The long‐term functional recovery of repair of sciatic nerve transection with biogenic conduits

The aim of this study was to evaluate long‐term regenerative capacity over a 15‐mm nerve gap of an autologous nerve conduit, the biogenic conduit (BC), 16 weeks after sciatic nerve transection in the rat.Methods : A 19‐mm long polyvinyl chloride (PVC) tube was implanted parallely to the sciatic nerve. After implantation, a connective tissue cover developed around the PVC‐tube, the so‐called BC. After removal of the PVC‐tube the BCs filled with fibrin ( n = 8) were compared to autologous nerve grafts ( n = 8). Sciatic functional index (SFI) was evaluated every 4 weeks, histological evaluation was performed at 16 weeks postimplantation. Regenerating axons were visualized by retrograde labelling.Results : SFI revealed no significant differences. Nerve area and axon number in the BC group were significantly lower than in the autologous nerve group ( P < 0.05; P < 0.01). Analysis of myelin formation showed no significant difference in both groups. Analysis of N ‐ratio revealed lower values in the BC group ( P < 0.001).Conclusion : This study reveals the suitability of BC for nerve gap bridging over a period of 16 weeks with functional recovery to comparable extent as the autologous nerve graft despite impaired histomorphometric parameters. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.