Abstract
Purpose: nerve regeneration and functional recovery are often incomplete after peripheral nerve damage. The aim of this study was to determine if chondroitinase ABC injection at the lesion site, 1 hour of electrical stimulation and the combination of these treatments at the time of repair could be effective in promoting muscle reinnervation.
Methods: the right sciatic nerve was completely sectioned in 32 female Sprague-Dawley rats. End-to-end microsuture repair was undertaken and fibrin glue was added. Five groups were studied: 1) suture (S) + fibrin glue (F) only; 2) S + F + chondroitinase ABC; 3) S + F + electrical stimulation; 4) S + F + chondroitinase ABC + electrical stimulation; 5) uninjured nerve.
Results: post recovery kinematics showed larger excursion of the hip-ankle-toe angle during walking in groups 2, 3 and 4 than in group 1 (p< 0.05). In vivo electromyographic activity and maximal muscle force were similar between groups 2, 3, 4 and 5, with higher values in all of them compared to group 1 (p< 0.05). Also, the distal stump of the sciatic nerve was excised, and cross-sectioning revealed that the number of axons were similar in all groups.
Conclusions: 150 days after nerve transection, recovery was incomplete with S and F only. Chondroitinase ABC injection at the lesion site and/or 1 hour of electrical stimulation of the proximal nerve stump were beneficial in promoting nerve regeneration and functional muscle reinnervation.