Adipose-derived mesenchymal stem cells accelerate nerve regeneration and functional recovery in a rat model of recurrent laryngeal nerve injury

Medialization thyroplasty or injection laryngoplasty for unilateral vocal fold paralysis cannot restore mobility of the vocal fold. Recent studies have shown that transplantation of mesenchymal stem cells is effective in the repair of nerve injuries. This study investigated wheth- er adipose-derived stem celt transplantation could repair recurrent laryngeal nerve injury. Rat models of recurrent laryngeal nerve injury were established by crushing with micro forceps. Adipose-derived mesenchymal stem cells （ADSCs; 8 ×105） or differentiated Schwann-like adipose-derived mesenchymal stem cells （dADSCs; 8×105） or extracellular matrix were injected at the site of injury. At 2, 4 and 6 weeks post-surgery, a higher density of myelinated nerve fiber, thicker myelin sheath, improved vocal fold movement, better recovery of nerve conduction capacity and reduced thyroarytenoid muscle atrophy were found in ADSCs and dADSCs groups compared with the extracellu- lar matrix group. The effects were more pronounced in the ADSCs group than in the dADSCs group. These experimental results indicated that ADSCs transplantation could be an early interventional strategy to promote regeneration after recurrent laryngeal nerve injury.

Experience of Cervical Plexus Reinnervation for Patients with Unilateral Recurrent Laryngeal Nerve Invasion or Injury

OBJECTIVE To explore the clinical and therapeutic effects ofcervical plexus reinnervation for infiltrated or injured unilateralrecurrent laryngeal nerve (URLN).METHODS Functional neck dissection for removal ofdifferentiated thyroid carcinoma (DTC) in patients was performed,in which cervical plexus reinnervation was adopted for patientswith stage Ⅰ disease and URLN with injury or with tumorinvasion.Outcomes of surgery were evaluated by examinationunder fibrolaryngoscope,and the patients'voices were evaluatedbefore and after surgery.RESULTS All cases were followed up for 3 mon-2 years(average 8 mon).Abductory motion of the vocal cords of 15patients was completely or partly restored,but 3 patients'vocalcords were immovable.The recovery rate of abductory motionof the paralyzed vocal cords was 83.33% (15/18).The functionof phonation in the 16 patients was restored to normal or nearnormal limits,and their hoarseness was improved significantly.CONCLUSION Cervical plexus-URLN reinnervation shouldbe considered when treating patients with unilateral vocal cordparalysis.Removing the tumor simultaneously with cervicalplexus reinnervation during surgery for repair of unilateralrecurrent laryngeal nerve injury was convenient and easy toperform with less functional damage compared with othermethods of reinnervation.The abductory motion of vocal cordcould be satisfactorily restored by this reinnervation.Surgicalperformance skills and application of neurotrophic drugs wereimportant for the success of the surgery.

Novel technique for lymphadenectomy along left recurrent laryngeal nerve during thoracoscopic esophagectomy

BACKGROUND In esophageal squamous carcinoma,lymphadenectomy along the left recurrent laryngeal nerve(RLN)is recommended owing to its highly metastatic potential.However,this procedure is difficult due to limited working space in the left upper mediastinum,and increases postoperative complications.AIM To present a novel method for lymphadenectomy along the left RLN during thoracoscopic esophagectomy in the semi-prone position.METHODS The fundamental concept of this novel method is to exfoliate a bilateral pedicled nerve flap,which is a two-dimensional membrane,which includes the left RLN,lymph nodes(LNs)along the left RLN,and tracheoesophageal vessels,by suspending the esophagus to the dorsal side and pushing the trachea to the ventral side(named“bilateral exposure method”).Then,the hollow-out method is performed to transform the two-dimensional membrane to a three-dimensional structure,in which the left RLN and tracheoesophageal vessels are easily distinguished and preserved during lymphadenectomy along the left RLN.This novel method was retrospectively evaluated in 116 consecutive patients with esophageal squamous carcinoma from August 2016 to February 2018.RESULTS There were 58 patients in each group.No significant difference was found between the two groups in terms of age,gender,postoperative pneumonia,anastomotic fistula,and postoperative hospitalization.However,the number of dissected LNs along the left RLN in this novel method was significantly higher than that in the conventional method(4.17±0.359 vs 2.93±0.463,P=0.0447).Moreover,the operative time and the rate of postoperative hoarseness in the novel method were significantly lower than those in the conventional method(306.0±6.774 vs 335.2±7.750,P=0.0054;4/58 vs 12/58,P=0.0312).CONCLUSION This novel method for lymphadenectomy along the left RLN during thoracoscopic esophagectomy in the semi-prone position is much safer and more effective.

Schwannoma originating from the recurrent laryngeal nerve in a thyroid cancer patient: A case report and review of the literature

BACKGROUND Schwannoma rarely originates from the recurrent laryngeal nerve, and there are few reports on schwannoma originating from the recurrent nerve in the mediastinum. Herein, we present an extremely rare case of schwannoma originating from the recurrent laryngeal nerve in the neck.CASE SUMMARY This is a case report of one patient diagnosed with thyroid cancer with schwannoma originating from the recurrent laryngeal nerve in the neck, which was incidentally found during a thyroidectomy, and a review of the literature.CONCLUSION Preoperative diagnostic examinations are of less use for detecting schwannoma originating from a recurrent laryngeal nerve in the neck in such small size, which may only incidentally be found during a thyroidectomy. Surgical excision with opening the capsule and shelling out the tumor is the treatment of choice. If the nerve is unable to be preserved, end-to-end recurrent laryngeal nerve anastomosis may be a simple and minimally invasive reconstruction procedure to improve phonation.

Total thyroidectomy is safer with identification of recurrent laryngeal nerve

Objective:To investigate the effect of recurrent laryngeal nerve(RLN)identification on the complications after total thyroidectomy and lobectomy.Methods:Total 134 consecutive patients undergoing total thyroidectomy or thyroid lobectomy from January 2003 to November 2004 were investigated retrospectively.Patients were divided into two groups:RLN identified (Group A)or not(Group B).The two groups were compared for RLN injury and hypocalcaemia.Results:The numbers of patients and nerves at risk were 71 and 129 in Group A,and 63 and 121 in Group B,respectively.RLN injury in Group A(0)was sig- nificantly lower than that in Group B(57.9%)patients,75.8%nerves)for the numbers of patients(P=0.016)and nerves at risk (P=0.006).Temporary hypocalcaemia was significantly higher in Group A than in Group B(1424.1%vs 610.3%,P=0.049). Permanent complications in Group B were significantly higher than those in Group A(1320.6%vs 45.6%,P=0.009).Con- clusion:RLN injury was prevented and permanent complications were decreased by identifying the whole course and branches of the recurrent laryngeal nerve during total thyroidectomy.

Applied anatomy of the cervical region of the recurrent laryngeal nerve

BACKGROUND AND OBJECTIVE： To avoid recurrent laryngeal nerve （RLN） injury during thyroid surgery, it is important to identify the nerve and to follow its projection carefully to discriminate it from the inferior thyroid artery. DESIGN, TIME AND SETTING： All studies were performed at the Anatomy Division of Shaoyang Medical College from May 2003 to May 2004 with repeated measurement design. MATERIALS： Fifty embalmed adult corpses, comprising 20 females and 30 males, were obtained by donation. METHODS AND MAIN OUTCOME MEASURES： The projection, branches, and the relationship of the RLN to the inferior thyroid artery were observed. RESULTS： The RLN in all cases ascended through the tracheoesophageal groove at the isthmus superior levels of the thyroid gland. However, the RLN in 14 cases were situated inferior to the isthmus of the thyroid gland; 11 cases were to the right side and 2 cases to the left side, projected in the tracheoesophageal groove, and ascended away from the groove after 4.5-6.5 mm. The RLN typically ramified at the thyroid isthmus plane （44 cases, 44% of all cases）. The RLN branches were variable. Type 2 rami were most common in the RLN, accounting for 55%; the second most common was RLN branches with no rami. RLN braches with type 3 rami, 4 rami, and 5 rami were less common. Approximately 54% of nerves were situated behind the main branch artery. The nerves located adjacent to the arteries, and between the arterial branches, were similar; the former applied to 19 cases, accounting for 19%, whereas the latter applied to 18 cases, accounting for 18%. Left nerves behind the artery, and right nerves before the artery, were more common. There were significant differences between the left and right nerves （P 〈 0.01）. CONCLUSION： There was not a significant difference in the projection of the RLN, while a significant difference in the number of RLN branches existed. In addition, the anatomical relationship of the RLN and the inferior thyroid artery exhibited side differences.

Anatomical Variations of Recurrent Laryngeal Nerve: The Danger in Thyroid Surgery

Objectives: We report two types of anatomical variations of the recurrent laryngeal nerve in two patients. Through these two patients we wanted to highlight our surgical approach of the recurrent nerve in an unusual position and to describe the surgical implication of these almost rare variations. Case report: patient aged 28 and 58 admitted for goiter. They underwent a right lobisthmectomy. Both recurrences were approached retrograde. The anatomical variations of the nerve concerned the non-recurrent laryngeal nerve in the first patient. In the second patient there were three anatomical variations, namely an extra laryngeal bifurcation of the nerve, a pre-vascular position of the nerve and a branch connecting the vagus nerve and the recurrent nerve. No recurrence nerve injury was noted. Conclusion: The anatomical variations of the nerve are numerous. A careful dissection is a guarantee of a good prognosis.

Clinical significance and characteristics of recurrent laryngeal nerve lymph node metastasis of thoracic esophageal cancer

Objective To investigate the clinical significance and characteristics of recurrent laryngeal nerve lymph node metastasis of thoracic esophageal cancer. Methods One hundred and twenty-four patients who had undergone thoracic esophageal resection with recurrent laryngealnerve lymph node dissection in our hospital from March 2007 to February 2010. All clinical data were retrospectively analysed. Results Recurrent laryngeal

Electrophysiological neuromonitoring of the laryngeal nerves in thyroid and parathyroid surgery: A review

Recurrent laryngeal nerve(RLN) injury is one of the most common complications of thyroid surgery. Injury to the external branch of the superior laryngeal nerve is less obvious and affects the voice variably; however, it can be of great significance to professional voice users. Recent literature has led to an increase in the use of neuromonitoring as an adjunct to visual nerve identification during thyroid surgery. In our review of the literature, we discuss the application, efficacy and safety of neuromonitoring in thyroid surgery. Although intraoperative neuromonitoring(IONM) contributes to the prevention of laryngeal nerves injury, there was no significant difference in the incidence of RLN injury in thyroid surgery when IONM was used compared with visual identification alone. IONM use is recommended in high risk patients; however, there are no clear identification criteria for what constitutes "high risk". There is no clear evidence that IONM decreases the risk of laryngeal nerve injury in thyroid surgery. However, continuous IONM provides a promising tool that can prevent imminent nerve traction injury by detecting decreased amplitude combined with increased latency.

Current landscape in motoneuron regeneration and reconstruction for motor cranial nerve injuries

The intricate anatomy and physiology of cranial nerves have inspired clinicians and scientists to study their roles in the nervous system. Damage to motor cranial nerves may result from a variety of organic or iatrogenic insults and causes devastating functional impairment and disfigurement. Surgical innovations directed towards restoring function to injured motor cranial nerves and their associated organs have evolved to include nerve repair, grafting, substitution, and muscle transposition. In parallel with this progress, research on tissue-engineered constructs, development of bioelectrical interfaces, and modulation of the regenerative milieu through cellular, immunomodulatory, or neurotrophic mechanisms has proliferated to enhance the available repertoire of clinically applicable reconstructive options. Despite these advances, patients continue to suffer from functional limitations relating to inadequate cranial nerve regeneration, aberrant reinnervation, or incomplete recovery of neuromuscular function. These shortfalls have profound quality of life ramifications and provide an impetus to further elucidate mechanisms underlying cranial nerve denervation and to improve repair. In this review, we summarize the literature on reconstruction and regeneration of motor cranial nerves following various injury patterns. We focus on seven cranial nerves with predominantly efferent functions and highlight shared patterns of injuries and clinical manifestations. We also present an overview of the existing reconstructive approaches, from facial reanimation, laryngeal reinnervation, to variations of interposition nerve grafts for reconstruction. We discuss ongoing endeavors to promote nerve regeneration and to suppress aberrant reinnervation and the development of synkinesis. Insights from these studies will shed light on recent progress and new horizons in understanding the biomechanics of peripheral nerve neurobiology, with emphasis on promising strategies for optimizing neural regeneration and identifying future directions in the field of motor cranial neuron research.

Experimental Studies on the Reinnervation of Posterior Cricoarytenoid Muscle by the Upper Branch of Phrenic Nerve

The purpose of this work was to reestablish the respiratory abduction of theparalyzed vocal cord through reinnervation of the posterior cricoarytenoid(PCA)mus-cle by part of phrenic fibres.In fifteen adult cats the adductor branch of the recurrentlaryngeal nerve(RLN)of the right side was cut and its distal end ligated,while the pro -ximal end was implanted into the PCA muscle belly.The whole RLN was then transectedin the tracheoesophageal groove and its distal stump anastomosed to the upper branchof the phrenic nerve.Various techniques for observation were used on day 40,80 and 150after operation.Direct laryngoscopy showed that the inspiratory abduction of the para-lyzed vocal cord recovered within 40 d in all cats.Eighty days later,a larger abducentmotion of the glottis was observed on the reinnervated side.Abduction was caused byreinnervation of the PCA muscle from phrenic motoneurons,as demonstrated by laryn-geal electromyogram,and the function of diaphragm maintained as revealed by monito-ring of the intrathoracic pressure.

Bronchial bleeding caused by recurrent pneumonia after radical esophagectomy for esophageal cancer

We herein report a case of bronchial bleeding afterradical esophagectomy that was treated with lobectomy.A 65-year-old male who underwent subtotal esophagectomy with three-field lymph node dissection for esophageal carcinoma was referred to our hospital because of sudden hemoptysis.After the esophagectomy,bilateral vocal cord paralysis was observed,and the patient suffered from repeated episodes of aspiration pneumonia.Bronchoscopy revealed hemosputum in the right middle lobe bronchus,and contrast-enhanced computed tomography showed tortuous arteries arising from the right inferior phrenic artery and left subclavian artery toward the right middle lobe bronchus.Although bronchial arterial embolization was performed twice to control the recurrent hemoptysis,the procedures were unsuccessful.Right middle lobectomy was therefore performed via video-assisted thoracic surgery.Engorged bronchial arterys with medial hypertrophy and overgrowth of the small branches were noted near the bronchus in the resected specimen.The patient recovered uneventfully and was discharged on postoperative day 14.

A three-dimensional digital visualization model of cervical nerves in a healthy person

Three-dimensional reconstruction nerve models are classically obtained from two-dimensional images of ＂visible human＂ frozen sections. However, because of the flexibility of nerve tissues and small color differences compared with surrounding tissues, the integrity and validity of nerve tissues can be impaired during milling. Thus, in the present study, we obtained two-dimensional data from a healthy volunteer based on continuous CT angiography and magnetic resonance myelography. Semi-automatic segmentation and reconstruction were then conducted at different thresholds in different tissues using Mimics software. Small anatomical structures such as muscles and cervical nerves were reconstructed using the medical computer aided design module. Three-dimensional digital models of the cervical nerves and their surrounding structures were successfully developed, which allowed visualization of the spatial relation of anatomical structures with a strong three-dimensional effect, distinct appearance, clear distribution, and good continuity, precision, and integrality. These results indicate the validity of a three-dimensional digital visualization model of healthy human cervical nerves, which overcomes the disadvantages of milling, avoids data loss, and exhibits a realistic appearance and three-dimensional image.

Identifying a Safe Range of Stimulation Current for Intraoperative Neuromonitoring of the Recurrent Laryngeal Nerve： Results from a Canine Model

Background： lntraoperative neuromonitoring （IONM） of the recunent laryngeal nerve （RLN） has been widely applied during thyroid surgery. However, the sale range of stimulation intensity for IONM remains undetermined, Methods： Total thyroidectomies were performed on twenty dogs, and their RLNs were stimulated with a current of 5 20 mA （step-wise in 5 mA increments） for 1 min. The evoked electromyography （EMG） of vocal muscles before and after supramaximal stimulation were recorded and compared. Acute microstructural morphological changes in the RLNs were observed immediately postoperatively under an electron microscope. Results： The average stimulating threshold for RLNs stimulated with 15 mA and 20 mA showed no significant changes compared to the unstimulated RLNs （15 mA group： 0.320 ± 0.123 mA vs. 0.315 ±0.097 mA, P =0.847; 20 mA group： 0.305 ± 0.101 mA vs. 0.300 ＋ 0.103 mA, P = 0.758）. Similar outcomes were shown in average evoked EMG amplitude （15 mA group： 1,026 ± 268 p.V xs. 1,021 ± 273 p.V, P = 0.834; 20 mA group： 1,162 ± 275 μV vs. 1,200 ± 258μV, P = 0.148）. However, obvious acute microstructural morphological changes were observed in the nerves that were stimulated with 20 mA. Conclusions： A stimulation intensity less than 15 mA might be safe for IONM of the RLN.

Role of Intra-Operative Nerve Monitoring in Thyroidectomies: An Institutional Review

Injury to the Recurrent Laryngeal Nerve (RLN) is a worrisome complication of a thyroidectomy. Intra-operative nerve monitoring (IONM) of the RLN has gained prevalence as an aid to prevent injury. We reviewed our series and other studies in literature for insight. A chart review was carried out to identify all patients who underwent a thyroidectomy between 2005 and 2010. IONM was implemented by the Otolaryngology service in 2007. All identified patients were separated into three groups: 1) Otolaryngology service with IONM, 2) Otolaryngology service without IONM, and 3) General Surgery service without IONM. Several factors were noted, including age, sex, thyroid disease, extent of thyroidectomy, and RLN injury along with recovery. 230 patients underwent thyroidectomy from 2005-2010. 60 patients were isolated in the IONM-Otolaryngology group with 3 patients suffering injury. 109 patients underwent a thyroidectomy by the Otolaryngology service without IONM with 8 patients suffering nerve damage. In the third group, 61 patients underwent a thyroidectomy by General Surgery without IONM with 4 patients suffering damage. Of the thyroid pathology, 10 patients had Multinodular Goiter while 4 had Papillary Cancer and 1 had a Follicular Adenoma. The most severe complication of a thyroidectomy is RLN injury. In order to further decrease the risk of RLN injury, IONM has been employed. From our review and other studies, there does not appear to be a significant difference in rates of RLN injury with or without use of nerve monitoring. An interesting note is the increased prevalence of nerve injuries in Multinodular Goiter—a finding that merits further study to evaluate the role of IONM.

Intraoperative monitoring of the recurrent laryngeal nerve in surgeries for thyroid cancer: a review

Intraoperative nerve monitoring(IONM)has evolved into an objective tool not only for the identification but also for the preservation and prognostication of function of the recurrent laryngeal nerve in thyroid surgeries.Technical improvements have resulted in the increasing incorporation of IONM into operating rooms around the world.The importance of adherence to recommended standards is also recognized as being vital in optimizing the efficacy of IONM.The advent of continuous IONM has made real-time nerve monitoring possible,thus providing the surgeon with an ally in difficult surgeries.Additionally,as thyroid surgeries are evolving into remote access and minimally invasive procedures,so also is the applicability of IONM.This review focuses on the use of IONM for nerve monitoring in thyroidectomies for neoplastic conditions while discussing the rationale,technique,and interpretation of findings and their implications.

T4a期甲状腺癌外科治疗的临床经验报告

目的分析T4a期甲状腺癌的临床特点及外科治疗策略。方法回顾性纳入2004年1月至2021年5月间在四川省肿瘤医院头颈外科住院手术的甲状腺恶性肿瘤患者,共计纳入T4a的甲状腺癌病例303例,分析患者的病理分型、受侵器官、手术方式、生存时间等。分析患者的总生存率,使用Kaplan Meier法分析患者术后生存曲线。结果在入组的303例患者中,共计53例患者失访,1年总生存率为98.4%(246/250),3年总生存率为97.0%(224/231),5年总生存率为90.2%(92/102)。其中喉返神经单独受侵94例,失访13例,1年总生存率为100%(81/81),3年总生存率为98.7%(77/78),5年总生存率为97.4%(38/39)。喉返神经合并气管/喉/食道受侵151例,失访31例,1年总生存率为96.7%(116/120),3年总生存率为95.3%(101/106),5年总生存率为82.2%(37/45)。在生存曲线分析中,喉返神经单独受侵组较喉返神经合并气管、喉或食道等器官受侵组在总生存时间上存在优势。结论T4a期甲状腺癌如果有手术机会,应该首选手术切除,通过合理的手术策略,根治性手术的同时重视重要组织器官的一期修复重建,患者可获得较好的生活质量和预后。

经颈超声检查评估咽喉部手术患者声带运动异常的价值

目的探讨经颈超声检查评估咽喉部手术患者声带运动异常的应用价值。方法选取2021年1月至2023年12月在海南省人民医院行甲状腺或咽喉部手术的49例患者纳入研究,所有患者术前及甲状腺患者术后均行喉镜及颈部超声检查声带运动情况,以喉镜评估声带运动为金标准,比较经颈超声与喉镜检查在评估声带运动方面有无差异。结果49例患者中行甲状腺肿瘤手术34例,术前超声检查显示声带区28例,超声与喉镜检查声带运动均正常。术后喉镜及超声检查均发现2例患者一侧声带固定,另喉镜提示1例患者一侧声带运动减弱,超声检查无阳性发现。喉部手术患者15例,均为喉癌;超声显示声带区结构的12例患者术前喉镜提示9例一侧声带固定,超声均正确诊断;另超声提示2例气道狭窄,声带运动减弱,因气道狭窄喉镜检查无法窥探至声带平面。将40例超声及喉镜均可显示声带区患者的声带运动情况进行比较,两者具有高度的一致性(Kappa值=0.826,P<0.001)。结论经颈超声检查作为一种非侵入式检查手段对部分患者声带运动情况的评估结果与喉镜检查结果具有高度的一致性,且简便易行,患者无需特殊准备,检查过程无痛苦,具有临床应用价值。

经皮针状电极在甲状腺术中喉返神经监测的研究

目的比较经皮针状电极和经口插管表面电极用于甲状腺术中神经监测的异同,并探讨在不适合经口插管或表面电极故障时,如何识别和保护喉返神经和迷走神经。方法收集并分析32例因甲状腺疾病接受手术治疗患者的临床资料,共计监测喉返神经和迷走神经各40侧,分别使用经口插管表面电极及经皮针状电极对神经进行监测,记录所获取的振幅及潜伏期。采用SPSS 26.0软件进行统计分析,采用配对t检验对潜伏期进行分析比较,采用秩和检验分析经皮针状电极与经口插管表面电极刺激所得振幅是否有差异。结果经皮针状电极用于甲状腺术中神经监测时,所有神经均被识别并获得与经口插管表面电极潜伏期和振幅相似的双相肌电信号,并可通过潜伏期有效鉴别喉返神经和迷走神经[(3.22±0.50)ms vs.(3.85±1.00)ms,P<0.05],与经口插管表面电极的监测效果[(3.04±0.58)ms vs.(3.89±1.07)ms,P<0.05]无明显差异;同时,经皮针状电极可视化操作度及安全性都更高,具有很大优势。结论经皮针状电极可有效辅助识别并保护喉返神经和迷走神经,是经口插管表面电极的重要补充。