Sensory nerve baby-sitting in reverse end-to-side fashion improves the recovery of denervated muscle in rats

Objective To delay the atrophy of denervated skeletal muscle by baby-sitting in reverse end-to-side fashion and explore the feasibility of this operation to improve the recovery of denervated muscle in rats. Methods From July, 2015 to March, 2016, 32 female SD rats were divided into 4 groups randomly and the tibial nerve of each rats was transected. In immediate repair group, the transected tibial nerve was sutured in situ. In unprotected group, the tibial nerve stump was putting-aside. The sural nerve was transected in other 2 groups. The proximal sural nerve was connected to the distal tibial nerve stump directly in end-to-end (ETE) protected group and to the side of the distal tibial nerve stump in end-to-side (ETS) protected group. After 3 months, connected the two ends of tibial nerve except immediate repair group. After another 3 months, the tibial nerve functional index, electrophysiological testing, histology and morphology were examined. Results The gastrocnemius muscle was atrophy obviously in unprotected group, while in other groups the muscle structure was well protected. The tibial nerve functional index (-39.54±24.32) , motor nerve conduction velocity[ (30.25±12.65) m/s], and muscle contraction [ (0.98 ± 0.38) N) ] indicated that the gastrocnemius muscle function in ETS protected group was statistically better recovery than in unprotected group [-75.65±32.13, (24.93±8.69) m/s and (0.64±0.20) N, respectively] and ETE protected group[-62.34±21.65, (16.90±7.92) m/s and (0.75±0.15) N, respectively] (P 0.05) . Conclusion Sensory nerve baby-sitting in reverse end-to-side fashion is a effective method to improve the recovery of denervated muscle in rats. Key words: Muscular atrophy; Denervated muscle; Nerve baby-sitting; End-to-side suture; Rat