Zhu Guo-Chen, Xiao Da-Jiang, Zhu Bi-Wen, Xiao Yan
Department of Otorhinolaryngology-Head and Neck Surgery, Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University; Department of Otorhinolaryngology-Head and Neck Surgery, Affiliated Wuxi Clinical College of Nantong University, Wuxi, Jiangsu Province, China.
College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, Guangdong Province, China.
Neural Regen Res. 2022 May;17(5):1131-1137. doi: 10.4103/1673-5374.324853.
Acellular nerve allografts conducted via chemical extraction have achieved satisfactory results in bridging whole facial nerve defects clinically, both in terms of branching a single trunk and in connecting multiple branches of an extratemporal segment. However, in the clinical treatment of facial nerve defects, allogeneic donors are limited. In this experiment, we exposed the left trunk and multiple branches of the extratemporal segment in six rhesus monkeys and dissected a gap of 25 mm to construct a monkey model of a whole left nerve defect. Six monkeys were randomly assigned to an autograft group or a xenogeneic acellular nerve graft group. In the autograft group, the 25-mm whole facial nerve defect was immediately bridged using an autogenous ipsilateral great auricular nerve, and in the xenogeneic acellular nerve graft group, this was done using a xenogeneic acellular nerve graft with trunk-branches. Examinations of facial symmetry, nerve-muscle electrophysiology, retrograde transport of labeled neuronal tracers, and morphology of the regenerated nerve and target muscle at 8 months postoperatively showed that the faces of the monkey appeared to be symmetrical in the static state and slightly asymmetrical during facial movement, and that they could actively close their eyelids completely. The degree of recovery from facial paralysis reached House-Brackmann grade II in both groups. Compound muscle action potentials were recorded and orbicularis oris muscles responded to electro-stimuli on the surgical side in each monkey. FluoroGold-labeled neurons could be detected in the facial nuclei on the injured side. Immunohistochemical staining showed abundant neurofilament-200-positive axons and soluble protein-100-positive Schwann cells in the regenerated nerves. A large number of mid-graft myelinated axons were observed via methylene blue staining and a transmission electron microscope. Taken together, our data indicate that xenogeneic acellular nerve grafts from minipigs are safe and effective for repairing whole facial nerve defects in rhesus monkeys, with an effect similar to that of autologous nerve transplantation. Thus, a xenogeneic acellular nerve graft may be a suitable choice for bridging a whole facial nerve defect if no other method is available. The study was approved by the Laboratory Animal Management Committee and the Ethics Review Committee of the Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University, China (approval No. 2018-D-1) on March 15, 2018.
通过化学萃取制备的脱细胞神经同种异体移植物，在临床上用于桥接整个面神经缺损，无论是单干分支还是颞外段多分支连接，均取得了满意的效果。然而，在面神经缺损的临床治疗中，同种异体供体有限。在本实验中，我们暴露了6只恒河猴的左侧主干和颞外段多分支，并解剖出25mm的间隙，构建了左侧全神经缺损的猴模型。6只猴子被随机分为自体移植组或异种脱细胞神经移植组。在自体移植组中，使用同侧自体耳大神经立即桥接25mm的全面神经缺损，在异种脱细胞神经移植组中，则使用带主干分支的异种脱细胞神经移植物进行桥接。术后8个月对面部对称性、神经-肌肉电生理学、标记神经元示踪剂的逆行运输以及再生神经和靶肌肉的形态进行检查，结果显示猴子面部在静态时看似对称，面部运动时略有不对称，且它们能够主动完全闭合眼睑。两组面瘫恢复程度均达到House-Brackmann II级。记录了复合肌肉动作电位，每只猴子手术侧的口轮匝肌对电刺激有反应。在损伤侧的面神经核中可检测到FluoroGold标记的神经元。免疫组织化学染色显示再生神经中有大量神经丝-200阳性轴突和可溶性蛋白-100阳性雪旺细胞。通过亚甲蓝染色和透射电子显微镜观察到移植段有大量有髓轴突。综上所述，我们的数据表明，小型猪的异种脱细胞神经移植物对修复恒河猴全面神经缺损是安全有效的，其效果与自体神经移植相似。因此，如果没有其他可用方法，异种脱细胞神经移植物可能是桥接全面神经缺损的合适选择。本研究于2018年3月15日获得中国南京医科大学附属无锡第二人民医院实验动物管理委员会和伦理审查委员会批准（批准号：2018-D-1）。
