterior part of the ring is formed by the submucouslymphoid clusters (lingual tonsil) on the posterior part of the tongue; the lateral portions consist of thepalatine tonsils and the lymphoid tissue in the vicinity of the auditory tubes, while the ring is completedbehind by the pharyngeal tonsil on the posterior wall of the pharynx. In the intervals between these mainsmaller collections of lymphoid tissue are found. This paper intends to give to the clinician an anatomicalreview about the subject.

[Morphologic study of the inferior cavo-atrial transition in man. Morphofunctional considerations]. / Estudo morfológico da transição cavo-atrial inferior no homem. Considerações morfo-funcionais.

PURPOSE: Analysis the fibrous elements of the transition between the inferior vena cava and right atrium. METHODS: Twenty adult (20-40 ys) were used. Properly preserved samples were analysed macro and microscopically. Fragments were excised from the inferior cavo-atrial transition and analysed under stereomicroscopic. RESULTS: The inferior vena cava valve was disposed at the wall of the vein. Insertions of striated muscular cardiac fibers bundles are seen at the anterior wall of inferior vena cava. These muscular bundles are directed towards the intima of the vein. There were at the venous posterior wall insertions of the cardiac muscular bundles, originated from the crista terminalis and from the interatrial septum, these bundles show an orientation predominantly oblique, with tendency to become circular. At the transition level, the bundles of smooth muscular fibers of the inferior vena cava, presented an oblique disposition, becoming predominantly circular. CONCLUSION: As the disposition of muscular cardiac fibers presents a predominantly circular direction and, the bundles of smooth muscular fibers of the inferior vena cava present the same direction, we could postulate that, when the atrial systole occurs, these muscular bundles would obliterate the cavo-atrial transition, preventing, this way, the venous reflux.

[Morphofunctional study of the cava-hepatic venous transition in humans]. / Contribuição para o estudo morfofuncional da transição venosa cavo-hepática no homem.

Using mesoscopic techniques, the authors observed that fibrous muscular bundles were distributed in three layers, from the external to the intima, in the cava-hepatic venous transition zone; these bundles start with a helical course, and bend progressively towards their outlet. Regarding the collagen component, two kinds of fibre bundles were observed: 1) as longitudinal strips, two for each vein that join in an arched form close to the outlet; 2) bundles running in the same direction as muscular bundles. The elastic tissue appears as a component of the myoelastic tendons or as independent bundles. The latter follow the direction of the muscular fibres, but show a decreasing amount when they approach the transition zone. At this point, however, the myoelastic tendons grow thicker.

[Anatomical variations in the hypoglossal canal]. / Contribuição ao estudo das variações anatômicas do canal do hipoglosso.

In this paper, 492 human dried skulls grouped according to sex and race (White and no White) were examined and the presence of a double hypoglossal canal was observed in 97 skulls. The statistical analysis allowed us to conclude that no significative difference exists in race X canal type; sex X canal type; race X side and sex X side interations.