环杓后肌延期神经再支配后收缩特性的定量分析

为观察延期神经再支配环杓后肌的收缩特性，比较不同神经再支配方法的疗效，我们选择２４只犬，在右喉返神经切断后，于即刻，４，６，８，１０和１２个月时，分别以２只犬行选择性膈神经与喉返神经吻合（切断内收肌支）支配右环杓后肌（神经吻合组）；另１２只犬分别以２只行颈袢胸骨甲状肌蒂植入右环杓后肌（神经植入组）。组后饲养６个月，测定环杓后肌收缩强度及时间。结果表明，两组术侧的环杓后肌收缩力恢复率随病程延长而下降     

不同延期神经再支配环杓后肌方法的疗效观察

目的：探讨环杓后肌延期神经再支配的方法及时机。方法：将２９只狗分成三组，两个实验组在喉返神经切断后即刻、４、６、８、１０、１２个月分别将膈神经与喉返神经吻合选择性支配环杓后肌和颈袢神经—胸骨甲状肌蒂植入环杓后肌，对照组喉返神经切断后各时间不作任何手术。结果：两个实验组６个月后行喉镜、神经肌电及肌收缩力、组织化学证实：神经吻合组各时间效果明显好于神经肌蒂植入组，但两种术式疗效均随病程延长而下降。结论：神经吻合法延期神经再支配环杓后肌６个月内效果较好，而神经肌蒂植入法治疗环杓后肌麻痹最好不晚于失神经后４个月，否则效果不佳     

不同延期神经再支配环杓的肌方法的疗效观察

探讨环杓后肌延期神经再支配的方法及时机。方法：将２９只狗分成三组，两个实验组在喉返神经切断后即刻、４、６、８、１０、１２个月分别将膈神经与喉返神经吻合选择性支配环杓后肌和颈袢神经一胸骨甲状肌蒂植入环杓后肌。     

喉起搏器治疗喉麻痹动物模型的研究

目的　研制呼吸频率调节型喉起搏器 ,在单侧喉返神经麻痹的动物模型中实验其是否能引起与呼吸同步的声带功能性外展运动。方法　喉起搏器带有感受呼吸信号的压力传感器 ,以气体压力的变化作为失神经环杓后肌的起搏信号来源 ,经电刺激使声带外展与呼吸同步。健康猫 6只 ,切断左侧喉返神经。将喉起搏器的刺激电极植入猫左侧环杓后肌。分别于术后即刻、1、2、4、8、1 2周间歇性刺激 ,刺激频率 30Hz ,脉宽 0 6ms ,刺激强度 0～ 8mA。在直接喉镜下观察声带活动情况。术后 1 2周摄录不同的刺激强度下声门图像 ,测量刺激与非刺激时相对声门面积。结果　在喉起搏器作用下 ,麻痹的声带外展与呼吸同步 ,相对声门面积增加 1 8%。喉麻痹 1周后 ,所需刺激强度阈值增大 ,1 2周时接近失神经初始时刺激阈值。结论　本实验研制的呼吸频率调节型喉起搏器 ,能感知动物呼吸节律的改变 ,依呼吸频率调节起搏频率 ,发放吸气期电刺激脉冲使患侧声带外展 ,有可能对喉麻痹的治疗提供一种新的技术方法     

环杓后肌失神经及神经再支配后兴奋性的研究

为研究环杓后肌失神经及其神经再支配后的兴奋性,将15只狗分成3组即神经植入组、神经肌蒂组及对照组,每组5只.术后6个月发现植入神经、带肌蒂的神经均与正常喉返神经兴奋性无显著性差异(P>0.05),且神经兴奋性高于肌肉兴奋性.两个恢复神经再支配组的环杓后肌与正常环杓后肌兴奋性亦无显著性差异(P>0.05),而失神经的环杓后肌与两个神经修复组及正常环杓后肌的兴奋性则有高度显著性差异(P<0.01),且其兴奋性最低.结果表明,当功能性电刺激治疗双侧喉返神经麻痹时,刺激电极安放在修复的神经上比安放在环杓后肌处效果要好.     

慢性电刺激对喉肌神经再支配的作用

为明确功能性电刺激对环杓后肌(PCA)神经再支配的作用,本文采用4条犬,均将右侧喉返神经切断再吻合,套上含有双极刺激的硅胶套,并将喉起搏器电刺激系统植入2条犬的左侧PCA中,另2犬作对照植入电极为5mm×5mm大小,包括多个刺激电极及记录电极,以保证PCA肌各个部位均受到刺激及不同部位的电位均能记录.另外诱发电位的刺激电极置于修复侧喉返神经近侧端,2周后记录PCA肌的自发及诱发电位,每只动物PCA肌的部位与电位关系绘成坐标图.     

实验性声带麻痹神经吻合术后神经传导初步研究

目的研究喉返神经完全性损伤后颈袢神经支单纯支配环杓侧肌的电生理恢复情况。方法将实验组犬左喉返神经完全切断,3个月后,再将其内收肌支与同侧颈袢胸舌肌支延期吻合,吻合术后6个月检测环杓侧肌肌电活动情况。结果吻合术后6个月,左环杓侧肌可见肌电动作电位,其潜伏期为1.60±0.05ms,与术前相比较无显著差异,但神经传导速度为15.60±0.25m/s,较术前减慢,差异有显著性。结论喉返神经损伤后3月再行选择性环杓侧肌神经支配吻合术,能基本恢复肌肉电生理功能,但要达到完全正常水平,仍有待继续观察。     

喉起搏器治疗喉麻痹动物模型的研究

目的 研制呼吸频率调节型喉起搏器，在单侧喉返神经麻痹的动物模型中实验其是否能引起与呼吸同步的声带功能性外展运动。方法 喉起搏器带有感受呼吸信号的压力传感器，以气体压力的变化作为失神经环杓后肌的起搏信号来源，经电刺激使声带外展与呼吸同步。健康猫6只，切断左侧喉返神经。将喉起搏器的刺激电极植入猫左侧环杓后肌。分别于术后即刻、1、2、4、8、12周间歇性刺激，刺激频率30Hz，脉宽0．6ms，刺激强度0～8mA。在直接喉镜下观察声带活动情况。术后12周摄录不同的刺激强度下声门图像，测量刺激与非刺激时相对声门面积。结果 在喉起搏器作用下，麻痹的声带外展与呼吸同步，相对声门面积增加18％。喉麻痹1周后，所需刺激强度阈值增大，12周时接近失神经初始时刺激阈值。结论 本实验研制的呼吸频率调节型喉起搏器，能感知动物呼吸节律的改变，依呼吸频率调节起搏频率，发放吸气期电刺激脉冲使患侧声带外展，有可能对喉麻痹的治疗提供一种新的技术方法。     

一侧膈神经上根选择性神经再支配环杓后肌的实验研究

目的 探讨一侧膈神经上根选择性神经再支配环杓后肌的可行性和有效性.方法 8只健康雄性青年Beagle犬作为实验动物,全麻下切断Beagle犬左侧膈神经上根与左侧喉返神经,两断端通过游离神经桥接的方式吻合,并将同侧喉返神经内收肌支切断并植入同侧环杓后肌中;右侧不做任何处理,作为正常对照侧.于手术前、神经修复术后即刻、术后6个月分别行电子喉镜和喉肌电图检查,在最后一次检查后处死动物,取双侧环杓后肌和喉内段喉返神经行组织学检查并与对侧比较.结果 术前8只犬的双侧声带运动正常,术后即刻左侧声带固定,术后6个月均恢复了吸气性外展运动.术前8只犬双侧环杓后肌均能记录到自发肌电位,并引出诱发电位;术后即刻左侧环杓后肌呈电静息,未记录到诱发电位;术后6个月均能记录到自发肌电位,并引出诱发电位,而且两种电位幅度分别与术前比较差异均无统计学意义(均为P>0.05).环杓后肌Masson染色示两侧肌肉纤维相对截面积、胶原纤维相对截面积、肌肉/胶原纤维截面积比差异均无统计学意义(均为P>0.05).喉内段喉返神经甲苯胺蓝染色后示神经纤维分布较均匀密集,且左右两侧喉返神经有髓神经纤维数量差异无统计学意义(P>0.05).结论 左侧膈神经上根选择性神经再支配环杓后肌能有效避免神经错向再生,恢复声带的生理性外展运动.     

用颈交感干和舌下神经袢再支配狗环杓后肌的研究

将8只狗的右侧喉返神经及其内收支切断，再分别将其中4只狗的右侧颈交感神经干和2只狗的右侧舌下神经袢切断后，各将其近侧端和已切断的喉返神经的远侧端吻合，其余2只狗作为失神经支配的对照组。分别于术前、术后即刻及术后4个月行声门照像、肌电图观察，最后行环杓后肌肉眼及组织化学观察。实验结果证明：采用两种神经修复喉返神经均可部分恢复环杓后肌功能，论证了用颈交感神经干修复的机理及各种神经修复法的优缺点，为今后进一步的研究和临床应用提供理论依据。     

Electrical pacing for dynamic treatment of unilateral vocal cord paralysis. Experiment in long-denervated muscle

In order to explore the possibility of clinical application of laryngeal pacing as a treatment for unilateral vocal cord paralysis, we examined the reactivity of atrophic muscle to electrical stimulation in dogs whose recurrent laryngeal nerves were damaged by crushing, dissection followed by resuturing, or a 3-cm neurectomy. The threshold level to induce enough vocal cord adduction reached the maximum at 2 weeks after nerve injury, decreased with time, and never surpassed 7 V in each case. On the basis of results of these preliminary probings, laryngeal pacing was conducted on a dog 15 months after resection of the laryngeal nerve. Adduction of the paralyzed vocal cord for synchrony with the intact cord was achieved by 7 V of electrical stimulation of the thyroarytenoid muscle that was triggered by signals from the cricothyroid muscle.     

Study on contractile properties of the posterior cricoarytenoid muscle after delayed reinnervation]

To study date on the contractile properties of posterior cricoarytenoid muscle after delayed reinnervation of different reinnervated methods. Twenty four dogs were reinnervated at 0,4,5,6,10 and 12 month interval following recurrent laryngeal nerve via the phrenic nerve anastomosed to the recurrent laryngeal nerve after cutting the adductor branch and ansa cervicalis-sternothyroid muscle pedicle implanted into the posterior cricoarytenoid muscle. After 6 months, a series of contractions were recorded from each side in twenty living dogs. The results showed that contractile force of reinnervated muscle decreased gradually with the time of denervation, but contractile force of muscle was no significantly difference between reinnervated side of nerve anastomosed group in 4 months after denervated and normal side, and it was significantly difference between nerve anastomosed group and nerve-muscle pedicle implanted group at some time of delayed reinnervation. The contractile time of reinnervated side of two operated groups was similar to that of normal side. The conclusion demonstrated that the contractile properties can indicate exactly reinnervated degree of muscle, and the earlier reinnervation was performed, the better curative effect was.     

Regeneration of the recurrent laryngeal nerve in the guinea pig: reorganization of motoneurons after freezing injury

The purpose of this study was to clarify the morphologic changes resulting from reinnervation after a freezing injury. We chose the freezing injury as the most promising nerve regeneration model in order to examine the mechanism behind the production of misdirected reinnervation. The left recurrent laryngeal nerve of the adult guinea pig was injured by freezing (-80 degrees C) at the level of the 10th tracheal ring. At intervals ranging from 2 weeks to 6 months after the injury, horseradish peroxidase was injected into the left posterior cricoarytenoid muscle to ascertain the presence of retrograde-labeled perikarya in the medulla oblongata. Projections to the individual laryngeal muscles and to the entire recurrent laryngeal nerve served as normal controls. In addition, we observed by electron microscopy the degeneration and regeneration processes of the recurrent laryngeal nerve following injury. From 2 to 6 months after the freezing injury, the number of labeled neurons in the nucleus ambiguus increased gradually from 20 to 90. In addition, the area occupied by neurons which project to the posterior cricoarytenoid muscle was expanded, but was confined within the region of perikarya projecting to the normal recurrent laryngeal nerve. Most axons degenerated within 3 days and showed regenerative sprouting with growth cones by 7 days postinjury. Despite the fact that freezing injury preserved the basal lamina tunnel with minimal disturbance of the recurrent laryngeal nerve fiber structure, target-specific reinnervation was incomplete.     

失神经喉内肌纤颤电位波幅的变化及临床意义

目的 评估喉肌电图中纤颤电位波幅测定的临床应用价值。方法；对５４例（共６５侧）喉返神经麻痹患者的甲杓肌，环杓后肌行肌电图检查，记录最大纤颤电位波幅，结果：不同性别，年龄及不同侧的纤颤电位波幅间的差异无显著性，失神经环杓后肌纤颤电位波幅值均在病程２～－〈４个月时最高，而失神经甲杓肌纤颤电位波幅均值在病程４～－〈６个月时最高，相当一部分患者的纤颤电位波幅晚期仍维持一定水平，并且神经完全损伤者和不完全的     

Quantitative assessment of laryngeal muscle morphology after recurrent laryngeal nerve injury: right vs. left differences

Objectives/Hypothesis: Reports of laryngeal response to denervation are inconsistent. Some document atrophy and fibrosis in denervated laryngeal muscles, whereas others indicate resistance to atrophy. Spontaneous reinnervation has also been documented. The goal of this study was to clarify the effects of nerve injury and reinnervation on thyroarytenoid (TA) and posterior cricoarytenoid (PCA) muscles. Study Design: Laboratory experiment. Methods: TA and PCA muscles of cats were harvested 5 to 6 months after transecting right or left recurrent laryngeal nerve (RLN). Images of muscle cross‐sections were acquired and studied using an image analysis workstation. Cross‐sectional areas as well as total cross‐sectional area of randomly selected muscle fibers were recorded. Results: TA reinnervation was robust on both sides, but there was less reinnervation of the PCA muscle after left‐sided RLN lesion than after right‐sided injury. Conclusions: Differences in reinnervation after RLN injury could contribute to the higher clinical incidence of left‐ vs. right‐sided laryngeal paralysis.