Experiment Study Of Effects Of High Frequency Electrotome On Preventing The Formation Of Painful Neuroma

Objective:The experiment was designed to investigate the feasibility and superiorities of highfrequency electrotome in the prevention of painful neuroma.Methods:56Sprague-Dawley (SD) rats aged3months, were randomly divided into four groupswith14rats in a group. And then the sciatic nerves of the rats were exposed to thefollowing four kinds of surgical approaches. Scalpel group: the sciatic nerves were cut byscalpel with a gap about0.5cm between the stumps. Electrocision group: the sciatic nerveswere cut by high frequency electrocision with a gap about0.5cm between the stumps.Electrocision and electrocoagulation group: the sciatic nerves were cut with a gap about0.5cm and the proximal ends were carbonized by high frequency electrocision. Scalpel andelectrocoagulation group: the sciatic nerves were cut by scalpel with a gap about0.5cmand the proximal ends were carbonized by high frequency electrocision. We regularlyobserved and evaluated the autotomy degree, the size of nerve stumps and tissue structureof rats of each group after operation. The structural changes of sciatic nerves in the fourgroups were observed by hematoxylin-eosin(HE) staining. Expression of NGF in theneuroma was tested by immunohistochemical staining.Results:1. No death occurred during the observation period. All rats paralyzed after theirbilateral sciatic nerves were cut off. With the time went by, autotomy became more andmore serious, and ulcers occurred on the feet of some rats.2. Compared with the other three groups, the rats of scalpel and electrocoagulationgroup produced the lowest autotomy levels at the end of the observation period; theaverage onset time of autotomy in this group was the longest; and the incidence of highautotomy was also the lowest. On the contrary, the electrocision group not only got thehighest autotomy levels, but also had the shortest average onset time of autotomy and the highest incidence of high autotomy.(P<0.05).3. The sciatic nerve stumps of rats in the scalpel and electrocoagulation group didn’thave significant changes. In the other three groups the nerve stumps appeared as a bulbousgrowth of various sizes and there were adhesions between the nerve stumps and thesurrounding tissue. And the nerves of electrocision group grew fastest and had the mostsevere adhesions among the four groups.(P<0.05).4. The results of HE staining showed that in scalpel and electrocoagulation group thesciatic nerve fibers arranged orderly and the connective tissue hyperplasia was not obvious.There were a lot of connective tissue hyperplasia and the nerve fibers were disorder in theother groups. The worst was electrocision group.5. NGF was secreted in all rats’ nerve stumps which was tested by immunehisto-chemical staining, and its secretion became less and less as time went by. And among thefour groups, the NGF expression level of scalpel and electrocoagulation group was thelowest, the highest was electrocision group at any time.(P<0.05).Conclusion:Our study confirmed that cutting nerve with scalpel and making the nerve stumpcarbonized with high frequency electrotome is an effective method to prevent theformation of painful neuroma, which is not only simple but also with low cost.