Tiam Mana Saffari

88 CHAPTER 5 ABSTRACT Introduction The specific patterns of revascularization of allograft nerves after addition of vascularization remain unknown. The aim of this study was to determine the revascularization patterns of decellularized processed nerve allograft after surgically induced angiogenesis to the wound bed in a rat sciatic nerve model. Materials and Methods In 51 Lewis rats, sciatic nerve gaps were repairedwith (i) autografts, (ii) nerve allograft and (iii) nerve allograft wrapped in a pedicled superficial inferior epigastric artery fascia flap (SIEF) to provide vascularization to the wound bed. At two, 12 and 16 weeks, the vascular volume and vascular surface area in nerve samples were measured using micro CT and photography. Cross-sectional images were obtained and the number of vessels was quantified in the proximal, mid and distal sections of the nerve samples. Results At two weeks, the vascular volume of SIEF nerves was comparable to control (P=0.1). The vascular surface area in SIEF nerves was superior to other groups (P<0.05). At 12 weeks, vascularity in SIEF nerves was significantly higher than allografts (P<0.05) and superior compared to all other groups (P<0.0001) at 16 weeks. SIEF nerves had a significantly increased number of vessels compared to allografts alone in the proximal (P<0.05) and mid-section of the graft (P<0.05). Conclusions Addition of surgical angiogenesis to the wound bed greatly improves revascularization. It was demonstrated that revascularization occurs primarily from proximal to distal (proximal inosculation) and not from both ends as previously believed and confirms the theory of centripetal revascularization.