膈神经椎体前移位并端侧吻合促进肺功能恢复的实验和机制研究

Pulmonary function disorders caused by phrenic nerve injury will seriously affect patients` quality of life. Due to the special rhythmic signals of phrenic nerve, there were no effective treatment for pulmonary dysfunction caused by phrenic nerve injury till now. How to effectively restore the function of phrenic nerve was always one of the difficulties in the field of peripheral nerve injury. Contralateral C7 nerve root transfer was first done in our country, and recently we developed a new method of nerve transfer recently, which caled pre-spinal contralateral C7 nerve root transfer. These progresses inspired us to transfer phrenic nerve through pre-spinal road,and using end-to-side neuroanastomosis to repair the affected phrenic nerve.The merit of the method keeps the function of contralateral phrenic nerve intact, while the cortical representation dominates the neural function at last. So a detailed study of the functional transfer of cerebral cortex caused by the operation, is very important to the final functional recovery. In this study, we will establish the animal model of phrenic nerve injury, pre-spinal phrenic nerve transfer and end-to-side neuroanastomosis.We will compare and acquire the best end-to-side neuroanastomosis method by various immunohistochemical, electrophysiological, histochemical, functional and electron microscopic examinations. What's more, we will evaluate the reinnervation of phrenic nerve, recovery of synapse and pulmonary function, and the evolution of cortical representation. And finally, we will verify the feasibility, efficacy of the technique, and the peripheral and central mechanisms of functional recovery.

膈神经损伤引起的肺功能及发育障碍将严重影响患者生活质量，由于膈神经具有特殊的节律性电信号，目前还没有有效方法治疗膈神经损伤引起的肺功能障碍，如何有效恢复膈神经功能一直是周围神经损伤领域的难点。由我国首创的健侧颈7神经根移位，尤其是近期成功开展的椎体前路移位新术式，启发了我们尝试利用患侧膈神经经椎体前移位，利用神经端侧吻合方法，在修复患侧膈神经的同时又保留健侧膈神经的完整性，而大脑皮层代表区最终控制着神经的功能，所以详细研究本术式所引起的大脑皮层代表区的变化对最终的功能恢复至关重要。本课题中，通过建立膈神经损伤、椎体前移位及端侧吻合动物模型，采用多种免疫组化，神经电生理，组织化学，功能学及电镜检查等方法，筛选最佳端侧吻合方法，评价膈神经再生，突触、膈肌及肺功能恢复程度，大脑皮层代表区演变过程等，最终验证该术式可行性，有效性，肺功能恢复的外周和中枢机制。

本课题通过建立大鼠单侧膈神经损伤的模型，研究单侧膈肌瘫痪后大鼠肺功能的变化情况，并且探讨通过健侧膈神经端侧吻合移位修复患侧膈肌的可行性、有效性及其可能的机制研究。本课题建立的大鼠单侧膈肌瘫痪的动物模型，分别比较了年轻大鼠和老年大鼠单侧膈肌瘫痪后的动物模型，结果发现年轻大鼠单侧膈肌瘫痪后4周，肺活量（VC）及肺总量（TLC）等反映基础肺功能的指标可逐渐恢复至正常水平。而深吸气量（IC）、吸气压（Pi）以及功能残气量（FRC）等反映膈肌功能及肺功能储备的指标无法通过代偿而恢复。单侧膈肌瘫痪的老年大鼠，由于机体代偿能力的降低导致基础肺功能以及膈肌功能均明显下降。实验发现通过腓肠神经移植健侧膈神经端侧吻合修复患侧膈肌功能是安全可行、有效的。并且通过螺旋缠绕两周端侧吻合修复效果更佳，这可能与吻合口有效接触面积增加有关。通过对其机制的研究发现：1、健侧膈神经端侧吻合术后患侧膈神经及膈肌均可以得到有效修复。2、健侧膈神经可通过芽生的方式支配患侧膈肌。3、健侧脊髓前角运动神经元可有效支配患侧膈神经。4、端侧吻合术后4周神经生长相关因子表达至高峰，而神经营养因子表达高峰则持续至术后8周。