Experimental study of histological changes in vascular loops according to the duration of the postoperative period: Application in reconstructive microsurgery

OBJECTIVES: To analyze the histological changes observed in venous grafts subjected to arterial blood flow as a function of the duration of the postoperative period to optimize their use in free flap reconstructions. METHOD: Twenty-five rats (7 females and 18 males) underwent surgery. Surgeries were performed on one animal per week. Five weeks after the first surgery, the same five animals were subjected to an additional surgery to assess the presence or absence of blood flow through the vascular loop, and samples were collected for histological analysis. This cycle was performed five times. RESULTS: Of the rats euthanized four to five weeks after the first surgery, no blood flow was observed through the graft in 80% of the cases. In the group euthanized three weeks after the first surgery, no blood flow was observed in 20% of the cases. In the groups euthanized one to two weeks after the first surgery, blood flow through the vascular loop was observed in all animals. Moreover, intimal proliferation tended to increase with the duration of the postoperative period. Two weeks after surgery, intimal proliferation increased slightly, whereas strong intimal proliferation was observed in all rats evaluated five weeks after surgery. CONCLUSION: Intimal proliferation was the most significant change noted in venous grafts as a function of the duration of the postoperative period and was directly correlated with graft occlusion. In cases in which vascular loops are required during free flap reconstruction, both procedures should preferably be performed during the same surgery.

Retalho lateral da coxa baseado na artéria genicular lateral superior: estudo anatômico, histomorfométrico e aplicações clínicas / Lateral genicular artery flap: anatomical and hystomorphometrical study and clinical applications

O retalho cutâneo lateral da coxa baseado no pedículo da artéria genicular lateral superior(AGLS) localiza-se na face lateral e distal da coxa e pode ser utilizado para reparação do revestimento cutâneo do joelho e da região proximal da perna. Nesse trabalho foi realizado estudo anatômico e histomorfométrico em 18 cadáveres, totalizando 36 peças anatômicas. O objetivo foi determinar os parâmetros de dissecção do retalho e suas características anatômicas. A sua aplicação clínica foi demonstrada em quatro pacientes. O pedículo vascular representado pela artéria genicular lateral e duas veias comitantes esteve presente em 100 por cento dos casos, com trajeto intramuscular em 40 por cento das vezes. Em relação ao côndilo lateral do femur está a uma distância média de 7,40 ± 2,77 cm tendo um trajeto no trígono delimitado anteriormente pelo músculo vasto lateral, posteriormente, pelo músculo bíceps femoral e distalmente, pelo próprio côndilo lateral do fêmur. O comprimento médio do pedículo foi de 6,09 ± 1,91 cm . O estudo demonstrou que o retalho apresenta anatomia constante e tem arco de rotação suficiente para as reconstruções do joelho e da região proximal e lateral da perna, conferindo revestimento cutâneo delgado com qualidade de pele semelhante à região adjacente.