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。     

喉外伤后声门旁注射肝细胞生长因子预防声带瘢痕形成的实验研究*

目的观察兔声带外伤局部注射肝细胞生长因子(hepatocyte growth factor,HGF)后组织病理学、增殖细胞抗原(proliferating cell nuclear antigen, PCNA)及主要细胞外基质（extracellular matrix,ECM）的变化特点。方法对40只实验用兔80侧声带进行锐性损伤,将兔随机分为治疗组和创伤组,另随机选5只试验兔作为对照组。治疗组于损伤后即刻在声门旁注射HGF,创伤组则注射生理盐水。损伤后1周～6个月时采用HE染色、免疫组化染色、ELISA测定及Masson染色法,观察声带组织学结构变化、PCNA及固有层内透明质酸（hyaluronic acid, HA）、胶原纤维等主要ECM的分布及含量变化。结果创伤组声带损伤3个月后局部开始出现瘢痕挛缩,以胶原纤维为主的大量纤维组织增生,6个月时仍紊乱分布于声带固有层各层,损伤后3个月内 PCNA增强(P<0.05),6个月内胶原纤维含量明显高于正常对照组(P<0.05),HA增加不明显。治疗组6个月时形态接近正常,早期的HA、PCNA的表达明显高于创伤组(P<0.05),中、后期差异性消失,胶原纤维含量在3月内有增高趋势,其后稳定,但总体水平均明显低于创伤组(P<0.05)。结论声门旁注射HGF后具有促进声带ECM分泌、合理分布及部分有序化排列的功能,具有促进声带修复再生的作用。     

Expression of fibroblast growth factor-2 in the nucleus ambiguus following recurrent laryngeal nerve injury in the rat

OBJECTIVES: To examine fibroblast growth factor-2 (FGF-2) immunoreactivity in the nucleus ambiguus (NA) after three different recurrent laryngeal nerve (RLN) injuries. STUDY DESIGN: Immunohistochemical analysis of FGF-2. METHODS: Thirty adult rats underwent left-sided RLN crush (group A). The left RLN was transected in groups B (n = 30) and C (n = 30); in group C, both nerve stumps were covered with silicone caps. FGF-2 in the NA was assessed as the ratio of the positive areas on the left (operated [O]) and right (unoperated [U]) sides. The ratio (O/U) was measured 1, 3, 7, 14, and 28 days after the procedure. Three rats underwent left-sided RLN exposure and were killed 7 days later (control). RESULTS: Left-sided RLN paralysis occurred until day 28 in group A. In the control group, O/U was approximately 1. In group A, O/U was significantly elevated on day 7; in group B, on days 3, 7, and 14; and in group C, on day 3. O/U in group B was significantly greater than that in group A on days 14 and 28. Maximal FGF-2 immunoreactivity was significantly lower in group C than in groups A and B. CONCLUSIONS: We demonstrated elevated production of FGF-2 in the NA after RLN injury. This endogenous FGF-2 might contribute to preventing lesion-induced neuronal death. Blockage of axonal regeneration might suppress FGF-2 production in the NA. Further understanding of the roles of FGF-2 after RLN injury may contribute to the prevention of neuronal death and facilitation of axonal regeneration.     

Nerve-muscle transplantation to the paraglottic space after resection of recurrent laryngeal nerve

OBJECTIVE: To evaluate a new method of nerve-muscle transplantation (NMT) to the paraglottic space after resection of the recurrent laryngeal nerve (RLN) during surgery for thyroid cancer. DESIGN: Review of nine consecutive patients with RLN paralysis caused by the thyroid cancer before surgery. METHOD: After the usual extirpation of the thyroid cancer with concomitant removal of the RLN, the lower part of the sternohyoid muscle approximately 1 cm in width and 2 cm in length with the ansa cervicalis nerve connected was inserted into the paraglottic space by way of anterior retraction of the thyroid ala with the inferior horn cut off. When the muscle or the nerve was adhesive to the cancer, the nerve-muscle on the opposite side was used with transfer through the space under the thyrohyoid muscles and the superior horn of thyroid ala. RESULTS: The voice quality was good or fair after surgery. In most patients, the maximum phonation time was 10 seconds or longer, and the mean flow rate was lower than 200 mL/s. The vocal functions were good immediately after surgery and maintained good values for 2 years or more after surgery. Vocal fold atrophy was not found in any patient. CONCLUSION: When the RLN is resected during surgery for thyroid cancer end-to-end anastomosis of the nerve is impossible, NMT to the paraglottic space is a useful method for preserving good voice and preventing atrophy of the vocal fold.     

Injection of basic fibroblast growth factor for unilateral vocal cord paralysis*

Objective: Unilateral vocal cord paralysis (UVCP) not only induces severe dysphonia, but aspiration as well. Although laryngeal framework surgery is usually performed to treat this condition, the procedure is not tolerated by some patients. In the previous study, basic fibroblast growth factor (bFGF) injections for vocal cord scarring and sulcus have been reported to provide favorable outcomes while being minimally invasive. In this study, the authors retrospectively investigated phonological outcomes after bFGF injection in patients with UVCP.

Methods: This study was registered in University hospital Medical Information Network – Clinical Trials Registry (UMIN000019347). Nineteen patients with unilateral cord paralysis were treated with bFGF injection. The treatment regimen involved a single injection of 50?μg of bFGF into the muscle layer. More than six months after the injection, aerodynamic and acoustic outcomes were examined.

Results: The voice handicap index, maximum phonation time, mean airflow rate, and pitch range improved significantly after injection of bFGF. No sex-related differences were observed in any phonological parameter.

Conclusion: bFGF injection, an easy method and suitable as an office procedure, significantly improved the hoarseness caused by UVCP. It is expected to be widely adopted and effective adjunctive drugs, and procedures are anticipated to be developed.     

Regenerative potential of basic fibroblast growth factor contained in biodegradable gelatin hydrogel microspheres applied following vocal fold injury: Early effect on tissue repair in a rabbit model

IntroductionPostoperative dysphonia is mostly caused by vocal fold scarring, and careful management of vocal fold surgery has been reported to reduce the risk of scar formation. However, depending on the vocal fold injury, treatment of postoperative dysphonia can be challenging.ObjectiveThe goal of the current study was to develop a novel prophylactic regenerative approach for the treatment of injured vocal folds after surgery, using biodegradable gelatin hydrogel microspheres as a drug delivery system for basic fibroblast growth factor.MethodsVideoendoscopic laryngeal surgery was performed to create vocal fold injury in 14 rabbits. Immediately following this procedure, biodegradable gelatin hydrogel microspheres with basic fibroblast growth factor were injected in the vocal fold. Two weeks after injection, larynges were excised for evaluation of vocal fold histology and mucosal movement.ResultsThe presence of poor vibratory function was confirmed in the injured vocal folds. Histology and digital image analysis demonstrated that the injured vocal folds injected with gelatin hydrogel microspheres with basic fibroblast growth factor showed less scar formation, compared to the injured vocal folds injected with gelatin hydrogel microspheres only, or those without any injection.ConclusionA prophylactic injection of basic fibroblast growth factor -containing biodegradable gelatin hydrogel microspheres demonstrates a regenerative potential for injured vocal folds in a rabbit model.     

碱性成纤维细胞生长因子对兔慢性高眼压视神经轴突的保护作用

目的 研究在兔慢性高眼压动物模型中,碱性成纤维细胞生长因子（bFGF）对视神经轴突的保护作用。方法 新西兰大白兔22只（44眼）,选取20只兔,用前房注入卡波姆的方法制成慢性高眼压动物模型,每只兔随机一眼为bFGF治疗组（20眼）,分别于建模同时及建模后7、14、21d重复玻璃体腔内注射2000U/50μL的bFGF;另一眼为外科对照组（20眼）,分别于相同时间玻璃体腔内注射等体积的PBS。另外2只兔不做任何注射为正常对照组（4眼）。观察bFGF治疗组和外科对照组两组动物不同时间段的眼底视乳头、杯盘面积比、视神经轴突形态、数目以及建模后28d时视神经轴突超微结构的改变。结果 14d时,外科对照组可见视乳头凹陷开始加深、颜色变淡,血管开始出现移位;21d时,外科对照组视乳头出现明显改变。bFGF治疗组杯盘面积比在14d及以后改变明显较外科对照组小（P＜0.05）。病理学观察可见,在各时期bFGF治疗组较外科对照组视神经纤维数目多,且存在统计学差异（P＜0.01）。电镜观察可见,28d时,外科对照组轴突排列紊乱、髓鞘变性,多见凋亡现象;但bFGF治疗组轴突内结构尚正常。结论 bFGF在慢性高眼压状态下对视神经轴突有保护作用。