Vocal Fold Research Articles

A prospective observational study on the anatomical variations of recurrent laryngeal nerve and its application in the prevention of injury during thyroid surgery in a tertiary care centre

BackgroundThyroid gland is the largest and most vascular structure among the endocrine glands. The recurrent laryngeal nerve and the superior laryngeal nerve are closely related to the thyroid gland; these nerves control voice and are vital in breathing. Anatomical preservation of the recurrent laryngeal nerve (RLN) is the gold standard in thyroid surgery. Visual identification of RLN has decreased the rates of permanent RLN palsy during thyroid and parathyroid operations. Prior knowledge about the branching patterns will help in predicting and preventing injury to the nerve during thyroid surgery.Aim and objectivesThe aim of the study is to observe the terminal branching pattern of recurrent laryngeal nerve before its entry into the larynx.MethodsAn observational study with 50 participants who fulfilled the inclusion and exclusion criteria were enrolled in the study. After a complete evaluation and pre-anaesthetic checkup, the patients were operated and intraoperative findings of RLN branching were recorded and compared for the study.ResultsIn our study, out of the 50 patients who underwent thyroid surgery during the course of the study, right-sided RLN branching was demonstrated in 25 patients (21 right hemithyroidectomy and 4 total thyroidectomy). Ten patients had RLN bifurcation, 7 had trifurcation, 5 had numerous branches, and 3 with no branching pattern were noted. Similarly, out of 29 patients (25 left hemithyroidectomy and 4 total thyroidectomy) in whom left-sided RLN branching was studied, bifurcation was seen in 10 patients, trifurcation in 12 patients, and multiple branching was observed in 7.ConclusionThe anatomical variations seen in RLN may increase the risk of vocal cord palsy due to its injury. Anatomical variations are categorized according to the original direction of the RLN and the number of terminal branches in the larynx. This classification aids in the identification and preservation of its branches, hence facilitating a safer thyroidectomy.

Dysphagia After Cervical Spinal Surgery: An Assessment of Incidence and Predisposing Factors

Background: Dysphagia is common following cervical spinal surgery (CSS) yet reported incidence and risk factors are highly heterogeneous. This case-control study aimed to determine the incidence of dysphagia after CSS and identify its predisposing factors. Methods: Records of 1199 patients who underwent CSS over a 2-year period at our center were reviewed. Patients with postoperative dysphagia and an equal number of randomly selected patients without dysphagia were included for analysis. Demographic, clinical, intraoperative, and perioperative factors were compared using univariate followed by multivariable logistic regression analysis. Results: The study population consisted of 94 (7.8%) patients with dysphagia and 94 controls. Patients with postoperative dysphagia were older [mean (SD) 60.7(12) vs 54.7(12), P = .002] and more likely to have preoperative dysphagia (16% vs 0%, P < .001). No other demographic or clinical factors were significant. Mid-level (C3-4, C4-5) (66% vs 48%, P = .018) and multilevel surgeries (67% vs 50%, P = .026) were associated with dysphagia. No other intraoperative factors were significant. The presence of any (abscess, dehiscence, hematoma, CSF leak, prevertebral edema, esophageal, or vocal cord injury) perioperative complication (20% vs 3.2%, P < .001) was associated with dysphagia, with dehiscence (6.5% vs 0%, P = .029) and hematoma (6.5% vs 0%, P = .029) showing the strongest association. Multivariable analysis identified age ≥70 [OR (95% CI): 2.8 (1-7), P = .031] and any perioperative complication [OR (95% CI): 6.7 (2-25), P = .004] as independent predictors of dysphagia. Conclusion: The incidence of dysphagia after cervical spine surgery is 7.8%. The risk of postoperative dysphagia is 6.7-times higher in those with perioperative complications and 2.8-times higher in patients over 70.

Sternotomy or thoracotomy for neonatal repair of coarctation of the aorta with aortic arch hypoplasia

ObjectiveFor neonatal repair of coarctation of the aorta, patients may either undergo thoracotomy with extended end-to-end anastomosis or sternotomy for aortic arch reconstruction with cardiopulmonary bypass. The objective of this study was to evaluate the comparative effectiveness of the 2 approaches in patients with arch hypoplasia. MethodsThis is a single-center retrospective cohort study from July 2005 through May 2022 of patients who underwent neonatal repair for isolated coarctation of the aorta with additional arch hypoplasia. Inverse probability of treatment weighting is a statistical method for creating comparable pseudopopulations and was used to account for baseline differences in population. The primary outcome was aortic reintervention, and secondary outcomes were vocal cord dysfunction, length of stay, chylothorax, and phrenic nerve palsy. ResultsThere were 130 patients who met inclusion criteria. After weighting, the interaction between distal transverse arch size and operative approach (sternotomy vs thoracotomy) was statistically significant, P < .05 for interaction. Among patients with a distal arch z score <−3.5, patients undergoing thoracotomy with extended end-to-end anastomosis had an increased hazard for reintervention. Sternotomy was associated with an increased length of stay in the intensive care unit by 4.7 days, P < .001, and odds of vocal cord dysfunction were also greater, odds ratio 7.1 (95% confidence interval, 1.66 to 41.26; P = .01). ConclusionsAmong patients with a distal arch z score smaller than −3.5, the hazard of reintervention was increased for patients undergoing thoracotomy with extended end-to-end anastomosis. However, length of stay and risk of vocal cord paresis was reduced in patients undergoing thoracotomy.

8728 Radiofrequency Thermal Ablation in Thyroid Microcarcinomas: Experience of the Brazilian Group with 143 Cases

Abstract Disclosure: L.G. Amato: None. P.H. Carani: None. L.D. Volpi: None. A. Rahal: None. E.M. Volpi: None. Introduction: Thyroid nodules are quite prevalent worldwide, with papillary thyroid carcinoma (PTC) being the most common histological subtype of thyroid malignant neoplasm, accounting for approximately 85% of thyroid cancers. When this carcinoma is less than 10 mm in its longest axis, it is defined as papillary thyroid microcarcinomas (mPTCs) which has had an increasing proportion of thyroid cancers and with a disease-specific survival of patients having this diagnosis more than 99% after 10 years of follow-up. Most guidelines concerning thyroid cancer care recommend a lobectomy as the first-line treatment strategy for low-risk unifocal mPTC but often results in aggressive overtreatment. Thyroid surgery comes with significant costs and morbidity rates caused by iatrogenic hypothyroidism and recurrent laryngeal nerve damage, resulting in poor quality of life, justifying the growing search for minimally invasive and effective methods in the treatment of mPTC and in this context Radiofrequency thermal ablation (RFA), a minimally invasive treatment that preserves thyroid function have been proposed for patients with low-risk mPTC. Clinical case: From April 2018 to January 2024, 143 patients with mPTC, were submitted to RFA and patient's follow-up were dated 1, 3, 6, 12 and 18 months after the procedure. During the follow-up we observed 3 (2%), complications, 1 case of permanent paralysis unilateral vocal cord, 1 Horner Syndromes and 1 case of transient paralysis, with total reversal. In all cases there was a reduction in the volume of the node after 6 months of the procedure. Conclusion: The reported incidence rate of postoperative hypothyroidism in patients underwent hemithyroidectomy is 10.9-48.8%, therefore, risks of complications with radioablation in our series were lower than those previously described during hemithyroidectomy. Radiofrequency thermal ablation (RFA) is a minimally invasive treatment that preserves thyroid function with a lower incidence of complications compared to thyroidectomy or lobectomy, and and should be considered the selection procedure for low-risk thyroid microcarcinomas. Presentation: 6/3/2024

8751 Radiofrequency Thermal Ablation in 32 Patients with Toxic Adenomas with Resolution of Hyperthyroidism in All Cases

Abstract Disclosure: L.G. Amato: None. E.M. Volpi: None. L.D. Volpi: None. P.M. Carani: None. A. Rahal: None. Introduction: In the general population, thyroid nodules are found in 3-7% of individuals on physical examination and in 20-76% on ultrasound. Around 8-10% of benign nodules may present autonomous behavior, being called hot nodules, causing symptoms of hyperthyroidism and being called toxic adenomas (TA). In TAs, autonomous hormone production can be caused by somatic activating mutations of genes regulating thyroid growth and hormone synthesis caused by somatic activating mutations of genes regulating thyroid growth and hormone synthesis. Classically, the proposed treatment for autonomous nodules was surgical resection or radioiodine ablation (RAI). In this context, the prevalence of hypothyroidism after the procedure varies from 2% to 3% following lobectomy, and lower after isthmusectomy in the unique circumstance in which the TA is confined to the thyroid isthmus. A study following 684 patients with TA treated with RAI reported a progressive increase in overt and sub-clinical hypothyroidism. Potential complications following near-total/total thyroidectomy include the risk of permanent hypoparathyroidism (&amp;lt; 2.0%) or recurrent laryngeal nerve injury (RLN) (&amp;lt; 2.0%). A small risk of permanent RLN injury exists with surgery for TA. Following RAI therapy, there have been reports of new-onset Graves Disease (up to 4% prevalence) as well as concern for thyroid malignancy and a very minimal increase in late non thyroid malignancy. Radiofrequency ablation (RFA) has been a precise and effective alternative for the treatment of many benign thyroid nodules over the past ten years, including hot nodules. RFA could preserves normal thyroid function compared to surgery or RAI. Clinical case: We evaluated the effectiveness of a single session of RFA in 32 patients with TA, through hormonal status, achieving normalization of thyroid and volumetric reduction of the nodule. Among the 32 patients included in this study, aged between 25 and 88 years, of these, 31 were women and 1 was a man, all of whom underwent a single RFA procedure (“moving shot” technique associated with hydrodissection). We had a single case of a reversible complication: a patient who had transient vocal cord paralysis, with total reversal. There was a reduction in the volume of all nodules as well as all patients progressed to a state of euthyroidism within 60 days of follow-up. Conclusion: A single session of RFA was effective in treating autonomous nodules, restoring euthyroidism in all patients. Presentation: 6/3/2024

7008 Challenges in the Management of Thyroid Lymphoma - Case Report

Abstract Disclosure: F. Toloza Bonilla: None. P. Veeraraghavan: None. R. Lakhotia: None. M. Roschewski: None. N. Nilubol: None. S. Gubbi: None. J. Klubo-Gwiezdzinska: None. Introduction: Primary thyroid lymphoma is an extremely rare thyroid malignancy accounting for less than 5% thyroid malignancies. The management depends on the histological subtype and tumor staging, typically involving chemotherapy alone or combined with radiotherapy. Although, surgical intervention is generally not recommended, given the potential surgical risks and the absence of additional benefits compared to chemoradiation therapy, it is reserved to obtain tissue diagnosis and to treat compressive symptoms. Clinical Case: A 66-year-old Caucasian female presented with dysphagia to solid food and acute neck swelling for a few weeks. History was negative for fever, weight loss or nocturnal diaphoresis. The patient had a history of primary hypertension, pre-diabetes, and Hashimoto’s hypothyroidism. A neck computed tomography (CT) scan showed a thyromegaly (8.3 x 5.8 cm) and bilateral cervical lymphadenopathy. Thyroid ultrasound showed sub centimeter nodules in the right mid-gland and a heterogeneous and irregular left thyroid lobe. TSH was normal (0.87 mcIU/mL [0.27-4.2]). She was treated for suspected subacute thyroiditis with prednisone for two weeks, showing initial clinical improvement, but symptoms recurred after steroids were stopped. Subsequently, a CT neck and fludeoxyglucose F18 (FDG) positron emission tomography (PET) scan demonstrated FDG avid thyroid enlargement with local adenopathy and rightward tracheal deviation. Lymph node, FNA, core biopsies and molecular testing were consistent with stage IIE MYC/BCL6 rearranged diffuse large B-cell lymphoma as she had no bone marrow or central nervous system (CNS) involvement. The patient’s treatments included four cycles of etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab with ibrutinib added after the first cycle and intrathecal methotrexate with cycles 3-6, to reduce the risk of CNS involvement. A 6-month post-therapy follow-up showed complete response (CR) on imaging with symptoms resolution. Four months later, she experienced worsening symptoms, including dysphagia with solids and liquids, and hoarseness despite CR to therapy and stable CT imaging. Laryngoscopic evaluation noted left vocal cord paralysis and extrinsic compression of the tracheoesophageal groove. Patient opted for a left hemithyroidectomy, experiencing excellent symptom relief. Surgical pathology showed findings consistent with a necrotic tumor and residual areas of lymphocytic thyroiditis. No active DLBCL was appreciated. The patient remains in remission and continues to be symptoms-free 24 months post-thyroid lymphoma treatment. Conclusion: While thyroidectomy is not typically recommended as the initial treatment for primary thyroid lymphoma, it emerges as a potentially effective option to manage recurrent or persistent compression symptoms following the completion of medical therapy. Presentation: 6/3/2024

7914 Staged Treatment with Radioiodine Following Lobectomy in a Case of High Risk Papillary Thyroid Carcinoma

Abstract Disclosure: L. Pathak: None. A. Sharma: None. K. Rao: None. M.G. Jakoby: None. Introduction: Radioiodine ([1]3[1]I ) is usually reserved for patients with differentiated thyroid carcinoma (DTC) who are at high risk of persistence or recurrence after thyroidectomy. We present a case of papillary thyroid carcinoma (PTC) with extrathyroidal extension managed by lobectomy and staged [1]3[1]I ablation of the contralateral lobe and metastases due to comorbidities that made oncologic resection prohibitive. Case Description: A 58-year-old male had a 2.2 cm focus of PTC in the left thyroid lobe that extended into extrathyroidal soft tissue, adjacent trachea, and completely compromised the left recurrent laryngeal nerve. Due to left vocal cord paralysis and subglottic tracheal stenosis, left lobectomy was performed but oncologic resection (total thyroidectomy and tracheal resection) was deferred. The patient underwent recombinant human TSH (rhTSH) stimulated treatment with 30 mCi (1.1 GBq) of [1]3[1]I for right thyroid lobe ablation followed 60 d later by 180 mCi (6.7 GBq) of [1]3[1]I to treat metastases. Response to treatment was incomplete, with unstimulated thyroglobulin level falling from 293.9 to 18.9 ng/mL 1 y after [1]3[1]I and CT of the neck notable for a 2.7 cm left thyroid bed mass with invasion of adjacent trachea and a 1.0 cm right paratracheal mass, both of which exhibited hypermetabolism on PET imaging and yielded cytology consistent with poorly differentiated thyroid carcinoma (PDTC). A cluster of left supraclavicular lymph nodes showed both hypermetabolism on PET and radioiodine uptake on rhTSH scan. This patient is being prepared for surgical resection of the left thyroid bed and right paratracheal tumors and left lateral lymph node dissection. Discussion: Radioiodine lobar ablation is an alternative to completion thyroidectomy in patients with an unexpected diagnosis of DTC after lobectomy, with a recent meta-analysis finding a success rate of 69%. No difference in thyroid cancer recurrence rates was found in nearly 500 matched pairs of patients undergoing completion thyroidectomy or radioiodine lobar ablation. Unfortunately, staged lobar ablation followed by high dose [1]3[1]I was not successful in treating this high-risk PTC patient. Cases of coexisting PTC and PDTC are reported, and [1]3[1]I treatment was unsuccessful at treating PDTC that was not apparent on postsurgical histopathology. This case indicates that surgery is preferable to staged [1]3[1]I treatment of patients with aggressive PTC, especially if there are no comorbidities that make total thyroidectomy a high-risk procedure. Presentation: 6/2/2024

Analysis of therapeutic effect of fibrocystic degeneration of vocal folds

Objective:To explore the differences in clinical presentation and therapeutic outcomes between vocal fold fibrocystic degeneration and other common benign lesions, such as vocal fold polyp and cyst. Methods:Vocal function was assessed before and after surgery in 10 cases of vocal fold fibrocystoids, 30 cases of vocal fold polyps and 10 cases of vocal fold cysts at Department of Voice Medicine, Xiamen University Zhongshan Hospital. The voice Assessments included GRBAS（G-scale）, VHI-10 scale, Reflux Symptom Index（RSI） scale, stroboscope, acoustic objective analysis, and aerodynamics measurements. The acoustice analysis parameters included fundamental frequency（F0）, fundamental frequency perturbation（Jitter）, amplitude perturbation（Shimmer） and voice disturbance severity index（DSI）, while the maximum phonation time（MPT） was assessed for aerodynamics. Stroboscopic parameters included vocal fold straightness, vocal fold color, glottic closure and mucosal wave. All three groups underwent phonomicrosurgery and a follow-up review was conducted one month later. Pre-and post-operative function assessment parameters were compared across the three groups. Results:Significant differences were founded in the G grade, Jitter, Shimmer, DSI, glottic closure and mucosal wave between the vocal fold fibrocystic degeneration group and the vocal fold polyp and vocal fold cyst group（P<0.05）. Most voice function parameters in all three groups showed significant improvement after surgery（P<0.05）. The improvement of VHI（10）, RSI and mucosal wave scores in the vocal fold fibrocystic lesion group was significantly different from that of the vocal fold polyp group（P<0.05）. Conclusion:Vocal fold fibrocystic degeneration is a more severe than that of vocal fold polyps and cysts, which are two common benign vocal fold lesions. Phonomicrosurgery is an effective treatment for vocal fold fibrocystic degeneration, but its curative effect are less favorable compared to those for vocal fold polyps and vocal fold cysts. Therefore, a detailed preoperative evaluation is essential for predicting surgical outcomes.

Accuracy of Diagnosis of Benign Vocal Fold Lesions among Ear, Nose, and Throat Residents.

Introduction Benign vocal fold lesions (BVFLs) disrupt the superficial lamina propria, impacting vocal fold pliability. Investigating the diagnostic competency of ear, nose, and throat (ENT) residents in identifying BVFLs, we hypothesize that factors such as residency year, subspecialty focus, and training center influence diagnostic accuracy. Objectives To assess the accuracy of diagnosis of BVFLs among ENT residents and to correlate diagnostic accuracy with the year of residency. Methods An observational cross-sectional study included all ENT residents in Saudi Arabia. It was performed in August and September 2021 using a self-administered online questionnaire that assessed demographic variables and included three images with open-ended questions on diagnosing vocal fold lesions. Results A total of 61 ENT residents (62.3% male) were included in this study. The images of vocal fold cyst, vocal fold polyp, and vocal fold nodule were correctly diagnosed by 60.7%, 88.5%, and 91.8% of residents, respectively. There was a correlation between the year of residency and the accuracy of diagnosing a vocal fold cyst ( p = 0.029). Residents interested in laryngology correctly diagnosed all three lesions more frequently than other residents. Conclusion The ability of residents to diagnose vocal fold cysts was moderate. In particular, the senior residents were able to diagnose polyps and nodules with excellent accuracy.

Measuring the outward migration of the nasotracheal tube at vocal cords with head and neck extension: a novel approach using a flexible bronchoscope in patients undergoing head and neck oncosurgery.

Head and neck extension achieves optimal surgical exposure during head and neck oncosurgeries. However, it can lead to cephalad migration of the tracheal tube, causing complications. Preventing shallow intubation is essential, especially in patients with difficult airway. Using an innovative technique, we aimed to measure the proximal migration of the nasotracheal tube at the vocal cords on neck extension in patients with difficult airway. We enrolled 60 adult patients undergoing head and neck oncosurgeries with a mouth opening of less than 1.5 cm. After nasotracheal intubation using a flexible bronchoscope (FB), the FB was introduced into the adjacent nostril and maneuvered to reach the glottis. The FB was used to view and align the intubation depth mark (IDM) on the tracheal tube (TT) with the vocal cords in the neutral position. The outward migration of the TT at the vocal cords with a 30° to 40° neck extension was measured using the same maneuver. Also, the TT tip-to-carina distance was noted in both neutral and extension using FB. The mean proximal migration of the TT at the vocal cords during neck extension was 3±0.3 mm. The TT tip-to-carina distance increased by a mean of 20±7 mm with extension. The proximal migration contributed 15%, whereas elongation of the trachea contributed 85% to this increase. The major contributing factor for the increase in TT tip-to-carina distance on neck extension was tracheal elongation rather than outward migration of the TT at vocal cords.

Immunocytochemistry assessment of vocal fold regeneration after cell-based implant in rabbits.

Cell-based outer vocal fold replacement (COVR) offers a potential treatment for severe vocal fold scarring or cancer reconstruction. Previous work in rabbits using human adipose-derived stem cells (ASC) in fibrin suggested that a hybrid structure emerged within 2 months, containing both implanted and host cells. This project uses immunocytochemistry to better define the phenotypic fate of implanted cells and features of the extracellular environment. Immunocytochemistry was performed on sections collected from rabbits 2 months after COVR implantation or scar surgery. Cellular targets included human leukocyte antigen (HLA), CD31, and smooth muscle actin (SMA). HLA was present in all implanted sections and was used to identify human cells. In adjacent sections, HLA-positive cells were identified expressing CD31. SMA was not identified in the same cells as HLA. These markers were also present in injured vocal folds not receiving COVR. SMA protein content did not differ according to treatment. Implanted human ASC persist in rabbit vocal folds. Some appear to express CD31, an endothelial marker. Smooth muscle actin, a marker of myofibroblast phenotype, was present in all sections regardless of treatment, and was not identified in hASC. Host cells also infiltrate the structure, producing a hybrid host-graft vocal fold.

Does Intralesional Steroid Injection Effectively Mitigate Vocal Fold Scarring in A Rabbit Model?

To assess the efficacy of intralesional steroid treatment in preventing vocal fold scarring following vocal fold surgery using a rabbit model. The research involved 42 male New Zealand white rabbits. Fourteen rabbits underwent vocal fold scar surgery using a 532nm laser and served as controls (control group). The remaining rabbits were divided into two groups of 14: one group received vocal fold scar surgery followed by dexamethasone injection (Dexa group) and the other received the same surgery followed by triamcinolone injection (Triam group). Four weeks after surgery, histological examinations and high-speed video analyses of vocal fold vibration were conducted. The maximum amplitude of vibration was the primary measure for assessing vocal fold function. In addition, real-time polymerase chain reaction (PCR) studies were undertaken to analyze scar regeneration and remodeling. The maximum amplitude differences were notably higher in the Dexa and Triam groups than in controls. Histologically, the collagen density (CD) ratios in both the Dexa and Triam groups were significantly reduced compared with controls. Real-time PCR analysis indicated marked elevations of Has-2 and Mmp-9 in the Dexa and Triam groups relative to controls. Intralesional steroid injections after vocal fold surgery are effective for reducing vocal fold scarring in a rabbit model. NA Laryngoscope, 2024.

Stereotactic Radiation Therapy in 3 Fractions for T1 Glottic Cancer

To report the results of a phase I-II study on SBRT for early glottic cancer. This a prospective study at a single Institution enrolling patients with T1 glottic cancer. The true vocal cords (TVC) were divided into thirds and the third(s) containing disease prescribed 36 Gy in 3 fractions. The portions of the TVCs next to the involved one were planned to receive 30 Gy in 3 fxs. SBRT was delivered by a LINAC-based approach using multiple arcs. Toxicity was scored by CTCAE and late events were considered those occurring 3 months after SBRT. Voice quality was investigated by the voice handicap index (VHI) at regular intervals. The planned sample size was 75 patients. Accrual was discontinued after 33 patients due to concerns for late toxicity. T stage was as follows: T1a: 23 pts (69.7%); T1b: 10 pts (30.3%). All patients received the planned treatment and the median follow-up time is 51.5 months (IQR: 47.9-61.0 months). At last follow up, all patients are alive and without evidence of disease but two patients who died for intercurrent causes. The local control rate is 100% at 4 yrs. Six patients (18.2%) developed soft tissue necrosis (N=4) or cartilage necrosis (N=2) after a median time of 14.9 months from SBRT. Five out of 6 necrotic events were observed in patients who kept smoking and/or had a recent COVID infection. All 4 soft tissue events healed with conservative therapy. After an initial deterioration the average VHI score significantly improved at 6 months over baseline. SBRT to 36 Gy in 3 fractions is highly effective in controlling T1 TVC carcinoma, but necrosis, though mostly transient, is a concern. Based on the present results, a reduction in total dose as well as a more accurate patient selection are warranted.

Efficacy analysis of ansa cervicalis anterior root-recurrent laryngeal nerve anastomosis in the treatment of unilateral vocal cord paralysis

Objective:Investigates the application and clinical efficacy of ansa cervicalis anterior root-recurrent laryngeal nerve（RLN） anastomosis in the treatment of unilateral vocal fold paralysis（UVFP）. Methods:A prospective study was conducted with 92 UVFP patients admitted to our department from January 2018 to January 2022 who received ansa cervicalis anterior root-RLN anastomosis. The course of nerve injury ranged from 6 to 24 months. Videostroboscopy, voice subjective auditory perceptual assessment（GRBAS）, Voice Handicap Index（VHI-10）, voice objective acoustic analysis and laryngeal electromyography（EMG） were used to evaluate the efficacy of the operation. Results:Videostroboscopy showed that although the movement of vocal cords did not return to normal 12 months after operation, their volume and muscle tension were significantly improved and their positions were adducted to the median or near-median. Also the glottic closure, vocal cord position, vocal cord edge, symmetry and regularity of vocal cord vibration were significantly improved than pre-operation（P<0.01）. The five indexes of GRBAS（Grade, Roughness, Breathiness, Asthenia, Strain） and VHI-10, as well as voice acoustic parameters（Jitter, Shimmer, NHR） post-operation were significantly reduced, while the maximum phonation time（MPT） was significantly longer（P<0.01）. The results of laryngeal EMG indicated that the maximum voluntary motor unit recruitment（VMUR） post-operation was significantly recovered（P<0.01）, which confirmed that the affected laryngeal muscle obtained effective nerve reinnervation. Conclusion:Ansa cervicalis anterior root-RLN anastomosis can effectively improve the voice function of patients which is safe and satisfactory. It is an ideal method for the treatment of unilateral RLN injury.

Clinical analysis of biomaterial-silicone keel complex in the vocal folds adhesion treatment

Objective:To retrospectively analyze the clinical effect of biomaterial combined with silicone keel technology in the prevention and treatment of vocal folds adhesion. Methods:The basic data, perioperative conditions and prognosis of 21 cases of vocal folds adhesion treated by biofilm-silicone keel complex were retrospectively analyzed in Huashan Hospital Fudan University. Results:A total of 21 patients were enrolled in this study（19 males（90.5%）, 2 females（9.5%）. Among these patients, 18 cases of early glottic laryngeal carcinoma（T1b）, 1 case of bilateral vocal folds leukoplecta and 2 cases of postoperative vocal folds adhesion. No accidental rupture of the silicone keel occurred during perioperative period, and the silicone keel was removed in 22.4±2.6 days. All patients were reviewed after removing the silicone keel, the overall effective rate was 90.5%（19/21）. Postoperative complications occurred in 5 patients（1 laryngeal infection, 4 granulation tissue hyperplasia）, all of whom were cured after conservative treatment. Conclusion:This study explored the feasibility of biomaterial in the treatment of vocal folds adhesion. The biomaterial-silicone keel complex technology is simple to operate and has effect on the prevention of vocal folds adhesions, which is worth of clinical promotion.

Analysis of the efficacy of non-surgical treatment mainly focus on voice therapy and it's influencing factors in patients with unilateral vocal fold paralysis

Objective:Retrospective analysis of the efficacy and it's influencing factors of non-surgical treatment mainly focus on voice therapy for patients with unilateral vocal fold paralysis. Methods:The retrospective study includes 57 patients who were diagnosed with unilateral vocal fold paralysis and presented with hoarseness as their main complaint at the Department of Voice Medicine, Zhongshan Hospital of Xiamen University from August, 2021 to August, 2023. Judging the efficacy of non-surgical treatment mainly focus on voice therapy through changes in acoustic, aerodynamic, and laryngoscopic parameters; Analyze the relationship between patients' age, gender, duration of disease, cause of nerve injury, type of nerve injury, side of nerve injury and efficacy of non-surgical treatment. Results:After non-surgical treatment mainly focused on voice therapy, there were statistically significant differences（P<0.01） in the changes of vocal fold bow, glottal gap, glottal compression, loudness, Jitter, Shimmer, IC, and NC parameters. There is a statistically significant correlation between the duration of the disease and changes in glottal gap, Shimmer, and IC（P<0.05）, the side of nerve injury can affect changes of glottal gap and NC（P<0.05）. Conclusion:Non-surgical treatment mainly focused on voice therapy has a good efficacy on patients with unilateral vocal fold paralysis. The duration of the disease and the side of nerve injury may affect the efficacy.

Histological characterization of rat vocal fold across different postnatal periods.

To evaluate the vocal fold histological characteristics during different postnatal periods in rats, especially older rats. Sprague-Dawley rats aged 4 days, 4 and 12 weeks, and 12 and 24 months were used for the experiment. Five larynges were obtained for each age and cut into 5-μm consecutive sections. The expression of Ki-67 was assessed using immunohistochemistry to examine cell proliferation. Elastic van Gieson staining was used to detect the collagen and elastin concentrations. The cell type was determined using multicolor immunofluorescence. Ki-67 was not expressed in the macula flava (MF) of 12-week-, 12-month-, and 24-month-old adults. Collagen fibers in the lamina propria (LP) increased with age. The elastic fiber concentrations in the LP decreased significantly at 24 months (p < .01) but remained stable in the MF. All posterior MF cells showed strong glial fibrillary acidic protein and vimentin-positive reactions with weaker expressions of CD68 and α-smooth muscle actin (α-SMA). The myofibroblasts (α-SMA-positive) and macrophages (CD68-positive) in the LP of the 24-month-old rats were significantly the highest (p < .01). The extracellular matrix in the LP increases with age, presenting as an increase in collagen with the loss of elastin, which may be due to myofibroblast proliferation. Moreover, the cellular properties or extracellular matrix components of the mature MF in rats are comparable to those in humans.

Delayed-onset vocal cord palsy after thyroidectomy occurring despite normal initial post-operative endoscopy.

Recurrent laryngeal nerve (RLN) injury is a known complication of thyroidectomy. Most cases manifest immediately and are promptly recognized. Rarely, some patients experience delayed-onset vocal cord palsy. This can occur despite normal findings on intra-operative nerve monitoring and initial post-operative endoscopy. This can cause considerable distress for patients, and its incidence and prognosis should be recognized. We report seven patients experiencing delayed-onset RLN palsy (RLNP) after thyroidectomy. All had normal findings on pre-operative flexible nasoendoscopy (FNE), intra-operative nerve monitoring at conclusion of surgery, and initial post-operative FNE. All diagnoses of RLNP were confirmed on endoscopy. Serial FNE examinations were performed to evaluate recovery. Of seven patients (43% male, median age 65 years), the median timing of delayed-onset RLNP was 12 (range 9-35) days. RLNP was diagnosed on the unilateral side of surgery in six out of seven patients (86%). All received conservative management, including referral to voice therapy. All seven patients recovered vocal cord function after a median duration of 24 weeks (range 8-52 weeks), and six within ~6 months (28 weeks). The incidence of this complication was 0.1% (among 6607 thyroidectomies). We report the first Australian series of delayed-onset vocal cord palsy after thyroidectomy. We explore its prognosis, discussing different pathophysiological mechanisms and the timeframe for recovery compared to most other RLN injuries. This may assist recognition of a rare complication, reassure patients, and facilitate early intervention to improve a patient's quality of life.

A two-person verbal check to confirm tracheal intubation: evaluation of practice changes to prevent unrecognised oesophageal intubation

BackgroundDeaths from unrecognised oesophageal intubation continue despite national campaigns emphasising the importance of capnography to confirm tracheal intubation. A two-person verbal intubation check is recommended in consensus guidelines intended to prevent such deaths. This check can be performed by the intubator with their assistant, either as a one-step process (identification of sustained exhaled carbon dioxide) or as a two-step process (adding identification of the tracheal tube passing through the vocal cords during videolaryngoscopy). MethodsIn two hospitals we introduced two-person checking of tracheal intubation. In one hospital this involved the one-step process and in the other the two-step process. We used anonymous online questionnaires before, during, and after these changes to collect opinions from anaesthetists and their assistants regarding the feasibility and acceptability of these changes. ResultsMost intubators (116/149, 78%) and intubators' assistants (70/72, 97%) reported that the two-person verbal intubation check would reduce the likelihood of unrecognised oesophageal intubation. Benefits and lack of negative aspects were reported for both one-step and two-step two-person intubation checks in both centres. Intubators judged that the checks improved communication and teamwork (118/149, 79%); intubators' assistants reported feeling more empowered to voice concerns if needed (69/72, 96%), a flattened team hierarchy (53/72, 74%), and feeling more valued as team members (64/72, 89%). Most intubators (122/149, 82%) and intubators' assistants (68/72, 94%) planned to continue using the two-person intubation check for all future intubations. ConclusionsOur results suggest that a two-person verbal intubation check is feasible and acceptable to all members of the intubating team.

The key problems of diagnosis and treatment of vocal cord paralysis

Vocal cord paralysis is a common condition that significantly impairs laryngeal function and can even be life-threatening. Over nearly a century, researchers have conducted extensive animal and clinical studies to achieve accurate diagnosis and restore laryngeal function, making significant progress. Approaches have evolved from mechanically narrowing the glottis to restore phonation, to enlarging the glottis to relieve breathing difficulties, and ultimately to the development of surgical techniques aimed at restoring vocal cord mobility, significantly advancing the field. The publication of expert consensus guidelines on the diagnosis and treatment of vocal cord paralysis has standardized the principles and technical standards for managing this condition. However, a vast amount of related knowledge-including the disease's pathogenesis, diagnostic criteria, surgical principles, and techniques-still requires broader dissemination and further refinement. Advancing this knowledge will guide clinical practice and further enhance the diagnosis and treatment of this condition in China.