Tiam Mana Saffari

133 FUNCTIONAL MOTOR RECOVERY OF ANGIOGENESIS OF NERVE ALLOGRAFTS 7 INTRODUCTION Traumatic nerve injuries are a common cause of severe disability and result in loss of sensory- and motor function 1 . The gold standard remains end-to-end tension-free neurorrhaphy 2,3 . When this is not possible, autograft interposition is needed, requiring harvest of a functional autologous nerve with the associated donor site morbidity 4 . Experimental models have investigated allogenic nerves, processed allografts, conduits and vein grafts for the reconstruction of peripheral nerve injuries 5-7 . While these substitutes have demonstrated successful recovery, outcomes have yet to exceed the results of autografts. It is widely accepted that functional results are poor when nerve grafts are transplanted into scarred recipient beds 8 , and that independent blood supply of nerve grafts could improve outcomes 9,10 . Processed nerve allografts are devoid of cellular materials, have no vascular supply and undergo revascularization from the surrounding tissue bed via centripetal revascularization 11 . Surgical addition of vascularization (surgical angiogenesis) has the advantage of ensured blood supply, potentially minimizing the period of ischemia and diminishing fibrosis and central necrosis. Immediate revascularization promotes axonal regeneration 12 and faster reinnervation, which could reduce denervation- induced muscle atrophy 13 . Furthermore, the addition of cellular-based therapy such as adipose-derived mesenchymal stem cells (MSC), could influence vascularization 13 . Adipose tissue itself is a rich source of MSCs, with proven beneficial effects on nerve regeneration 13-18 . The superficial inferior epigastric artery fascial (SIEF) flap is an easily harvested flap that provides surgical angiogenesis while improving nutrition and circulating pluripotent cells to the wound site, as well as a layer of adipose tissue to the nerve injury bed, a potential source of stem cells 19 . Application of either vascularized nerve grafts (VNG) or vascularized flaps around nerve grafts has been suggested to improve outcomes, however, there are conf licting clinical and basic science reports on its efficacy 15,20-23 . In the present study, we investigated the effect of surgical angiogenesis of decellularized nerve allografts on functional motor recovery after segmental nerve repair in rats by comparing allografts placed in a vascularized bed to allografts alone and autografts.