植入式膈神经刺激器在兔颈脊髓半切损伤模型的应用研究

中文关键词:  脊髓半切损伤  膈神经  膈神经刺激器  兔  膈肌

英文关键词:Hemisection spinal cord injury  Phrenic nerve  Phrenic nerve stimulator  Rabbit  Diaphragm

中文摘要:

  【摘要】 目的：应用兔C3脊髓半切损伤模型造成单侧膈肌瘫痪，观测植入式膈神经刺激器对膈肌功能恢复的有效性和组织相容性。方法：30只新西兰大白兔随机分为对照组（A组）和实验组（B组），每组15只，建立兔C3脊髓半切损伤模型造成单侧膈肌瘫痪，并植入膈神经刺激器。B组组每日施加电刺激干预（每日1次，每次8h），A组不施加电刺激干预。两组分别于颈髓损伤前、术后1、2、4周行血气分析检测；术后1、2、4周对膈肌、膈神经进行形态学观察，并对膈肌肌纤维细胞横截面的面积进行统计学分析。结果：颈髓损伤术后1周，两组PaO2值都下降，PaCO2都升高，但组间比较无统计学意义（P>0.05）；术后2周A组PaO2值开始回升，PaCO2值无明显变化，B组PaO2值继续降低，PaCO2值继续增大，两组间比较存在统计学差异（P<0.05）；术后4周B组PaO2值明显升高（未恢复至正常水平），PaCO2恢复至正常水平，与A组相比存在统计学差异（P<0.05）。术后1周两组膈肌细胞横截面积无显著差异（P>0.05），术后2周、4周A组膈肌细胞横截面积均较B组组明显减小，与B组存在统计学差异（P<0.05）。A组2周时膈肌细胞肌束膜及肌内膜边界不清，4周时局部肌细胞破坏；B组4周时肌细胞肌束膜及肌内膜边界仍清晰。A组术后1周时膈神经结构正常，2周时可见髓鞘增生，鞘索比例增大，数目减少；4周时可见髓鞘异常增生明显，神经间质水肿，微管微丝线粒体大量缺失。B组膈神经始终为正常结构。结论：植入式膈神经刺激器能够促进颈髓损伤后新西兰大白兔膈肌呼吸功能的恢复，其机制可能与膈神经刺激能够延缓颈髓损伤后膈肌萎缩和膈神经变性有关。

英文摘要:

  【Abstract】 Objectives: To develop a tailored implantable phrenic nerve stimulator, and to evaluate the effectiveness and compatibility of stimulator in the setting of rabbit cervical spinal cord hemisection injury model. Methods: Thirty New Zealand white rabbits were randomly divided into control group(group A) and experimental group(group B), with 15 rabbits in each group. C3 spinal cord hemisection injury model was established, which resulted in ipsilateral diaphragm paralysis confirmed by MEP. Simulator was implanted into the posterior triangle of neck between both groups, then electrical stimulation was regularly applied to the phrenic nerve only in group B. Blood gas was analyzed before and after injury. Diaphragm and phrenic nerve were collected for morphological observation at 1, 2, 4 weeks after injury. Results: The value of PaO2 got down and PaCO2 went up one week after injury in both groups with no statistically difference(P>0.05). PaO2 returned to the normal range and PaCO2 slightly decreased from two to four weeks after injury in group B, while PaO2 decreased and PaCO2 increased continuously at the same time in group A. There was a significant difference between group A and B. The dimension of diaphragm muscle cells in group A was significantly less than that in group B at 2 and 4 weeks. The structures of phrenic nerve in group B were well preserved compared with group A. Conclusions: The customized implantable phrenic nerve stimulator can facilitate the improvement of respiratory dysfunction resulted from rabbits cervical cord hemisection injury, in the meanwhile better biological compatibility is observed. The potential mechanism of this benefit might be that electrical stimulation postpones or reverses the atrophy of diaphragm and degeneration of phrenic nerve as well.