Evaluation of nociception and edema in experimental sciatic nerve compression model in Wistar rats treated with cryotherapy

Abstract

ABSTRACT BACKGROUND AND OBJECTIVES: Considering the scarcity of studies addressing cryotherapy to treat peripheral nervous injuries, this study aimed at evaluating nociception and edema in an experimental sciatic nerve compression model with Wistar rats treated with cryotherapy. METHODS: Forty-two rats were randomly distributed in groups: G1 - control, euthanized in the 15th postoperative day; G2, G3 and G4 - submitted to sciatic nerve compression and euthanized in the 3rd, 8th and 15th postoperative day, respectively; G5, G6 and G7 - submitted to sciatic nerve compression and treated with cryotherapy, euthanized in the 3rd, 8th and 15th postoperative day, respectively. Nociception evaluation at injury site and plantar region, and observation of edema were performed before injury, in the 2nd postoperative day and in the day corresponding to euthanasia of each injured group. Mixed ANOVA was used for statistical analysis, considering significant 5%. RESULTS: There has been decreased pain threshold at injury site in injured groups, however there has been increase in the same groups with regard to evaluations in the 8th and 15th postoperative days. Nociception in the plantar region was similar to previous one, however threshold has not increased. With regard to edema, there has been significant difference in evaluations in the 3rd and 2nd postoperative days corresponding to G1, G4 and G7, which had higher values as compared to pre-injury. CONCLUSION: Cryotherapy has not increased nociceptive threshold or decreased the edema. RESUMO JUSTIFICATIVA E OBJETIVOS: Considerando a carência de estudos a respeito da crioterapia como tratamento de lesão nervosa periférica, este estudo teve como objetivo avaliar a nocicepção e o edema em modelo experimental de compressão do nervo isquiático em ratos Wistar, tratados com crioterapia. MÉTODOS: Foram utilizados 42 ratos separados aleatoriamente nos grupos: G1 - controle, eutanasiado no 15º de pós-operatório; G2, G3 e G4 - submetidos à compressão do nervo isquiático, eutanasiados no 3º, 8º e 15º de pós-operatório, respectivamente; G5, G6 e G7 - submetidos à compressão do nervo isquiático e tratados com crioterapia, eutanasiados no 3º, 8º e 15º de pós-operatório, respectivamente. As avaliações da nocicepção no local da lesão e na região plantar, e a verificação do edema aconteceram nos momentos pré-lesão, 2º dia de pós-operatório e no dia correspondente a eutanásia de cada grupo lesionado. A análise estatística foi pela ANO…