Estudo da viabilidade de enxertos de nervos mantidos em soluções conservadoras

AUTOR(ES)
DATA DE PUBLICAÇÃO

1998

RESUMO

Traumatic lesions are very often on peripheral nervous system, and have reserved prognostic when a loss important nerve segment occurs. However, the knowledge about the cellular and the molecular events promoting the nerve regeneration, besides the use of microsurgical techniques, gives a better perceptive to improve the peripheral nerve repair nowadays. In this scenario, several assays were done to develop a nerve bank that would be used for surgery when a graft is necessary to repair a nerve gap. In this study we investigate the morphological and quantitative aspects of the nerve regeneration across autologous nerve grafts previously stored in two types of preserve solutions. Forty Wistar male rats were used and 16 of them had the left and right tibial nerves removed and stored during 24 or 72 hours in Wisconsin/Belzer solution or in Collins solution (4°C). Following previous stórage period those nerves are processed for histology. Other 4 animals had the left and the right tibial nerve removed and immediately processed for histology. A group of 15 animals had the left tibial nerve removed and stored during 24 and 72 hours in Wisconsin/Belzer solution or in Collins solution and subsequently transplanted in the right side. Other 5 animals had the left tibial nerve removed and immediately transplanted to the right side. After 50 days of the transplant, the animals were reoperated to remove the nerve graft. It was exposed, dissected, fixed "in situ" using a fixative solution (2% paraformaldehyde, 1 % glutaraldehyde, in PBS 0,1 M, pH 7,4) and removed. Following, the nerve graft was postfixed in OS04 and embedded in resin. Semi-thin (1,0 µm) cross sections of the middle region of the nerve graft were obtained, stained in toluidine blue and observed in light microscopy. To perform the quantitative analysis the cross section of the graft was sampled in 5 different fields and the density of mielinated nerve fibers on 1 0 m2 was computed using an electronic counter. The morphological analysis shows that the structure of the nerve was well preserved after 24 or 72 hours storage in Wisconsin/Belzer or Collins solutions. The nerve fiber regeneration, 50 days after the graft transplantation, was more advanced in the grafts previously stored in Wisconsin/Belzer solution related to the graft stored in Collins solution, and similar to the observed in fresh nerve graft. The quantitative data confirm these morphological results. The nerve fibers density in nerve graft previously stored during 24 or 72 hours in Wisconsin/Belzer solution was significantly (p

ASSUNTO(S)

transplante homologo sistema nervoso - regeneração

ACESSO AO ARTIGO

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