Tiam Mana Saffari

70 CHAPTER 4 ABSTRACT Introduction Nerve regeneration involves multiple processes which enhance blood supply that can be promoted by growth factors. Currently, tools are lacking to visualize the vascularization patterns in transplanted nerves in vivo . Materials and Methods A protocol to visualize the vasculature of the sciatic nerves has been developed with two available techniques. In this study, we describe a step-by-step procedure for preservation of the vasculature of sciatic nerve autografts (N=12) and contralateral non-operated control nerves (N=12) in the Lewis rat at 12 and 16weeks postoperatively. After sacrifice of the rats, Microfil® contrast compound was injected and the nerves were cleared while preserving the vasculature. The amount of vascularization was measured by quantifying the vascular surface area using conventional photography (two dimensional) and the vascular volume was calculated with micro-computed tomography (micro CT, three dimensional). Results Successful preservation of vasculature was achieved in all nerve samples. Using micro CT, the vascular volume was significantly increased from 12 to 16 weeks in both groups. The same trend was seen in the vascular surface area, but this was not significant. The correlation between both methods was statistically significant. Conclusions Both methods are considered to successfully reflect the degree of vascularization. Application of this technique could be used to visualize and objectively quantify angiogenesis of the transplanted nerve graft. Moreover, this simple method is easily reproducible and could be extrapolated to any other desired target organ ex vivo in small animals to investigate the vascular network.