Objective: Polyethylene glycol hydrogel (PEG) is capable of fusing transected axons
and restoring axonal continuity. The technique requires precise nerve coaptation
alignment and stability which is difficult to achieve utilizing conventional microsuture
neurorrhaphy. Nerve Tape (NT) is a microhook based nerve coaptation device engineered
to facilitate stable and accurate nerve end alignment. The primary objective was
to modify and validate NT assisted PEG fusion using a rabbit proximal tibial nerve
repair model at an intermediate time point.
Methods: Three groups of rabbits underwent mid-thigh tibial nerve transection and
immediate repair with NT + PEG (n=6), Suture + PEG (n=6), or Suture only (n=6). PEG
induced axonal fusion was acutely confirmed via demonstration of compound motor action
potential (CMAP) restoration. Final outcome testing at 16 weeks included electrodiagnostic
testing, nerve histomorphology, and muscle morphology.
Results: All 18 animals demonstrated immediate restoration of CMAPs. At 16 weeks,
there were no statistical differences in nerve conduction velocity or amplitude, no
statistical differences between groups in axon counts or g-ratios either near the
nerve coaptations or at the ankle, and no differences in normalized gastrocnemius
weight or girth.
Conclusions: PEG fusion did not improve nerve regeneration or functional recovery
in a rabbit tibial nerve repair model at 16 weeks. Modified Nerve Tape did not improve
the reliability or efficacy of the PEG fusion process compared with microsuture neurorrhaphy.
