| 摘要: |
| 目的：探讨长期失喉返神经后人的环杓后肌形态学的变化规律, 为临床晚期喉神经修复的有效性提供理论依据。方法：不同时限喉返神经损伤的患者环杓后肌标本按神经损伤时限分为4个组：6～12个月（12例）、1～2年（10例）、2～3年（8例）及大于3年组（8例）。以正常环杓后肌作为对照组（12例）。采用MASSON三色染色、图像分析系统定量分析失神经后喉肌截面的肌纤维和胶原结缔组织纤维截面积的变化；采用肌肉琥珀酸脱氢酶（SDH）染色和运动终板胆碱酯酶(AchE) 染色，细胞计数分析失神经不同时限的环杓后肌两类肌纤维和运动终板数量的变化。结果：随着失神经时限的延长，胶原纤维截面积逐渐增加，而肌纤维的截面积逐渐减少。各组间比较均有显著性差异（P＜0.01)，失神经0.5～2年内肌肉截面积/胶原截面积比率下降最为明显，失神经2年以后肌纤维化明显减缓，但失神经3年后仍残留肌纤维相对截面积为正常对照组的48％。长期失神经后会导致肌纤维类型发生变化，红肌的比例逐渐上升，白肌的比例逐渐下降，各组间比较均有显著性差异（P＜0.01)。运动终板的数量随失神经时限的延长而减少，1年以上标本未观察到AchE染色的运动终板。结论：长期失神经喉肌和胶原结缔组织截面积变化提示失神经2年内是肌肉纤维化最严重时期，但失神经3年后仍残留肌纤维相对截面积为正常对照组的48％。失神经后喉肌纤维类型的变化提示该变化的目的是为了减少肌细胞凋亡。人环杓后肌运动终板消失时限为1年。本实验表明晚期神经修复仍能获得部分或全部喉功能是有其形态学基础。 |
| 关键词: 环杓后肌 喉返神经 创伤和损伤 |
| DOI：10.3724/SP.J.1008.2007.00946 |
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| 基金项目: |
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| Myofiber morphology of posterior cricoarytenoid muscles in patients with long-term denervation of recurrent laryngeal nerve |
| ZHANG Xian1, ZHENG Hong-liang2, CHEN Shi-cai2 |
| (1. Department of Otorhinolaryngology,Fuzhou General Hospital,PLA Nanjing Military Area Command,Fuzhou 350025, China; 2.Department of Otorhinolaryngology, Changhai Hospital, Second Military Medical University, Shanghai 200433) |
| Abstract: |
| Objective：To study the morphological changes of posterior cricoarytenoid muscles (PCM) in patients with long-term denervation of recurrent laryngeal nerve (RLN), so as to provide theoretical evidence for repair of recurrent laryngeal nerve at advanced clinical stage. Methods: Thirty-eight patients with damaged RLN were divided into 4 groups according to the duration of their RLN damage: 6-12 months group (n=12), 1-2 years group (n=10), 2-3 years group (n=8), and over 3 years group (n=8). Twelve subjects with normal PCM served as control. Trichrome Masson staining and imaging analyzing system were used to quantitatively analyze the transverse section areas of myofibers, collagen fiber and connective tissues. SDH and AchE staining and cell counting method were used to analyze changes of two kinds of myofibers and motor end plate numbers at different times after denervation of recurrent laryngeal nerve. Results: The transverse areas of myofibers gradually decreased and those of collagen fibers gradually increased with the prolongation of denervation; the difference was significant between different groups (P<0.01).The ratio of transverse area of myofiber to that of collagen fibers reached the lowest level 0.5-2 years after denervation. The fibrosis of muscle obviously slowed down 2 years after denervation. The transverse section of 48％ of myofibers remained 3 years after denervation. Long-term denervation resulted in the changes of muscle fiber types: the ratio of red muscles was increased and the ratio of white muscles was decreased after denervation; the difference was significant between different groups (P<0.01). The number of motor end plate decreased with the prolongation of denervation and disappeared after 1 year. Conclusion: The morphological alteration in long-term denervation PCM indicates the worst myofibrosis occurs within 2 years of denervation, but 48％of myofibers remain 3 years after denervation. The type alteration of denervated muscles may decrease the apoptosis of skeletal muscle. The structure of myoceptors disappears within 1 year of denervation. Our experiment indicates that there is a morphological basis for regaining total or partial muscle function by nerve repair after long-term denervation. |
| Key words: posterior cricoarytenoid muscles recurrent laryngeal nerve wounds and injuries |
