Axonal Supercharging with Reverse End-to-Side Nerve Transfer in Delayed Peripheral Nerve Repair: Its Impact in SV2B mRNA Expression in Rat Sciatic Nerve Injury Model

Abstract

To investigate the role of reverse end-to-side nerve transfer in delayed repair of peripheral nerve injury, a rat sciatic nerve injury model was used. The dynamic of SV2B mRNA expression was investigated. Sixteen Wistar rats were divided into four groups (four rats in each group). In Group I, the right tibial nerve was ligated 1 cm proximal to sciatic trifurcation, and the peroneal nerve was ligated distally at its entrance to peroneal tunnel. Two weeks later, the resulting neuroma was excised and the tibial nerve was repaired in end-to-end (ETE) fashion. The peroneal nerve was transferred to the distal stump of the tibial nerve in a reverse end-to-side fashion (RETS / axonal supercharging). In Group II, similar procedure to create the sciatic nerve injury was performed. Two weeks later, the tibial nerve was repaired in ETE fashion.No axonal supercharging procedure was added. In Group II, the sciatic nerve was exposed, and the wound was closed again (sham surgery / positive control). In Group IV, the sciatic nerve was injured in similar fashion, and never repaired (negative control). SV2B mRNA was measured from venous blood, taken at baseline, prior to nerve repair, and at the end of study (ten weeks after repair). Results from the test showed that the expression of SV2B mRNA, which represents the formation of neuromuscular junction, indicated that recovery of the denervated muscles was promoted by axonal supercharging (RETS transfer), and the result was better than conventional repair alone. In conclusion, axonal supercharging (RETS transfer) may be useful in delayed peripheral nerve repair for nerve injuries-in-continuity