Prophylactic Effects Of Edaravone On Extremity After Limb Replantation

Objective: Amputated injury of the extremity is common in the field of hand surgery.The development of microsurgical techniques and scientific technologies have led to greater success in replantation, which shift clinicians'focus from survival rate to improving postoperative limb function. therefore, How to preserv the extremity preferably and how to prevent ischemia-reperfusion injury effective are exploring. Reducing the ischemia-reperfusion injury after replantation,predominantly to the skeletal muscle,is relative to extremity function.Ischemia-reperfusion injury is defined as adverse functional,metabolic,or structural changes in ischemic tissue resulting from the restoration of blood flow to the tissue,including swelling,hemorrhage,necerosis,and damage from free radicals,whose mechanism is prefound. Edaravone,a newly synthesized free-radical scavenger,was approved in Japan for treating acute brain infarction on 2001.The purpose of this study was to improved a previously established animal reperfusion model,add sample size and index,and investigate whether or not edaravone is effective in reducing ischemia-reperfusion injury after replantation.Methods: Eighteen healthy SD rabbits were chosen to set up replantation of amputated limb models in the left hindlimbs, According to different interventions, all of the rabbits were randomly divided into 3 groups: control group, ischemia-reperfusion group and edaravone group. In ischemia-reperfusion group and edaravone group,after anesthesia through 17% pentobarbital(40～60mg/ kg), the femoral artery and vein and superficial epigastric artery and vein was exposed by microscope, ligate by bulldog clamp, and then amputate the left hindlimbs except those blood vessels, In the control group, expose these structure merely. ischemia-reperfusion group,after ischemia 2.5h, the shaft of femur was fixed by Kirschner wire, amputated skeletal muscle was sutured in 0.5h, and then the blood circulation was restored.In edaravone group, before the blood circulation was restored, the rabbits were given 1.5mg/kg of edaravone in 50 ml/h though superficial epigastric artery.The quality of tibialis anterior muscles tissues of rabbits about 0.8 gram were preversed, and Superoxide Dismutase (SOD), malondialdehyde (MDA), myeloperoxidase (MPO), Na+-K+-ATP ase, Ca2+-ATP ase, W/D were analyzed,and morphology of tibialis anterior muscles were observed under microscope in 2h, 4h, 8h, 12h after blood circulation was restored.Results: The result of microscope examination showed that morphological leision in edaravone group was significantly slighter compared with that in ischemia-reperfusion group,including swelling, hemorrhage, inflammation and necerosis.In control group, the tissue is similar to the normal.After statistics,all index show that every group had statistical difference(P<0.05). And the index in edaravone group were significantly better than that in IR group along with the time. Conclusions: Edaravone perfusion solution can improve the ischemia-reperfusion to the extremity after limb replantation and combined usage of multiple medicine to different links of the mechanism of ischemia-reperfusion injury is a more effective method to preveat ischemia-reperfusion injury.