Protocol of a Nerve Neurotmesis Sciatic Repair using Polyvinyl Alcohol Biofilm in Wistar Rats

Abstract Background  Animal models are commonly used to assess the efficacy of new materials to be employed in the surgical repair of a nerve injury. However, there is no published surgical repair protocol for sciatic nerve neurotmesis in rats. Objective  To produce and evaluate a protocol for the tubing technique using a polyvinyl alcohol biofilm after sciatic nerve neurotmesis. Methods  Eighteen rats were randomized into 3 groups ( n  = 6 per group): control group - CG, neurotmesis group - NG, and neurotmesis biofilm group - NBG. The NG and NBG animals were submitted to neurotmesis of the sciatic nerve at 60 days of life, followed by suture of the nerve stumps; in the NBG, the animals had the suture involved by polyvinyl alcohol biofilm. A descriptive evaluation of the surgical technique was performed after the experimental period. The Shapiro-Wilk normality test was used for body weight, and analysis of variance (ANOVA) with Bonferroni posthoc ( p  < 0.05) was applied. Results  All groups showed good repair of the skin and muscle sutures; however, 33.30% of the CG presented disruption of skin points. Furthermore, 16.70% of the stumps were not structurally aligned and 33.30% had neuromas in the NG, while in the NBG, all stumps were aligned and none of them had neuroma . Conclusions  The present study was able to produce a protocol with high reproducibility in view of the mechanical stability, targeting of the nerve stumps, muscle healing, the low frequency of skin breakage and the low complexity level of the technique, and it can be used in future studies that aim to evaluate other biomaterials for nerve repair in rats.