Distribution of saphenous vein valves and its pratical importance / Distribuição das válvulas da veia safena magna e sua importância prática

Objective: Among the veins used as a graft in myocardial revascularizations and ends, great saphenous vein is the most used. Knowing the presence and location of valves has great importance when evaluating the surgical anatomy of the great saphenous vein. Despite major surgical application and many works involving great saphenous vein, the number of valves present in it from the saphenous hiatus to the medial epicondyle of the femur is still described inaccurately. The objective of this study is to quantify the valves of the great saphenous vein from the saphenous hiatus to the medial epicondyle of the femur to determine the best portion of the great saphenous vein to perform revascularization surgeries. Methods: This is a crosssectional observational study in which it was analyzed great saphenous vein extracted from 30 cadavers. It was measured the length of the veins; (diameter) at its proximal, middle and distal, quantifying the number of valves in each one and the total number of valves at the great saphenous vein. Results: The frequency of valves in the great saphenous vein taken from the medial epicondyle of the femur to the saphenous hiatus was 4.82, ranging between 2 and 9. Moreover, there is a significant difference in the number of valves in the proximal and distal relative to the average. Conclusion: the median and distal portions of the saphenous vein in the thigh, are the best options for the realization of bridges due to the fact that these portions have fewer valves which therefore would tend to decrease the risk of complications connected with the valves in these grafts. .

Objetivo: Dentre as veias empregadas para revascularizações do miocárdio e de extremidades, a veia safena magna é a mais utilizada. Conhecer a presença e localização de válvulas é de grande importância quando se avalia a anatomia cirúrgica da veia safena magna. Apesar de grande aplicação cirúrgica e de muitos trabalhos envolvendo a veia safena magna, o número de válvulas presente nela desde o hiato safeno até o epicôndilo medial do fêmur ainda é descrito de forma imprecisa. O objetivo do presente trabalho é quantificar as válvulas da veia safena magna desde o hiato safeno até o epicôndilo medial do fêmur para determinar a melhor porção da veia safena magna para a realização de cirurgias de revascularização. Métodos: Este é um estudo transversal e observacional em que foram analisadas veias safena magna extraídas de 30 cadáveres. Foram realizadas as medidas das variáveis do comprimento das veias; (diâmetro) em suas porções proximal, média e distal; quantificação do número de válvulas nestas e número de válvulas total na veia safena magna. Resultados: A frequência de válvulas da veia safena contadas desde o epicôndilo medial do fêmur até o hiato safeno foi de 4,82, podendo variar entre 2 e 9. Além disso, houve diferença significante do número de válvulas da porção proximal em relação à média e distal. Conclusão: As porções média e distal da veia safena magna na coxa são as melhores opções para a realização de pontes em decorrência do fato destas porções terem menor quantidade de válvulas o que, portanto, tenderia a diminuir o risco de complicações relacionadas as válvulas nestes enxertos. .

Applied Anatomy of the Femoral Veins in Macaca fascicularis / Anatomía Aplicada de las Venas Femorales en Macaca fascicularis

The aim was to understand the anatomical features of the venous valve in Macaca fascicularis and to compare it with that of humans. The bilateral lower limbs (24 limbs from 12 animals) of Macaca fascicularis cadavers were dissected, and the femoral veins (FVs) were equally divided into distal, intermediate, and proximal sections. The external diameter of the FV in each section was measured. The venous valves were observed microscopically and stained with hematoxylin and eosin as well as trichrome. Data describing the human venous valve were collected from the current literature. No great saphenous veins were found among the 24 lower limbs from the Macaca fascicularis cadavers. The external diameters of the FVs in the distal, intermediate, and proximal sections were 3.53 ± 0.37 mm, 3.42 ± 0.55 mm, and 3.37 ± 0.54 mm, respectively. In most cases, there was one venous bivalve located in the FV approximately 0-2.71 mm below the junction of the FV and the deep femoral vein. Endothelium covered the luminal and sinusal surfaces of the leaflets. Abundant collagen fibers were found under the endothelial cells beneath the luminal surface of the leaflets. An elastin fiber network was located under the sinus endothelial surface. Smooth muscle cells in the FV extend to the edge of the valve. The venous valve of Macaca fascicularis is similar to that of humans, both morphologically and histologically. However, there is only one venous bivalve and no great saphenous vein in Macaca fascicularis.

El objetivo fue comprender las características anatómicas de la válvula venosa en Macaca fascicularis y compararla con la de los humanos. Fueron disecados bilateralmente los miembros pélvicos (24 miembros de 12 animales) de cadáveres de Macaca fascicularis; las venas femorales (VF) fueron divididas en secciones distal, media y proximal. Se midió el diámetro externo de las VFs en cada sección. Las válvulas venosas se observaron microscópicamente y se tiñeron con H-E y tricrómico. Los datos para describir la válvula venosa humana se obtuvieron desde la literatura. No se encontraron venas safenas magnas entre los 24 miembros inferiores. Los diámetros externos de las VFs en las secciones distal, media y proximal fueron 3,53±0,37 mm, 3,42 mm±0,55, y 3,37±0,54 mm, respectivamente. En la mayoría de los casos, hubo vena bivalva situada aproximadamente 0-2,71 mm debajo de la unión de la VF y la vena femoral profunda. El endotelio cubrió las superficies luminal y sinusal. Se observaron abundantes fibras de colágeno en las células endoteliales bajo la superficie luminal de las válvulas. Una red de fibras de elastina se encontró bajo la superficie del seno endotelial. Las células musculares lisas en las VFs se extiendían hasta el margen de la válvula. La válvula venosa del Macaca fascicularis es similar a la de los seres humanos, morfológica e histológicamente. Sin embargo, sólo hubo una vena bivalvular, y no se observaron venas safenas en Macaca fascicularis.