Tiam Mana Saffari

132 CHAPTER 7 ABSTRACT Background Surgical angiogenesis applied to nerve grafts has been suggested to enhance nerve regeneration after nerve injury. We hypothesized that surgical angiogenesis to decellularized nerve allografts would improve functional recovery in a rat sciatic nerve defect model. Materials and Methods Sixty Lewis rats were divided in three groups of 20 animals each. Unilateral sciatic nerve defects were repaired with (i) autografts, (ii) decellularized allografts and (iii) decellularized allografts wrapped with a superficial inferior epigastric fascial (SIEF) flap to add surgical angiogenesis. Twelve and 16 weeks after surgery, nerve regeneration was assessed using functional, electrophysiological, histological and immunofluorescence analyses. Ultrasonography was used during the survival period to noninvasively evaluate muscle atrophy and reinnervation by measuring cross- sectional muscle area. Results Surgical angiogenesis of allografts demonstrated significantly improved isometric tetanic force recovery at 12 weeks, compared to allograft alone, which normalized between groups at 16 weeks. Cross-sectional muscle areas showed no differences between groups. Electrophysiology showed superiority of autografts at both time points. No differences were found in histological analysis, besides a significantly inferior N-ratio in allografts at 12 weeks. Immunofluorescent expression of CD34, indicating vascularity, was significantly enhanced in the SIEF group compared to allografts at 12 weeks, with highest expression at 16 weeks compared to all groups. Conclusions Surgical angiogenesis with an adipofascial f lap to the nerve allograft increases vascularity in the nerve graft, with subsequent improvement of early muscle force recovery, comparable to autografts.