BRAIN-DERIVED NEUROTROPHIC FACTOR AND COLLAGEN TUBULIZATION ENHANCE FUNCTIONAL RECOVERY AFTER PERIPHERAL-NERVE TRANSECTION AND REPAIR

Objective: To investigate the effect of brain-derived neurotrophic fac tor (BDNF) and collagen tubulization (CT) on the regeneration of trans ected peripheral nerves. Methods and Design:: The left sciatic nerve o f 40 Sprague-Dawley rats was transected then repaired using one of fou r techniques: epineurial coaptation, CT, CT with BDNF delivered by an osmotic pump to the repair site, or CT with BDNF covalently cross-link ed to the collagen matrix (CT/linked-BDNF). Sciatic functional indices were measured preoperatively and then postoperatively at 10-day inter vals for 90 days. Segments of the sciatic nerves proximal and distal t o the repair site were harvested at 90 days for histologic and morphom etric evaluation. Results: Animals repaired by CT/linked-BDNF (n=10) d emonstrated the most favorable functional recovery of all groups, with statistically significant differences seen compared with animals repa ired by CT (n=10, P=.05) and epineurial coaptation (n=9, P<.001). Anim als repaired by CT with BDNF delivered by an osmotic pump (n=8) and CT also showed statistically superior functional recovery compared with those repaired by epineurial coaptation (P=.005 and P=.02, respectivel y). Nerves repaired by CT/linked-BDNF had the largest mean axon diamet ers proximal and distal to the repair site. Conclusions: Brain-derived neurotrophic factor and CT improve the rate and the degree to which r ecovery of sciatic function occurs after nerve transection and repair. Animals repaired by CT/BDNF-linked demonstrated the most favorable fu nctional recovery of all groups. Animals whose repair technique includ ed BDNF had the largest mean axon diameters of all groups.