RESUMO
Aim: The aim of this study was to compare two tubulization techniques, inside-out veins and standard veins, both filled with skeletal muscle or not, in sciatic nerve by morphological and histomorphometric study. Methodology: Seventy Wistar rats were divided in 4 experimental groups (IOVNF - inside-out vein with no filling; IOVSM - inside-out vein filled with skeletal muscle; SVNF - standard vein with no filling; and SVSM - standard vein filled with skeletal muscle) and a control group (Sham). The left external jugular vein was sectioned into about 14 mm segments to be used as autologous vein grafts. A 10 mm gap was then created in the sciatic nerve and the vein graft was inserted into the vein with or without filling of the right caudal tibial muscle. The animals were euthanized 12 weeks after surgery. Results: Myelinated and unmyelinated nerve fibers were observed in the histological analyses for all groups, as well as neoformation of the perineurium and intraneural organization of fascicles and blood vessels. In the morphometric analysis of the distal stump, regarding the myelin sheath area, all groups had a significant difference. The IOVNF group had the highest means for fiber, axon and myelin sheath areas. The SVSM group had the lowest means in all features measured, except for the axon area (4.95±1.72 graft; 3.71±0.90 distal stump). Conclusion: These results show that sciatic nerve repair with inside-out veins and no filling (IOVNF) had the best results, in the majority of measured variables, when compared to the other groups.
RESUMO
Aim: The process of bone repair is of evident importance in both the clinical and functional spheres. For this reason, the field of bioengineering has taken it as an object of study, seeking to perfect the implantation of materials that allow for adequate bone neoformation. This study investigated the process of bone repair after anionic bovine tendon grafting in rat tibias by conducting a morphological, histomorphometric and immunohistochemical study. Methodology: The experimental model consisted of 36 rats randomly divided into two groups: a control group (CG, n=18), in which a surgical cavity in the tibia was filled with blood clots; and an experimental group (EG, n=18), in which a surgical cavity in the tibia was filled with an anionic bovine tendon graft. In the experimental group, the major axis of the collagen fiber bundle was placed perpendicularly to the long axis of the tibia. Microscopic, morphometric and immunohistochemical evaluations were conducted at 7, 15, and 30 days postoperative. Results: The analyzes showed an increase in bone neoformation in the experimental group during the assessed periods. There was a significant difference between day 7 and day 30 and evident vascular proliferation was detected by the immunohistochemical analysis. Conclusion: It can be concluded that the anionic bovine tendon collagen proved to be an adequate and biocompatible material for bone regeneration, with osteogenic capabilities that allow it to be used as a scaffold for bone repair.
RESUMO
Foram utilizados 30 animais(Rattus norvegicus) com o objetivo de avaliar histologicamente a neoformação óssea com a utilização de um modelo de alcoolismo crônico experimental em tíbia de ratos. Os animais forma separados em 2 grupos: Controle e Experimental. Os animais do Grupo Controle bebiam apenas água de dieta líquida e os do Grupo Experimental bebiam álcool etílico diluído a 6 por cento. Após 60 dias de tratamento, os animais dos dois grupos foram submetidos à cirurgia experimental na qual a tíbia recebeu uma perfuração de dois milímetros de diâmetro. Os animais foram sacrificados com 10, 20 e 40 dias após a cirurgia. Nas lâminas pode-se observar que nos três períodos a neoformação óssea foi menor em todos os espécimes do Grupo Experimental, quando comparados aos Controles. Ocorreu um retardo no preenchimento ósseo da loja cirúrgica, incompleto até os 40 dias de reparação, nos animais do Grupo Experimental. No Grupo Controle a cavidade cirúrgica estava completamente preenchida de tecido ósseo neoformado. Esses resultados permitem concluir que a dieta alcoólica interfere na reparação óssea, retardando a neoformação...