利用较细的供体神经多段叠加小间隙桥接修复周围神经损伤的研究

A large segmental defect of peripheral nerves caused by injury has been common in clinical. According to the phenomenon that one axon may grow more lateral buds during regeneration, our previous studies have verified a possibility that a small adjacent nerve can be used as a donor for repairing a large nervous deficiency. .If there were no alternative donor nerves in the vicinity of the damaged nerve, it will be necessary to get some distant neural segments for anastomosis. In the proximal anastomosis, the proximal segment of the damaged nerve will be connected to the smaller donor nerve, in which some nascent buds grown from the proximal nerve segment were difficult to squeeze in the smaller donor nerve, which reduced the efficiency of regeneration. In previous studies, we used multiple donor nerves together to repair the defect by epineurium suture, which led to a promising recovery; however, the procedure of epineurium suture also impeded the ability of peripheral nerve to regenerate. To solve this problem, we conduct this study, in which the ipsilateral sural nerve of SD rats will be cut into three segments, then bundled and overplayed together to serve as donor to bridge the small space between two ends of damaged sciatic nerves with the help of biodegradable conduit. The number and morphology of regenerated myelinated fibers, nerve function index and electrophysiological factors, motor endplate ultrastructure and fiber morphology of gastrocnemius muscle will be measured subsequently. The recovery of neural structures and functions will be evaluated, and the possibility and superiority of using biodegradable conduit to bridge multiple smaller nerves between small gap will be evaluated. This study will provide better clinical method in treatment of a large segment defect of peripheral nerve.

周围神经损伤致大段缺损临床常见。根据神经再生时可发出更多新生轴芽，前期研究验证了以损伤附近的细小神经作为供体修复较大神经的可行性。而当受损神经附近无合适的供体神经时，需从较远部位切取供体神经段修复受损神经，形成两个吻合口，近端吻合口为较粗的受损神经连接于较细的供体段，那么，近端新生的较多轴芽很难挤进较细的供体神经，进而影响了修复效果。以往研究采用多段供体神经叠加外膜缝合修复受损神经，取得一定效果，但外膜缝合不利于神经选择对位特性的发挥。基于此，本研究以SD大鼠为研究对象，将腓肠神经切为多段经叠加后作为供体借助生物套管小间隙桥接缝合修复坐骨神经缺损，通过检测再生有髓纤维状况、神经功能指数及电生理、运动终板超微结构及腓肠肌纤维形态等指标，评价神经结构功能及效应器再支配的恢复状况，探索多段供体神经借助生物套管小间隙缝合修复神经缺损的可行性和优越性，拟为临床大段神经缺损选择更佳修复方法提供科学依据