Vocal Fold Paralysis Following Benign Thyroid Nodule Laser Thermal Ablation.

Laser thermal ablation (LTA) is an increasingly common procedure to treat benign and malignant thyroid nodules, allowing patients to avoid thyroidectomy. There are few reported postprocedural complications of LTA among patients with benign thyroid nodules. While vocal fold paralysis is a well-known potential complication after thyroidectomy, we present the first case report of vocal fold paralysis following LTA. A female in her 80s presented to an outside endocrinologist with symptoms of hyperthyroidism and benign thyroid nodules. The patient underwent a fine needle aspiration biopsy, radioiodine uptake scan, radioactive thyroid ablation, and LTA at an outside institution. The patient first noticed hoarseness 2days after LTA, and she presented to our office with a weak, breathy voice more than 4months postprocedure. Videostroboscopic examination revealed immobility of the left vocal fold with incomplete glottic closure. After awake injection laryngoplasty in the office, the patient experienced voice improvement. In conclusion, LTA is a relatively new treatment modality with limited literature on adverse outcomes. As minimally invasive techniques such as LTA are becoming more common, it is essential to remain fully aware of risks to recognize and mitigate complications like vocal fold paralysis.

Alternative Sources of Cautery in Thyroid Surgery and the Risk of Recurrent Laryngeal Nerve Injury: A Retrospective, Risk-Adjusted Analysis From the National Surgical Quality Improvement Program.

OBJECTIVES: A risk-adjusted analysis was completed using data from the National Surgical Quality Improvement Program (NSQIP) to compare the rates of recurrent laryngeal nerve injury in thyroid surgery using traditional versus alternative sources of cautery (defined as Harmonic Scalpel© and LigaSure©). METHODS: A retrospective cohort study was completed using the NSQIP database on adult patients who underwent total thyroidectomy, subtotal thyroidectomy, or completion thyroidectomy between 2016 and 2018. The primary outcome measure was recurrent laryngeal nerve injury. The exposure variable was use of conventional or alternative sources of cautery. Multivariable linear and logistic regression analyses were performed to control for potentially confounding variables. RESULTS: A total of 13,961 cases were analyzed; 9450 used alternative sources of cautery compared to 4511 where traditional cautery was used. There was no significant difference in rates of postoperative recurrent laryngeal nerve injury between the 2 sources of cautery compared. CONCLUSIONS: Risk of recurrent laryngeal nerve injury should not be a factor when choosing method of cautery for thyroid surgery. Therefore, other factors like cost-effectiveness can be considered.

[Efficacy of prevention of recurrent laryngeal nerve injury in thyroid surgery]. / Effektivnost' profilaktiki povrezhdenii vozvratnogo gortannogo nerva pri operatsiyakh na shchitovidnoi zheleze.

OBJECTIVE: To evaluate the effectiveness of prevention of recurrent laryngeal nerve injury depending on thyroid gland lesion and extent of surgery. MATERIAL AND METHODS: There were 2412 thyroid surgeries between 2000 and 2020. Patients were divided into the main group (1689 patients) and the control group (729 patients). Patients with nodular thyroid gland lesions prevailed in both groups (987 (58.4%) and 415 (56.9%), respectively). All ones underwent atraumatic extrafascial desection and thyroid resection (ultrasonic scalpel). RESULTS. T: He upper laryngeal nerve injury occurred in 35 cases (1.4%). The number of surgeries with thyroid remnant preservation was significantly lower in the main group. The number of procedures with subtotal thyroid resection and thyroidectomy increased by 2.4 times (from 414 to 1010 operations, p<0.05). CONCLUSION: Improvement of surgical treatment of thyroid gland lesions consisting in new operative technique of recurrent laryngeal nerve isolation using ultrasonic scalpel reduces the incidence of recurrent laryngeal nerve injury from 2.3% to 1%. At the same time, the number of extended procedures in the main group significantly exceeded that in the control group (by 2.5 times).

Tissue-Engineered Implant for Hemilaryngectomy Reconstruction with Recurrent Laryngeal Nerve Injury.

OBJECTIVE: Laryngeal cancer resections often require excision of portions of the larynx along with sacrifice of the ipsilateral recurrent laryngeal nerve (RLN). In such cases, there are no reconstructive options that reliably restore laryngeal function, rendering patients with severe functional impairment. To address this unmet clinical need, we extend our evaluation of a 3-implant mucosal, muscle, cartilage reconstruction approach aimed at promoting functional laryngeal restoration in a porcine hemilaryngectomy model with ipsilateral RLN transection. METHODS: Six Yucatan mini-pigs underwent full-thickness hemilaryngectomies with RLN transection followed by transmural reconstruction using fabricated collagen polymeric mucosal, muscle, and cartilage replacements. To determine the effect of adding therapeutic cell populations, subsets of animals received collagen muscle implants containing motor-endplate-expressing muscle progenitor cells (MEEs) and/or collagen cartilage implants containing adipose stem cell (ASC)-derived chondrocyte-like cells. Acoustic vocalization and laryngeal electromyography (L-EMG) provided functional assessments and histopathological analysis with immunostaining was used to characterize the tissue response. RESULTS: Five of six animals survived the 4-week postoperative period with weight gain, airway maintenance, and audible phonation. No tracheostomy or feeding tube was required. Gross and histological assessments of all animals revealed implant integration and regenerative remodeling of airway mucosa epithelium, muscle, and cartilage in the absence of a material-mediated foreign body reaction or biodegradation. Early voice and L-EMG data were suggestive of positive functional outcomes. CONCLUSION: Laryngeal reconstruction with collagen polymeric mucosa, muscle, and cartilage replacements may provide effective restoration of function after hemilaryngectomy with RLN transection. Future preclinical studies should focus on long-term functional outcomes. LEVEL OF EVIDENCE: NA Laryngoscope, 134:4604-4613, 2024.

Surgeon-performed transcutaneous laryngeal ultrasound for vocal cord assessment after total thyroidectomy: a prospective study : Original article.

PURPOSE: Assessing vocal cord mobility is crucial for patients undergoing thyroid surgery. We aimed to evaluate the feasibility and efficacy of surgeon-performed transcutaneous laryngeal ultrasound (TLUS) compared to flexible nasolaryngoscopy. METHOD: From February 2022 to December 2022, we conducted a prospective observational study on patients scheduled for total thyroidectomy at our Institution. All patients underwent TLUS followed by flexible nasolaryngoscopy by a blinded otolaryngologist. Findings were classified as normal or vocal cord movement impairment and then compared. Patients evaluable on TLUS were included in Group A, while those not evaluable were included in Group B, and their features were compared. RESULTS: Group A included 180 patients, while Group B included 21 patients. Male sex (p < 0.001), age (p = 0.034), BMI (p < 0.001), thyroid volume (p = 0.038), and neck circumference (p < 0.001) were associated with Group B. TLUS showed a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%, 99.4%, 94.4%, 100%, and 99.4%, respectively. Cohen's K value was 0.984. CONCLUSION: TLUS is a valid, easy-to-perform, non-invasive, and painless alternative for evaluating vocal cords in selected patients. It can be used either as a first level exam and as screening tool for selecting cases for flexible nasolaryngoscopy. TLUS should be integrated into routine thyroid ultrasound examination.

Transcriptome Analysis of Left Versus Right Intrinsic Laryngeal Muscles Associated with Innervation.

OBJECTIVES/HYPOTHESIS: Recurrent laryngeal nerve injury diagnosed as idiopathic or due to short-term surgery-related intubation exhibits a higher incidence of left-sided paralysis. While this is often attributed to nerve length, it is hypothesized there are asymmetric differences in the expression of genes related to neuromuscular function that may impact reinnervation and contribute to this laterality phenomenon. To test this hypothesis, this study analyzes the transcriptome profiles of the intrinsic laryngeal muscles (ILMs), comparing gene expression in the left versus right, with particular attention to genetic pathways associated with neuromuscular function. STUDY DESIGN: Laboratory experiment. METHODS: RNA was extracted from the left and right sides of the rat posterior cricoarytenoid (PCA), lateral thyroarytenoid (LTA), and medial thyroarytenoid (MTA), respectively. After high-throughput RNA-Sequencing, 88 samples were organized into 12 datasets according to their age (P15/adult), sex (male/female), and muscle type (PCA/LTA/MTA). A comprehensive bioinformatics analysis was conducted to compare the left-right ILMs across different conditions. RESULTS: A total of 774 differentially expressed genes were identified across the 12 experimental groups, revealing age, sex, and muscle-specific differences between the left versus right ILMs. Enrichment analysis of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways implicated several genes with a left-right laryngeal muscle asymmetry. These genes are associated with neuronal and muscular physiology, immune/inflammatory response, and hormone control. CONCLUSION: Bioinformatics analysis confirmed divergent transcriptome profiles between the left-right ILMs. This preliminary study identifies putative gene targets that will characterize ILM laterality. LEVEL OF EVIDENCE: N/A Laryngoscope, 134:3741-3753, 2024.

Mini-invasive video-assisted thyroidectomy vs robot-assisted transaxillary thryoidectomy: analisys and comparison of safety and outcomes.

Thyroid surgery is characterized by large volumes and typically affects a young female population. Mini-invasive or remote access surgical techniques are born driven by the desire to improve aesthetic outcomes of the traditional technique, following technological advances that have upset the surgical world in the last 20 years. In our multicenter, retrospective observational study, we first compared an endoscopic technique with a robotic one: minimally invasive video-assisted thyroidectomy (MIVAT) and robot-assisted transaxillary thyroidectomy (RATT). We evaluated intraoperative features, complications, and cosmetic outcomes in a cohort of 609 patients. The efficacy and safety of these techniques are proven by a large literature and the comparison made in our study does not show inferiority of one technique compared to the other. Even the aesthetic results tend to be equal in the long term. It is desirable that further prospective and randomized studies are conducted to evaluate the outcomes of these procedures and the cost-benefit ratio.

Development and Application of Automated Vocal Fold Tracking Software in a Rat Surgical Model.

OBJECTIVE: The rat is a widely used model for studying vocal fold (VF) function after recurrent laryngeal nerve injury, but common techniques for evaluating rat VF motion remain subjective and imprecise. To address this, we developed a software package, called RatVocalTracker1.0 (RVT1.0), to quantify VF motion and tested it on rats with iatrogenic unilateral vocal fold paralysis (VFP). METHODS: A deep neural network was trained to identify the positions of the VFs and arytenoid cartilages (ACs) in transoral laryngoscope videos of the rat glottis. Software was developed to estimate glottic midline, VF displacement, VF velocity, and AC angle. The software was applied to laryngoscope videos of adult rats before and after right recurrent and superior laryngeal nerve transection (N = 15; 6M, 9F). All software calculated metrics were compared before and after injury and validated against manually calculated metrics. RESULTS: RVT1.0 accurately tracked and quantified VF displacement, VF velocity, and AC angle. Significant differences were found before and after surgery for all RVT1.0 calculated metrics. There was strong agreement between programmatically and manually calculated measures. Automated analysis was also more efficient than nearly all manual methods. CONCLUSION: This approach provides fast, accurate assessment of VF motion in rats with minimal labor and allows for quantitative comparison of lateral differences in movement. Through this novel analysis method, we can differentiate healthy movement from unilateral VFP. RVT1.0 is open-source and will be a valuable tool for researchers using the rat model for laryngology research. LEVEL OF EVIDENCE: NA Laryngoscope, 134:340-346, 2024.

Changes in vocal fold gene expression and histology after injection augmentation in a recurrent laryngeal nerve injury model.

OBJECTIVE: To investigate changes in neuroregenerative pathways with vocal fold denervation in response to vocal fold augmentation. METHODS: Eighteen Yorkshire crossbreed swine underwent left recurrent laryngeal nerve transection, followed by observation or augmentation with carboxymethylcellulose or calcium hydroxyapatite at two weeks. Polymerase chain reaction expression of genes regulating muscle growth (MyoD1, MyoG and FoxO1) and atrophy (FBXO32) were analysed at 4 and 12 weeks post-injection. Thyroarytenoid neuromuscular junction density was quantified using immunohistochemistry. RESULTS: Denervated vocal folds demonstrated reduced expression of MyoD1, MyoG, FoxO1 and FBXO32, but overexpression after augmentation. Healthy vocal folds showed increased early and late MyoD1, MyoG, FoxO1 and FBXO32 expression in all animals. Neuromuscular junction density had a slower decline in augmented compared to untreated denervated vocal folds, and was significantly reduced in healthy vocal folds contralateral to augmentation. CONCLUSION: Injection augmentation may slow neuromuscular degeneration pathways in denervated vocal folds and reduce compensatory remodelling in contralateral healthy vocal folds.

Diagnostic Accuracy of Laryngeal Ultrasound for Evaluating Vocal Fold Movement Impairment in Children.

PURPOSE: Vocal fold movement impairment (VFMI) secondary to recurrent laryngeal nerve (RLN) injury is a common source of morbidity after pediatric cervical, thoracic, and cardiac procedures. Flexible laryngoscopy (FL) is the gold standard to diagnose VFMI yet can be challenging to perform and/or risks possible clinical decompensation in some children and is an aerosolizing procedure. Laryngeal ultrasound (LUS) is a potential non-invasive alternative, but limited data exists in the pediatric surgical population regarding its efficacy. We aimed to investigate the diagnostic accuracy of LUS compared to FL in evaluating VFMI. METHODS: A prospective, single-center, single-blinded (rater) cohort study was undertaken on perioperative pediatric patients at risk for RLN injury. Patients underwent FL and LUS. Cohen's kappa was used to determine chance-corrected agreement. RESULTS: Between 2021 and 2023, 85 paired evaluations were performed with patients having a median (IQR) age of 10 (4, 42) months and weight of 7.5 (5.4, 13.4) kilograms. The prevalence of VFMI was 27.1%. Absolute agreement between evaluations was 98.8% (kappa 0.97, 95% CI: 0.91-1.00, P < 0.001). The sensitivity and specificity of LUS in detecting VFMI was 95.7% and 100%, yielding a positive predictive value (PPV) of 100% and negative predictive value (NPV) of 98.4% (95% CI: 90-100%). Diagnostic accuracy was 98.8% (95% CI: 93-100%). CONCLUSION: LUS is a highly accurate modality in evaluating VFMI in children. While FL remains the gold standard for diagnosis, LUS offers a low-risk screening modality for children at risk for VFMI such that only those with an abnormal LUS or presence of clinical symptoms discordant with LUS findings should undergo FL. TYPE OF STUDY: Prospective, single-center, single blinded (rater), cohort study. LEVEL OF EVIDENCE: Level II.

Refining postoperative monitoring of recurrent laryngeal nerve injury in esophagectomy patients through transcutaneous laryngeal ultrasonography.

BACKGROUND: Recurrent laryngeal nerve injury (RLNI) leading to vocal cord paralysis (VCP) is a significant complication following minimally invasive esophagectomy (MIE) with upper mediastinal lymphadenectomy. Transcutaneous laryngeal ultrasonography (TLUSG) has emerged as a non-invasive alternative to endoscopic examination for evaluating vocal cord function. Our study aimed to assess the diagnostic value of TLUSG in detecting RLNI by evaluating vocal cord movement after MIE. METHODS: This retrospective study examined 96 patients with esophageal cancer who underwent MIE between January 2021 and December 2022, using both TLUSG and endoscopy. RESULTS: VCP was observed in 36 out of 96 patients (37.5%). The incidence of RLNI was significantly higher on the left side than the right (29.2% vs. 5.2%, P < 0.001). Postoperative TLUSG showed a sensitivity and specificity of 88.5% (31/35) and 86.5% (45/52), respectively, with an AUC of 0.869 (P < 0.001, 95% CI 0.787-0.952). The percentage agreement between TLUSG and endoscopy in assessing VCP was 87.4% (κ = 0.743). CONCLUSIONS: TLUSG is a highly effective screening tool for VCP, given its high sensitivity and specificity. This can potentially eliminate the need for unnecessary endoscopies in about 80% of patients who have undergone MIE.

An Exposition on Surgical Experiences in Identification, Exposure, and Injuries of Recurrent Laryngeal Nerve (RLN) During Thyroid Operations: Gleanings, Narrative, and the Reflections.

BACKGROUND: Identifying and preserving the recurrent laryngeal nerve (RLN) is of paramount importance during thyroid surgeries. Iatrogenic injuries to RLN (RLNI) are considered one of the most serious and feared complications of thyroidectomies. Surgically, there are four routes/approaches (lateral, inferior, superior, and medial) for localizing and identifying the RLN. This study aims to estimate the incidence of RLNI in the context of various approaches taken intra-operatively for nerve localization and identification. MATERIALS AND METHODS: This retrospective analytical study included 54 cases of thyroidectomies operated for various benign and malignant thyroid disorders in a tertiary care center from January 2018 to December 2020. Intraoperative search, identification, and dissection of the nerve were done with superior, inferior, medial, and lateral approaches. The chi-square test and exact test were used to analyze the data and p-value < 0.05 was considered significant. Pre- and post-operative recurrent laryngeal nerve evaluation was done with 90 degrees Hopkins laryngoscope. RESULTS: Overall in this series, the incidence of post-thyroidectomy RLNI was 3.7% and 3.7% for permanent and temporary nerve insults, respectively. Non-recurrent RLN on the right side was identified in one case and extra-laryngeal branching of RLN was identified in two cases. There was no statistically significant difference (p = 0.929) between the different approaches taken and the incidence of RLNI. The type of surgery and pathology also expressed no statistically significant relevance with the incidence of RLNI (p = 0.463 and p = 0.277, respectively). CONCLUSION: Adoption of a particular surgical approach to localize and identify RLN during thyroid surgery carries no statistically significant difference between RLNI and approaches taken. Meticulous handling and dissection of the tissue in the correct surgical plane are crucial determinants in preventing RLNIs.

Complications after radiofrequency ablation of hyperparathyroidism secondary to chronic kidney disease.

OBJECTIVE: To study the complications of ultrasound-guided radiofrequency ablation (RFA) in chronic kidney disease (CKD) patients undergoing renal replacement therapy with secondary hyperparathyroidism (SHPT). METHODS: This retrospective study reviewed the clinical data, including general information, examination results, treatment times, time interval, and postoperative complications, of 103 SHPT patients who received ultrasound-guided RFA treatment from July 2017 to January 2021. RESULTS: Of 103 patients, 52 required two sessions of RFA within a month. The incidence of recurrent laryngeal nerve injury at the second treatment was significantly higher than that at the first treatment (first session vs. second session, 5.77% vs. 21.15%; p = .021). Of all the enrolled 103 patients, 27 suffered complications after the first session of RFA. When we separated patients into complications group and non-complication group, we detected more ablated nodules in the complications group (Z = -2.222; p = .0026). Subgroup analysis further showed that the patients in the severe hypocalcemia group were younger (p = .005), had more ablated nodules (p = .003) and higher blood phosphorus (p = .012) and alkaline phosphatase (ALP) levels (p = .002). Univariate analysis showed that age, serum phosphorus, ALP, and number of ablated nodules were associated with a higher risk of severe hypocalcemia after the first session of RFA. CONCLUSIONS: An interval of more than 1 month between two treatments may help to avoid recurrent laryngeal nerve injury. Age, serum phosphorus, ALP, and number of ablated nodules were associated with a higher risk of severe hypocalcemia after the first session of RFA.

Mechanisms of recurrent laryngeal nerve injury in endoscopic thyroidectomy for papillary thyroid carcinoma: A large data from China.

Purpose: To investigate the mechanisms of recurrent laryngeal nerve (RLN) injury during endoscopic thyroidectomy via breast approach (ET-BA) in patients with papillary thyroid carcinoma (PTC). Methods: The records of 416 PTC patients who underwent ET-BA with intraoperative neural monitoring (IONM) from May 2015 to May 2021 in Beijing Friendship Hospital affiliated to Capital Medical University were retrospectively analyzed. Results: All patients were women. Mean age was 37.80 (7.87) years. The ET-BA was performed in 416 patients. Overall incidence of RLN injury was 4.3% (18 patients). Injury was transient in 13 patients (3.1%) and permanent in five (1.2%). Macroscopic physical changes were apparent in the injured nerve in five patients (27.8%) and postoperative hoarseness or cough after drinking water were present in 11 (61.1%). Two RLN injuries occurred during nerve identification at the RLN laryngeal entry point into the surgical field, 15 during early nerve dissection somewhere between the first 0.5 and 2 cm of the nerve's course through the surgical field, and one occurred distal to 2 cm. The percentage of patients with separation, transection, traction and thermal mechanisms of injury was 27.8%, 22.2%, 22.2%, and 16.7%, respectively. The mechanism of injury was unknown in 11.1%. Conclusions: RLN injury may still occur during ET-BA despite endoscopic magnification and early nerve identification even when IONM is used. Separation, transection, and traction injuries were the most frequent causes of injury.

Screening for Vocal Fold Movement Impairment in Children Undergoing Esophageal and Airway Surgery.

INTRODUCTION: Children undergoing cervical and/or thoracic operations are at risk for recurrent laryngeal nerve injury, resulting in vocal fold movement impairment (VFMI). Screening for VFMI is often reserved for symptomatic patients. OBJECTIVE: Identify the prevalence of VFMI in screened preoperative patients prior to an at-risk operation to evaluate the value of screening all patients at-risk for VFMI, regardless of symptoms. METHODS: A single center, retrospective review of all patients undergoing a preoperative flexible nasolaryngoscopy between 2017 and 2021, examining the presence of VFMI and associated symptoms. RESULTS: We evaluated 297 patients with a median (IQR) age of 18 (7.8, 56.3) months and a weight of 11.3 (7.8, 17.7) kilograms. Most had a history of esophageal atresia (EA, 60%), and a prior at-risk cervical or thoracic operation (73%). Overall, 72 (24%) patients presented with VFMI (51% left, 26% right, and 22% bilateral). Of patients with VFMI, 47% did not exhibit the classic symptoms (stridor, dysphonia, and aspiration) of VFMI. Dysphonia was the most prevalent classic VFMI symptom, yet only present in 18 (25%) patients. Patients presenting with a history of at-risk surgery (OR 2.3, 95%CI 1.1, 4.8, p = 0.03), presence of a tracheostomy (OR 3.1, 95%CI 1.0, 10.0, p = 0.04), or presence of a surgical feeding tube (OR 3.1, 95%CI 1.6, 6.2, p = 0.001) were more likely to present with VFMI. CONCLUSION: Routine screening for VFMI should be considered in all at-risk patients, regardless of symptoms or prior operations, particularly in those with a history of an at-risk surgery, presence of tracheostomy, or a surgical feeding tube. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:3564-3570, 2023.

The Role of Primary Repair of the Recurrent Laryngeal Nerve during Thyroid/Parathyroid Surgery in Vocal Outcomes-A Systematic Review.

Recurrent laryngeal nerve (RLN) injury is a well and long-known complication of thyroid and parathyroid surgery that significantly affects the quality of life of patients. Despite the advances in surgical techniques and technology, it still occurs in clinical practice either as temporary paresis or as permanent paralysis of the corresponding vocal cord. The purpose of the current systematic review is to examine the value of intraoperative repair of the RLN in voice restoration. A systematic review of the existing literature was conducted using PubMed, Scopus, Cochrane Library, and Google Scholar databases according to the PRISMA guidelines. The systematic review resulted in 18 studies, which met the inclusion criteria. An improvement in phonatory function and voice quality was observed in all these studies after immediate RLN reconstruction (not always statistically significant). This improvement appears to be comparable to or even higher than that achieved with other methods of repair, and in some cases, the improvement approaches levels found in normal subjects. Intraoperative RLN reconstruction is not widely used in clinical practice, but the evidence so far makes it a viable and safe alternative to traditional techniques with better long-term results, as it prevents the occurrence of atrophy of the vocal cord and should be considered in the operating room if possible.

Recurrent laryngeal nerve injury after thyroidectomy: A national study from Saudi Arabia.

OBJECTIVES: To determine the incidence and possible risk factors of recurrent laryngeal nerve injury, to provide a relevant literature review of studies from other centers in Saudi Arabia, and to present basic statistical data for future studies in our local community. METHODS: A retrospective study enrolled patients who were surgically treated for thyroid disease between January 2015 and December 2021. For concerns during the procedure, direct laryngoscopy was carried out before extubation to assess the vocal cords. Similarly, indirect laryngoscopy was carried out for patients who developed postoperative voice changes. All patients were evaluated clinically 2-3 weeks after surgery. Nerve monitors were not used in either case. RESULTS: The study examined 437 participants: 361 (82.6%) female and 76 (17.4%) male individuals. The incidence of recurrent laryngeal nerve injury was 1.1%. The demographic characteristics, pathology (benign vs. malignant), and extent of thyroidectomy were not significantly associated with the risk of recurrent laryngeal nerve injury. CONCLUSION: A recurrent laryngeal nerve injury is a serious complication, and further studies are required to determine the safest techniques for thyroidectomy. However, centralization of thyroid surgery in high-volume centers might reduce this risk.

Cricopharyngeal muscle origin transection for oropharyngeal dysphagia, a novel surgical technique.

BACKGROUND: Cricopharyngeal myotomy improves pharyngeal dysphagia by resecting the cricopharyngeal muscle. METHODS: Our procedure, cricopharyngeal muscle origin transection (CPM-OT) is performed through a midline skin incision at the cricoid cartilage level under local anesthesia. CONCLUSIONS: Sixteen patients demonstrated preservation of vocal fold movement without laryngeal nerve injury immediately after CPM-OT in the awake state during aspiration prevention surgery using the glottic closure technique. Postoperative videofluoroscopic examination of swallowing revealed the cricopharyngeal bar was absent and pharyngeal passage of the bolus and Food Intake LEVEL Scale was improved in all patients. CPM-OT is a feasible and less invasive treatment option.

Intraoperative Monitoring of the Recurrent Laryngeal Nerve with Electromyography Endotracheal Tube in Anterior Cervical Discectomy and Fusion.

Objective: Recurrent laryngeal nerve (RLN) injury is common complication after anterior cervical discectomy and fusion (ACDF). In the present study, we evaluated RLN function during ACDF surgery using intraoperative RLN monitoring with an electromyography-endotracheal tube (EMG-ET). Methods: In the present study, we retrospectively compared the postoperative RLN injury outcomes between patients who had undergone ACDF with and without an EMG-ET at Vajira Hospital from March 2017 to March 2022. Results: The analysis included 85 patients, 58 (68.2%) of whom had undergone surgery without an EMG-ET and 27 (31.8%) with an EMG-ET. Of the no EMG-ET group, 8 (13.8%) and 1 (1.7%) patient had developed immediate postoperative dysphagia and hoarseness, respectively, with complete recovery within 12 months. In the EMG-ET group, 2 (7.4%) and 1 (3.7%) patient had developed dysphagia and hoarseness, respectively, with complete recovery within 3 months for all 3 patients. Persistent postoperative RLN palsy had occurred in 5 patients (8.6%) without the EMG-ET but in none of the patients with the EMG-ET. The sensitivity and specificity for the use of intraoperative EMG-ET to detect a potential RLN injury were 67.0% and 96.0%, respectively. The use of an EMG-ET reduced the retractor time (P = 0.003), and a retractor time of <70 minutes was associated with a decreased incidence of postoperative RLN injury (odds ratio, 0.122; 95% confidence interval, 0.015-0.981; P = 0.048). Conclusions: The use of an EMG-ET for RLN monitoring during ACDF surgery was helpful in detecting postoperative RLN injury with fair sensitivity and high specificity and resulted in a shorter retractor time, thereby significantly reducing the risk of postoperative RLN injury.

Augmentation and vocal fold biomechanics in a recurrent laryngeal nerve injury model.

Objectives/hypothesis: Composite vocal fold (VF) biomechanical data are lacking for augmentation after recurrent laryngeal nerve (RLN) injury. We hypothesize resulting atrophy decreases VF stiffness and augmentation restores native VF biomechanics. Methods: Sixteen Yorkshire Crossbreed swine underwent left RLN transection and were observed or underwent carboxymethylcellulose (CMC) or calcium hydroxyapatite (CaHa) augmentation at 2 weeks. Biomechanical measurements (structural stiffness, displacement, and maximum load) were measured at 4 or 12 weeks. Thyroarytenoid (TA) muscle cross-sectional area was quantified and compared with two-way ANOVA with Tukey's post hoc test. Results: After 4 weeks, right greater than left structural stiffness (mean ± SE) was observed (49.6 ± 0.003 vs. 28.4 ± 0.002 mN/mm), left greater than right displacement at 6.3 mN (0.54 ± 0.01 vs. 0.46 ± 0.01 mm, p < .01) was identified, and right greater than left maximum load (72.3 ± 0.005 vs. 40.8 ± 0.003 mN) was recorded. TA muscle atrophy in the injured group without augmentations was significant compared to the noninjured side, and muscle atrophy was seen at overall muscle area and individual muscle bundles. CMC augmentation appears to maintain TA muscle structure in the first 4 weeks with atrophy present at 12 weeks. Conclusions: VF biomechanical properties match TA muscle atrophy in this model, and both CMC and CaHa injection demonstrated improved biomechanical properties and slower TA atrophy compared to the uninjured side. Taken together, these data provide a quantifiable biomechanical basis for early injection laryngoplasty to improve dysphonia and potentially improve healing in reversible unilateral vocal fold atrophy. Level of evidence: N/A.