RESUMO
RATIONALE AND OBJECTIVES: We monitored the regeneration of the rat sciatic nerve after its transection and the concomitant alteration in the high-energy phosphates content in the target tibialis anterior muscle. METHODS: Rat sciatic nerve was resected and the gap connected with a prosthesis of polytetrafluoroethylene. Progress of reinnervation was monitored by 1H MR imaging, whereas muscular energy metabolism was evaluated by localized 31P MR spectroscopy. RESULTS: Reconstitution between the nerve stumps was resumed 8-12 weeks postoperatively. The ratio of phosphocreatine to inorganic phosphate reached a plateau at 46% of the initial level approximately 8 weeks after the operation and recovered thereafter. Immediately after the surgery, muscular pH became slightly alkaline and returned to normal with the progress of reinnervation. CONCLUSION: Recovery of the muscular energy metabolism began after the reconnection of the severed nerve stumps. The combination of MR imaging and MR spectroscopy followed noninvasively the progress of reinnervation and muscular energy metabolism of the prosthesis-guided nerve regeneration.
Assuntos
Metabolismo Energético/fisiologia , Músculo Esquelético/inervação , Músculo Esquelético/metabolismo , Regeneração Nervosa/fisiologia , Nervo Isquiático/fisiologia , Animais , Implante de Prótese Vascular , Análise de Fourier , Concentração de Íons de Hidrogênio , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Masculino , Fosfatos/metabolismo , Politetrafluoretileno , Ratos , Ratos Wistar , Fatores de TempoAssuntos
Ductos Biliares/cirurgia , Doenças Biliares/etiologia , Transplante de Fígado , Complicações Pós-Operatórias/epidemiologia , Adolescente , Adulto , Fatores Etários , Anastomose em-Y de Roux , Anastomose Cirúrgica , Doenças Biliares/cirurgia , Criança , Pré-Escolar , Seguimentos , Humanos , Lactente , Transplante de Fígado/mortalidade , Pessoa de Meia-Idade , Reoperação , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de TempoAssuntos
Hepatopatias/cirurgia , Transplante de Fígado , Adolescente , Atresia Biliar/cirurgia , Criança , Pré-Escolar , Seguimentos , Encefalopatia Hepática/cirurgia , Humanos , Lactente , Hepatopatias/classificação , Transplante de Fígado/mortalidade , Doenças Metabólicas/cirurgia , Reoperação , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de TempoAssuntos
Ciclosporina/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Transplante de Fígado/imunologia , Tacrolimo/uso terapêutico , Adulto , Bilirrubina/sangue , Criança , Pré-Escolar , Monitoramento de Medicamentos , Seguimentos , Hepatite C/fisiopatologia , Humanos , Pessoa de Meia-Idade , Recidiva , Reoperação , Tacrolimo/administração & dosagem , Tacrolimo/sangue , Falha de Tratamento , Resultado do TratamentoRESUMO
The aim of our study was to evaluate in the rat the ability of a polytetrafluoroethylene microprosthesis (PTFE), to guide the peripheral nerve regeneration between the two extremities of a transected sciatic nerve. In 15 adult male Wistar rats, weighing 200 g, a segment of the right sciatic nerve was resected, leaving a gap of about 1 cm, bridged with microprosthesis, using our original microsurgical technique. Neurophysiological evaluations were performed at 6 and 9 months post-operatively to study the distal motor latency either in the right sciatic nerve or in the unoperated control side. In all the rats myoelectrical responses with an increased latency of the operated side were produced from the interosseous muscle of the foot. The animals were sacrificed 9 months post surgery. Histological sections at the level of the graft were done in all the rats, and in 10 animals biopsies of the tibialis anterior muscle (TA) of each side were performed. An active process of axonal regeneration was documented inside the graft, with no infiltration of nerve fibers through the wall of the prosthesis. A connective fibrous reaction was present around the external wall of the graft. Muscle biopsies showed definite signs of muscle reinnervation, with residual features of variable degree of denervation. These findings stress and confirm the ability of the PTFE graft to allow effective regeneration in a peripheral nerve gap in the rat.