Experimental Study Of Reconstructing Brachial Plexus Injury With End-to-side Neurorrhaphy

Objective To compare the curative effectiveness of standard end-to-side neurorrhaphy and other modifications.Methods 126 SD rats were randomized into 7 groups. The right musculocutaneous nerves were transected in all animals. The ipsilateral ulnar nerve served as the donor nerve. In group 1 the ulnar nerve and musculocutaneous nerve were coaptated in end-to-end pattern. In group 2, the musculocutaneous nerve was coaptated with ulnar nerve in standard end-to-side pattern. Side-to-side neurorrhaphy with and without removal of the epineural sheath were undergone in group 3 and 4. In group 5 and 6, the recipient nerve was coaptated with the donor nerve in helicoid pattern, with and without removal of the Epineurium The musculocutaneous nerve in group 7 were not reconstructed, and served as controlling group. Electrophysiological and histological analyses were performed in the 1st,2nd and 3rd month postoperatively.Results By the end of the experiment, regenerative signs were observed in all end-to-side groups. The curative effectiveness of end-to-side coaptation was not as satisfactory as that of the end-to-end neurorrhaphy. There was no significant difference in end-to-side groups (p>0.05).The most unsatisfactory result was observed in groups without removal of the epineural sheath.Conclusion There was no significant difference in end-to-side coaptation patterns. Epineurium had negative impact to nerve regeneration after end-to-side neurorraphy. The effectiveness of end-to-side operative modification to improve the nerve regeneration was limited Objective To evaluate the regenerate efficacy of different donor nerves in reconstructing brachial plexus injury by end-to-side coaptationMethods 90 SD rats were subjected to brachial plexus upper thunk injury and randomized into 5 groups. The right musculocutaneous nerves of 4 groups were reconstructed by both end-to-side and end-to-end neurorraphy using phrenic nerve and ipsilateral C7 root respectively. Another group served as controlling group without treatment. Electrophysiologic and histologic examinations, accompanied with behavioral tests were performed in the 1st,2nd and 3rd month postoperatively.Results By the end of the experiment, regenerative signs indicate that reinnervation was possible by end-to-side neurotization. But the outcomes were only passable. The application of the ipsilateral C7 root resulted unsatisfactorily.Conclusion It is available to reconstruct the musculocutaneous nerves in rats of brachial plexus injury by end-to-side neurorraphy. The efficacy of various donor nerves is distinct. The phrenic nerve served as a better motor nerve in end-to-side coaptation, comparing with the ipsilateral C7 root. Unless there is no choice of end-to-end neurorraphy, the end-to-side coaptation would be an alternative for brachial plexus reconstruction.Objective To explore the effectiveness of end-to-side neurorraphy for reconstruction in brachial plexus injury and the spinal localization of regenerating axons using flurorescence retrograde tracing.Methods 24 female SD rats were subjected to brachial plexus superior trunk injurys and randomized into 4 groups:phrenic nerve to musculocutaneous nerve end-to-end transfer, phrenic nerve to musculocutaneous nerve end-to-side transfer ipsilateral cervical 7 root to musculocutaneous nerve end-to-end transfer and ipsilateral cervical 7 root to musculocutaneous nerve end-to-side transfer.3 months after surgery, the musculocutaneous nerve and the donor nerves were retrograde neurotraced with True Blue and Diamidino Yellow respectively. C2 to T2 dorsal root ganglion(DRG) and spinal cord were harvested after perfusion fixation 3,7 and 14 days later.30μm-thinkness slices were observed under the fluromicroscope.Results Fluorescence labeled neurons were seen both in DRG and anterior horn of the spinal cord. There were more and more positively labeled neurons with pass of time. The fluorescence labeled neurons of C7 group were observed only in C7-DRG and anterior corner in correspond spinal cord.The ones of phrenic nerve were found in C3 to C5-DRG and anterior corner in. correspond spinal cord. Two kinds of single labeled neurons or double labeled neurons were observed in the same site in the groups of end-to-side neurorraphyConclusion Nerve regeneration is possible in an end-to-side neurorraphy brachial plexus reconstruction model. Fluorescence retrograde tracing can be used for precise neuron locating.Objective To study the influence of different delayed-repairing time on end-to-side neurorraphy and to discuss the possible reasons of the disparity between the experimental studies and the clinical applications.Methods 30 female SD rats were subjected to musculocutaneous nerve transsection and randomized into 5 groups. The musculocutaneous nerve were reconstructed in the end-to-side way with the ipsilateral ulnar nerve in different time. 1 week,3 weeks and 6 weeks were passed before the reconstructive surgery in delayed-reconstructed groups together with the immediately reconstructed group and the controlling group, in which the repair was abandoned.3 months after surgery, electrophysiologic and histologic examinations were taken.among the models.Results 3 months later,1-week delayed group performed significantly better in electrophysiologic and histologic examinations than the other groups. There was no noticeable difference between immediately reconstructed group and 3-week delayed group in some tests. The outcomes were decreased in 6-week delayed group, which was significantly different with other groups (p<0.05).Conclusion Delayed-rerairing time can influence the effectiveness of end-to-side neurorraphy after nerve injuries. The outcomes of the surgery were better after 1-week nerve pre-degeneration, but the therapeutic effect of end-to-side coaptation decreased with pass of time. Aggravation of myatrophy meight be one of the possible reasons to explain the imcompatible results between the experimental studies and the clinical applications.