Nerve Repair and Orthodromic and Antidromic Nerve Grafts: An Experimental Comparative Study in Rabbit

Abstract

Purpose. Although many surgeons have anecdotally described reversing the polarity of the autograft with the intent of improving regeneration, the optimal orientation of the autogenous nerve graft remains controversial. The aim of this study was to compare (1) the outcomes of orthodromic and antidromic nerve grafts to clarify the effect of nerve graft polarity and (2) the outcome of either form of nerve grafts with that of nerve repair. Methods. In 14 of the 26 rabbits used in this study, a 1 cm defect was made in the tibial nerve. An orthodromic nerve graft on one side and an antidromic nerve graft on the other were performed using a 1.2 cm long segment of the peroneal nerve. In the remaining 12 rabbits, the tibial nerve was transected completely and then repaired microscopically on one side but left untreated on the other. Electrophysiologic studies were performed in all animals at 8 weeks after surgery, and the sciatic nerves were harvested. Results. Compound motor action potential was visible in all rabbits treated by nerve repair but in only half of the rabbits treated by nerve graft. There was no significant difference in the compound motor action potential, nerve conduction velocity, or total number of axons between the orthodromic and antidromic nerve graft groups. However, in both groups, the outcome was significantly poorer than that of the nerve repair group. Conclusion. There was no significant difference by electromyographic or histologic evaluation between orthodromic and antidromic nerve grafts. Direct nerve repair with moderate tension may be a more effective treatment than nerve grafting.

Comparison between normal and reverse orientation of graft in functional and histomorphological outcomes after autologous nerve grafting: An experimental study in the mouse model

“…The topic on normal or reverse proximodistal orientation of autologous nerve grafts has been discussed for many decades and the conclusion has been well known by microsurgeons. Although previous animal studies have shown that proximodistal orientation has no impacts on nerve regeneration and functional recovery (Afshari et al, 2018; Kim et al, 2020; Nakatsuka et al, 2002; Sanders & Young, 1942; Sotereanos et al, 1992; Stromberg et al, 1979), many surgeons anecdotally reverse autograft orientation with the intent of improving nerve regeneration (Roberts et al, 2017). Furthermore, nerve autograft is the gold standard for repair of nerve injuries with gaps, accordingly this topic is still of value among microsurgeons.…”

“…Ansselin and Davey provided the theoretical basis of this belief by showing that reverse‐oriented autografts promoted axonal regeneration better than normally oriented autografts in a rat sciatic nerve model (Ansselin & Davey, 1988; Ansselin & Davey, 1993). However, other animal studies have not shown differences between the normal or reversed orientations of autografts in functional and histological analyses (Afshari et al, 2018; Kim et al, 2020; Nakatsuka et al, 2002; Sanders & Young, 1942; Sotereanos et al, 1992; Stromberg et al, 1979).…”

Effects of normal or reversed proximodistal orientation of autologous nerve grafts on functional and histomorphological outcomes

“…Most studies did not nd signi cant differences between normally or reverse-oriented autografts [5][6][7][8][9][10] .…”

“…In total, eight animal studies using rat or rabbit models have been performed to investigate the effect of autograft orientation on neural and functional regeneration during interpositional nerve grafting, with most conducted >2-3 decades ago [3][4][5][6][7][8] . Recent studies have used advanced tools to assess outcomes after autografting, including immunohistochemical staining of cross-sectioned nerves using antibodies against choline acetyltransferase or NF, and diffusion tensor imaging of the nerve 9,10 . In our study, we used behavioral evaluation of sciatic nerve function, morphometric analysis using immunohistochemicalstained cross-sectioned and whole-mount nerves, and morphometric analysis using H&E-stained crosssectioned muscles to investigate the effect of autograft orientation on nerve regrowth.…”

“…Ansselin and Davey provided the theoretical basis of this belief by showing that reverse-oriented autografts promoted axonal regeneration better than normally oriented autografts in a rat sciatic nerve model 3,4 . However, other animal studies have not shown differences between the normal or reversed orientations of autografts in functional and histological analyses [5][6][7][8][9][10] .…”