Bioengineered larynx and vocal folds: where are we today? A review.

The larynx is responsible for breathing, producing sound, and protecting the trachea against food aspiration through the cough reflex. Nowadays, scaffolding surgery has made it easier to regenerate damaged tissues by facilitating the influx of cells and growth factors. This review provides a comprehensive overview of the current knowledge on tissue engineering of the larynx and vocal folds. It also discusses the achievements and challenges of data sources. In conducting a literature search for relevant papers, we included 68 studies from January 2000 to November 2023, sourced from PubMed and Scholar Google databases. We found a need for collaboration between voice care practitioners, voice scientists, bioengineers, chemists, and biotechnologists to develop safe and clinically valid solutions for patients with laryngeal and vocal fold injuries. It is crucial for patients to be knowledgeable about the available choices of laryngeal tissue engineering for successful tissue repair. Although few human trials have been conducted, future works should build upon previously completedin-vivostudies in an effort to move towards more human models.

Airway obstruction secondary to vocal cord polyp.

ABSTRACT: Patients with vocal cord polyps commonly present with symptoms of hoarseness. Although rare, large polyps can cause shortness of breath and stridor and should be included in the differential for patients with airway obstruction. Dysphonia or hoarseness can be a symptom of underlying disease, such as head and neck cancer. This case illustrates the importance of prompt and accurate diagnosis in a patient with persistent symptoms and a history of smoking. Obtaining a laryngoscopy is crucial to appropriately evaluate the larynx. Proper visualization of the laryngeal structures will help direct patient care toward further diagnostic imaging and medical or surgical intervention if indicated.

Laryngeal tuberculosis, the great deceiver: A series of 10 cases.

BACKGROUND: Laryngeal involvement is rare in tuberculosis, representing around 1% of all cases of this infection worldwide. Given the larynx' location in the airway, this form of tuberculosis is of particular importance because it is highly contagious. With our hospital being in a high tuberculosis burden area, we propose to characterize the clinical presentation, evolution, and laryngoscopy findings of a series of laryngeal tuberculosis cases in order to reduce misdiagnosis. METHODS: Epidemiological and clinical data from 10 patients diagnosed with laryngeal tuberculosis in the Otorhinolaryngology department of (Blinded for manuscript) between January 2011 and December 2021 were retrieved and analyzed. RESULTS: There were eight males and two females. Seven patients had a history of smoking and alcohol abuse and four had silicosis. Hoarseness was the most reported symptom (n = 9). The most frequent site of involvement were the true vocal cords (n = 6). All patients but one had concomitant active pulmonary tuberculosis. Patients had full resolution of laryngeal symptoms between 4 and 16 weeks after initiating antituberculosis treatment. CONCLUSION: Laryngeal tuberculosis is indeed a great deceiver. On one hand it can look like a simple polypoid lesion or simulate laryngopharyngeal reflux; but on the other hand its risk factors, symptoms and appearance simulate laryngeal carcinoma like no other. Since most patients present with concomitant pulmonary tuberculosis, all suspect laryngeal lesions should perform a chest radiograph prior to rigid laryngoscopy. Antituberculosis treatment is effective in both alleviating symptoms and reducing the risk of transmission.

[Heterogeneous acellular dermal matrix for wound repair after endoscopic Type-â ¤a cordectomy].

Objective:To observe the clinical effect of placing heterogeneous acellular dermal matrix membrane for laryngeal cavity wound healing after CO2 laser Type-Ⅴa cordectomy for glottic carcinoma. Methods:Thirty-five patients with bilateral vocal cord laryngeal cancer who underwent endoscopic CO2 laser surgery at the Department of Otorhinolaryngology Head and Neck Surgery, the Second Xiangya Hospital of Central South University from March 2018 to December 2019 were selected and divided into 2 groups, including 18 patients in the study group and 17 patients in the control group. The control group was simply placed silicone tube stent, while in the study group, heterogeneous acellular dermal matrix membrane was coated with silicone tube stent. The postoperative laryngeal wound repair and clinical manifestations were observed and compared between the two groups. Results:Compared postoperative laryngeal wound after 6 months: no patients in the study group had granulation tissue, whereas 4 patients in the control group had granulation tissue; 3 patients in the study group developed moderate to severe tissue adhesion, while 9 patients in the control group; 10 patients in the control group developed 2nd to 4th degree laryngeal obstruction, compared with only 4 patients in the study group. Conclusion:The primary placement of ADM can reduce laryngeal granulation tissue and tissue adhesion after CO2 laser Type-Ⅴa cordectomy for laryngeal cancer, and may reduce the occurrence of postoperative laryngeal obstruction.

Laryngeal nodular fasciitis in a 75-year-old man: a rare case report and review of the literature.

Nodular fasciitis (NF) is a benign and self-limiting fibroblastic proliferation that originates from the superficial fascia and extends into the subcutaneous tissue or muscle. It typically manifests in individuals aged 20 to 35 years, with rare occurrences observed in patients over the age of 60 years. We herein report a case involving a 75-year-old man with NF in the right vocal cord. The patient sought medical attention at the Department of Otolaryngology of our hospital because of a 1-month history of hoarseness and breathlessness. The diagnosis was unable to be confirmed through preoperative pathological examination. After admission to our hospital, various examinations were completed and surgical treatment was performed, and the postoperative histopathological findings revealed the presence of NF in the right vocal cord. NF of the vocal cord is a rare clinical entity. Given its rapid progression and propensity for marked infiltration, it often poses diagnostic challenges because it can mimic various malignant soft tissue tumors. Therefore, thorough exclusion of other neoplastic lesions is imperative prior to confirming the diagnosis of NF through pathological examination. Local surgical resection remains the primary treatment modality.

Asymmetric triangular body-cover model of the vocal folds with bilateral intrinsic muscle activation.

Many voice disorders are linked to imbalanced muscle activity and known to exhibit asymmetric vocal fold vibration. However, the relation between imbalanced muscle activation and asymmetric vocal fold vibration is not well understood. This study introduces an asymmetric triangular body-cover model of the vocal folds, controlled by the activation of bilateral intrinsic laryngeal muscles, to investigate the effects of muscle imbalance on vocal fold oscillation. Various scenarios were considered, encompassing imbalance in individual muscles and muscle pairs, as well as accounting for asymmetry in lumped element parameters. Measurements of amplitude and phase asymmetries were employed to match the oscillatory behavior of two pathological cases: unilateral paralysis and muscle tension dysphonia. The resulting simulations exhibit muscle imbalance consistent with expectations in the composition of these voice disorders, yielding asymmetries exceeding 30% for paralysis and below 5% for dysphonia. This underscores the relevance of muscle imbalance in representing phonatory scenarios and its potential for characterizing asymmetry in vocal fold vibration.

Percutaneous Vocal Fold Lateralization in children - a case series of a Brazilian tertiary pediatric hospital (pediatric vocal fold lateralization cases in a Brazilian hospital).

OBJECTIVES: Percutaneous Vocal Fold Lateralization (PVFL) consists of external fixation with non-absorbable percutaneous suture of the vocal fold in a lateral position, under direct glottic visualization. The objective of this study is to determine the effectiveness of PVFL in a university pediatric hospital, as well as to describe the potential risks and complications of the surgery. METHODS: Retrospective cohort study, with data collected from electronic medical records. The study was approved by the Research Ethics Committee of the institution. Surgeries were performed with the modified Lichentenberg technique and data, and outcomes were analyzed. RESULTS: Six patients with Bilateral Vocal Fold Paralysis who underwent Percutaneous Vocal Fold Lateralization were evaluated. Three patients were male. The age at diagnosis ranged from 2 to 132 days (mean 10.5 days). The reason for investigating the upper airway was the presence of increased work of breathing and stridor. Five patients had a favorable clinical evolution, with spontaneous ventilation in room air and absence of stridor or ventilatory effort, without the need for tracheostomy. Surgical results in this series corroborate the findings of other similar cohorts, which showed Percutaneous Vocal Fold Lateralization as a safe and effective procedure in avoiding tracheostomy or allowing decannulation in children with Bilateral Vocal Fold Paralysis. CONCLUSIONS: PVFL seems to be a safe and effective procedure, but it has morbidity, due to immediate, and probably late, non-serious complications. Studies with a larger number of patients, with longer follow-up and using a controlled and randomized clinical design are needed to establish the role of PVFL in the treatment of BVFP in newborns and infants. LEVELS OF EVIDENCE: Level 4 (step 4).

Tyrosine-Like Crystalloids Localize to Non-Neoplastic True Vocal Cord and Attachments.

BACKGROUND: Tyrosine-rich or tyrosine-like crystalloids (TC) were initially described in salivary gland pleomorphic adenoma. The presence of TC in non-neoplastic tissues is rare, and it has been reported exclusively in the larynx. This study aims to characterize the frequency and anatomical localization of TC in total laryngectomy specimens. METHODS: Review of consecutive laryngectomy specimens in which the cassette summary documented parasagittal section sampling of the right and left vocal folds and the anterior commissure. Data collected included patient demographics, underlying diagnoses, history of radiation therapy, presence, and location of TC. RESULTS: Of 86 laryngectomy specimens, 16 (19%) contained amphophilic to eosinophilic TC. The study cohort included 11 males and 5 females, aged 37 to 85 years (mean 62, median 63). Laryngectomy surgery was performed for advanced untreated squamous cell carcinoma (SCCa) (7/16, 43.75%), recurrent post-treatment SCCa (7/16, 43.75%), previously untreated laryngeal large cell neuroendocrine carcinoma (1/16, 6.25%), and non-functional larynx post-chemoradiation (1/16, 6.25%). According to the macroscopic cassette summary, TC were predominantly found in the anterior commissure Sect. (13/16, 81.25%), with fewer cases in sections containing the left (2/16, 12.5%) or the right (1/16, 6.25%) vocal folds. Microscopically, TC localized to the anterior macula flava and/or adjacent vocal ligament (12/16, 75%) and the anterior commissure tendon (4/16, 25%). CONCLUSIONS: TCs are predominantly reported as admixed with a neoplasm, however this study confirms that TC can also occur in non-neoplastic tissues of the larynx. There was no clear relationship between the presence of TC and prior radiation therapy. TC in the specialized connective tissues of the macula flava and true cord tendinous insertions distinct from tumor may form in response to alterations in mechanical stress, though an age-related change within the spectrum of normal laryngeal microanatomy also remains a possibility.

Characterization of non-epithelial cells embedded within the vocal fold epithelial barrier.

The vocal folds vibrate to produce voice, undergoing significant stress due to contact and shearing force. The epithelium operates as the primary protective layer of the tissue against stress and vibratory damage, as well as to provide a barrier against foreign organisms and toxins. Within the vocal fold epithelium, non-epithelial cells were identified that may interrupt the epithelium and compromise the epithelial barrier's protective function. Human vocal fold samples with a variety of pathologies were compared to normal vocal folds. Analysis included the number of cells in the epithelium and epithelial thickness. Vocal fold sections from 10 human tissue samples were assessed via H&E staining and immunofluorescent co-labeling. Three cell populations (vimentin expressing, CD-45 expressing, and cells expressing both) were identified within the epithelium. Statistical analysis revealed that the abnormal samples had a significantly greater number of vimentin-positive cells/area within the epithelium compared to the normal samples. Additionally, normal tissue samples had a significantly greater epithelial depth, suggesting a more robust epithelial barrier compared to tissue with pathology. Knowledge of the function of these cells could lead to a better understanding of how the local immune environment near and within vocal fold epithelium changes in the presence of different pathologies.

Assessment of Voice Quality and Vocal Cord Paralysis After Endarterectomy.

Introduction: Recurrent laryngeal nerve palsy is a rare but important complication after endarterectomy (CEA). The impact on voice quality after this procedure is also important. The aim of the study was to assess voice quality and vocal cord function after CEA. Material and Methods: 200 patients were enrolled in the study. Inclusion criteria were indications for CEA and patient consent to the procedure. Endoscopic examination of the larynx was performed before the procedure, immediately after the procedure, on the 2nd day after the procedure, then 3 month and 6 months after the procedure. Voice was assessed by maximum phonation time (MPT), GRBAS scale, Voice Handicap Index (VHI) and the Voice-Related Quality of Life (V-RQOL) questionnaire. Results: In the study group, the results on the GRBAS scale were significantly worse and the average MPT was shorter compared to the control group. In the V-RQOL assessment, patients rated their voice as fair or good, significantly more often noticed that they had difficulty speaking loudly and being heard, and that they felt short of air when speaking. In VHI-30, the total score was significantly higher in the study group compared to the control group. Voice disorders after the procedure were reported by 68 patients, while a disorder of the recurrent laryngeal nerve was observed immediately after the procedure in 32 patients. Most vocal cord disorders were transient. Ultimately, 3% of patients were diagnosed with vocal cord paralysis. Conclusion: Cranial nerves paralysis, including the recurrent laryngeal nerve, are a common complication after CEA. Majority the paralysis is transient, but requires appropriate diagnostic and therapeutic procedures. Vocal cord evaluation is a non-invasive and widely available examination and should be performed pre- and postoperatively after all neck surgeries. The incidence of voice disorders after CEA significantly affects the quality of life of patients and requires voice rehabilitation and patient care with psychological support.

Factors of postoperative recurrent laryngeal nerve paralysis and recovery of vocal cord movement in thyroid surgery.

OBJECTIVE: Postoperative recurrent laryngeal nerve paralysis is one of the complications of thyroid surgery, and the prevention and management of paralysis is an important issue for surgeons. In this study, in order to gain further understanding of recurrent laryngeal nerve paralysis after thyroid surgery, we analyzed and examined the usefulness of nerve stimulators for recurrent laryngeal nerve paralysis and the factors that may cause recurrent laryngeal nerve paralysis. Furthermore, in cases where transient recurrent laryngeal nerve paralysis occurred, we analyzed and examined the timing of improvement in vocal cord movement for each intraoperative finding and intraoperative operation that caused the paralysis. METHODS: At the Department of Otorhinolaryngology Head and Neck Surgery, Sapporo Medical University Hospital, between January 2012 and December 2021, the subjects were 543 thyroid surgery cases (692 nerves) without preoperative paralysis or cancer nerve invasion performed. The relationship between postoperative transient and permanent paralysis of the recurrent laryngeal nerve was evaluated using univariate and multivariate analysis. The factors evaluated were gender, age, BMI, total thyroidectomy, benignity, malignancy, Graves' disease, using IIONM (intermittent intraoperative nerve monitoring), using CIONM (continuous intraoperative nerve monitoring), malignant tumor T3b or higher, with lateral neck dissection, and years of experience of the surgeon. Furthermore, by targeting 87 nerves with transient paralysis, surgical operations were divided into three groups: minor injury, major injury, and adhesion, and their relationship with the timing of postoperative vocal fold movement improvement was evaluated. RESULTS: Permanent paralysis of the recurrent laryngeal nerve occurred in 12 nerves (1.7 %), and transient paralysis occurred in 100 nerves (14.5 %). Univariate analysis showed no association with each factor, but multivariate analysis showed that transient paralysis was significantly lower in men and in patients using IIONM. The improvement time for vocal cord paralysis was 2.8 months in the minor injury group, 4.5 months in the major injury group, and 3.2 months in the adhesion group, indicating a statistically significant difference between the minor injury group and the major injury group. CONCLUSION: This study suggests that the use of IIONM and gentle manipulation of women may prevent recurrent laryngeal nerve paralysis during thyroid surgery. In addition, understanding the period of nerve recovery for each operation for postoperative transient recurrent laryngeal nerve paralysis may contribute to patient explanations and determining the timing of therapeutic intervention for speech improvement surgery.

Synthetic, self-oscillating vocal fold models for voice production researcha).

Sound for the human voice is produced by vocal fold flow-induced vibration and involves a complex coupling between flow dynamics, tissue motion, and acoustics. Over the past three decades, synthetic, self-oscillating vocal fold models have played an increasingly important role in the study of these complex physical interactions. In particular, two types of models have been established: "membranous" vocal fold models, such as a water-filled latex tube, and "elastic solid" models, such as ultrasoft silicone formed into a vocal fold-like shape and in some cases with multiple layers of differing stiffness to mimic the human vocal fold tissue structure. In this review, the designs, capabilities, and limitations of these two types of models are presented. Considerations unique to the implementation of elastic solid models, including fabrication processes and materials, are discussed. Applications in which these models have been used to study the underlying mechanical principles that govern phonation are surveyed, and experimental techniques and configurations are reviewed. Finally, recommendations for continued development of these models for even more lifelike response and clinical relevance are summarized.

Platelet Rich plasma injection of the vocal folds in benign vocal pathologies.

PURPOSE: There are few options for treatment of dysphonia secondary to vocal pathology related to lamina propria scar, atrophy, sulcus, or inflammatory disorders. Platelet rich plasma (PRP) may provide anti-inflammatory and regenerative properties seen with other tissue engineering therapies without the risks associated with these treatments. We evaluated vocal fold (VF) injection of PRP for feasibility, phonatory effects, patient satisfaction and durability. METHODS: Patients with dysphonia secondary to vocal fold scar, atrophy, sulcus and inflammatory lesions were included. PRP injections were administered in office, to bilateral vocal folds. Patients were followed up at 1 week, 1 month, 3 months and 6 months to assess outcomes (GRBAS scale, maximum phonation time, vocal fatigue index (VFI), voice handicap index (VHI-10) and stroboscopy). RESULTS: 75 intracordal PRP injections were administered to 48 patients. All injections were completed, and no adverse reactions were experienced. Improvements in VHI-10 scores at 1,3,6 months were seen (mean VHI 21.73 at baseline, 15.62 at six months, p < 0.001). 72.3% rated improvement at 7 or above on Likert scale. 95.7% of patients would consider a future PRP injection. Secondary outcomes VFI, MPT, and GRBAS also demonstrated significant improvements over time. Patients receiving a single PRP injection (n = 26) still demonstrated significant VHI-10 improvements at 1,3 and 6 months. CONCLUSIONS: VF office PRP injections are feasible and safe and can provide phonatory benefit and reduce vocal effort in benign VF disorders. A single PRP injection is sufficient to provide sustained benefit in some cases. LEVEL OF EVIDENCE: Level III: prospective cohort study.

Glottic insufficiency caused by vocal fold atrophy with or without sulcus: systematic review of outcome measurements.

PURPOSE: Identifying outcome measurements instruments (OMIs) to evaluate treatment efficacy in patients with vocal fold atrophy and/or sulcus. METHODS: Systematic review of records published before March 2021 by searching Pubmed and EMBASE. Included studies reported on adults (> 18 year) with dysphonia caused by glottic insufficiency due to vocal fold atrophy with or without sulcus, who were enrolled into a randomized controlled trial, a non-randomized controlled trial, a case-controlled study or a cohort study. All included studies described an intervention with at least one outcome measurement. RESULTS: A total of 5456 studies were identified. After removing duplicates, screening title and abstract and full text screening of selected records, 34 publications were included in final analysis. From these 50 separate OMIs were recorded and categorized according to the ELS protocol by DeJonckere et al. (Eur Arch Otorhinolaryngol 258: 77-82, 2001). With most OMIs being used in multiple studies the total number of OMIs reported was 265. Nineteen (19) individual OMIs accounted for 80% of reports. The most frequently used OMIs according to category were: VHI and VHI-10 (subjective evaluation); G of GRBAS (perceptual evaluation); F0, Jitter and Shimmer (acoustic evaluation); MPT and MFR (aerodynamic evaluation) and glottic closure and mucosal wave (endoscopic evaluation). Of these OMIs VHI had a high percentage of significance of 90%. CONCLUSION: This systematic review identifies the most used OMIs in patients with glottic incompetency due to vocal fold atrophy and/or sulcus as a step toward defining a Core Outcome Set (COS) for this population. PROSPERO REGISTRATION: 238274.

A computational study of the influence of thyroarytenoid and cricothyroid muscle interaction on vocal fold dynamics in an MRI-based human laryngeal model.

A human laryngeal model, incorporating all the cartilages and the intrinsic muscles, was reconstructed based on MRI data. The vocal fold was represented as a multilayer structure with detailed inner components. The activation levels of the thyroarytenoid (TA) and cricothyroid (CT) muscles were systematically varied from zero to full activation allowing for the analysis of their interaction and influence on vocal fold dynamics and glottal flow. The finite element method was employed to calculate the vocal fold dynamics, while the one-dimensional Bernoulli equation was utilized to calculate the glottal flow. The analysis was focused on the muscle influence on the fundamental frequency (fo). We found that while CT and TA  activation increased the fo in most of the conditions, TA activation resulted in a frequency drop when it was moderately activated. We show that this frequency drop was associated with the sudden increase of the vertical motion when the vibration transited from involving the whole tissue to mainly in the cover layer. The transition of the vibration pattern was caused by the increased body-cover stiffness ratio that resulted from TA activation.

[The effect of narrow band imaging in CO2 laser therapy in early-stage glottic cancer].

Objective:To explore efficacy of narrow band imaging（NBI） technique in CO2laser therapy in Early-Stage Glottic cancer. Methods:The clinical data of patients with Early-Stage Glottic cancer who underwent CO2laser vocal cord resection from June 2011 to August 2022 were retrospectively analyzed. Among these, 27 patients who underwent surgery assisted by NBI were assigned to the observation group, while 25 patients who underwent conventional CO2 laser microsurgery with a suspension laryngoscope were assigned to the control group. The differences between the two groups were analyzed in terms of intraoperative frozen pathology results, postoperative recurrence rates, 5-year cumulative disease-free survival rates, complications, and voice recovery. Results:All 52 patients were operated successfully. Temporary tracheostomy and serious complications did not occur during the operation. The postoperative patient's pronunciation was satisfactory. One patient experienced vocal cord adhesion, but there were no severe complications such as breathing difficulties or bleeding, with an overall complication rate of 1.92%. Postoperative follow-up was 1-5 years. The 5 years recurrence free survival in the general group was 77.90％, and the 5 years recurrence free survival in the NBI group was 100％, the difference was statistically significant（P<0.05）. NBI endoscopy is safer and more accurate than the general group in determining the safe margin of tumor mucosal resection（P<0.05）. Among the patients who accepted the voice analysis, the difference was no statistically significant（P>0.05）. Conclusion:Compared with conventional CO2laser surgery under microscope, NBI guided laser resection of Early-Stage Glottic cancer is more accurate. NBI guided laser resection could improve 5 years recurrence free survival rate. In a word, narrow-band imaging endoscopy can has very high value in clinical application.

Principal dimensions of voice production and their role in vocal expression.

How we produce and perceive voice is constrained by laryngeal physiology and biomechanics. Such constraints may present themselves as principal dimensions in the voice outcome space that are shared among speakers. This study attempts to identify such principal dimensions in the voice outcome space and the underlying laryngeal control mechanisms in a three-dimensional computational model of voice production. A large-scale voice simulation was performed with parametric variations in vocal fold geometry and stiffness, glottal gap, vocal tract shape, and subglottal pressure. Principal component analysis was applied to data combining both the physiological control parameters and voice outcome measures. The results showed three dominant dimensions accounting for at least 50% of the total variance. The first two dimensions describe respiratory-laryngeal coordination in controlling the energy balance between low- and high-frequency harmonics in the produced voice, and the third dimension describes control of the fundamental frequency. The dominance of these three dimensions suggests that voice changes along these principal dimensions are likely to be more consistently produced and perceived by most speakers than other voice changes, and thus are more likely to have emerged during evolution and be used to convey important personal information, such as emotion and larynx size.

A Prospective Comparative Analysis to Study the Impact on Voice Changes Following Endoscopic Thyroidectomy.

BACKGROUND: Endoscopic approach has come up as a safe and feasible procedure for thyroidectomy with better cosmetic outcomes. However, concerns over its safety in terms of nerve injury and postoperative voice changes remain. This prospective study evaluated the role of vocal cord function assessment using laryngeal examination and voice analysis in patients who underwent endoscopic hemithyroidectomy either by the trans-oral endoscopic thyroidectomy vestibular approach (TOETVA) or the bilateral axillobreast approach (BABA). METHODS: Thirty-nine consecutive patients were randomly allocated to either of the 2 groups of endoscopic hemithyroidectomy; 19 in TOETVA and 20 in the BABA groups. Vocal cord function was assessed subjectively using the GRBAS scale and objectively by acoustic analysis of parameters such as jitter, shimmer, mean frequency (F 0 ), noise-to-harmonic ratio (NHR), and maximum phonatory time (MPT) at baseline, postoperative day 10, and 3 months after surgery. RESULTS: There were no significant differences in mean GRBAS scores and values of mean frequency, jitter and shimmer between the 2 groups and on postoperative day 10 and at 3 months compared with baseline. The mean NHR and MPT showed no differences between the 2 procedures. However, there was a significant decrease in their values on day 10 postsurgery, compared with baseline. These values returned to their baseline at 3 months. The other operative parameters were comparable between the 2 groups, except for the shorter mean operative time in the TOETVA group. CONCLUSIONS: Perioperative quantitative voice parameters were comparable with no statistically significant difference between the 2 techniques of endoscopic thyroidectomy.

Injectable Tissue Adhesive Microgel Composite Containing Antifibrotic Drug for Vocal Fold Scarring.

Vocal fold (VF) scarring, a complex problem in laryngology, results from injury and inflammation of the layered architecture of the VFs. The resultant voice hoarseness, for which successful therapeutic options are currently limited, affects the patient's quality of life. A promising strategy to reverse this disorder is the use of antifibrotic drugs. The present study proposes a novel microbead-embedded injectable hydrogel that can sustain the release of the anti-fibrotic drug pirfenidone (PFD) for vocal fold scarring. Microbeads were developed using sodium alginate and gelatin, which were further embedded into a biomimetic and tissue adhesive gellan gum (GG) hydrogel. The microbead-embedded hydrogel exhibited improved injectability, viscoelasticity, tissue adhesiveness, degradability, and swelling compared to the hydrogel without beads. Additionally, the bead-embedded hydrogel could sustain the release of the PFD for a week. In vitro studies showed that the drug-loaded hydrogel could reduce the migration and proliferation of fibroblast cells in a dose-dependent manner. In summary, this study demonstrates the potential of a PFD-loaded injectable hydrogel with enhanced viscoelastic and tissue-adhesive properties for vocal fold scarring applications.

Evaluation of neck ultrasound measurements as a difficult airway predictor: A prospective observational study.

This study aimed to investigate the relationship between cervical measurements and difficult airways using ultrasonographic measurements. American Society of Anesthesiologists grade I to III, male or female, 120 adult patients, undergoing elective surgery were enrolled in the study. The study involved measuring the distance of the trachea, cricoid cartilage, thyroid cartilage, vocal cord anterior commissure, and hyoid bone to the skin using a 10 to 13 MHz linear ultrasound probe in the transverse plane. Additionally, the length of the cricothyroid and thyrohyoid membranes, along with their distance from the skin, were measured using the probe in the sagittal plane. Subsequently, another experienced anesthesiologist conducted mask ventilation and intubation after the patient's induction of general anesthesia. Throughout this process, the patient was assessed for difficulties in mask ventilation, laryngoscopy, and intubation. 28 (23.3%) patients had a difficult airway. Analyzing the measurements associated with difficult airways, the most reliable predictor was the epiglottis midline-skin distance [AUC (area under the curve): 0.847, P < .001, cutoff: >19.9, sensitivity: 78.6%, specificity: 79.4%]. Additionally, other factors such as hyoid bone to skin distance, thyroid cartilage to skin distance, thyrohyoid membrane to skin distance, and vocal cord anterior commissure-skin distance were also identified as predictors for a difficult airway. The increase in the distance of the epiglottis midline, vocal cord anterior commissure, hyoid bone, thyrohyoid membrane, and thyroid cartilage to the skin at the level of the isthmus measured by ultrasonography is predictive of difficult airways. Based on our study outcomes, we assert that ultrasonographic evaluation can be used in the prediction of difficult airways.