Recovery of vocal fold immobility following isolated patent ductus arteriosus ligation

Objective

Identify laryngoscopic and functional outcomes of infants with vocal fold immobility (VFI) following patent ductus arteriosus (PDA) ligation and identify predictors of recovery.

Methods

Retrospective review of patients with VFI following PDA ligation from 2001 to 2012 at a single institution. Inclusion criteria were: (1) PDA ligation as only cardiac surgical procedure; (2) left VFI documented by laryngoscopy; (3) minimum follow up 120 days, with at least 2 laryngoscopies performed. Resolution of VFI was determined at follow-up laryngoscopy. Univariate logistic regression models were used to identify variables associated with VFI recovery.

Results

66 subjects were included with median follow up of 3.0 (±2.1) years. The mean gestational age was 24.5 ± 1.4 weeks, mean birth weight 673 ± 167 g, and mean age at procedure was 18.6 ± 14.3 days. Patients presented with respiratory symptoms (39%), dysphonia (78%) and dysphagia (55%). Resolution of VFI was observed in 2/66 (3%) patients. Recovery was documented at 20 days and 11 months respectively. Respiratory symptoms, dysphagia, and dysphonia persisted at last follow up in 11%, 47%, and 20% of patients.

Conclusions

VFI associated with ligation of the ductus arteriosus has a low rate of recovery. Clinical symptoms frequently persist, and as such regular follow-up by otolaryngologists to mitigate morbidity is indicated.     

喉返神经损伤后喉肌病理生理研究

目的：通过对犬喉返神经损伤及再生过程中喉肌电生理及其病理变化进行研究,探讨喉返神经不同损伤形式的病理生理改变及转归特点。方法：实验用犬20只（40侧）分为喉返神经完全损伤组（全切法）、不完全损伤组（结扎法、挫灭法、半切法）及对照组,造模成功后的即刻、1、3、6和12个月观察甲杓肌和环杓后肌肌电特征及组织病理学改变。结果：造模后即刻全切法及结扎法肌电为电静息,挫灭法和半切法存在部分正常单个运动单位（MUP）及振幅减小的MUP混合肌电。神经损伤后1～3个月可出现纤颤电位,不完全损伤组3～6个月出现再生电位。全切法诱发电位基本无法引出,结扎法和半切法早期无诱发电位,后期可以引出振幅减小的诱发电位,结扎法小于半切法;而挫灭法始终都可以引出诱发电位,振幅与对照组无显著性差异,诱发电位潜伏期呈现先延长后缩短的趋势。随着全切、结扎、半切、挫灭损伤程度不同,肌纤维平均直径及肌束直径逐渐增大,单位面积细胞核数逐渐减少。结论：不同损伤,肌电特征及声带运动状态呈动态变化,喉返神经的损伤程度依次为完全损伤、不完全损伤（结扎法、半切法、挫灭法）,喉肌电图检查是声带麻痹诊断和评估的重要方法。     

Spontaneous laryngeal reinnervation after recurrent laryngeal or vagus nerve injury

OBJECTIVES: The status of innervation in patients with laryngeal paralysis is somewhat controversial. Electromyographic activity has been frequently documented in the laryngeal muscles of patients with laryngeal paralysis, and animal experiments report a strong propensity for reinnervation after laryngeal nerve injury. However, a study of intraoperative electromyography performed in patients during reinnervation surgery failed to document activity with stimulation of the recurrent laryngeal nerve (RLN). Noting the long-observed differences in the symptoms of patients with vagus nerve injury and those with RLN injury, I hypothesized that reinnervation is influenced by the site of nerve injury. METHODS: Cats were sacrificed at various intervals after resection of 1 cm of either the RLN or the vagus nerve, without any attempt to repair the nerve. RESULTS: Four months after RLN resection, distal nerve biopsy revealed unmyelinated axons scattered through fibrous tissue. By 6 months, myelinated axons were organized, and electromyographic and histologic examination showed preferential reinnervation of the thyroarytenoid muscle. After vagotomy, the RLN was fibrotic and no axons were present. Both the thyroarytenoid and posterior cricoarytenoid muscles were fibrotic and had no electromyographic activity. CONCLUSIONS: The results confirm the strong propensity for laryngeal reinnervation after RLN injury, but not after vagus nerve injury. Preferential reinnervation of adductor muscles may account for a medial position of the paralyzed vocal fold.     

Recurrent laryngeal nerve damage following formalin infiltration of ductus arteriosus

Formalin infiltration of the ductus arteriosus, a recent palliative procedure in neonates with certain congenital cardiac defects, has been shown to result in delayed left recurrent laryngeal nerve paralysis. Implication for the airway and later management are discussed.     

Unilateral vocal cord paralysis following patent ductus arteriosus ligation in extremely low-birth-weight infants

OBJECTIVE: To determine if unilateral vocal cord paralysis (UVCP) following patent ductus arteriosus (PDA) ligation is associated with respiratory and swallowing morbidities in extremely low-birth-weight (ELBW) infants. DESIGN: Case-control study. SETTING: Tertiary care neonatal intensive care units and pediatric hospital. PARTICIPANTS: Twenty-three infants undergoing PDA ligation (subdivided into the main study group of 12 infants with UVCP and 11 without paralysis) and 12 weight- and gestational age-matched ELBW controls. MAIN OUTCOME MEASURES: Incidence of UVCP, time requiring supplemental oxygen and ventilatory support, length of hospital stay, incidence and duration of tube feeding following discharge, and incidence of chronic lung disease. RESULTS: The overall incidence of UVCP was 52% (12/23), increasing to 67% (12/18) in ELBW infants. Infants without UVCP following PDA ligation were heavier (P = .006), with a more advanced gestational age (P = .03). Patients with UVCP required longer tube feeding (relative risk, 8.25; 95% confidence interval, 1.93-46.98; P = .003), supplemental oxygen (P = .004), and ventilatory support (P = .001) and had a longer hospital stay (P < .001). In comparison to matched controls, infants with UVCP required longer tube feeding (relative risk, 9.00; 95% confidence interval, 2.08-51.30; P = .003), supplemental oxygen (P = .03), and ventilatory support (P = .002) and had a longer hospital stay (P < .001). CONCLUSIONS: There was a high incidence of occurrence of UVCP (67%) associated with PDA ligation in ELBW infants. Unilateral vocal cord paralysis following PDA ligation does seem to be associated with increased requirements for tube feeding, respiratory support, and hospital stay in these ELBW infants.     

甲状腺切除病例喉返神经损伤的分析

目的：研究甲状腺切除术的主要并发症－－喉返神经（ＲＬＮ）麻痹的相关因素。方法：回顾性研究１５６３例甲状腺手术患者的临床资料,重点分析ＲＬＮ损伤与术式、ＲＬＮ在术中是否被分离保护以及与甲状腺疾病的病理关系。结果：ＲＬＮ损伤率是７．８％,与组织病理恶性程度明显相关（Ｐ〈０．０１）,但术中如明确找到ＲＬＮ并加以保护,术后则无ＲＬＮ永外性损害,暂时麻痹仅１．６％。结论：术中对ＲＬＮ的保护应该强调避免医源性     

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.     

甲状腺外科无喉返神经损伤的可能性

目的探讨甲状腺外科手术喉返神经(recurrenlaryngealnerve,RLN)零损伤的可能性。方法回顾性分析我科2001年3月～2005年3月659例甲状腺疾病的手术方式、术后RLN损伤、甲状旁腺功能低下、术后出血和术后复发等并发症的发生。术中常规解剖RLN,保护并勿过度解剖甲状旁腺及其供应的血管。结果甲状腺一侧腺叶加对侧腺叶部分切除376例、甲状腺一侧腺叶加峡部切除87例、甲状腺双侧腺叶次全切除76例、甲状腺全切除73例、颈部低位领式切口入路切除胸骨后结节性甲状腺肿47例。术后无一例发生RLN损伤。术后暂时性低钙血症发生率为1.67%(11/659)。无永久性低钙血症。术后出血需再手术止血和术后伤口血肿的发生率分别为0.60%(4/659)和0.45%(3/659)。甲状腺功能低下和术后复发的发生率分别为0.45%(3/659)和0.15%(1/659),无切口感染。结论甲状腺外科手术中熟悉RLN的解剖知识,常规紧贴甲状腺被膜外分离并全程解剖RLN及其分支可避免RLN的损伤。     

喉返神经损伤后环杓关节变化的观察

为观察喉返神经（ＲＬＮ）损伤后杓状软骨及环杓关节的变化，将１８只犬分为３组。第１单侧ＲＬＮ不完全损伤，第２组为单侧ＲＬＮ完全损伤，第３组为双侧ＲＬＮ损伤。结果第１组随着ＲＬＮ的自行修复，杓状软骨恢复正常无环杓关节纤维化；第２组随着时间的推移，出现杓状软固定，环杓关节纤维化亦加重；第３组较时时间就出现杓状软骨固定，且随时间推移，环杓关节纤维化程度亦较第２组严重     

Paroxysmal laryngospasm after laryngeal nerve injury.

OBJECTIVE: Describe a clinical syndrome of laryngeal hypersensitivity following laryngeal nerve injury. STUDY DESIGN: Retrospective review of six patients with laryngeal paralysis sustained during neck surgery who presented with paroxysms of coughing and stridor, progressing to brief episodes of complete airway occlusion. METHODS: Chart review. RESULTS: Superior laryngeal nerve blockade temporarily improved symptoms in four of five patients. Botulinum toxin relieved spasm in two of three patients and reduced symptoms in the third. Symptoms gradually diminished or resolved in four patients from 1 to 2.5 years later. One patient underwent arytenoidectomy and one patient has a tracheostomy. CONCLUSIONS: Patients with laryngeal injury may present with stridor and acute airway obstruction secondary to paroxysmal laryngospasm. The authors have found that superior laryngeal nerve blockade or botulinum toxin may be effective in temporary relief of symptoms.     

Modulation of nerve fibers in the rat thyroarytenoid muscle following recurrent laryngeal nerve injury

Conclusion. The present study suggested that a high level of thymidine phosphorylase (TP) gene expression is significantly associated with favorable prognosis of patients treated with 5-fluorouracil (5-FU)-based chemotherapy. Further studies consisting of large series should be performed to confirm our present results. Background. Expression levels of the thymidylate synthase (TS) and 5-FU metabolic enzymes including dihydropyrimidine dehydrogenase (DPD), TP, and orotate phosphoribosyl transferase (OPRT), are reported to be associated with sensitivity to 5-FU-based chemotherapy in several cancers. Patients and methods. Intratumoral mRNA expression levels of TS, DPD, TP, and OPRT in pretreatment biopsy specimens were quantified in 27 patients with advanced oropharyngeal squamous cell carcinomas. Association of these expression levels with response to platinum and 5-FU-based chemotherapy and survival were analyzed statistically. Results. By Spearman's correlation analysis, significant correlation was observed between TS and TP (γ=0.51, p=0.018). While no correlation was observed between the tumor regression and expression of any of the genes investigated, significant association was observed between prognosis and mRNA expression levels of TS and TP. Multivariate Cox regression analysis revealed that TP mRNA expression level is a significant factor predicting prognosis (hazard ratio (HR) = ? 0.204, p=0.043).