Growth and development of epiglottis and preepiglottic space of larynx as it acquires vocal tract.

Objectives: The growth and development of the epiglottis and preepiglottic space (PES) of the human larynx as it acquires the vocal tract were investigated. Methods: Three newborns, one infant, four children (2, 7, 8, and 12 years old), and two adult normal larynges were investigated and compared using the whole organ serial section technique. Results: The newborn PES occupied a small area just anterior to the epiglottis. It was composed of immature adipose tissue and areolar tissue. The epiglottis lay on a somewhat horizontal axis and is partially obscured behind the hyoid bone. The hyoid bone overlapped the thyroid cartilage, partially obscuring the superior thyroid notch. The newborn epiglottic cartilage was immature elastic cartilage, and the elastic fiber component was sparse. In the first 8 years of life, as the PES grew, the PES was located not only anterior to but also posterolateral and inferolateral to the epiglottic cartilage and thyroepiglottic ligament. Meanwhile, the epiglottic cartilage matured. Conclusions: In order to develop the vocal tract for speech production, it is reported that the human larynx descends as the child grows in the first 9 years of life. This study showed that the PES, occupying a small area just anterior to the epiglottis, grew and existed astride the epiglottis as the larynx descended and the vocal tract developed. Consequently, its distribution allows the epiglottis to more effectively play the role of retroflection during swallowing in order to prevent aspiration. The human speech faculty likely develops in conjunction with swallowing physiology.

Oropharyngeal swallowing hydrodynamics of thin and mildly thick liquids in an anatomically accurate throat-epiglottis model.

Understanding the mechanisms underlying dysphagia is crucial in devising effective, etiology-centered interventions. However, current clinical assessment and treatment of dysphagia are still more symptom-focused due to our limited understanding of the sophisticated symptom-etiology associations causing swallowing disorders. This study aimed to elucidate the mechanisms giving rise to penetration flows into the laryngeal vestibule that results in aspirations with varying symptoms. Methods: Anatomically accurate, transparent throat models were prepared with a 45° down flapped epiglottis to simulate the instant of laryngeal closure during swallowing. Fluid bolus dynamics were visualized with fluorescent dye from lateral, rear, front, and endoscopic directions to capture key hydrodynamic features leading to aspiration. Three influencing factors, fluid consistency, liquid dispensing site, and dispensing speed, were systemically evaluated on their roles in liquid aspirations. Results: Three aspiration mechanisms were identified, with liquid bolus entering the airway through (a) the interarytenoid notch (notch overflow), (b) cuneiform tubercle recesses (recess overflow), and (c) off-edge flow underneath the epiglottis (off-edge capillary flow). Of the three factors considered, liquid viscosity has the most significant impact on aspiration rate, followed by the liquid dispensing site and the dispensing speed. Water had one order of magnitude higher aspiration risks than 1% w/v methyl cellulose solution, a mildly thick liquid. Anterior dispensing had higher chances for aspiration than posterior oropharyngeal dispensing for both liquids and dispensing speeds considered. The effects of dispending speed varied. A lower speed increased aspiration for anterior-dispensed liquids due to increased off-edge capillary flows, while it significantly reduced aspiration for posterior-dispensed liquids due to reduced notch overflows. Visualizing swallowing hydrodynamics from multiple orientations facilitates detailed site-specific inspections of aspiration mechanisms.

Sleep apnea patients with epiglottic collapse elevate their larynx more with swallowing; videofluoroscopic swallowing study of 80 patients.

OBJECTIVE: The epiglottis plays an integral role in the swallowing mechanism and is also implicated as an obstruction site in obstructive sleep apnea (OSA). The underlying causes of epiglottic collapse during sleep remain unclear. This study aimed to investigate the cognitive functions using the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) and the neurophysiological and anatomical factors using videofluoroscopic swallowing studies (VFSS). We compared patients with OSA exhibiting epiglottic collapse to those without, assessing differences in anatomical or neurophysiological characteristics. METHODS: The study included 12 patients with epiglottic collapse (Epi-group) and 68 without (non-Epi group), all undergoing overnight polysomnography (PSG), drug-induced sleep endoscopy (DISE), LOTCA, and VFSS. Oral transit time (OTT), pharyngeal delay time (PDT), and pharyngeal transit time (PTT) were considered as neurophysiological traits, and laryngeal elevation length (LE) as anatomical trait, and were measured across various test diets (10 ml of liquid, soft, or solid). RESULTS: The study comprised 80 individuals, 57 men and 23 women, with no significant age, sex, body mass index or PSG parameters between groups, or DISE findings, with the exception of epiglottic collapse. Swallowing metrics from VFSS were normal, with no differences in OTT, PDT, PTT, or LOTCA scores. Notably, patients with epiglottic collapse showed a greater laryngeal elevation when swallowing soft and solid foods (p = 0.025 and p = 0.048, respectively). CONCLUSIONS: Patients with epiglottic collapse do not exhibit neurophysiological or cognitive impairments when compared to non-Epi group. However, the Epi-group displayed a significantly increased laryngeal elevation length. This suggests that anatomical factors may have a more substantial role in the development of epiglottic collapse than neurophysiological factors.

Epiglottic capillary hemangioma in an adult female: A rare case report.

INTRODUCTION AND IMPORTANCE: Capillary hemangioma of larynx can occur in both pediatric and adult population. However, epiglottic capillary hemangioma in adults is a very rare presentation. Its pathophysiological basis involves self limiting and self expanding vascularization and it is a characteristically well delineated benign mass. CASE PRESENTATION: Here we present a case of a 40-year-old female who presented with complaint of per oral bleed in spitting which was about a teaspoon in quantity since 1 month. There was no associated hoarseness, dysphagia, respiratory distress, hemoptysis or neck swelling. There were no other systemic manifestations i.e. weight loss, fatigue or anemia. There was no familial history. CLINICAL DISCUSSION: On examination, Indirect Laryngoscopy (IDL) revealed a mass on the posterior surface of epiglottis. 70° view endoscope confirmed the findings of IDL. All other neighboring structures i.e. vocal cords, anterior and posterior commissures and pyriform fossa were normal and no mass or pathology was seen. Imaging studies contrast enhanced CT scan of neck soft tissue window showed isodense opacity in supraglottic region. Surgical excision and hemostasis were carried out using Colorado bipolar cauterization. The histopathological investigation of the mass revealed a benign lesion compatible with capillary hemangioma. CONCLUSION: As until now, no case of capillary hemangioma of epiglottis has been reported, head and neck surgeons are not well aware of this case. This case report will add valuable insight to the relative surgeons/clinicians.

Adult Laryngomalacia: A Scoping Review.

OBJECTIVE: This review sought to determine the characteristics of adults diagnosed with new onset laryngomalacia including airway symptoms, laryngoscopic findings, treatments, and outcomes. Moreover, we wanted to highlight suspected limitations in the literature. DATA SOURCES: Studies were identified through CINAHL, Cochrane Review, PubMed, and Scopus published between 1966 and 2023. REVIEW METHODS: The search was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis Extension for Scoping Reviews checklist by 2 independent investigators. A meta-analysis of proportions and continuous measures was conducted. RESULTS: Of the 1121 abstracts identified, 33 articles pertaining to laryngomalacia in the adult population were included. The most common presenting symptoms were stridor at rest (78.3%, 65.1-88.3) and dyspnea with exertion (83.8%, 64.8-96.3). The most suspected etiology was exercise-induced (86.0%, 69.4-95.5), and the most common description of laryngomalacia on visualization was collapse of supraglottic structures during exercise (93.3%, 79.0-99.1). Nonsurgical options were attempted in 87.0% (54.0-99.1), which included oral appliances, respiratory retraining, breathing techniques, and working with a speech pathologist. Surgical options were ultimately performed in 84.2% (75.0-91.0). Complete resolution of symptoms following therapy was seen in 61.9% (48.0-74.6). CONCLUSION: Adult onset laryngomalacia is difficult to characterize. It typically presents in patients during exercise, with neurological injury, or idiopathically. Surgical management can lead to improvement or complete resolution of symptoms. The need for a universal nomenclature is highlighted in this review, as it is inconsistently classified.

A Large Cohort Analysis of Epiglottic Phenotypes and Pharyngeal Residue.

OBJECTIVE: To describe the phenotypic characteristics of the epiglottis at rest and their impact on vallecular residue. METHODS: Videofluoroscopic studies (VFSS) were pooled from 2 Laryngology practices, and Image J was used to measure epiglottic anatomic features at rest. Studies were rated by the MBSImp and presence of vallecular residue following swallow of thin and puree boluses. A conditional inference tree analysis was performed to isolate which epiglottic parameters were risk factors for presence of vallecular reside followed by logistic regression. RESULTS: The majority of patients had a normal shaped epiglottis, followed by omega shape. The mean angle of the epiglottis from the hyoid was approximately 90°. Only abnormal epiglottic movement was associated with increased risk of residue for thin boluses (OR 35.09, CI 10.93-158.66, P < .001). However, in those with normal epiglottic movement, age >70 years old was associated with increased risk of residue (OR 3.98, CI 1.73-9.23, P = .001). For puree boluses, a normal or omega shaped epiglottis was associated with residue (OR 5.19, CI 2.41-11.51, P < .001), and this relationship was further modulated by increased distance of the epiglottic tip from the posterior pharyngeal wall. No other anatomic features of the resting epiglottis were associated with residue. Comorbidities potentially affecting swallow were infrequent in the cohort and were not associated with residue. CONCLUSION: Abnormal epiglottic movement is associated with aspiration, and in this study we find that abnormal epiglottic movement increases the risk of vallecular residue and that older age is a risk factor for residue. The resting properties of the epiglottis do not appear to be associated with abnormal epiglottic movement or residue.

Transcervical Epiglottopexy: A versatile technique for managing epiglottic prolapse.

OBJECTIVE: Epiglottic prolapse (EP) presents a unique management challenge. The objective of the present case series is to present clinical outcomes using a novel technique of transcervical epiglottopexy (TCE) in etiologically diverse cases of EP and to discuss the evolution of the surgical technique with technical modifications to optimize the surgical procedure. STUDY DESIGN: A retrospective case series review. SETTING: Tertiary care academic setting. METHODS: Pediatric cases with EP over a 3-year period. Demographic data including age, sex, presenting symptoms, operative details, and polysomnographic indices were collected. RESULTS: A total of 18 patients with a mean age of 48.88 ± 37.3 months underwent TCE. Sixty-seven percent of patients had high-grade EP (grades 3 and 4). A previous endolaryngeal epiglottopexy had been performed in 5 (28%) patients. Fourteen (78%) patients had a concurrent airway procedure performed including 4 undergoing single-stage laryngotracheal reconstruction. The mean suspension time only for the TCE part ranged from 8 to 17 minutes with a mean of 11.23 ± 3.4 minutes. A stable EP defined as a healed glossoepiglottic adhesion was achieved in all but 1 case with an overall success rate of 95%. All cases with previous failed endoscopic epiglottopexy had a stable epiglottopexy. No immediate complications were noticed. Among the late complications, the most common was the formation of granulation tissue at the site of silastic disc placement which was seen in 3 patients. CONCLUSION: TCE using an exo-endolaryngeal technique can achieve stable epiglottopexy in children with EP and can be adapted for any kind of EP.

Treatment of a floppy epiglottis with upper airway stimulation therapy.

PURPOSE: To evaluate the efficacy of upper airway stimulation therapy in patients with a floppy epiglottis who have experienced continuous positive airway pressure failure or intolerance. METHODS: A retrospective single-center cohort study was conducted. Patients who received an Inspire Upper Airway Stimulation system and had a 1-year follow-up were included. Baseline and one-year in-laboratory polysomnography examinations were performed. Patient characteristics, Epworth Sleepiness Scale scores and upper airway stimulation device settings were collected. RESULTS: A total of 75 patients were included, of whom 10 had a floppy epiglottis. Patients with a floppy epiglottis had a significant therapeutic response to upper airway stimulation therapy, similar to patients without a floppy epiglottis. According to the Sher's success criteria, 90% of patients with a floppy epiglottis and 68% of patients without a floppy epiglottis were responders to therapy (p = 0.149). In the floppy epiglottis group, the apnea-hypopnea index decreased from 35.1 ± 5.5 events/hour to 11.2 ± 11.3 events/hour (95% CI (15.0, 32.9), p < 0.001), similarly in the non-floppy epiglottis group, the decline was from 36.4 ± 8.3 events/hour to 14.4 ± 9.5 events/hour (95% CI (18.6, 25.2), p < 0.001, between groups p = 0.659). Comparable reductions were observed for the other respiratory parameters. CONCLUSION: Treatment of patients with obstructive sleep apnea and a floppy epiglottis can be challenging. Continuous positive airway pressure may aggravate the epiglottis collapse. Upper airway stimulation therapy can be considered an effective alternative treatment option for patients with a floppy epiglottis who have encountered either continuous positive airway pressure failure or intolerance.

Hyperangulated blades or direct epiglottis lifting to optimize glottis visualization in difficult Macintosh videolaryngoscopy: a non-inferiority analysis of a prospective observational study.

Purpose: It is unknown if direct epiglottis lifting or conversion to hyperangulated videolaryngoscopes, or even direct epiglottis lifting with hyperangulated videolaryngoscopes, may optimize glottis visualization in situations where Macintosh videolaryngoscopy turns out to be more difficult than expected. This study aims to determine if the percentage of glottic opening (POGO) improvement achieved by direct epiglottis lifting is non-inferior to the one accomplished by a conversion to hyperangulated videolaryngoscopy in these situations. Methods: One or more optimization techniques were applied in 129 difficult Macintosh videolaryngoscopy cases in this secondary analysis of a prospective observational study. Stored videos were reviewed by at least three independent observers who assessed the POGO and six glottis view grades. A linear mixed regression and a linear regression model were fitted. Estimated marginal means were used to analyze differences between optimization maneuvers. Results: In this study, 163 optimization maneuvers (77 direct epiglottis lifting, 57 hyperangulated videolaryngoscopy and 29 direct epiglottis lifting with a hyperangulated videolaryngoscope) were applied exclusively or sequentially. Vocal cords were not visible in 91.5% of the cases with Macintosh videolaryngoscopy, 24.7% with direct epiglottis lifting, 36.8% with hyperangulated videolaryngoscopy and 0% with direct lifting with a hyperangulated videolaryngoscope. Conversion to direct epiglottis lifting improved POGO (mean + 49.7%; 95% confidence interval [CI] 41.4 to 58.0; p < 0.001) and glottis view (mean + 2.2 grades; 95% CI 1.9 to 2.5; p < 0.001). Conversion to hyperangulated videolaryngoscopy improved POGO (mean + 43.7%; 95% CI 34.1 to 53.3; p < 0.001) and glottis view (mean + 1.9 grades; 95% CI 1.6 to 2.2; p < 0.001). The difference in POGO improvement between conversion to direct epiglottis lifting and conversion to hyperangulated videolaryngoscopy is: mean 6.0%; 95% CI -6.5-18.5%; hence non-inferiority was confirmed. Conclusion: When Macintosh videolaryngoscopy turned out to be difficult, glottis exposure with direct epiglottis lifting was non-inferior to the one gathered by conversion to hyperangulated videolaryngoscopy. A combination of both maneuvers yields the best result. Clinical trial registration: ClinicalTrials.gov, NCT03950934.

Defining Epiglottic Collapses Patterns in Obstructive Sleep Apnea Patients: Francia-Lugo Classification.

Obstructive Sleep Apnea (OSA) is characterized by repetitive collapse of the upper airway during sleep. Drug-Induced Sleep endoscopy (DISE) is used to identify the collapse site. Among the possible sites of collapse, the epiglottis occurs more frequently than previously described. In this study, we reviewed DISE findings and classified different epiglottic collapse patterns. We found 104 patients (16.4%) with epiglottis collapse (primary 12.5% and secondary 3.9%). We described the following patterns of epiglottis collapse: Anterior-Posterior (AP) collapse with rigid component "trapdoor type" (48%); AP collapse with lax component "floppy type" (13.5%); Lateral- Lateral (LL) collapse with omega shape component "book type" (14.5%); and secondary due to lateral pharyngeal wall or tongue base collapse (24%). The identification of the epiglottic collapse pattern is crucial in decision-making when attempting to ameliorate OSA. These findings in OSA phenotyping could influence the type of treatment chosen.

Design and Superior Performance of a New Endotracheal Tube to Avoid the Asphyxiation of Premature Infants.

Background Neonatal endotracheal intubation attempts often fail, with failures typically attributable to unintended esophageal intubation, with asphyxia, brief or prolonged, as the consequence. Standard-of-care neonatal endotracheal tubes have changed little over recent decades, even as the gestational age of neonates thought eligible for resuscitation and intensive care has decreased. Methods A new neonatal endotracheal tube was patterned after the soft steering mechanism of a two-string fishing line trocar. The new tube remains patent throughout the intubation for air movement and CO2 detection and allows for a finger on the intubator's hand to stiffen, curve, and elevate the tip of the tube over the epiglottis and into the trachea without occluding the vision through a laryngoscope. This tube's engineering principles were studied prospectively in a controlled open-label pilot study in premature infants. Infants were observed during 12 intubations in a one-to-one comparison with standard practice.  Results The new design in comparison to a conventional neonatal endotracheal tube (CNETT) was found to be superior. The average intubation time (mean 36.6 sec, median 30 sec) was shorter (mean 44.6 sec, median 45 sec) in the new design. Intubation attempts were fewer (0 vs. 3), and unintended esophageal intubations were also fewer (0 vs. 4). Conclusion Tracheal intubation of premature infants with the new soft-steering mechanism endotracheal tube was associated with less asphyxia, fewer intubation attempts, and fewer esophageal intubations.

Congenital Absence of the Epiglottis in a 35 Years Old Patient.

Absent epiglottis is a rare reported anomaly in adults with unknown incidence. Most patients with absent epiglottis have presented with life-threatening symptoms of respiratory distress or severe aspiration in infancy or early childhood. We report a case of a 35 year old male patient with complete absence of epiglottis, presented with complaint of hoarseness of voice since birth.

Direct versus indirect epiglottis elevation in cervical spine movement during videolaryngoscopic intubation under manual in-line stabilization: a randomized controlled trial.

BACKGROUND: During videolaryngoscopic intubation, direct epiglottis elevation provides a higher percentage of glottic opening score than indirect epiglottis elevation. In this randomized controlled trial, we compared cervical spine movement during videolaryngoscopic intubation under manual in-line stabilization between the two glottis exposure methods. METHODS: Videolaryngoscopic intubation under manual in-line stabilization was performed using C-MAC® D-blade: direct (n = 51) and indirect (n = 51) epiglottis elevation groups. The percentage of glottic opening score was set equally at 50% during videolaryngoscopic intubation in both groups. The primary outcome measure was cervical spine movement during videolaryngoscopic intubation at the occiput-C1, C1-C2, and C2-C5. The secondary outcome measures included intubation performance (intubation success rate and intubation time). RESULTS: Cervical spine movement during videolaryngoscopic intubation was significantly smaller at the occiput-C1 in the direct epiglottis elevation group than in the indirect epiglottis elevation group (mean [standard deviation] 3.9 [4.0] vs. 5.8 [3.4] °, P = 0.011), whereas it was not significantly different at the C1-C2 and C2-C5 between the two groups. All intubations were successful on the first attempt, achieving a percentage of glottic opening score of 50% in both groups. Intubation time was longer in the direct epiglottis elevation group (median [interquartile range] 29.0 [24.0-35.0] vs. 22.0 [18.0-27.0] s, P < 0.001). CONCLUSIONS: When performing videolaryngoscopic intubation under manual in-line stabilization, direct epiglottis elevation can be more beneficial than indirect epiglottis elevation in reducing cervical spine movement during videolaryngoscopic intubation at the occiput-C1. TRIAL REGISTRATION: Clinical Research Information Service (number: KCT0006239, date: 10/06/2021).

Successful Surgical Excision of Retropharyngeal Plexiform Neurofibroma in a Non-neurofibromatosis Adult Male.

Plexiform neurofibromas are benign tumors that arise from neuronal cells and are commonly associated with neurofibromatosis type 1 (NF1) patients. However, the occurrence of plexiform neurofibromas in the pharyngeal region is extremely rare. In this particular case, we report the successful diagnosis of a retropharyngeal plexiform neurofibroma in an adult male patient without a history of neurofibromatosis. The diagnosis was made using magnetic resonance imaging (MRI) and confirmed by a biopsy. Following the diagnosis, the tumor was surgically excised, resulting in a successful removal of the neurofibroma.

Recurrent Pediatric Extranasopharyngeal Angiofibroma of the Epiglottis: Case Report.

Angiofibroma is a non-encapsulated, highly vascular tumor that usually originates in the nasopharynx. Laryngeal cases of extranasopharyngeal angiofibroma (ENA) are a very rare pathology, especially in children. Only eight ENA laryngeal cases have been described in the literature, and only one of them is a pediatric case. In this report we present an 11-year-old child with epiglottic ENA resected with transoral endoscopic ultrasonic surgery (TOUSS) with review of the literature. Because of reccurrence after five months he underwent re-excision with CO2 laser. Recurrences in ENA are infrequent, but as demonstrated in our case, close endoscopic follow-up is mandatory in this location. Endoscopic hemostatic procedures like TOUSS and CO2 laser ensure bloodless surgery for the management of this type of vascular laryngeal tumors.

Comparative Histoanatomy of the Epiglottis and Pre-epiglottic Space of the Chimpanzee Larynx.

OBJECTIVES: Understanding of the evolution of the larynx clarifies the physiology and functional histoanatomy of the present-day human organ. Comparative histoanatomy of the epiglottis and pre-epiglottic space of the chimpanzee larynx (a hominid, phyletic closest relative of humans) was investigated. METHODS: Two normal adult chimpanzee larynges obtained from natural deaths were investigated. The whole organ serial section technique was employed. RESULTS: The histoanatomical structures of the chimpanzees' epiglottis and pre-epiglottic space were considerably similar to those of human adults. The chimpanzees' epiglottic cartilage was relatively thin and composed of elastic cartilage. These histologic findings of epiglottis indicate that the chimpanzee's epiglottis is flexible and plays the role of retroflection. The chimpanzees' larynges had a pre-epiglottic space composed of adipose tissue and loose connective tissue. Epiglottic cartilage was connected to the thyroid cartilage anteroinferiorly with an intervening thyroepiglottic ligament and to the hyoid bone anteriorly with an intervening hyoepiglottic ligament. These histoanatomical structures of the epiglottis and pre-epiglottic space reflect the fact that chimpanzees have a descended larynx and acquire the pharyngeal space of the vocal tract. CONCLUSION: The results of this study are consistent with the hypothesis that, in the process of evolution, the histoanatomical structures of the epiglottis and pre-epiglottic space change and allow the larynx to descend and lengthen the pharyngeal space of the vocal tract which facilitates speech production in humans. Moreover, the distribution of the human pre-epiglottic space likely allows the epiglottis to more effectively play the role of retroflection during swallowing in order to prevent aspiration.

Development of a Deep Learning-Based Epiglottis Obstruction Ratio Calculation System.

Surgeons determine the treatment method for patients with epiglottis obstruction based on its severity, often by estimating the obstruction severity (using three obstruction degrees) from the examination of drug-induced sleep endoscopy images. However, the use of obstruction degrees is inadequate and fails to correspond to changes in respiratory airflow. Current artificial intelligence image technologies can effectively address this issue. To enhance the accuracy of epiglottis obstruction assessment and replace obstruction degrees with obstruction ratios, this study developed a computer vision system with a deep learning-based method for calculating epiglottis obstruction ratios. The system employs a convolutional neural network, the YOLOv4 model, for epiglottis cartilage localization, a color quantization method to transform pixels into regions, and a region puzzle algorithm to calculate the range of a patient's epiglottis airway. This information is then utilized to compute the obstruction ratio of the patient's epiglottis site. Additionally, this system integrates web-based and PC-based programming technologies to realize its functionalities. Through experimental validation, this system was found to autonomously calculate obstruction ratios with a precision of 0.1% (ranging from 0% to 100%). It presents epiglottis obstruction levels as continuous data, providing crucial diagnostic insight for surgeons to assess the severity of epiglottis obstruction in patients.

Epiglottic Hemangioma: A Rare Case of Hemoptysis in Adults.

Hemangiomas are benign slow growing vascular tumors of endothelial origin, commonly seen in young. Laryngeal hemangiomas are rare entities with varied clinical presentations depending upon their location and size. We hereby report a rare case of recurrent hemoptysis in a 65-year-old lady with epiglottic hemangioma.

The size, number, and distribution of nerve endings around and within the human epiglottis, focusing on tracheal intubation maneuvers.

The aim of this study was to examine the distribution of nerve endings in the mucosa, submucosa, and cartilage of the epiglottis and the vallecula area and to quantify them. The findings could inform the choice of laryngoscope blades for intubation procedures. Fourteen neck slices from seven unembalmed, cryopreserved human cadavers were analyzed. The slices were stained, and cross and longitudinal sections were obtained from each. The nerve endings and cartilage were identified. The primary metrics recorded were the number, area, and circumference of nerve endings located in the mucosa and submucosa of the pharyngeal and laryngeal sides of the epiglottis, epiglottis cartilage, and epiglottic vallecula zone. The length and thickness of the epiglottis and cartilage were also measured. The elastic cartilage of the epiglottis was primarily continuous; however, it contained several fragments. It was covered with dense collagen fibers and surrounded by adipose cells from the pharyngeal and laryngeal submucosa. Nerve endings were found within the submucosa of pharyngeal and laryngeal epiglottis and epiglottic vallecula. There were significantly more nerve endings on the posterior surface of the epiglottis than on the anterior surface. The epiglottic cartilage was twice the length of the epiglottis. The study demonstrated that the distribution of nerve endings in the epiglottis differed significantly between the posterior and anterior sides; there were considerably more in the former. The findings have implications for tracheal intubation and laryngoscope blade selection and design.

Downfolding of the Epiglottis Through the Vocal Cords: A Case Report.

This report presents an unusual case of epiglottic downfolding through the vocal cords which occurred during direct laryngoscopy and loss of view with intubation. Few indicators of an issue were present postintubation, but the providers' interest in one peculiar detail led to timely discovery of the issue avoiding any further injury or complications to the patient.