Vocal Cord Function Return After Larynx Preservation is Associated With Recurrence-Free Probability.

OBJECTIVES: Vocal cord fixation is one of the main upstaging features of laryngeal cancer. In our previously conducted retrospective study, vocal cord (VC) mobility restoration after chemoradiotherapy was a favorable prognostic variable. In this prospective study, we examined the significance of VC mobility restoration after definitive treatment as a prognostic variable. METHODS: In this prospective cohort study, we enrolled 30 patients with squamous cell carcinoma of the larynx with VC impairment/fixation (T2/3, T4a) who underwent definitive chemoradiotherapy with complete response. Video laryngoscopy before and at 3 months after treatment was used to evaluate VC mobility. The primary endpoint of the study was the local recurrence-free probability. Secondary endpoints included recurrence-free probability, disease-specific survival (DSS), and overall survival (OS). RESULTS: The median age of patients was 62 years (IQR 54-67). The primary subsites were the glottis (n = 13) and supraglottis (n = 14). After treatment, 18 (60%) patients had a full recovery of VC mobility, and 12 (40%) patients' VCs were fixed or impaired. Five-year local recurrence-free probability was worse in the VC-impaired group compared to a group with restored VC mobility (46% vs. 85%, p = 0.012). Recurrence-free probability, OS, and DSS differences were not statistically significant in both groups. VC mobility restoration predicted local recurrence-free probability on univariable analysis (HR 6.15, 95% CI 1.23-30.6). CONCLUSION: In this prospective study, we show that the absence of VC mobility restoration is associated with worse local recurrence-free probability after definitive laryngeal preservation treatment. Patients with persistent vocal cord immobility warrant closer follow-up to detect recurrence early. LEVEL OF EVIDENCE: III Laryngoscope, 2024.

Patient-Reported Outcomes after False Vocal Folds Injections for Adductor Spasmodic Dysphonia.

OBJECTIVES: The primary objective of this study is to investigate if false vocal folds (FVF) or simultaneous FVF with thyroarytenoid (FVF+TA) Botox® injections achieve comparable treatment effects to standard TA injections. This study also aims to determine how patient-reported outcomes contribute to the transition to, and continuation of, FVF or FVF+TA injections. METHODS: Retrospective chart review was performed for all patients receiving Botox® for adductor spasmodic dysphonia at a laryngology practice between 2005 and 2018. Twenty out of 103 patients met the study's inclusion criteria. All subjects began standard treatment with TA injections. Based on response to injection, patients either continued to receive TA injections (group TA; n = 7), switched to FVF injections (group FVF; n = 7), or switched to FVF+TA injections (group FVF+TA; n = 6). A comparison of group means before and after initiation of FVF±TA injections was performed between groups FVF and FVF+TA to group TA for the injection dosage, the duration of injection cycles, the patient-reported duration of best voice, and the presence and duration of breathiness and choking. Within-group observations were also compared before and after FVF±TA injections. RESULTS: There were no significant findings for the variables between group FVF and group TA before FVF injections. The duration of injection cycles was significantly shorter for group FVF than group TA after FVF injections (95% CI: -66.05, -0.34; P = 0.05). However, duration of best voice quality, breathiness, and choking were similar (P > 0.05) for group FVF to group TA after FVF injections. Group FVF+TA had a significantly shorter duration of injection cycles (95% CI: -66.97, -3.22; P = 0.03), best voice (95% CI: -0.76, -0.03; P = 0.04), and choking (95% CI: -2.68, 0.02; P = 0.05) than group TA before FVF+TA injections. Group FVF+TA displayed a similar duration (P > 0.05) of injection cycles, best voice quality, breathiness, and choking to group TA after FVF+TA injections. Within-group, increased duration of injection cycles and best voice were observed after FVF±TA injections for both group FVF and FVF+TA. Acute adverse events were variable within groups after FVF±TA injections. CONCLUSION: This study compared outcomes of FVF or FVF+TA injections to successive TA injections among patients. FVF injections displayed similar duration of best voice quality, breathiness, and choking to TA injections. FVF+TA injections achieved similar duration of injection cycles, best voice quality, breathiness, and choking to TA injections. This study demonstrates that patients guided by a reduced duration of adverse events, while tolerating a shorter injection cycle, may benefit from initiation and continuation of FVF injections. Patients guided by increased duration of injection cycle and best voice, while tolerating the duration of adverse events, may benefit from initiation and continuation of FVF+TA injections.

Transoral Excision of an Intracordal Schwannoma: A Case Report and Review.

We discuss a novel approach to resecting a large 1.5 cm intracordal schwannoma via direct laryngoscopy with combined endoscopic and microlaryngoscopic techniques. Removing relatively bulky masses within the vocal cord soft tissue can be challenging secondary to difficult visualization of the operative field during direct laryngoscopy. We describe a case where a bulky atypical spindle cell schwannoma was removed via direct laryngoscopy via combined endoscopic and microlaryngoscopic techniques. The tumor obstructed 40% of the visual field of the laryngoscope. In this case, a 44-year-old female presented to the head and neck surgery clinic with 1.5 years of progressive hoarseness. On fiberoptic laryngoscopy, a mass was noted medializing the right true vocal cord. The patient was taken to surgery and after intubation and suspension with a Dedo laryngoscope, the mass was removed trans-orally through the laryngoscope with visualization using a combination of rigid and flexible endoscopy as well as with a microscope. Although visualization can sometimes be reduced using direct laryngoscopy, surgical excision of relatively large laryngeal masses can be performed in selected cases without the need to approach the masses trans-cervically.

Office-Based Steroid Injection for Benign Lesions of the Vocal Folds: Case Series and Review of the Literature.

OBJECTIVES: To present the authors' experience on intralesional steroid injection (ILSI) for benign lesions of the vocal folds and a review of the literature. STUDY DESIGN: Retrospective chart review. METHODS: The medical records of patients with vocal folds nodules, polyps, Reinke's edema, laryngitis/localized edema, and vocal fold granuloma who underwent ILSI were reviewed. Disease regression was assessed by reviewing the video recordings of laryngeal endoscopy before and after surgery. Subjective and objective voice outcome measures were compared before and after office-based ILSI. RESULTS: Forty-seven patients with 81 lesions were included. The most common lesion treated was Reinke's edema followed by vocal fold nodules. All patients who presented for follow-up (n = 37) had partial or complete regression of their disease. When stratified by disease type, vocal fold polyps showed the highest percentage of complete regression (66.7%) followed by vocal fold nodules (65%). The mean voice handicap index-10 (VHI-10) score of the study group dropped from 16.63 ± 6.95 to 6.21 ± 6.09 points (P < 0.001). Patients with vocal fold polyps had the highest drop in the mean VHI-10 score by 16.66 ± 4.73 (P = 0.026). There was no significant difference in the mean acoustic and aerodynamic parameters before and after office-based steroid injection. CONCLUSIONS: ILSI is an effective treatment modality for benign lesions of the vocal folds leading to partial or complete disease regression and self-reported improvement in voice quality.

In Vitro Investigation of Vocal Fold Cellular Response to Variations in Hydrogel Porosity and Elasticity.

Tissue regeneration is intricately influenced by the dynamic interplay between the physical attributes of tissue engineering scaffolds and the resulting biological responses. A tunable microporous hydrogel system was engineered using gelatin methacryloyl (GelMA) and polyethylene glycol diacrylate (PEGDA), with polyethylene glycol (PEG) serving as a porogen. Through systematic variation of PEGDA molecular weights, hydrogels with varying mechanical and architectural properties were obtained. The objective of the present study was to elucidate the impact of substrate mechanics and architecture on the immunological and reparative activities of vocal fold tissues. Mechanical characterization of the hydrogels was performed using tensile strength measurements and rheometry. Their morphological properties were investigated using scanning electron microscopy (SEM) and confocal microscopy. A series of biological assays were conducted. Cellular morphology, differentiation, and collagen synthesis of human vocal fold fibroblasts (hVFFs) were evaluated using immunostaining. Fibroblast proliferation was studied using the WST-1 assay, and cell migration was investigated via the Boyden chamber assay. Macrophage polarization and secretions were also examined using immunostaining and ELISA. The results revealed that increasing the molecular weight of PEGDA from 700 Da to 10,000 Da resulted in decreased hydrogel stiffness, from 62.6 to 8.8 kPa, and increased pore dimensions from approximately 64.9 to 137.4 µm. Biological evaluations revealed that hydrogels with a higher stiffness promoted fibroblast proliferation and spreading, albeit with an increased propensity for fibrosis, as indicated by a surge in myofibroblast differentiation and collagen synthesis. In contrast, hydrogels with greater molecular weights had a softer matrix with expanded pores, enhancing cellular migration and promoting an M2 macrophage phenotype conducive to tissue healing. The findings show that the hydrogels formulated with a PEGDA molecular weight of 6000 Da are best among the hydrogels considered for vocal fold repair. The microporous hydrogels could be tuned to serve in other tissue engineering applications.

Describing the Cellular Impact of IQOS™ Smoke Extract and Vibration on Human Vocal Fold Fibroblasts.

OBJECTIVES: The isolated or combined effects of vibration and smoke extract (SE) from the IQOS™ "heat-not-burn" technology on human vocal fold fibroblasts (hVFF) were evaluated in an in vitro setting in order to elucidate their influence on vocal fold (patho-) physiology. STUDY DESIGN: Experimental pilot study using intervention with IQOS™-SE in vitro. METHODS: Immortalized hVFF were exposed to IQOS™-SE or control medium under static or vibrational conditions. A phonomimetic bioreactor was used to deliver vibrational patterns to hVFF over a period of 5days. Cytotoxicity was quantified by lactate dehydrogenase assay. Effects on extracellular matrix production, inflammation, fibrogenesis, and angiogenesis were assessed by reverse transcription-quantitative polymerase chain reaction, western blot, enzyme-linked immunosorbent assay, and Magnetic Luminex assays. RESULTS: We observed significant changes induced either by IQOS™-SE exposure alone (matrix metalloproteinase 1, fibronectin, cyclooxygenase (COX)1, interleukin-8 gene expression), or by the combination of IQOS™-SE and vibration (hyaluronidase 2, COX2, interleukin-8 protein levels, vascular endothelial growth factor D). CONCLUSION: Short-term in vitro exposure of hVFF to IQOS™-SE did not result in cytotoxicity and reduced the gene expression of measured inflammation mediators, but had no effect on their protein expression. However, the clinical effects of long-term IQOS™ use are still not known and further research is needed in order to assess, if IQOS™ is in fact less harmful than conventional cigarettes.

Drug delivery systems for wound healing treatment of upper airway injury.

INTRODUCTION: Endotracheal intubation is a common procedure to maintain an open airway with risks for traumatic injury. Pathological changes resulting from intubation can cause upper airway complications, including vocal fold scarring, laryngotracheal stenosis, and granulomas and present with symptoms such as dysphonia, dysphagia, and dyspnea. Current intubation-related laryngotracheal injury treatment approaches lack standardized guidelines, relying on individual clinician experience, and surgical and medical interventions have limitations and carry risks. AREAS COVERED: The clinical and preclinical therapeutics for wound healing in the upper airway are described. This review discusses the current developments on local drug delivery systems in the upper airway utilizing particle-based delivery systems, including nanoparticles and microparticles, and bulk-based delivery systems, encompassing hydrogels and polymer-based approaches. EXPERT OPINION: Complex laryngotracheal diseases pose challenges for effective treatment, struggling due to the intricate anatomy, limited access, and recurrence. Symptomatic management often requires invasive surgical procedures or medications that are unable to achieve lasting effects. Recent advances in nanotechnology and biocompatible materials provide potential solutions, enabling precise drug delivery, personalization, and extended treatment efficacy. Combining these technologies could lead to groundbreaking treatments for upper airways diseases, significantly improving patients' quality of life. Research and innovation in this field are crucial for further advancements.

What kind of phonation causes the strongest vocal fold collision? - A hemi-larynx phonation contact pressure study.

This paper presents a measurement setup which is able to measure the distribution of small scale pressure on an area of 15.2 mm × 30.4 mm with a sample rate up to 1.2 kHz. It was used to investigate the contact pressures of vocal folds during phonation. This was performed in ex vivo experiments of 11 porcine larynges. The contact pressure at the medial surface and other phonation parameters, as the glottal resistance and the closing velocity of the vocal fold, were measured at different adduction and elongation levels and air flow rates. A statistical analysis was carried out. It could be shown that the contact pressure rises, when the vocal fold is manipulated or when the flow rate is increased.

Laryngeal Leishmaniasis: A Neglected, Emerging Disease in Northern Italy.

Leishmaniasis represents an emerging public health issue in Mediterranean countries. The incidence of this condition has progressively risen in Northern Italy due to the growing number of immunocompromised people and probably due to climate changes. We hereby describe a case of relapsing laryngeal leishmaniasis in a female immunocompetent patient, presenting as aspecific chronic laryngitis. She was affected by severe asthma treated by inhaled steroid therapy, likely responsible for the parasite's diffusion through a locus minori resistentiae. The aspecific clinical presentation led to a delayed diagnosis and the lack of guidelines for the treatment caused multiple relapses. Biopsies of laryngeal lesions in the follow-up were performed by operative flexible videolaryngoscopy, thus avoiding general anesthesia and reducing associated healthcare costs. The aim of this report is to underline the diagnostic and therapeutic challenges that patients with this condition face and to present what is, to the best of our knowledge, the first application of prophylactic aerosolized pentamidine for relapsing laryngeal leishmaniasis.

The sensitivity of laryngeal findings in predicting high-grade dysplasia in patients with vocal fold leukoplakia undergoing office-based biopsies: A retrospective analysis of 100 cases.

Objective: To investigate the sensitivity of laryngeal findings in predicting high-grade dysplasia/carcinoma in situ (CIS) and squamous cell carcinoma (SCC) in patients with vocal fold leukoplakia. Methods: A retrospective review of the medical records and video recordings of the laryngeal examination of patients with vocal fold leukoplakia who underwent un-sedated office-based laryngeal biopsy in a tertiary referral center between January 2022 and August 2023 was conducted. Laryngeal findings included the size, surface, projection, and edges of the lesion. Vocal fold leukoplakia was classified according to the WHO as benign, low-grade dysplasia, high-grade dysplasia/CIS, and squamous cell carcinoma. Results: Seventy patients with 100 vocal fold leukoplakia were included. Size was found to have the highest sensitivity with an AUC of 0.730 (95% CI [0.618-0.842], p = 0.002) followed by surface and projection with AUCs of 0.672 (95% CI [0.548-0.795], p = 0.019) and 0.675 (95% CI [0.546-0.804], p = 0.017), respectively. Furthermore, the odds of diagnosing high-risk lesions (high-grade dysplasia/CIS and SCC) were the greatest when the lesion was large and rough (OR = 10.28; 95% CI [3.08-34.36]). Conclusion: The morphological features of vocal fold leukoplakia may assist the physician in predicting the risk of malignancy. Large and rough lesions were more likely to harbor high-grade dysplasia/CIS and SCC compared to small and smooth lesions.

Injuries of Different Surgical Instruments on the Vocal Folds of Dogs.

OBJECTIVE: This study aimed to compare the damage of vocal folds caused by four different surgical instruments: CO2 laser, electrosurgical knife, plasma radiofrequency ablation, and steel knife. STUDY DESIGN: Randomized controlled study. METHODS: The CO2 laser, electrosurgical knife, plasma radiofrequency ablation, steel knife, and other instruments were used to simulate the laryngeal microsurgery on experimental dogs. Both total vocal fold resection and punctate ablation were performed. On the day of surgery and 6 days later, the vocal fold tissue from the surgical site was removed for histological evaluation. The extent of vocal fold damage was assessed using the automatic digital pathological scanning system. RESULTS: We detected varying degrees of damage to the laryngeal tissues. Only the steel knife caused epidermal defects on the vocal fold tissue, while other instruments produced thermal damage of different degrees. Furthermore, the steel knife also showed better and faster healing. The plasma radiofrequency ablation was found to cause more severe thermal burns to vocal folds than other surgical instruments (P < 0.05). Six days postsurgery the inflammatory reaction from the steel knife had basically subsided, with only hyperplasia and tissue repair visible microscopically, showing the best healing degree. On the other hand, the radiofrequency ablation group showed the heaviest inflammatory reaction, indicating relatively poor prognosis (P < 0.05). CONCLUSION: Compared with the CO2 laser, the electrotome and steel knife showed less damage and better healing, while the plasma radiofrequency ablation showed the most obvious thermal burns to laryngeal and vocal tissues during surgery, with relatively poor healing.

Better Breathing, Tougher Speaking? A Scoping Review of the Effects of Inhaled Corticosteroids on the Voice Quality of Asthmatic Children.

BACKGROUND: Inhaled corticosteroids (ICS) are a common treatment for certain lung diseases, including chronic obstructive pulmonary disorder in adults, and asthma across the lifespan. There is a link between the use of ICS and dysphonia in adults. This scoping review aims to investigate the incidence of dysphonia, in children aged under 12, who use ICS to treat asthma. METHODS: A scoping review was conducted, in accordance with the guidelines prescribed by Arksey and O'Malley (2005). ASHAWire, Science Direct, PubMed, and ProQuest databases were searched. Out of the total yield of 1471 articles, four articles met the inclusion criteria, that is, were primary studies reporting on voice quality in children who use ICS, who present with asthma and/or allergy. RESULTS: The majority of papers yielded from the initial search were retrieved because of the use of the term "dysphonia" in the basic definitions of asthma and descriptors of its side effects. Only four studies presented primary data about the presence of dysphonia in asthmatic children (with or without comorbid allergic conditions). None specifically investigated the relationship between ICS and dysphonia. Research questions focused on side effects associated with allergies and asthma, which included some information about medication. Only three of the four studies conducted a comprehensive review of the voice and utilized video laryngoscopy. DISCUSSION: The evidence of a relationship, between ICS and dysphonia in children, is not conclusive, and is complicated by the connection between asthma, and breath support for phonation. There is a need for more thorough and focused investigation of the relationship between ICS, with or without bronchodilator use, and any resultant effects on children's vocal quality.

Sensitivity of Phonation Onset Pressure to Vocal Fold Stiffness Distribution.

Phonation onset is characterized by the unstable growth of vocal fold (VF) vibrations that ultimately results in self-sustained oscillation and the production of modal voice. Motivated by histological studies, much research has focused on the role of the layered structure of the vocal folds in influencing phonation onset, wherein the outer "cover" layer is relatively soft and the inner "body" layer is relatively stiff. Recent research, however, suggests that the body-cover (BC) structure over-simplifies actual stiffness distributions by neglecting important spatial variations, such as inferior-superior (IS) and anterior-posterior gradients and smooth transitions in stiffness from one histological layer to another. Herein, we explore sensitivity of phonation onset to stiffness gradients and smoothness. By assuming no a priori stiffness distribution and considering a second-order Taylor series sensitivity analysis of phonation onset pressure with respect to stiffness, we find two general smooth stiffness distributions most strongly influence onset pressure: a smooth stiffness containing aspects of BC differences and IS gradients in the cover, which plays a role in minimizing onset pressure, and uniform increases in stiffness, which raise onset pressure and frequency. While the smooth stiffness change contains aspects qualitatively similar to layered BC distributions used in computational studies, smooth transitions in stiffness result in higher sensitivity of onset pressure than discrete layering. These two general stiffness distributions also provide a simple, low-dimensional, interpretation of how complex variations in VF stiffness affect onset pressure, enabling refined exploration of the effects of stiffness distributions on phonation onset.

Vision-Based Assistance for Vocal Fold Identification in Laryngoscopy with Knowledge Distillation.

Laryngoscopy images play a vital role in merging computer vision and otorhinolaryngology research. However, limited studies offer laryngeal datasets for comparative evaluation. Hence, this study introduces a novel dataset focusing on vocal fold images. Additionally, we propose a lightweight network utilizing knowledge distillation, with our student model achieving around 98.4% accuracy-comparable to the original EfficientNetB1 while reducing model weights by up to 88%. We also present an AI-assisted smartphone solution, enabling a portable and intelligent laryngoscopy system that aids laryngoscopists in efficiently targeting vocal fold areas for observation and diagnosis. To sum up, our contribution includes a laryngeal image dataset and a compressed version of the efficient model, suitable for handheld laryngoscopy devices.

Acute Effects of Systemic Glucocorticoids on the Vocal Folds in a Pre-Clinical Model.

OBJECTIVES/HYPOTHESIS: Systemic glucocorticoids (GC)s are employed to treat various voice disorders. However, GCs have varying pharmacodynamic properties with adverse effects ranging from changes in epithelial integrity, skeletal muscle catabolism, and altered body weight. We sought to characterize the acute temporal effects of systemic dexamethasone and methylprednisolone on vocal fold (VF) epithelial glucocorticoid receptor (GR) nuclear translocation, epithelial tight junction (ZO-1) expression, thyroarytenoid (TA) muscle fiber morphology, and body weight using an established pre-clinical model. We hypothesized dexamethasone and methylprednisolone will elicit changes in VF epithelial GR nuclear translocation, epithelial ZO-1 expression, TA muscle morphology, and body weight compared to placebo-treated controls. METHODS: Forty-five New Zealand white rabbits received intramuscular injections of methylprednisolone (4.5 mg; n = 15), dexamethasone (450 µg; n = 15), or volume matched saline (n = 15) into the iliocostalis/longissimus muscle for 6 consecutive days. Vocal folds from 5 rabbits from each treatment group were harvested at 1-, 3-, or 7 days following the final injection and subjected to immunohistochemistry for ZO-1 and GR as well as TA muscle fiber cross-sectional area (CSA) measures. RESULTS: Dexamethasone increased epithelial GR nuclear translocation and ZO-1 expression 1-day following injections compared to methylprednisolone (P = .024; P = .012). Dexamethasone and methylprednisolone increased TA CSA 1-day following injections (P = .011). Methylprednisolone decreased body weight 7 days following injections compared to controls (P = .004). CONCLUSIONS: Systemic dexamethasone may more efficiently activate GR in the VF epithelium with a lower risk of body weight loss, suggesting a role for more refined approaches to GC selection for laryngeal pathology.

Subtotal Submucosal Arytenoidectomy with Lateralization Sutures (SMALS) Covered by a Mucosal Flap.

OBJECTIVE: Glottic airway stenosis (GAWS) may result from bilateral paralysis (BVFP) or posterior glottic stenosis (PGS). Since the glottis is the principal airway sphincter, surgeons shift on the balance between airway, aspirations, and voice. We aim to describe our surgical technique and outcome of the SMALS procedure for GAWS correction. METHODS: A retrospective cohort of patients who underwent SMALS for PGS between 2018 and 2021. SMALS involves: endoscopic submucosal subtotal arytenoidectmy (preserving medial mucosal flap) and lateralization sutures. The sutures lateralize the mucosal flap to cover the arytenoidectomy bed without lateralization of the membranous vocal fold; expanding the posterior glottis, while preserving a relatively good voice. Covering the arytenoidectomy bed enhances healing. Medical and surgical data, airway, voice, and swallowing symptoms were collected. Relative glottic opening area (RGOA) and relative glottic insufficiency area (RGIA) were calculated. RESULTS: Eleven PGS patients who underwent 15 SMALS were included (4 bilateral), all patients had post-intubation PGS, 1 patient also had prior radiation to the larynx. All patients were tracheostomy-dependent. There were no major complications. No granulation or retracting scar was observed at follow-up. None had a persistent voice or swallowing disability. Successful outcome (decannulation) was achieved in 8 (73%); RGOA increased in all (Δ = 0.37; p = 0.003), while RGIA remained relatively stable (Δ = 0.02; p = 0.055). CONCLUSIONS: SMALS is a safe and effective, novel modification of the classic arytenoidectomy, for GAWS correction that can be easily applied and may expand the airway without significant glottic insufficiency symptoms. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:353-360, 2024.

De Novo Granuloma of the Membranous Vocal Fold: A Marker of Occult Malignancy.

OBJECTIVE: De novo occurrence of granuloma (granulation tissue) on the membranous vocal fold is not readily explained by usual causes of granuloma at the vocal process. We describe a series of patients. STUDY DESIGN: Case series. SETTING: Single academic institution. METHODS: Cases were identified over a 16-year period. All patients exhibited granulation tissue on pathology. Demographic details, presentation, treatment, histology, and clinical outcomes were recorded. RESULTS: Five patients (mean age: 74.0 ± 6.1 years, 40.0% male, 40.0% former smokers) underwent a biopsy. Persistent or recurrent granulation led to a second biopsy in 4 patients an average of 1423.5 days later, revealing a new diagnosis of squamous cell carcinoma (SCC) in situ in one and mild dysplasia in another. Further persistence or recurrence led to a third biopsy or excision an average of 302.3 days later in 3 patients, demonstrating SCC in situ in 1. An average of 2.5 biopsies were required with a mean time to SCC in situ diagnosis of 919.5 days from presentation. Two patients continued to demonstrate persistent granulation tissue on histology. CONCLUSION: The membranous vocal fold is an atypical location for granuloma and portends a risk of occult malignancy. The occurrence of de novo granuloma at this site should prompt close long-term clinical surveillance with a low threshold for biopsy. Consideration should be given to tissue collection in the operating room to adequately sample the lesion's base. Concern should persist even after a negative biopsy, and serial observation with repeat biopsy as needed should be pursued.

Glottal Airflow Estimation using Neck Surface Acceleration and Low-Order Kalman Smoothing.

The use of non-invasive skin accelerometers placed over the extrathoracic trachea has been proposed in the literature for measuring vocal function. Glottal airflow is estimated using inverse filtering or Bayesian techniques based on a subglottal impedance-based model when utilizing these sensors. However, deviations in glottal airflow estimates can arise due to sensor positioning and model mismatch, and addressing them requires a significant computational load. In this paper, we utilize system identification techniques to obtain a low order state-space representation of the subglottal impedance-based model. We then employ the resulting low order model in a Kalman smoother to estimate the glottal airflow. Our proposed approach reduces the model order by 94% and requires only 1.5% of the computing time compared to previous Bayesian methods in the literature, while achieving slightly better accuracy when correcting for glottal airflow deviations. Additionally, our Kalman smoother approach provides a measure of uncertainty in the airflow estimate, which is valuable when measurements are taken under different conditions. With its comparable accuracy in signal estimation and reduced computational load, the proposed approach has the potential for real-time estimation of glottal airflow and its associated uncertainty in wearable voice ambulatory monitors using neck-surface acceleration.

Vocal Fold Fat injection for Glottic Insufficiency: Systematic Review.

Vocal fold fat injection is a technique for treating glottic insufficiency (GI) resulting from various conditions. The use of fat as a graft has several advantages over other grafts. Similar pliability, and vibratory characteristics as a normal vocal fold, not causing foreign body reactions, having the potential to contain stem cells, and often can be done in the office. Long-term results, however, are unpredictable. The objective of this study is to carry out a systematic review of published articles using the technique of fat injection in the vocal folds. STUDY DESIGN: Systematic review. REVIEW METHODS: A literature search was conducted utilizing the combination of the following keywords "vocal folds fat injection," "laryngoplasty," and "autologous fat injection vocal folds." The criteria inclusion of the study for the systematic review were based on PICOTS (population, intervention, comparison outcome, timing, and setting) and Preferred Reporting Items for Systematic Reviews and Meta-analyses statements. Outcomes reviewed included technique, study duration, perceptual and acoustic analysis, and quality of life preoperation and 1-year postoperation. RESULTS: A systematic review on PubMed, Cochrane, and Embase databases included 13 studies analyzing the data of 472 patients, that had fat injection laryngoplasty for treatment of GI. The causes of GI varied substantially across studies. Considerable heterogeneity across studies was found, including technique for harvest, processing the fat, site of injection, and acoustic analysis. In the studies that measured maximum phonation time (MPT) there was a significant improvement in a follow-up of at least 1 year after the injection. The patient's perception of vocal quality, measured by the Voice Handicap Index, also showed significant improvement in several studies after fat injection laryngoplasty. CONCLUSION: Fat injection laryngoplasty seems to be safe and effective for GI for at least 12 months. Multiple studies show favorable outcomes, but the lack of control groups, the heterogeneity in inclusion criteria, nonstandardized techniques, and objective voice evaluations limit this evaluation.

Intraoperative Neuromonitoring Does Not Reduce the Risk of Temporary and Definitive Recurrent Laryngeal Nerve Damage during Thyroid Surgery: A Systematic Review and Meta-Analysis of Endoscopic Findings from 73,325 Nerves at Risk.

BACKGROUND: While intraoperative neuromonitoring (IONM) helps the early identification of recurrent laryngeal nerve (RLN) damage, IONM's role in RLN damage prevention is not defined, given the lack of large studies on the subject. METHODS: In a PRISMA-compliant framework, all original thyroid surgery prospective studies providing early postoperative endoscopic data for all patients were pooled in a random-effects meta-analysis. We compared the temporary (and definitive where available) RLN damage rates according to IONM use and IONM type (intermittent, I-IONM, or continuous, C-IONM). RESULTS: We identified 2358 temporary and 257 definitive RLN injuries in, respectively, 73,325 and 66,476 nerves at risk. The pooled temporary and definitive RLN injury rates were, respectively, 3.15% and 0.422% considering all procedures, 3.29% and 0.409% in cases using IONM, and 3.16% and 0.463 in cases not using IONM. I-IONM and C-IONM, respectively, showed a pooled temporary RLN injury rate of 2.48% and 2.913% and a pooled definitive injury rate of 0.395% and 0.4%. All pooled rates had largely overlapping 95% confidence intervals. CONCLUSIONS: Our data suggest that IONM does not affect the temporary or definitive RLN injury rate following thyroidectomy, though its use can be advised in selected cases and for bilateral palsy prevention.