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Objectives: The primary objective was to assess the perspectives of recent laryngology fellowship graduates on office‐based procedure training, with a secondary objective to compare this with previous research on perspectives of fellowship directors. Methods: Recent laryngology fellowship graduates were surveyed via an online survey platform regarding post‐fellowship practice and various aspects of office‐based procedure training, including perceived competence, mentorship, and barriers. Results: There were 51 respondents. Seventy‐six percent of respondents felt they "definitely" received adequate office procedure training. Number of procedures as primary surgeon was significantly associated with perception of adequate training (OR 1.54, 95% CI: 1.08–2.19, p = 0.018) and high post‐fellowship office procedure volume (OR 1.56, 95% CI: 1.02–2.39, p = 0.040). Fellows reported a lower percentage of procedures as primary surgeons compared with program directors (46.8% vs. 61.9%, p = 0.028). Fellows and directors agreed that informal debriefs were more commonly employed than more structured training elements such as checklists and simulators. Of nine office procedures, laryngeal electromyography, KTP laser, and transnasal esophagoscopy had the greatest decreases in practice after training. Conclusion: Although most recent laryngology fellowship graduates endorse adequate office‐based procedure training, a range of individual experiences exists, and office procedure volume, both overall and across individual procedures, may decrease after fellowship. Fellows performing office procedures as primary surgeons may be linked to perceived quality of training and post‐fellowship volume. Level of Evidence: NA Laryngoscope, 134:1802–1806, 2024 [ABSTRACT FROM AUTHOR]

Objective: Operating room (OR) injection of botulinum toxin (BTX) injection is effective in the management of retrograde cricopharyngeal dysfunction (RCPD). This study aims to analyze the efficacy and safety of in‐office (IO) 30 Unit BTX injection into the cricopharyngeus via lateral transcervical approach. Methods: A retrospective chart review of patients who underwent BTX injection either in the OR or IO for RCPD was performed. Postoperative success, defined by patient‐reported complete or near complete resolution of symptoms, side effects, and complication rates of each group was determined and compared. To determine the learning curve of IO injections, success rates of the injections performed in the early and late 6 months were compared. Chi‐square test was used for determining the statistical significance. Results: Overall, 78 injections (37 IO and 41 OR) for RCPD were performed by the senior author. The success rate of OR injections (90.2%) is significantly higher than IO injections (64.9%) at the first‐month follow‐up (p = 0.022). No significant difference was found in the side effect rates. Success and side effect rates were also similar in early and late injections (p > 0.05). Conclusions: IO lateral transcervical BTX injection for RCPD is a safe method that does not require general or topical anesthesia. While the side effects are similar and IO injections have many advantages, the success rates are lower than OR injections. Level of Evidence: 3 Laryngoscope, 134:283–286, 2024 [ABSTRACT FROM AUTHOR]

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

Objectives: Recurrent laryngeal nerve (RLN) injury results in synkinetic reinnervation and vocal fold paralysis. Investigation of cues expressed in the developing brainstem that influence correct selective targeting of intrinsic laryngeal muscles may elucidate post‐injury abnormalities contributing to non‐functional reinnervation. Primary targets of interest were Hoxb1 and Hoxb2, members of the Hox family that create overlapping gradients in the developing brain, and their target Phox2b, a transcription factor necessary for cranial nerve branchio‐ and visceromotoneuron survival. Methods: Rat embryos at developmental days E14, E16, E18, and E20 (4 animals/age) were sectioned for RNA in situ hybridization to detect Hoxb1, Hoxb2, and Phox2b mRNA within the brainstem. Slides were costained with Islet1 antibody for identification of the nucleus ambiguus. Results were confirmed using immunohistochemistry. Sections were imaged on a confocal microscope. RNA and protein expressions were quantified using QuPath. Statistical analyses were performed using R. Results: Hoxb1, Hoxb2, and Phox2b expressions varied according to embryologic age. Hoxb1 and Hoxb2 expression peaked at E16, with significant decreases at E18 and E20 (one‐way ANOVA p = 0.001 for both). Phox2b expression was highest at E14 and trended downward with increased embryologic age (one‐way ANOVA p = 0.005). Conclusion: Peak expression of Hoxb1 and Hoxb2 is observed at time points when the RLN arrives at the larynx and begins to branch toward individual muscles, positioning these gene products to be involved in cueing laryngeal motoneuron identity and target identification. Higher expression of Phox2b earlier in development suggests a role in laryngeal motoneuron formation. Level of Evidence: NA Laryngoscope, 133:3462–3471, 2023 [ABSTRACT FROM AUTHOR]

Objective: The nucleus ambiguus (NAmb) is a column of neurons in the medulla oblongata, involved in bulbar functions. Expression of Glial Cell‐Derived Neurotrophic Factor (GDNF) and its receptors (GDNFR) is observed within the cell bodies during reinnervation following recurrent laryngeal nerve (RLN) injury. Little is known regarding GDNFR expression in the formation of the NAmb and the laryngeal innervation during embryogenesis. Understanding the timing and pattern of GDNFR expression in embryogenesis versus after RLN injury may provide insights into therapeutic targets for regeneration after RLN injury. Study Design: Laboratory experiment. Methods: Rat brainstems at E14.5/E16.5/E18.5/E20.5/adult were stained for GDNFR: GFRα‐1/GFRα‐2/GFRα‐3/Ret. Islet1 and choline acetyltransferase were used as cell body markers. Sections were observed using fluorescent microscopy and quantified through manual cell counting. Results: Expression of GFRα‐1, GFRα‐3, and Ret was identified within the NAmb, hypoglossal, and facial nuclei of the adult medulla. During development, GFRα‐1 immunoreactivity was seen at E20.5. GFRα‐2 expression was not observed at any timepoint. GFRα‐3 expression began at E16.5. Ret expression within nerve fibers in the NAmb were observed beginning at E14.5, but never in the cell bodies. Conclusion: Embryonic GDNFR expression in the NAmb differs from that of the adult after RLN injury. The developing brainstem experienced upregulation at discrete timepoints with signaling sustained through adulthood. In contrast, adult RLN‐transected rats experienced patterns of up and down regulation. GFRα‐1 may contribute to muscle targeting and neuromuscular junction maturation, GFRα‐3 may contribute to both, as well as axon guidance. It is likely that GDNF is functioning via a Ret‐independent pathway. Level of Evidence: NA Laryngoscope, 133:2240–2247, 2023 [ABSTRACT FROM AUTHOR]

Objective: Somatosensory feedback from upper airway structures is essential for swallowing and airway defense but little is known about the identities and distributions of human upper airway neurons. Furthermore, whether sensory innervation modifies with aging is unknown. In this study, we quantify neuronal and chemosensory cell density in upper airway structures and correlate with age. Methods: Participants underwent biopsies from base of tongue, lateral and midline pharyngeal wall, epiglottis, and arytenoids (N = 25 13 female/12 male; 20–80 years, mean 51.4 years without clinical diagnosis of dysphagia or clinical indication for biopsy). Tissue sections were labeled with antibodies for all neurons, myelinated neurons, and chemosensory cells. Densities of lamina propria innervation, epithelial innervation, solitary chemosensory cells, and taste buds were calculated and correlated with age. Results: Arytenoid had the highest density of innervation and chemosensory cells across all measures compared to other sites. Taste buds were frequently observed in arytenoid and epiglottis. Base of tongue, lateral pharynx, and midline posterior pharynx had minimal innervation and few chemosensory cells. Epithelial innervation was present primarily in close proximity to chemosensory cells and taste buds. Overall innervation and myelinated fibers in the arytenoid lamina propria decline with aging. Conclusion: Findings establish the architecture of healthy adult sensory innervation and demonstrate the varied distribution of laryngopharyngeal innervation, necessary steps toward understanding the sensory basis for swallowing and airway defense. We also document age‐related decline in arytenoid innervation density. These findings suggest that sensory afferent denervation of the upper airway may be a contributing factor to presbyphagia. Level of Evidence: NA Laryngoscope, 133:773–784, 2023 [ABSTRACT FROM AUTHOR]

Objective: The aim is to use a simulation lung model to assess the possibility of performing bronchoscopy through endotracheal tubes (ETT) less than 8.0‐mm while appropriately ventilating patients with normal and ARDS lungs in the setting of SARS‐CoV‐2. Methods: Five SHERIDAN® ETTs were used to ventilate SimMan® 3G under respiratory compliance levels representing normal and severe ARDS lungs. Baseline measurements of peak pressure, plateau pressure, and auto‐positive end expiratory pressure (auto‐PEEP) were recorded at four different inspiratory times (Ti). Three different‐sized disposable bronchoscopes were inserted, and all measurements were repeated. Results: Normal lung model: Slim bronchoscopes in 6.0‐mm ETTs resulted in plateau pressures <30 cm H2O, and increasing Ti to minimize peak pressure resulted in low auto‐PEEP. Regular bronchoscopes in 7.0‐mm ETTs had similar results. Large bronchoscopes in 7.5‐mm ETTs generated plateau pressures ranging from 28 to 35 cm H2O with modest auto‐PEEP. Severe ARDS lung model: Slim bronchoscopes in 6.0‐mm ETTs resulted in plateau pressures of 46 and an auto‐PEEP of 5 cm H2O. Regular bronchoscopes in 7.0‐mm ETTs generated similar results. Large bronchoscopes in 8.0‐mm ETTs displayed plateau pressures of 44 and an auto‐PEEP of 2 cm H2O. Conclusion: To mitigate risk of laryngeal injury, larger ETTs during bronchoscopy should be avoided. Our data show bronchoscopy with any ETT causes auto‐PEEP and high plateau pressures, especially in lungs with poor compliance; however, ETT less than 7.5 mm can be used when considering several factors. Our data also suggest similar studies in patients with varying degrees of ARDS would be informative. Level of Evidence: NA Laryngoscope, 133:147–153, 2023 [ABSTRACT FROM AUTHOR]