健侧颈7神经根移位修复下干治疗全臂丛神经根性撕脱伤的实验研究

Experimental study of direct transfer of contralateral C7 to the lower trunk for the treatment of total root avulsions of the brachial plexus

目的通过大鼠在体实验，观察健侧颈，神经根移位修复下干治疗全臂丛神经根性撕脱伤的可行性和有效性。方法雌性SD大鼠36只，随机分成三组：A组，健侧颈。神经根移位修复下干组；B组，对照组；C组，未修复组。术后通过电生理检查、神经肌肉组织学检查、肌肉横截面积、肌肉湿重和运动终板形态学检查进行综合评价。结果健侧颈，神经根移位术后24周，在尺神经和正中神经，神经纤维的平均直径、N率（N Ratio），A、B组差异无统计学意义（P〉0．05）；在尺神经，神经纤维总数A、B组差异无统计学意义（P〉0．05），但在正中神经A组明显少于B组（P〈0．05）。电生理检测提示，尺侧腕屈肌波幅及潜伏期，A、B组差异无统计学意义（P〉0．05）；指浅屈肌波幅A组小于B组，潜伏期A组长于B组（P〈0．05）。肌肉湿重，尺侧腕屈肌A、B组差异无统计学意义（P〉0．05），但A组重于C组；指浅屈肌A组轻于B组（P〈0．05），但重于C组（P〈0．05）。尺侧腕屈肌和指浅屈肌的横截面积，A组均小于B组（P〈0．05），大于C组（P〈0．05）。光镜下A、B组的尺侧腕屈肌及指浅屈肌的肌节和肌丝排列整齐，未见断裂、崩解现象。结论健侧颈，神经根移位修复下干是可行的，就神经和肌肉的组织学、电生理的恢复而言是有效的。

Objective To investigate the feasibility and effectiveness of contralateral C7 transfer to the lower trunk for total root avulsion of the hrachial plexus. Methods Thirty-six female SD rats were randomly divided into three groups. In group A, coutralateral C7 nerve root was transferred to the lower trunk directly. Group B was the normal control group, while group C had total root avulsiou without repair. Twenty-four weeks after the surgery, electrophysiological examination, neuromorphometry, muscle cross-sectional area, muscle wet weight and motor endplate detection were carried out to evaluate the outcomes of each group. Results Nerve fiber diameter and N ratio in the ulnar nerve and median nerve were not significantly different between group A and group B （ P 〉 0.05）. Total myelinated fiber counts in the ulnar nerve were not different between group A and group B （ P 〉 0.05）, while there were significantly fewer myelinated fibers in the median nerve of group A than in the median nerve of group B （ P 〈 0.05）. CMAP of flexor carpi ulnaris （FCU） had similar latency and amplitude in group A and group B （ P 〉 0.05）. In flexor digitorum superficialis （FDS）, group A had lower CMAP amplitude and longer latency than group B （ P 〈 0.05 ）. Wet muscle weight of FCU in group A was comparable to group B （ P 〉 0.05） but greater than group C （ P 〈 0.05）. Wet muscle weight of FDS in group A was lighter than group B （ P 〉 0.05） but heavier than group C （ P 〉 0.05）. Muscle cross-sectional areas of both FCU and FDS in group A were smaller than group B （ P 〈 0.05 ） but larger than group C （ P 〈 0.05 ）. Conclusion Direct contralateral C7 transfer to the lower trunk is feasible. Its effectiveness is shown by recovery in electrophysiology, neuromorphometry, and muscle histology.