Comparison of nerve repair with end to end, end to side with window and end to side without window methods in lower extremity of rat

Although, different studies on end-to-side nerve repair, results are controversial. The importance of this method in case is unavailability of proximal nerve. In this method, donor nerves also remain intact and without injury. In compare to other classic procedures, end-to-side repair is not much time consuming and needs less dissection. Overall, the previous studies in this field have just evaluated nerve recovery by non functional or functional parameters. As it has proven, the results of functional and non functional studies are not always matched. Therefore, this study was designed to evaluate this method by functional (Sciatic function index) and non functional parameters (histochemical study). In this experimental study, forty adult male Wistar rats (200-250g) were used their left proneal nerve was cut and divided into four groups: 1- control group (n=10). In this group, nerve was exposed and cut and implanted onto adductor muscles, 2- end-to-end anastomosis (n=10). In this group, peroneal nerve cut and two segments were anastomosed end-to-end, 3- end-to-side anastomosis with window (n=10). In this group, peroneal nerve was cut and anastomosed with window to tibial nerve, 4- end-to-side anastomosis without window (n=10). In this group, peroneal nerve was cut and anastomosed without window to tibial nerve. After 1, 8 and 16 weeks, functional (Sciatic function index) and after 16 weeks non functional studies (histochemical study) were performed and the results compared. All experimental groups (group 2, 3, 4) motor recovery at 8th, 16 th week were not statistically different (p>0.05). In histological study axons count in end -to-side with window anastomosis were higher than other experimental groups (p<0.05). According to our findings, the authors believe that end to side neuroraphy leads to axon growth and comparable functional recovery with end to end neuroraphy in rat model. Due to the fact that the diameter of nerves and muscles which might be neurotised in human are much bigger and not comparable with rat, it is suggested to set up some set of experiments on the bigger size animals such as primates in further studies for generalization of results to human being.