Tiam Mana Saffari

229 MICRO CT ANALYSIS AFTER STEM CELL DELIVERY AND ANGIOGENESIS 10 Other limitations include the effective voxel size (10 mm). As such, the smallest branches are not visible, resulting in some arterial and venous trees not to be connected in the macroscopic figures. Furthermore, the use of Microfil® is limited to ex vivo analysis of specimens, hampering longitudinal studies in one animal 39 . Although these limitations exist, visualization of vessels after Microfil® preservation remains a highly advanced yet relatively simple technique with a broad application range to evaluate vessel volume and distributions in any organ or animal model 12 . Future studies are needed to explore the role of surgical angiogenesis and stem cell delivery on nerve allografts on the long-term in rats and in larger animal models (e.g. rabbits) to provide evidence needed for clinical translation in the future. As limited studies are available that discuss their role on the immunogenicity of nerve allografts 25,40 , increased understanding of the alteration of the micro-environment of nerve and its effect on immune tolerance will contribute to improve reconstructive options for peripheral nerve injuries. CONCLUSIONS Accurate interpretation of 3D angioarchitecture provides insight into hierarchical assembly and changes in vascular patterns, thus understanding of the interaction between vascularity and stem cells. Based on this study, we can conclude that surgical angiogenesis contributes to revascularization of nerve allografts. The combination of surgical angiogenesis with undifferentiated MSCs specifically, results in the greatest increase of revascularization, size of vessels, and stimulation of vessels to reach the mid-section of the nerve allograft. Acknowledgements The authors would like to thank Jim Postier (Rochester, MN) for the artwork of Figure 1 and Andrew J. Vercnocke for his help with the ERODE/DILATE program. This work was supported in part by the Mayo Clinic X-ray Imaging Core. Conflicts of interest None declared.