Introduction: Although phonatory glottal posture and airflow pulse shape affect voice quality, studies to date have been limited by visualization of vocal fold (VF) vibration from a superior view. We performed a 3D reconstruction of VF vibratory motion during phonation from a medial view and assessed the glottal volume waveform and resulting acoustics as a function of neuromuscular stimulation.Study Design: In vivo canine hemilarynx phonation. Methods: Across 121 unique combinations of the superior laryngeal nerve (SLN) and recurrent laryngeal nerve (RLN) stimulation, the hemilarynx was excited to the oscillation with airflow. VF medial surface reference points were tracked on high-speed video, mapped into 3D space, and surface shape was restored using cubic spline interpolation. Glottal surface shape, reconstruction-based parameters, and glottal volume waveform were calculated. Fundamental frequency (F0), cepstral peak prominence (CPP), and harmonic amplitude (H1-H2) were measured from high-quality audio samples.Results: The glottis was convergent during opening and divergent during closing. Neuromuscular activation changed phonatory glottal shape and reduced glottal volume. Significant reduction in glottal volume and closing quotient were present with SLN stimulation. RLN stimulation significantly increased F0 and CPP and decreased H1-H2 (constricted glottis), while SLN effects were similar and synergistic with concurrent RLN stimulation.Conclusion: 3D reconstruction of in vivo medial surface vibration revealed effects of laryngeal nerve stimulation on glottal vibratory pattern and acoustic correlates of voice quality. SLN activation resulted in significantly quicker glottal closure per cycle, decreased glottal volume, and higher-pitched, less breathy, and less noisy voice. RLN had a similar effect on acoustic measures.

Objective To demonstrate the safety profile of platelet‐rich plasma (PRP) as an injectable therapeutic for the treatment of vocal fold scarring and atrophy. Methods Preliminary report on a prospective clinical trial of patients with vocal fold scar or atrophy undergoing unilateral vocal fold subepithelial infusion with autologous PRP. Enrolled patients underwent four subepithelial injections spaced 1 month apart. Adverse events were assessed peri and post‐injection at each session. Patient‐reported outcomes were collected at every visit using the Voice Handicap Index‐10 (VHI‐10) and Vocal Fatigue Index (VFI) questionnaires. Results Twelve patients underwent unilateral vocal fold injection with autologous PRP prepared according to Eclipse PRP® system protocol. Forty‐three injections were performed using a peroral or percutaneous approach. An average of 1.57 ± 0.4 cc (range 0.6–2.0 cc) injectate was used. All patients tolerated the procedure without difficulty or peri‐procedural complications. The average duration of follow‐up was 3.6 ± 1.8 months. No significant inflammatory reactions or adverse events were seen to date. There was statistically significant improvement in patient‐reported outcomes at the 3 month follow up (n = 9) follow‐up (mean ΔVHI‐10 = 10.8, p < 0.001, mean ΔVFI = 18.9, p = 0.01, t test, paired two sample for means, two‐tail). All nine patients who completed the series of four injections subjectively (yes/no) reported they were satisfied with the results. Conclusion This prospective study cohort demonstrated a favorable safety profile, with no adverse events or peri‐procedural complications. Subjective improvements in vocal quality and reduction in vocal fatigue need to be clinically correlated with further study. Level of Evidence 4 Laryngoscope, 133:647–653, 2023

Objective. Partial epiglottidectomy has a role in improving dysphagia due to epiglottic obstruction. This study evaluates objective parameters of swallow function in patients who underwent partial epiglottidectomy.Study Design. Retrospective study design.Setting. Tertiary Care University Academic Medical Center. Methods.A review was performed of patients who underwent CO 2 laser partial epiglottidectomy for the treatment of dysphagia at a single tertiary care academic center over a 4-year period. Objective swallowing parameters were evaluated from pre-and postoperative modified barium swallow studies using SwallowTail Advanced Measurement software using blinded reviewers. The postswallow pharyngeal residue (bolus clearance ratio or BCR), spatiotemporal swallowing variables (oropharyngeal [OPT], hypopharyngeal [HPT], and total pharyngeal transit times [TPT]), and airway protection (Penetration-Aspiration Scale [PAS]) were analyzed. Student paired t test was used to determine significant changes in outcome parameters pre-and postsurgery.Results. Forty-three patients (age range 45-92 years, median 70) met the inclusion criteria. A majority (69.8%) had a history of external beam radiation therapy for head and neck cancer. BCR decreased significantly from a mean of 31.7% presurgery to 24.2% (p = .01) postsurgery. OPT, HPT, and TPT did not differ significantly postsurgery. The mean Eating Assessment Tool-10 score improved from 25.1 to 20.2 after treatment (p = .03). PAS score improved by 15.4% and remained stable at 66.2% after surgery. Conclusion.Partial epiglottidectomy improves pharyngeal bolus clearance in properly selected patients with dysphagia due to epiglottic obstruction. Patients demonstrated stable swallow function with the benefit of reduced postswallow residue following surgical intervention.

ObjectivePatients with advanced laryngeal cancer are typically presented with divergent treatment options, namely chemoradiation versus total laryngectomy. This study aims to understand general perspectives of the factors involved in this decision‐making process.MethodsSurveys were constructed using specialized conjoint analysis software. Seven attributes integral to the decision‐making process for advanced laryngeal cancer treatment were included.ResultsThree hundred one healthy adult volunteers completed the decision‐making program. The relative impact of each treatment attribute on decision making across all participants was scored with an average importance score (standard deviation) as follows: Lifespan 22.2% (±8.5), Voicing 21.4% (±5.9), Swallowing 19.1% (±7.3), Cancer Cure 14.9% (±6.2), Mode of Breathing 11.0% (±3.7), Self‐Image 6.7% (±2.9), and Treatment Type 4.8% (±3.0).ConclusionsGeneral public opinion ranked lifespan, voicing, and swallowing aspects as similarly important, and all were ranked more important than probability of cure. These data demonstrate a variety of priorities among participants and the need for tailored discussions when determining treatment choice for advanced laryngeal cancer.Level of EvidenceLevel 4.

Multi-echo independent component analysis (ME-ICA) has been shown to differentiate the effects of head motion from desired BOLD signal in fMRI data, but this method has not been tested in motor-task studies with high amounts of task-correlated head motion. We investigated four denoising models on multi-echo motor-task data with limited and amplified task-correlated motion: Aggressive, Moderate, and Conservative ME-ICA nuisance regression models and a conventional optimally combined (OC) model. ME-ICA models were found to better dissociate head motion and BOLD signal variance than the OC model. Among them, the Aggressive model had the most consistent activation results with amplified motion.

ObjectivesDespite gross anatomic and histologic differences between human and canine vocal folds, similar wave patterns have been described yet not fully characterized. We reconstructed vocal fold (VF) vibration in a canine hemilarynx and performed histologic examination of the same vocal fold. We demonstrate comparable wave patterns while exploring the importance of certain anatomic architectures.MethodsAn in vivo canine hemilarynx was phonated against a glass prism at low and high muscle activation conditions. Vibration was captured using high‐speed video, and trajectories of VF medial surface tattooed landmarks were 3D‐reconstructed. The method of empirical eigenfunctions was used to capture the essential dynamics of vibratory movement. Histologic examination of the hemilarynx was performed.ResultsOscillation patterns were highly similar between the in vivo canine and previous reports of ex vivo human models. The two most dominant eigenfunctions comprised over 90% of total variance of movement, representing opening/closing and convergent/divergent movement patterns, respectively. We demonstrate a vertical phase difference during the glottal cycle. The time delay between the inferior and superior VF was greater during opening than closing for both activation conditions. Histological examination of canine VF showed not only a thicker lamina propria layer superiorly but also a distinct pattern of thyroarytenoid muscle fibers and fascicles as described in human studies.ConclusionsHistologic and vibratory examination of the canine vocal fold demonstrated human vocal fold vibratory patterns despite certain microstructural differences. This study suggests that the multilayered lamina propria may not be fundamental to vibratory patterns necessary for human‐like voice production.Level of EvidenceN/A (Basic science study) Laryngoscope, 2023

In laryngeal research, studying the vertical vocal fold oscillation component is often disregarded. However, vocal fold oscillation by its nature is a three-dimensional process. In the past, we have developed an in-vivo experimental protocol to reconstruct the full, three-dimensional vocal fold vibration. The goal of this study is to validate this 3D reconstruction method. We present an in-vivo canine hemilarynx setup using high-speed video recording and a right-angle prism for 3D reconstruction of vocal fold medial surface vibrations. The 3D surface is reconstructed from the split image provided by the prism. For validation, reconstruction error was calculated for objects located at a distance of up to 15 mm away from the prism. The influence of camera angle, changing calibrated volume, and calibration errors were determined. Overall average 3D reconstruction error is low and does not exceed 0.12 mm at 5 mm distance from the prism. Influence of a moderate (5°) and large (10°) deviation in camera angle led to a slight increase in error to 0.16 mm and 0.17 mm, respectively. This procedure is robust towards changes in calibration volume and small calibration errors. This makes this 3D reconstruction approach a useful tool for the reconstruction of accessible and moving tissue surfaces.

Objectives Surgical manipulations to treat glottic insufficiency aim to restore the physiologic pre‐phonatory glottal shape. However, the physiologic pre‐phonatory glottal shape as a function of interactions between all intrinsic laryngeal muscles (ILMs) has not been described. Vocal fold posture and medial surface shape were investigated across concurrent activation and interactions of thyroarytenoid (TA), cricothyroid (CT), and lateral cricoarytenoid/interarytenoid (LCA/IA) muscles. Study Design In vivo canine hemilarynx model. Methods The ILMs were stimulated across combinations of four graded levels each from low‐to‐high activation. A total of 64 distinct medial surface postures (4 TA × 4 CT × 4 LCA/IA levels) were captured using high‐speed video. Using a custom 3D interpolation algorithm, the medial surface shape was reconstructed. Results Combined activation of ILMs yielded a range of unique pre‐phonatory postures. Both LCA/IA and TA activation adducted the vocal fold but with greater contribution from TA. The transition from a convergent to a rectangular glottal shape was primarily mediated by TA muscle activation but LCA/IA and TA together resulted in a smooth rectangular glottis compared to TA alone, which caused rectangular glottis with inferomedial bulging. CT activation resulted in a lengthened but slightly abducted glottis. Conclusions TA was primarily responsible for the rectangular shape of the adducted glottis with synergistic contribution from the LCA/IA. CT contributed minimally to vocal fold medial shape but elongated the glottis. These findings further refine laryngeal posture goals in surgical correction of glottic insufficiency. Level of Evidence NA, Basic science Laryngoscope, 133:1690–1697, 2023