A Experimental Study On Peripheral Nerve Defect Repair By Vascularized Nerve With Different Degeneration Time

Objective: Investigation the effect of nerve regeneration of vascularized nerve graft with different degeneration time.Method: 108 Wistar rats were randomized into 3 groups according to different degeneration time of 0,land4weeks.Each group consisted of 36 rats.another 12 rats were used a control group.then,both of forearms were divided into two groups according to the blood supply of grafting ulnar nerve.so all rats were devided into 6 groups.Group Al:Vascularized fresh nerve group; Group A2: Non-vascularized fresh nerve group;Group Bl: Vascularized nerve graft with degeneration time of 1 week; Group B2: Non-vascularized nerve graft with degeneration time of 1 week; Group C1: Vascularized nerve graft with degeneration time of 4 weeks; Group C2: Non-vascularized nerve graft with degeneration time of 4 weeks;Every rat was performed two times.The first operation was performed to insect ulnar nerve;the segment of ulnar nerve was harvested to bridge defect of median nerve in the second operation. The segment of grafting ulnar nerve and distal segment ofmedian nerve were harvested at 4 8 and 12weeks after nerve grafting . Morphology of regenerating nerve were performed and analysised by microscopic and electon microscopic observation. Electro-physiological examination was done at 12 weeks postoperation too.ResultsrThere are not obvious adhesion to surrounding tissue and neuroma in group A and group B,The appearance of nerves show no distinct difference among 6 groups. Vascularized nerve graft is superior to Non-vascularized nerve graft in the neural axon regeneration rate and the result of Electro-physiological examination.There is not statistical variant of neural axon regeneration rate between groupAl and group Bl,so is between groupA2 and group B2. There is not statistical variant of electrophysiological examination among groupAl, Bl andCl,so is among group A2,B2andC2. Electron microscopic observation showed the greatest number of regenerating axon with the most mature mophology of regeneratingnerve in group Al and group Bl.Conclusions: There are not different in nerve grafting between nerve graft with degeneration time of 1 week and fresh nerve graft. Vascularized nerve graft is superior to non- Vascularized nerve graft. Vascularized nerve with short-time degeneration can be used to replace fresh nerve to repair peripheral nerve defect.