Application of the bionic multi-channel nerve conduit in the rabbit sciatic nerve defect by reducing mismatch of regenerated nerve fibers

Abstract

Objective To investigate the role of the bionic multi-channel nerve conduit by reducing mismatch of regenerated nerve fibers in the rabbit sciatic nerve defect. Methods The experiment was conducted from July, 2017 to February, 2019. A total of 55 New Zealand white rabbits were randomly divided into two groups (First group, n=30 and Second group, n=25). There were 5 subgroups (n=6) in the first group, which were autograft and custom-anatomic nerve conduits (CANC) with different channel (1-CANC, 2-CANC, 3-CANC, 4-CANC) that implanted to repair the rabbit sciatic nerve defect (10 mm). The electrophysiological, triceps muscle wet weight recovery rate, histological study and ankle index analysis were used to evaluate the treatment of each group at 12 and 24 weeks postoperatively. There were 5 subgroups (n=5) in the second group. The simultaneous retrograde tracing method was applied to compare with the number of mismatched nerve fibers at 24 weeks postoperatively. All data were recorded and analyzed by One-way ANOVA method, the Turkey’s method was used to compare the differences between each subgroup. The difference was considered to be statistically significant if P<0.05. Results The autograft group showed the best recovery in the electrophysiology, histology study and ankle index at 12 and 24 weeks postoperatively (P 0.05), but diameters of nerve fiber and myelin thickness were higher in 2-CANC and 3-CANC [(10.67±0.56) μm,(10.65±0.53) μm, respectively] compared with 1-CANC and 4-CANC groups [(8.43±0.63) μm, (9.03±0.55) μm, respectively]. The differences were similar in electrophysiological, wet weight recovery rate of triceps muscle, histological study and ankle index analysis. Simultaneous retrograde tracing showed that the autograft group had highest total number of labeled profiles, but no significant difference of the total number of labeled profile was showed among the CANC groups. However, the 1-CANC group[(7.1±2.4)%] showed highest percentage of the FB-NY-neurons than other CANC groups[(2.7±1.9)% in 2-CANC, (2.5±2.3)% in 3-CANC, and(2.2±1.2)% in 4-CANC](P<0.05). Conclusion The autograft group showed the best results among all groups. Compared with the 1-CANC group, the 2-CANC and 3-CANC group obtained more mature regenerated nerve fibers and with a fewer mismatch rate. Moreover, that did not affect the number of regenerated fibers. Key words: Rabbit; Sciatic nerve defect; Nerve conduit; Bionic; Multi-channel; Regenerative nerve fiber mismatch