VASCULARIZED NERVE TUBE - AN EXPERIMENTAL ALTERNATIVE FOR VASCULARIZED NERVE GRAFTS OVER SHORT GAPS

Multilayered tubes fabricated from human amnion were placed subcutaneo usly and/or longitudinally in contact with an axial artery and vein in rats. Histologic evaluation at the third postoperative week showed th at the tubes had incorporated with the surrounding fibrovascular tissu e. New capillary formation within the tube wall was well demonstrated by microangiography Vascularized amnion tubes were then used to bridge a 1-cm-long femoral nerve gap in an artificially-created, relatively avascular bed in rats. An avascular bed was created by wrapping the co rresponding nerve segment with a thin silicone sheet. After 3 months, nerve regeneration was assessed using morphometric analysis. The vascu larized amnion conduits showed comparable nerve regeneration to vascul arized nerve grafts (p > 0.05), and superior nerve regeneration when c ompared to nonvascularized amnion conduits and nonvascularized nerve g rafts as well (p < 0.05). This suggests that, in the rat model, a cond uit can be neovascularized and used as a prefabricated tissue, to brid ge short nerve gaps in a compromised bed.