The Comparation Between Different Reinervation Methods In Different Time Of The Denervated Rabbit Platysma

Objective: When the facial muscles denervated for some trauma, they attenuate over time; the peripheral branches of facial nerve will encounter the Waller degeneration meanwhile, which results in facial palsy. This experiment reinnervate the rabbit platysma by the end-to-end anastomosis and implantation. The results of the two surgery methods are compared at different times, and the results of the single surgery method at different time are measured too.Methods: Divide 24 New Zealand rabbits equally into groups A and B, A uses end-to-end anastomosis; B uses implantation. Each group was divided into 4 subgroups based on different reinnervation surgery time (1,3,5,7 months), each subgroup contained 3 animals, and 6 samples. The cervical branch of each subgroup animal was transected and performed the corresponding reinnervation surgery method at the corresponding time. At 2 months after the operation, gross observation and morphologic observation of the platysma were conducted along with myoneuroelectric activity. Compared the results of the different surgery methods at the same time and same surgery method at different times.Results: Within the time duration of experiment, muscle shrinked and became pale gradually, the cervical branch get thiner. Under the light microscope, it can be seen that cross-section of myofibre get smaller, and the arrangement became irregularly and the boundaries becomes unclear with the infiltration of fat cells and fibrous tissue. Two months after surgery, The reinnervation were achieved in experiment duration by both methods. When facial branch was damaged at 1 month and 3 months, end-to-endanastomosis was better than implantation. For the 5 months group, it is shown that there's not much difference between the two methods. For the 7 months group, implantation better than end-to-end anastomosis, the mean difference is significant at the 0.05 level. A and B group shows that there is a discrepancy at different times.Conclusion: Within 7 months after facial branch is damaged, both implantation and end-to-end anastomosis can realize the reinnervation. It is more appropriate and reliable to use end-to-end surgery within 5 months, and this method also fits the physical state better; therefore, it is highly recommended to use end-to-end operation to repair the facial nerve. At 7 months, implantation will work better. This method is simple, easy to perform, and utilizing this method will yield a better result without microsurgery techniques or similar conditions. For both methods, better recovery can be achieved if the methods are applied earlier.