Tiam Mana Saffari

80 CHAPTER 4 Figure 5. Vascular surface area of control and nerve autograft samples at 12 and 16 weeks using digital photography. Results are expressed as a percentage (vessel %) of the total nerve area and are given as the mean ±SEM. SEM: Standard error of the mean. DISCUSSION In this study, the authors successfully preserved the vasculature of the sciatic nerve in rats to provide more insight in the amount of angiogenesis and the patterns of neoangiogenesis occurring in nerve regeneration. Due to the limited options available to visualize the small vessels of the rat had previously impeded the understanding of the underlying neoangiogenesis patterns after nerve graft reconstruction. The utility of the method described in the current study is two-fold. First, it provides an objective quantification of the amount of angiogenesis, independently from the size of the vessels, in relation to the size of the nerve. Second, it eminently demonstrates the patterns of angiogenesis in (transplanted) nerves. Nerve revascularization is postulated to be composed of angiogenesis and neoangiogenesis; vessels that sprout into the existing vascular tree and vessels that create new pathways 27 . However, this theory has yet to be objectively described. The vascularization of nerves and in particular, the alignment of vessels in nerves is attributed to a directional role for regenerating axons 28,29 . Applying the described techniques at several time points after