Tiam Mana Saffari

111 THE LOCAL MICROENVIRONMENT OF NERVE ALLOGRAFTS AFTER ANGIOGENESIS 6 chondroitinase and elastase, sterilized using g-irradiation and stored in phosphate buffer saline (PBS) at 4°C until surgery. Surgical procedure Rats were anesthetized in an isof lurane chamber, shaved and positioned in the nosecone to maintain anesthesia throughout the procedure. Preoperatively the following were subcutaneously injected; Enrofloxacin (Infection profylaxis, Baytril, Bayer, Germany, 10mg/kg), 5 mL of NaCl 0.9% and buprenorphine SR (pain control, Buprenorphine SR-LAB, ZooPharm pharmacy, 0.6mg/kg). Body temperature was maintained at 37°C with a heating pad. The sciatic nerve was fully exposed proximally from the inferior margin of the piriformis muscle to approximately 5 mm distal to the bifurcation, under an operating microscope (Zeiss OpMi 6, Carl Zeiss Surgica, Oberkochen, Germany). A 10-mm segment of the sciatic nerve was excised by sharp transection with microsurgical scissors. In group I, the nerve segment was reversed and placed as an interposition autograft with six 10-0 nylon (10-0 Ethilon, Ethicon Inc., Sommerville, NJ, USA), epineural interrupted sutures on either side. In group II, the nerve gap was bridged with a 10-mm nerve allograft using a similar surgical technique. In group III, a 10-mm nerve allograft was used to reconstruct the nerve defect and wrapped in a pedicled adipofascial flap harvested from the abdomen to provide vascularization to the nerve allograft. Preparation of the superficial inferior epigastric fascial (SIEF) f lap was previously described 14 . Briefly, a 4-cm paramedian abdominal incision was made on the ipsilateral side of the nerve reconstruction. The femoral artery was identified in the groin and the superficial inferior epigastric (SIE) vessels were exposed. The 4 x 3 cm SIEF flap containing subcutaneous fat, inguinal fat, the femoral vasculature and SIE vessels, was tunneled subcutaneously toward the nerve reconstruction and wrapped around the nerve. Both the proximal and distal nerve anastomoses were covered with the flap. In all groups, wounds were closed in layers, approximating muscle with two 5-0 absorbable interrupted sutures. The skin was closed subcutaneously (5-0 Vicryl Rapide, Ethicon Inc., Sommerville, NJ, USA). Postoperatively, the rats were kept warm with towels.