End-to-side neurorraphy using different donor nerves for reconstructing brachial plexus injury: an experimental study in a rat model

Abstract

Objective To evaluate the effectiveness of end-to-side coaptation using different donor nerves in nerve reconstruction of brachial plexus injuries. Methods Ninety SD rats were subjected to brachial plexus upper trunk injury and randomized into 5 goups.The right musculocutaneous nerves of 4 groups were reonstructed by both end-to-side and end-to-end neurorraphy using phrenic nerve and ipsilateral C7 root respectively.Another group served as control without any nerve reconstruction.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 at 3rd month postoperatively,regenerative signs indicated that reinnervation was possible by end-to-side neurotization.However its outcomes were significantly inferior to these of the end-to-end neurorrhaphy (P ＜ 0.05).The use of the ipsilateral C7 root as a donor nerve in the end-to-side neurorrhaphy resulted in least regeneration judging by behavioral tests,compound muscle action potential and neuromorphometry(P＜0.05). Conclusion It is possible 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.End-to-side neurorrhaphy cannot achieve the same results as end-to-end neurorraphy,and therefore should be used with caution as an alternative for brachial plexus reconstruction. Key words: Nerve regeneration; End-to-side neurorraphy; Experimental study