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.

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.

[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).

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.

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.

Morbidity Associated With Surgical Removal of Substernal Thyroid Goiters.

INTRODUCTION: Surgical excision of substernal thyroid goiters (STG) can be challenging while minimizing postoperative morbidity. Postoperative complication rates associated with transcervical and transthoracic approaches (i.e., partial or total sternotomy) for STG compared to multinodular goiters (MNG) limited to the neck (i.e., non-substernal) remains unclear. This study examines postoperative morbidity related to surgical approaches in the removal of STG and MNG. METHODS: A retrospective review of prospectively collected data of 988 patients with STG and non-substernal MNG from a single institution between 2010 and 2021 was performed. Patients were stratified by STG and conventional non-substernal MNG limited to the neck excised by transcervical and transthoracic approach. Postoperative complications including neck hematoma requiring return to the operating room, permanent recurrent laryngeal nerve injury and hypocalcemia, and transient or temporary recurrent laryngeal nerve injury and hypocalcemia were identified. Demographics including age, sex, and race, among others, were analyzed. RESULTS: Of the 988 cases, there were 887 (90%) MNG and 101 (10%) STG. Of the STG cohort, 11 (11%) required a partial sternotomy and 4 (4%) required a total sternotomy. Permanent complication rates for non-substernal MNG and STG patients were 1.5% and 0.9%, respectively. Only transient or temporary hypocalcemia rates were statistically different between the STG and MNG cohorts (9.9% versus 3.8%, P < 0.001). CONCLUSIONS: Regardless of transcervical or transthoracic approach, postoperative complications associated with the surgical removal of STG are low in the hands of experienced, high-volume thyroid surgeons.

Non-energy devices to dissect recurrent laryngeal nerve lymph nodes of non-small cell lung cancer under video-assisted thoracic surgery.

BACKGROUND: Systematic nodal dissection plays a crucial role in improving survival and staging in resectable non-small cell lung cancer (NSCLC) patients but at the cost of increasing the occurrence of recurrent laryngeal nerve injury. Technology should be improved to protect the recurrent laryngeal nerve (RLN) during surgery. METHODS: NSCLC patients who underwent video-assisted thoracic surgery (VATS) surgical treatment by the same surgeon at our hospital from January 2016 to December 2017 were included as the research subjects and were divided into an energy-device group and a non-energy-device group. Their procedures included anatomic pulmonary resection, normative N1 dissection, and systemic N2 dissection. RESULTS: The rate of metastatically involved recurrent laryngeal nerve lymph nodes (RLNLNs) was 5.19% (39/752). Dissection device, side of primary, FEV1, operative time and BMI were independent predictors of recurrent laryngeal nerve injury (RLNI) (hazard ratio (HR) = 3.576, 95% confidence interval (CI): 1.490-8.583, P = 0.004; HR = 0.175, 95% CI: 0.072-0.424, P = < 0.001; HR = 3.008, 95% CI: 1.30-6.927, P = 0.010; HR = 0.328, 95% CI: 0.136-0.794, P = 0.013; HR = 0.344, 95%CI: 0.147-0.801, P = 0.013, respectively). Patients in the non-energy-device group had significantly less RLNI than the energy-device group (P = 0.016) and nearly half of the non-thermal RLNI recovered in 2 weeks (P = 0.025) whereas most thermal RLNI required 3 months for recovery. CONCLUSIONS: Every station of RLNLN had some degree of cancer metastasis in NSCLC patients and when dissecting RLNLNs, dissection device was an independent and artificially controlled predictor of RLNI. Using a non-energy device is a feasible method to protect the RLN as well as an improved recovery time of RLNI.

Diagnostic and management strategies for congenital H-type tracheoesophageal fistula: a systematic review.

BACKGROUND: H type tracheoesophageal fistula (H-TEF) is a rare congenital anomaly. Management may be complicated by late diagnosis and variation(s) in the therapeutic strategy. A systematic review of published studies explores the utility of diagnostic studies, operations and postoperative complications. METHODS: Medline and PubMed database(s) were searched for ALL studies reporting H-TEF during 1997-2020. Using PRISMA methodology, manuscripts were screened for eligibility and reporting. RESULTS: Forty-seven eligible studies were analysed. Primary diagnosis varied widely with surgeons performing oesophagography and trachea-bronchoscopy. Preoperative localisation techniques included fluoroscopy, guidewire placement and catheterisation. A cervical approach (209 of 272 cases), as well as thoracotomy, thoracoscopy and endoscopic fistula ligation, were all described. Morbidity included fistula recurrence (1.7%), leak (2%), tracheomalacia (3.4%) and respiratory sequelae (1%). The major adverse complication in all studies was vocal cord palsy secondary to laryngeal nerve injury (18.5%) yet strikingly few centres routinely reported undertaking vocal cord screening pre or postoperatively. CONCLUSION: This study shows that paediatric surgeons record low volume activity with H type tracheoesophageal fistula. Variation(s) in clinical practice are widely evident. Laryngeal nerve injury and its subsequent management warrant special consideration. Care pathways may offset attendant morbidity and define 'best practice.'

Comparison study between the usage of harmonic scalpel versus classical suture method for thyroidectomy in Iraqi patients.

OBJECTIVE: To compare the outcome of harmonic scalpel use in thyroid surgery versus conventional suture method in a sample of Iraqi patients. METHODS: A prospective, comparative, interventional study with analytic elements was conducted on 76 patients complaining of different types of goitre attending Al-Yarmouk Teaching Hospital, Baghdad, from October 2017 to October 2019. Patients were divided into two groups, a test group including 25 patients operated upon by harmonic scalpel and the control group of 51 patients who underwent conventional suture ligation. Informed consent was obtained from all patients after explaining the procedure. The necessary investigations were done preoperatively with anaesthetic consultation. After surgery, type of thyroidectomy (Total, near total, subtotal, lobectomy), time of surgery, the results of the postoperative checkup including vital signs, voice state, any stridor or dyspnoea, drains (amount drained) and signs of hypocalcaemia were noted. RESULTS: The 76 patients were divided into 2 groups. Most of the patients were female (61 females, 23 in harmonic & 38 in conventional group" Vs. 15 males, 2 in harmonic & 13 in conventional group). The mean ages in both groups were comparable. The mean age was 40.0±9.7 years for conventional suture ligation group with females being 39.7±10.3 years and males being 40.8±7.9 years old. The mean age of patients in the harmonic scalpel group was 40.5±11.7 years with females being 40.4±12.5 years old and males 42.0±1.0 of age. Most of the HS devise patients had thyrotoxic goiter in comparison to simple goiter in the control group. The study shows a significant reduction in the time of surgery in the harmonic scalpel group, therefore most of them showed a significant reduction in the amount of blood in their drain and the drain was removed within 24 hours. Regarding the remaining post-operative complications like bleeding, stridor, and recurrent laryngeal nerve injury. The results had no statistical significant difference in both groups. CONCLUSIONS: Both HS and ligation sutures were effective in thyroid surgery except the reduction in operation time and postoperative drainage in the HS group. Both techniques were taken as reasonably safe procedures.

Prevention of intra-thoracic recurrent laryngeal nerve injury with robot-assisted esophagectomy.

PURPOSE: Transthoracic esophagectomy for esophageal cancer is one of the most invasive procedures in surgery for gastrointestinal cancer. Serious complications sometimes occur after esophageal cancer surgery, including recurrent laryngeal nerve injury and pneumonia. The purpose of this study was to access the possibility of robot-assisted thoracoscopic esophagectomy for esophageal cancer in terms of preventing recurrent laryngeal nerve injury. METHODS: Operations in thoracic part were performed in prone position with bilateral ventilation. During dissection of the recurrent laryngeal nerve lymph nodes, thin blood vessels were coagulated with Maryland bipolar forceps in the left hand and then dissected with monopolar scissors in the right hand. Especially when dissecting left recurrent laryngeal nerve lymph nodes, the nerve was left unisolated from the vascular sheath that involves the aortic arch. Short-term outcomes including operative time, estimated blood loss, and postoperative complications including recurrent laryngeal nerve injury were accessed. RESULTS: From November 2018 to January 2020, 20 patients underwent robot-assisted thoracoscopic esophagectomy for esophageal cancer. Thoracic operative time was 242 min, estimated blood loss in the thoracic part was minimal, the number of dissected mediastinal lymph nodes was 19 (all median), and the incidence rates of recurrent laryngeal nerve injury and pneumonia were 10% (2 case) and 10% (2 cases), respectively. CONCLUSION: Robot-assisted thoracoscopic esophagectomy for esophageal cancer has the possibility of reducing recurrent laryngeal nerve injury even in the introductory period. Randomized controlled trials are required to confirm this advantage of the robotic surgery.

Incidence, Risk Factors, and Comorbidities of Vocal Cord Paralysis After Surgical Closure of a Patent Ductus Arteriosus: A Meta-analysis.

Surgical closure of a patent ductus arteriosus (PDA) is considered standard treatment for symptomatic neonates refractory to medical therapy. Sometimes, iatrogenic injury to the left recurrent laryngeal nerve during the procedure can result in vocal cord paralysis (VCP). This study aimed to estimate the incidence of VCP in patients after surgical PDA closure and to identify any associated risk factors and morbidities associated with VCP in the preterm infant population. A thorough search of the major electronic databases was conducted to identify studies eligible for inclusion into this meta-analysis. Studies reporting data on the incidence of VCP (primary outcomes) or risk factors and morbidities associated with VCP in premature infant population (secondary outcomes) were included. A total of 33 studies (n = 4887 patients) were included into the analysis. Overall pooled incidence estimate of VCP was 7.9% (95%CI 5.3-10.9). The incidence of VCP after PDA closure was significantly much higher in premature infants (11.2% [95%CI 7.0-16.3]) than in non-premature patients (3.0% [95%CI 1.5-4.9]). The data showed that VCP was most common after surgical ligation and in studies conducting universal laryngoscopy scoping. The risk factors for postoperative VCP in preterm infants included birth weight and gestational age. In addition, VCP was significantly associated with the occurrence of bronchopulmonary dysplasia, gastrostomy tube insertion, and increased duration of mechanical ventilation. Vocal cord paralysis remains a frequent complication of surgical closure of a PDA, especially in premature neonates, and is associated with significant post-procedural complications.

A retrospective study of complications of total thyroidectomy; is it a safe approach for benign thyroid conditions.

OBJECTIVE: To assess frequency of complications of total thyroidectomy for benign thyroid diseases. METHODS: The retrospective descriptive study was conducted at Shifa College of Medicine, Islamabad, Pakistan, and comprised patient data from March 2016 to March 2018 of all patients who had undergone total thyroidectomy at the centre. Operative findings and post-op complications were documented in a self-generated proforma. Followup visits documented in the charts were also reviewed. Patients who did not keep the follow-up appointment were interviewed over the phone. Data was analysed using SPSS 20. RESULTS: Of the 96 patients, 78(81.2%) were female and 18(18.7%) were male. The overall mean age was 32.9 } 9.84 years. Hypocalcaemia was the most common complication in 4(4.1%) cases, transient in 3(3.1%) and permanent in only 1(1.04%) case. Haemorrhage occurred in 1(1.04) patient, and recurrent laryngeal nerve injury in 2(2.08%). . CONCLUSIONS: Simple multi-nodular goitre was effectively treated with total thyroidectomy with minor complications.

Risk factors and prognosis of voice disorders after surgical treatment of thyroid and parathyroid diseases. / Faktory riska i prognozirovanie narushenii golosa posle khirurgicheskogo lecheniia zabolevanii shchitovidnoi i okoloshchitovidnykh zhelez.

AIM: To analyze risk factors and prognosis of voice disorders after surgical treatment of thyroid and parathyroid diseases. MATERIAL AND METHODS: There were 1272 patients who were operated in the endocrine surgery department for the period from January 1, 2016 to April 30, 2017. We studied the incidence of VF paresis, VF paralysis, and persistent dysphonia as clinical outcomes. Potential risk factors have to be analyzed were sex and age of patients, BMI, diagnosis, surgical technique, thyroid volume, experience of the surgeon and assistant, use of intraoperative neuromonitoring, etc. RESULTS: Significant relationships of risk factors with various complications of thyroid surgery were found. In logistic regression analysis, the independent predictors of complications were the following: 1) for VF paresis - extent of surgery and thyroid volume; 2) for VF paralysis - sex, extent of surgery and thyroid volume; 3) for persistent postoperative dysphonia - age and thyroid volume. CONCLUSION: The correlation of various risk factors with development of VF paresis, VF paralysis and persistent dysphonia were identified in patients undergoing thyroid and parathyroid surgery.

Recurrent Laryngeal Nerve Injury In Total Versus Subtotal Thyroidectomy.

BACKGROUND: Both Total and Subtotal Thyroidectomy are correct treatment options for symptomatic Euthyroid Multinodular Goitre. The choice depends upon surgeon's preference due to consideration of disadvantages like permanent hypothyroidism in Total Thyroidectomy and high chances of recurrence in Subtotal Thyroidectomy. Many surgeons believe that there is a higher incidence of Recurrent Laryngeal nerve injury in Total Thyroidectomy which affects their choice of surgery. This study aimed to compare the incidence of recurrent laryngeal nerve injury in total versus subtotal thyroidectomy. METHODS: This non randomized controlled trial was carried out at Department of Surgery and ENT of Ayub Teaching Hospital Abbottabad, and Combined Military Hospital Rawalpindi from 1st September 2013 to 30th August 2014. During the period of study, patients presenting in surgical outpatient department with euthyroid multinodular goitre having pressure symptoms requiring thyroidectomy were divided into two groups by convenience sampling with 87 patients in group 1 and 90 patients in group 2. Group-1 was subjected to total thyroidectomy and Group -2 underwent subtotal thyroidectomy. All the patients had preoperative Indirect Laryngoscopy examination and it was repeated postoperatively to check for injury to the recurrent laryngeal nerve. RESULTS: A total of 177 patients were included in the study. Out of these, 87 patients underwent total thyroidectomy (Group-1). Two of these patients developed recurrent laryngeal nerve injury (2.3%). In group-2 subjected to subtotal thyroidectomy, three of the patients developed recurrent laryngeal nerve injury (3.3%). The p-value was 0.678. The overall risk of injury to this nerve in both surgeries combined was 2.8%. CONCLUSIONS: There is no significant difference in the risk of recurrent laryngeal nerve damage in patients undergoing total versus subtotal thyroidectomy.

Longitudinal voice outcomes following laryngeal reinnervation via vagus-to-recurrent laryngeal nerve anastomosis after vagal nerve sacrifice: a case series.

OBJECTIVE: This study aimed to describe longitudinal voice outcomes of vagus-to-recurrent laryngeal nerve anastomosis following operative vagal nerve sacrifice. METHODS: Two patients who underwent anastomosis were assessed by a multidisciplinary voice team at 1, 4, 9, 12, and 18 months after vagal sacrifice. RESULTS: Long-term changes in voice function based on auditory perceptual measures of voice quality and visual perceptual changes in glottal closure were observed and maintained for 18 months after vagus-to-recurrent laryngeal nerve anastomosis in 2 patients with proximal vagal nerve sacrifice. Patients achieved acceptable voice outcomes and elected not to undergo further treatment, which was supported by Voice Handicap Index scores. CONCLUSION: Gradual restoration of voice following operative vagal sacrifice can be achieved over an 18-month period using vagus-to-recurrent laryngeal nerve anastomosis and warrants further investigation in appropriately selected patients.

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.

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.

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.

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.

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.