Fascial pedicle artificial nerve tissue compared with silicone tube bridging to repair sciatic nerve defects in rats

BACKGROUND: Silicone tube bridging for peripheral nerve defects has been shown to be successful in guiding neural regeneration.However,this method is accompanied by complications.Because materials for bridging nerve fibers should exhibit biocompatibility,the development of novel artificial tissues to bridge nerve grafts has become important in the field of nerve tissue engineering for the repair of peripheral nerve defects.OBJECTIVE: To investigate effectiveness and feasibility of fascial pedicle artificial nerve tissue to repair peripheral nerve defects,and to compare to autologous nerve grafts and silicone tube bridging methods.DESIGN,TIME,AND SETTING: Randomized,controlled,neural tissue engineering-based,animal experiments were performed at the Laboratory of Human Anatomy in Qingdao University Medical College from March 2006 to March 2007.MATERIALS: Medical absorbable collagen sponge was purchased from Henan Province Tiangong Bio-Material,China.Cantata 2-track 4-trace EMG-evoked potential instrument was purchased from Dantec,Denmark.Medical silicone tube was purchased from Shenzhen Legend Technology,China.METHODS: Forty healthy,adult,male,Sprague Dawley rats were randomly assigned to four groups: fascial pedicle nerve,autologous nerve,silicone tube,and normal,with 10 rats in each group.A 10-mm defective sciatic nerve section was produced in rats following the removal of the fascial pedicle.The fascial flap surrounding the defect was harvested;one side of the nerve pedicle was maintained and then sutured into a tube with the fascia surface as the pipe inner wall.The tube was filled with a medical absorbable collagen (Bodyin) to construct a bridge between the artificial tissue nerve graft and the damaged sciatic nerve.The sciatic nerve defects in the autologous nerve and silicone tube groups were bridged using autologous nerve grafts and a medical silicone tube with matched specifications.MAIN OUTCOME MEASURES: At 4 months after transplantation,electromyogram was used to detect sciatic nerve conduction velocity and action potential amplitude.Hematoxylin-eosin and Nissl staining were used to determine the number of spinal cord anterior horn motor neurons and neurites.Osmium tetroxide staining of the sciatic nerve bridge section was performed to detect the number and diameter of nerve fibers.RESULTS: There were no differences in sciatic nerve conduction velocity,action potential amplitude,the number of spinal cord anterior horn motor neurons and neurites,sciatic nerve fiber number,and diameter between the autologous nerve graft and normal groups (P > 0.05).However,these values were significantly greater than in the silicone tube group (P < 0.05).CONCLUSION: Quantitative results suggested that artificial nerve tissue,with an autologous tissue fascia flap as a nerve conduit,could be used to repair peripheral nerve defects.The regenerated fascial pedicle artificial nerve tissue was similar to an autologous nerve graft in terms of morphology and functional recovery and was superior to results from silicone tube bridging transplants.