The efficacy of end‐to‐end and end‐to‐side nerve repair (neurorrhaphy) in the rat brachial plexus

Abstract

Proximal nerve injury often requires nerve transfer to restore function. Here we evaluated the efficacy of endto-end and end-to-side neurorrhaphy of rat musculocutaneous nerve, the recipient, to ulnar nerve, the donor. The donor was transected for end-to-end, while an epineurial window was exposed for end-to-side neurorrhaphy. Retrograde tracing showed that 70% donor motor and sensory neurons grew into the recipient 3 months following end-to-end neurorrhaphy compared to 40-50% at 6 months following end-to-side neurorrhaphy. In end-to-end neurorrhaphy, regenerating axons appeared as thick fibers which regained diameters comparable to those of controls in 3-4 months. However, end-to-side neurorrhaphy induced slow sprouting fibers of mostly thin collaterals that barely approached control diameters by 6 months. The motor end plates regained their control density at 4 months following end-to-end but remained low 6 months following end-to-side neurorrhaphy. The short-latency compound muscle action potential, typical of that of control, was readily restored following end-to-end neurorrhaphy. End-to-side neurorrhaphy had low amplitude and wide-ranging latency at 4 months and failed to regain control sizes by 6 months. Grooming test recovered successfully at 3 and 6 months following end-to-end and end-to-side neurorrhaphy, respectively, suggesting that powerful muscle was not required. In short, both neurorrhaphies resulted in functional recovery but end-to-end neurorrhaphy was quicker and better, albeit at the expense of donor function. End-to-side neurorrhaphy supplemented with factors to overcome the slow collateral sprouting and weak motor recovery may warrant further exploration.

End-to-side versus end-to-end neurorrhaphy at the peroneal nerve in rats

“…The most important result was that all three methods retained the nerve and muscle function without difference in quality and time recovery. Unlike these findings, Liao et al 18 and Jaeger et al 22 found superior results regarding the time and quality of recovery for the group with end-to-end neurorrhaphy. However, we could observe that the the research conducted comparing the end-to-end and end-to-side neurorrhaphy used different donor nerves, which causes an important bias in the research and makes it difficult to compare with our findings, since we were careful to marter the same nerve as a donor in all techniques 18,19,22 .…”

“…However, many authors doubted wether this nerve repair could substitute completely the traditional end-to-end neurorrhaphy and keep saying that this is the best method to use in nerve repair 18,19,22 . The present study compared the efficiency of three different techniques of neurrorhaphy: the end-to-end, end-to-side and side-to-end.…”

“…Some authors demonstrated that nerve growth factors and other substances are probably involved 18 . Although many authors believe the ES or SE neurrorhaphies are good procedures, they only use them in difficult cases, where no other options could be used.…”

“…Although many authors believe the ES or SE neurrorhaphies are good procedures, they only use them in difficult cases, where no other options could be used. It is almost a consensus that the EE is superior to both ES or SE 18,19 . Some experimental studies found superiority of the EE compared to the ES or SE, but they used different donor nerves 18,19 .…”

“…It is almost a consensus that the EE is superior to both ES or SE 18,19 . Some experimental studies found superiority of the EE compared to the ES or SE, but they used different donor nerves 18,19 . The objective of this study is to compare end-to-side, sideto-end and end-to-end neurorrhaphies of the peroneal nerve in rats with the same donor nerve, the peroneal nerve.…”