【作者】 张志凌；

【导师】 陈爱民；

【作者基本信息】 第二军医大学 ， 外科学， 2013， 博士

【摘要】 伴随城市化建设，高速度的工具的使用，骨盆骨折越发常见，骶丛损伤在骨盆后环骨折中多见，损伤后直接导致下肢感觉、运动功能障碍，并可能合并大小便功能障碍。目前临床治疗手段单一，因此骶丛撕脱伤的治疗成为目前骨科临床面临的难点及重点之一。为探讨骶丛撕脱伤的病理改变及治疗，动物实验研究是必要的途径。鉴于在动物进化上大鼠相对接近人类，大鼠的动物模型常被作为神经及功能重建的基础性研究。本课题组前期已经成功建立SD大鼠骶丛撕脱伤的模型，并有可靠指标判定模型的标准[1]，本文在椎管外建立大鼠骶丛撕脱伤模型基础上，以健侧腰4神经根作为新的动力源神经修复大鼠患侧骶丛撕脱伤，通过大鼠术后一般状况的观察、下肢三组主要肌肉的湿重对比、并结合电镜观察吻合后神经再生情况、肌肉横切面免疫组化、坐骨神经功能指数、脊髓前角细胞改变，小动物PET-CT等指标分析以采用健侧腰4神经根作为动力源神经修复骶丛撕脱伤的可行性及有效性，本文主要分三部分阐述。第一部分健侧L4移位修复大鼠骶丛撕脱伤研究目的：探讨采用健侧L4神经根作为动力源神经的可行性。研究方法：选用体重200-300g的成年SD大鼠共30只（上海医科大学动物部提供），雌雄不限，随机分为3组（假手术组、撕脱组、L4-L5吻合组）每组10只，左侧为对照侧，右侧为实验侧。术后观察各组大鼠的存活情况，对受试老鼠进行术后后肢BBB评分；双侧下肢三组主要肌肉（股二头肌、小腿三头肌、胫前肌）进行称重及肌肉横截面HE染色的对比；肌电图检查（EMG），电子显微镜检查吻合口远端神经生长情况；坐骨神经功能指数以评价吻合的有效性。结果：术后3个月大鼠BBB评分吻合组较撕脱组高，差异有统计学意义（P=0.001）。吻合组右侧的股二头肌、小腿三头肌、胫前肌与撕脱组相比均有不同程度恢复，差异有统计学意义。三组肌群恢复速度在L4-L5吻合组内有差异，其中近端股二头肌恢复效果相对较好，神经电镜观察吻合口远端可见大量再生有髓神经纤维。双通道肌电图记录均可三组肌肉的波幅，以近侧股二头肌及小腿三头肌峰值较高，远侧胫前肌峰值则相对较低。结论：健侧腰4（L4）神经根移位与患侧L5神经根直接吻合能恢复大鼠坐骨神经的部分功能，以近侧股二头肌肉恢复相对较好。第二部分骶神经移位修复后脊髓前角改变研究目的：健侧骶神经移位修复大鼠骶丛撕脱伤后脊髓前角运动细胞变化。研究方法：利用HE染色及Tunnel法检测脊髓前角运动神经元的存活及凋亡情况。真蓝逆行示踪，判断神经再生情况。术后12周，取L4-L5吻合组大鼠在患肢大腿中段暴露坐骨神经干，用微量进样器分4点注射5％FG共100μl，留针数秒后，缓慢退针。动物存活30h后，灌注取材。根据解剖定位，小心切除骶部椎板，切开硬膜囊，暴露脊髓，在手术显微镜（×10）下切取L4－6节段脊髓。切片后，荧光显微镜下观察观察阳性标记细胞的位置和数量。结果：吻合组脊髓前角成活率高，凋亡率低，差异有统计学意义。吻合组可见L4-6段右侧脊髓内有蓝色荧光，说明吻合后神经通路恢复良好。结论：健侧骶神经移位修复大鼠骶丛撕脱伤在对应的脊髓前角可检测到阳性细胞，说明对应的脊髓前角细胞受到了保护，并在一定程度上恢复了脊髓的神经通路。第三部分骶神经移位修复后脑PET显像研究目的：健侧骶神经移位修复大鼠骶丛撕脱伤后大脑PET显像。研究方法：选用体重200-300g的成年SD大鼠30只，雄雌不限，将其随机分为3组：第一组：右侧骶丛撕脱伤损伤不修复组，10只；第二组：健侧L4神经根移位修复组，10只；第三组：假手术组，仅仅做皮肤切开缝合，不做其他特殊处理，10只。术后3个月，大鼠禁食12小时，尾静脉注射0.2ml¹⁸F-FDG，通过滤波反射投影法重建冠状面、横断面、矢状面断层进行分析。重建后的图像利用西门子Inveon ResearchWorkplace（IRW）3.0获取3D的感兴趣区对数据进行定量分析并获取感兴趣区随时间变化的动态SUV值。结果：第一组大鼠刺激右侧坐骨神经双侧大脑未见¹⁸F-FDG摄取增多，脑部基本无明显显像，第二组大鼠刺激大鼠右侧坐骨神经在可见双侧大脑葡萄糖代谢率增高，¹⁸F-FDG摄取增多，双侧均有显像，第三组大鼠左侧脑部显像较为明显。结论：健侧L4神经移位修复大鼠骶丛撕脱伤后在对应的大脑功能区有较为活跃的葡萄糖代谢率改变，¹⁸F-FDG摄取增多，说明吻合后大脑神经通路可获得一定程度恢复。更多还原

【Abstract】 Pelvic fracture is a common fracture in clinic, which may induce the Ventral rootavulsion. or ventral injury with the functional impairment of movement and feeling of lowerlimb. Nowadays, we have no efficient method to deal with them. To further study the injuryof sacral plexus root, we need animal experiments. Rat is the ideal model in the study ofsacral plexus root. in this article,we emphasis on the animal researches of adopting thenormal sacral plexus root to reconstruct the injured sacral plexus root. We use many ways toevaluate the efficiency of this kind of therapy post-operation.Part OneTo evaluate the efficiency of adopting L4transposition to Reconstruct the sciatic nerveMethods:30adult SD rats were chosen to establish the animal model of sacral plexusroot avulsion at random after avulsing the right L4-6out of intervertebral foramina. Rats weredivided into3groups(n=10). In one group rats we did not reconstruct the sciatic nerve. Inanother groups we adopted the L4transposition to reconstruct the injured sacral plexus root.After the model establishment,12weeks after operation, rat in each group were selected forthe histomorphology of the nerves was observed under the microscope and the electronmicroscope. The models were evaluated by the observation of the survival rates of the rates,BBB scores, electron microscope weight and muscle fiber CSA(cross section area) of doublebiceps femoris, triceps surae and tibial muscle.Results:12weeks after operation, the BBB scores indicated significant differences（P=0.001） between3groups. We found remarkable significances between the ratio ofweight and muscle fiber CSA of double biceps femoris, triceps surae and tibial muscle. the Efficiency was different between the two groups (L4-L5and avulsing), the former was better.In the L4-L5group, the recovery of biceps femoris, triceps surae and tibial muscle wasdifferent. The former was better. The histomorphology of the nerves was observed under themicroscope and the electromicroscope.Conclusion: L4transposition can reconstruct the partial function of sciatic nerve the inparaplegia rats. Objective: To evaluate the degeneration of motor neurons in cornu anterius medullaespinalisMethods:30adult SD rats were chosen to establish the animal model of sacral plexusroot avulsion at random after avulsing the right L4-6out of intervertebral foramina. rats weredivided into3groups(n=10). GroupA-C.12week after operation, degeneration of motorneurons in cornu anterius medullae spinalis was elevated by HE and Tunnel.Results: The survival rates of motor neurons in cornu anterius medullae spinalis decreasedgradually and apoptosis index increased gradually. The survival rates and apoptosis index ofmotor neurons in cornu anterius medullae spinalis changed greatly in L4-L5group.Conclusion: in L4-L5group the survival rates and apoptosis index of motor neurons incornu anterius medullae spinalis changed greatly. Objective: To evaluate the efficiency of adopting L4transposition to Reconstruct thesciatic nerve in brainMethods: After12weeks, mice were subjected to PET/CT analysis. PET/CT imaging wasperformed on an Inveon MM Platform (Siemens Preclinical Solutions, Knoxville, Tennessee,USA) with a computer-controlled bed and8.5cm transaxial and5.7cm axial fields of view(FOV). The animals were anesthetized with2%isoflurane in O2gas for [18F]-FDG injection (a single injection of0.1ml FDG with an activity of10MBq intravenously in the tail vein aspreviously described), immediately awakened afterwards and placed back in the anesthesiacage. Two hours after administration of the tracer injection, animals were anesthetized withisoflurane, placed prone on the PET scanner bed near the central field of view and weremaintained under continuous anesthesia during the study with1.5%isoflurane in oxygen at2L/min. Inveon Acquisition Workplace(IAW)1.5.0.28was used for scanning process.10minCT X-ray for attenuation correction was scanned with a power of80Kv and500uA and anexposure time of1100ms before PET scan. Ten-minute static PET scans were then acquired,and images were reconstructed by an OSEM3D (Three-Dimensional Ordered SubsetsExpectation Maximum) algorithm followed by MAP (Maximization/Maximum a Posteriori)or FastMAP provided by IAW. The3D regions of interest (ROIs) were drawn over the heartguided by CT images and tracer uptake was measured using the software of Inveon ResearchWorkplace (IRW)3.0. Individual quantification of the [18F]-FDG uptake in each of them wascalculated. Mean standardized uptake values (SUV) were determined by dividing the relevantROI concentration by the ratio of the injected activity to the body weight.Conclusion: L4transposition can reconstruct the partial function of sciatic nerve the inparaplegia rats.更多还原