Association of the "Jet Phenomenon" with Positive Symptom Outcome Following Surgical Treatment of Cricopharyngeus Muscle Dysfunction.

OBJECTIVES: Cricopharyngeus muscle dysfunction (CPMD) is a common cause for progressive dysphagia and can lead to dietary restriction, reduced nutrition, weight loss, and pneumonia. Controversy exists whether CPMD is best managed with primary surgical treatment of the cricopharyngeus muscle and who represents a good surgical candidate. METHODS: Retrospective review of patients diagnosed with CPMD who underwent surgical treatment were evaluated through prospectively collected pre- and postoperative Eating Assessment Tool-10 (EAT-10) and Functional Oral Intake Scale (FOIS). Videofluoroscopic swallowing studies (VFSS) were reviewed for presence or absence of a high-pressure barium stream through the upper esophageal sphincter, termed the jet phenomenon (JP). RESULTS: We identified 42 patients with CPMD who underwent surgical treatment and had serial Eating Assessment Tool (EAT-10) measures obtained pre- and postoperatively. Mean EAT-10 scores improved by 12.1 points (95%CI = 8.6-15.6), p < 0.0001. There was a significantly greater improvement among patients with JP (|∆EAT-10|= 17.0, 95%CI = 12.5-21.4) compared to those without (|∆EAT-10|= 6.2, 95%CI = 1.6-10.8), p = 0.0013. Patients with JP also showed improved FOIS score (p = 0.0023) while those without JP did not. CONCLUSION: This study provides the initial report on the utility of JP as a VFSS feature that is strongly associated with improved outcomes following surgical treatment of CPMD. Further work determining the physiologic correlates responsible for JP will help clarify its predictive capabilities. LEVEL OF EVIDENCE: Level 3.

Developing an Objective Structured Assessment of Technical Skills (OSATS) for Microlaryngoscopy.

BACKGROUND: Microlaryngoscopy is a basic technical skill in Oto-HNS. It is essential for residency programs to have a competency-based assessment tool to evaluate residents' performance of this procedure. An Objective Structured Assessment of Technical Skills (OSATS) is a procedure-specific assessment, which consists of the following: (a) Operation-Specific Checklist and (b) Global Rating Scale (GRS). OBJECTIVE: The objective of this study was to create an OSATS for adult microlaryngoscopy. METHODS: This was a prospective study, with an initial qualitative phase for OSATS development (Phase I), and a clinical pilot phase (Phase II). In Phase I, interviews were conducted with three laryngologists to establish a stepwise description of adult microlaryngoscopy and review a previously validated GRS for relevance to microlaryngoscopy. Responses were used to create a framework for the OSATS. The OSATS was then presented to Oto-HNS residents and laryngologists in an alternating fashion, for review of clarity and relevance. A pilot study was then performed to evaluate the resident performance of adult microlaryngoscopy. Multiple regression analysis was carried out to investigate whether training level, case complexity, and previous OSATS exposure could predict participant scores. RESULTS: Phase I of this study led to the creation of a 34-item OSATS. The pilot study (N = 28 procedures) revealed that training level was significantly correlated with increased OSATS scores. There was no statistically significant correlation between case complexity and resident scores. Assessors reported the perceived utility of the OSATS and intent for use in residency training. CONCLUSION: Application of the proposed OSATS will allow for competency-based assessment of the resident performance of microlaryngoscopy. LEVEL OF EVIDENCE: NA Laryngoscope, 133:2719-2724, 2023.

The American Broncho-Esophagological Association Position Statement on Swallowing Fluoroscopy.

OBJECTIVES: To develop an expert consensus statement on the clinical use of swallowing fluoroscopy in adults that reduces practice variation and identifies opportunities for quality improvement in the care of patients suffering from swallowing impairment. METHODOLOGY: A search strategist reviewed data sources (PubMed, Embase, Cochrane, Web of Science, Scopus) to use as evidence for an expert development group to compose statements focusing on areas of controversy regarding swallowing fluoroscopy. Candidate statements underwent two iterations of a modified Delphi protocol to reach consensus. RESULTS: A total of 2184 publications were identified for title and abstract review with 211 publications meeting the criteria for full text review. Of these, 148 articles were included for review. An additional 116 publications were also included after reviewing the references of the full text publications from the initial search. These 264 references guided the authors to develop 41 candidate statements in various categories. Forty statements encompassing patient selection, fluoroscopic study choice, radiation safety, clinical team dynamics, training requirements, videofluoroscopic swallow study and esophagram techniques, and interpretation of swallowing fluoroscopy met criteria for consensus. One statement on esophagram technique reached near-consensus. CONCLUSIONS: These 40 statements pertaining to the comprehensive use of swallowing fluoroscopy in adults can guide the development of best practices, improve quality and safety of care, and influence policy in both the outpatient and inpatient settings. The lack of consensus on some aspects of esophagram technique likely reflects gaps in knowledge and clinical practice variation and should be a target for future research. Laryngoscope, 133:255-268, 2023.

Developing an Artificial Intelligence Tool to Predict Vocal Cord Pathology in Primary Care Settings.

OBJECTIVES: Diagnostic tools for voice disorders are lacking for primary care physicians. Artificial intelligence (AI) tools may add to the armamentarium for physicians, decreasing the time to diagnosis and limiting the burden of dysphonia. METHODS: Voice recordings of patients were collected from 2019 to 2021 using smartphones. The Saarbruecken dataset was included for comparison. Audio files were converted to mel-spectrograms using TensorFlow. Diagnostic categories were created to group pathology, including neurological and muscular disorders, inflammatory, mass lesions, and normal. The samples were further separated into sustained/a/and the rainbow passage. RESULTS: Two hundred three prospective samples and 1131 samples were used from the Saarbruecken database. The AI detected abnormal pathology with an F1-score of 98%. The artificial neural network (ANN) differentiated key pathologies, including unilateral paralysis, laryngitis, adductor spasmodic dysphonia (ADSD), mass lesions, and normal samples with 39%-87% F-1 scores. The Calgary database models had higher F-1 scores in a head-to-head comparison to the Saarbruecken and combined datasets (87% vs. 58% and 50%). The AI outperformed otolaryngologists using a standardized test set of recordings (83% compared to 55% ± 15%). CONCLUSION: An AI tool was created to differentiate pathology by individual or categorical diagnosis with high evaluation metrics. Prospective data should be collected in a controlled fashion to reduce intrinsic variability between recordings. Multi-center data collaborations are imperative to increase the prediction capability of AI tools for detecting vocal cord pathology. We provide proof-of-concept for an AI tool to assist primary care physicians in managing dysphonic patients. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:1952-1960, 2023.

Functional Outcomes of Swallowing Following Surgery for Obstructive Sleep Apnea.

OBJECTIVE: Identification and evaluation of swallowing dysfunction in patients undergoing upper airway surgery for obstructive sleep apnea (OSA) is limited. This study evaluated subjective swallowing function pre and postoperatively in patients undergoing multi-level reconstructive pharyngeal sleep surgery. METHODS: A retrospective analysis of prospectively-administered Eating Assessment Tool (EAT-10) scores was conducted among adult patients undergoing surgery for OSA at a tertiary sleep surgery center. Preoperative and 1, 3, and 6-month postoperative time points were assessed. Patients were subdivided into two groups based on the degree of upper airway reconstruction performed. All patients underwent uvulopalatopharyngoplasty +/-tonsillectomy and tongue-base reduction. Patients undergoing Phase 1 reconstructive surgery additionally underwent tongue-base advancement procedures. RESULTS: A total 100 patients underwent airway reconstructive surgery. Forty-one patients underwent Phase 1 surgery; 59 patients underwent Mini-Phase 1 surgery. Neither group demonstrated preoperative dysphagia. Both groups experienced significant subjective dysphagia at 1-month postoperatively, which was greater among Phase 1 patients (mean EAT-10 14.8; SD 10.4) versus Mini-Phase 1 patients (mean EAT-10 6.7; SD 7.5) (p < 0.001). Swallowing function among both groups normalized by 3 and 6 months postoperatively. Phase 1 patients with pre-operative dysphagia (mean EAT-10 9.6; SD 5) demonstrated initial worsening of their swallowing postoperatively; however, reported improved swallowing versus pre-operative levels by 6 months postoperatively (mean EAT-10 3.6; SD 4.3) (p = 0.03). CONCLUSION: Pharyngeal surgery resulted in no significant, persistent adverse change in swallowing function. Among both groups, significant subjective dysphagia was reported at 1 month postoperatively, yet returned to preoperative levels by 6 months postoperatively. OSA patients with pre-existing dysphagia undergoing Phase 1 surgery trended towards improved swallowing function postoperatively. LEVEL OF EVIDENCE: 2 Laryngoscope, 133:199-204, 2023.

Effect of socioeconomic status on wait times for patients undergoing treatment for laryngeal conditions in a universal healthcare system.

Objectives: As one of the world's only fully publicly administered, universal healthcare systems, Canada intends to provide equitable access to services for all patients. Socioeconomic status (SES) can affect treatment wait times with implications on health outcomes; however, this has not been evaluated in the setting of laryngeal disease, which incorporates urgent and elective conditions, in a universal healthcare system. This study aims to identify whether SES-affected treatment wait times for laryngeal therapies in this system. Methods: A retrospective review was conducted on a cohort of patients with laryngeal disease at an academic, tertiary center who underwent laryngeal surgery over a three-year period. Data retrieved through medical records; surgical and voice therapy wait times were normalized to each practitioner's average wait time for respective diagnostic categories. Income was used to assess SES and was derived from Statistics Canada census information based on patient postal codes. Results: Data analysis identified 578 patients (59% male). Mean wait time to surgery for all conditions was 123.5 (95% confidence interval 113.1-133.9) days. Analysis of variance analysis found no difference in wait times between different SES groups (p = .28), regardless of laryngeal disease category. Patients with cancer or airway obstruction had shorter wait times compared with benign conditions (p < .0001). Conclusions: SES did not affect treatment wait times for laryngeal therapies in a universal healthcare system. Wait times were shorter for oncologic and obstructive conditions compared with benign conditions, reflecting an ability to accommodate clinical needs without impacting care access at the detriment of different SES statuses. Level of Evidence: 4.

The Prospective Implementation of the 2015 ATA Guidelines and Modified ATA Recurrence Risk Stratification System for Treatment of Differentiated Thyroid Cancer in a Canadian Tertiary Care Referral Setting.

Objective: To present clinical outcomes of the prospective implementation of the 2015 American Thyroid Association (ATA) guidelines for the management of thyroid nodules and differentiated thyroid cancer (DTC) using the modified ATA recurrence risk (RR) stratification system. Methods: We prospectively analyzed 612 patients with DTC treated between April 2017 and December 2021 in Calgary, Alberta. Each patient was prospectively assigned a modified ATA RR and American Joint Committee Cancer 8th edition stage. Initial risk stratification and consideration of the 2015 ATA guidelines guided surgical management as well as the indication for and dose of radioiodine (RAI) and other adjuvant therapies. Patients were assessed for their response to treatment (RTT) at 2-years postoperatively. Results: There were 479 patients who had 2-year follow-up data and were included in the study. Of these patients, there were 253 (53%) low-, 129 (27%) intermediate-, and 97 (20%) high-RR patients. Of these, 227 patients (47%) underwent total thyroidectomy (TTX) plus RAI, 178 (37%) underwent TTX only, and 74 (16%) underwent lobectomy. The RTT at 2 years was excellent for 89% (66) of patients with lobectomy, 84% (149) for TTX only, and 53% (121) for TTX plus RAI. Among 253 patients who were deemed low RR, 85% (216) had excellent RTT, 13% (32) indeterminate RTT, 2% (4) biochemical incomplete RTT, and 1 patient had structural incomplete RTT. The intermediate RR group had the following RTT outcomes: 64% (83) excellent, 23% (30) indeterminate, 6% (7) biochemical incomplete, and 7% (9) structural incomplete. The high RR group had the worst RTT outcomes, with 38% (37) excellent, 19% (18) indeterminate, 10% (10) biochemical incomplete, and 33% (32) structural incomplete RTT. Conclusions: The 2015 ATA RR stratification system is useful for predicting disease status at 2-year post-treatment in patients with DTC. The 2015 ATA guidelines and modified ATA RR stratification treatment recommendations may reduce thyroid cancer overtreatment by including lobectomy as a definitive treatment option for low-risk thyroid cancers and selective use of RAI for intermediate and high-risk patients.

Treatment of Essential Vocal Tremor: A Scoping Review of Evidence-Based Therapeutic Modalities.

OBJECTIVES/HYPOTHESIS: Essential vocal tremor (EVT) is an uncommon but challenging condition to manage. Several medical and interventional treatment options have been reported but efficacy remains unclear. We performed a scoping review of high-quality clinical trials to identify effective evidence-based treatments for EVT. STUDY DESIGN: Scoping review. METHODS: Relevant studies were identified using the databases MedLine, Cochrane Central Register of Controlled Trials, and Embase. Subjective and objective outcomes for each modality were analyzed and the effect sizes were quantified using Hedges' g measure to allow comparison between studies. RESULTS: We identified 421 studies eligible for screening with 11 included in the final analysis. Evidence supporting effective EVT treatments was found for bilateral versus unilateral deep brain stimulation (DBS) (Hedges' g 0.65, 95% CI = 0.10-1.20) and octanoic acid (Hedges' g 1.15, 95% CI = 0.40-1.90). Evidence to support the use of methazolamide was not sufficient (Hedges' g 0.51, 95% CI = -0.64 to 1.66). Botulinum toxin (BT) injections were equivalent when comparing unilateral versus bilateral (Hedges' g -0.18, 95% CI = -1.06 to 0.70); BT did not display any advantage over propranolol (Hedges' g -0.47, 95% CI = -1.73 to 0.78) or injection augmentation (Hedges' g 0.068, 95% CI = -0.98 to 1.12). CONCLUSIONS: Our review finds very little high-quality evidence supporting any treatment for EVT. Octanoic acid reduced fluctuations in EVT but did not affect the perception of the tremor. In refractory cases, bilateral DBS was superior to unilateral DBS in improving subjective voice outcomes. Unilateral and bilateral BT injections were equivalent, and BT injection was not more effective than injection augmentation. Further direct comparison in well-designed prospective studies may help clarify optimal treatment for EVT patients.

Long-Term Voice Outcomes Following Cricotracheal Resection for Subglottic Stenosis: A Retrospective Analysis.

OBJECTIVES/HYPOTHESIS: Cricotracheal resection (CTR) is an effective treatment for refractory idiopathic subglottic stenosis (iSGS) but is associated with persistent dysphonia. Outcomes were measured longitudinally to characterize how patients' voices and self-perceived voice handicaps changed after CTR. STUDY DESIGN: Retrospective case-series. METHODS: We conducted a retrospective cohort study of patients with refractory iSGS treated by CTR from 2006 to 2017. Voice Handicap Index (VHI), Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V), and acoustic analysis were prospectively collected preoperatively and postoperatively at 1, 3, 6, 12, and 24-month intervals. A linear mixed model was used to evaluate temporal change. RESULTS: Thirty-three patients (97% female) were included. VHI scores increased significantly from baseline preoperative score (27.2 ± 22.7) to a mean value of 44.3 ± 25.6 (P < .001) 1-month postoperatively but decreased below preoperative scores after 2 years (18.8 ± 11.9, P = .795). Mean fundamental frequency (F0) values in speech decreased significantly from 192.0 ± 24.9 Hz preoperatively to 167.1 ± 19.8 Hz at a 2-year follow-up (P = .002), with a nadir value at 1-month postoperatively (148.4 ± 20.5, P < .001). CAPE-V scores increased significantly from preoperative to 1-month postoperative (3.0 ± 2.3 vs. 21.9 ± 17.3, P < .001) but returned toward baseline values at 24 months after CTR (6.9 ± 4.8, P = .027). CAPE-V measurements postoperatively were correlated with VHI and F0 (Pearson coefficient = 0.54 (VHI), -0.46 (F0), P < .001). CONCLUSIONS: Following CTR, mean F0 values were significantly and consistently lower but did increase over time, correlating with patients' improving VHI and CAPE-V scores. VHI values indicate that patient's perception of their voice is not significantly impacted in long term. These results provide a framework to counsel patients about long term voice expectations. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:1054-1060, 2022.

Natural History of Cricopharyngeus Muscle Dysfunction Symptomatology.

Cricopharyngeus muscle dysfunction (CPMD) is a common cause for progressive dysphagia and can lead to dietary restriction, reduced nutrition, weight loss, and pneumonia. There is a continuum between small, non-obstructive cricopharyngeus bars representing mild disease and severely obstructive bars or Zenker's diverticulum forming late-stage disease, but the natural history of untreated CPMD and the associated time course for progression is unknown. Retrospective longitudinal cohort study from a tertiary outpatient dysphagia centre. Patients diagnosed with CPMD by fluoroscopy and either awaiting surgical treatment or electing non-operative management were evaluated through prospectively collected Eating Assessment Tool-10 (EAT-10) and Functional Oral Intake Scale (FOIS). Review of available imaging identified degree of CPMD. We identified 174 patients with CPMD diagnosed between July 1, 2016, and June 30, 2020; 52 patients had serial Eating Assessment Tool (EAT-10) measures obtained at time of diagnosis and follow up appointment without operative treatment. Mean EAT-10 scores increased from 17.1 to 20.6 (3.5 ± 8.1 points, p = 0.002) points. This change was related to those with a Zenker's diverticulum rather than an isolated cricopharyngeus bar. Dietary outcomes measured by FOIS were stable. While some patients showed fluoroscopic progression of bar size, no patients developed a Zenker's diverticulum from a pre-existing bar in this population. Our data indicate patients with a cricopharyngeus bar do not decline in subjective dysphagia score or diet tolerance, however those with a Zenker's diverticulum worsen over time. This has implications for treatment timing and counselling patients but also reflects a need to understand the pathophysiology behind CPMD and the subset of patients who show progression.

Prevalence and incidence of idiopathic subglottic stenosis in southern and central Alberta: a retrospective cohort study.

BACKGROUND: Subglottic stenosis (SGS) is a reportedly rare disease that causes recurrent severe airway obstruction. Etiologies reported for SGS include idiopathic, iatrogenic, autoimmune, congenital, and traumatic, with variable ratios among different centres. From empiric observation, southern and central Alberta was hypothesized to have a disproportionate distribution of SGS driven by increased idiopathic SGS (iSGS) compared to previous literature. Identification of causative agents of iSGS will help understand and guide future management options, so this study aimed to characterize the demographics of SGS subtypes, define prevalence and incidence rates of iSGS in southern Alberta, and geographically analyze for clustering of iSGS prevalence. METHODS: SGS patients from Alberta census divisions No. 1-9 and 15 were retrospectively reviewed. Patients were subtyped according to etiology of SGS and characterized. Idiopathic SGS prevalence and incidence was assessed; prevalence was further geographically segregated by census division and forward sortation area (FSA). Significant clustering patterns were assessed for using a Global Moran's I analysis. RESULTS: From 2010 to 2019 we identified 250 SGS patients, who were substantially overrepresented by idiopathic patients (80.4%) compared to autoimmune (10.0%), iatrogenic (7.6%), congenital (1.2%), and traumatic (0.8%). The total iSGS prevalence was 9.28/100,000 with a mean annual incidence rate of 0.71/100,000 per year. Significant clustering was observed (Moran's index 0.125; z-score 2.832; p = 0.0046) and the highest rates of prevalence were observed in southern Alberta and in rural communities heterogeneously dispersed around Calgary FSAs. CONCLUSION: In southern and central Alberta, iSGS patients were disproportionately over-represented in contrast to other subtypes with the highest prevalence in southern Alberta. There was a three-fold higher annual incidence compared to previous literature demonstrating the highest rates of disease reported worldwide. Future research aims to expand the geographical scope and to assess for demographic or environmental differences within significant clusters that may contribute to disease pathophysiology. LEVEL OF EVIDENCE: III.

Correlating Dysphagia Severity with Fluoroscopic Parameters in Patients with Zenker's Diverticulum.

Zenker's diverticulum (ZD) is an uncommon condition characterized by formation of a pseudodiverticulum in the hypopharynx that presents with considerable variability in swallowing symptomatology. Identifying radiographic features of ZD most associated with clinical impact could prove useful in counseling patients and predicting treatment response. This study was a retrospective case series of patients undergoing videofluoroscopic swallowing studies (VFSS) for Zenker's diverticulum at a tertiary dysphagia center. Anatomic parameters identified on VFSS of patients with ZD were correlated with subjective perception of swallowing using Eating Assessment Tool (EAT-10) scores. Upper esophageal sphincter (UES) opening at the point of maximal distention, area of diverticulum on the lateral view, height of the diverticulum, and entrance angle of the esophagus were measured. We identified 40 patients with ZD (52.5% male, mean age = 71.2 years). Narrow UES opening was significantly correlated with dysphagia severity (r = - 0.3445, p = 0.035). Largest area of diverticulum (r = 0.0188, p = 0.87), diverticulum height (r = 0.1435, p = 0.45), and esophageal entrance angle (r = 0.1677, p = 0.42) were not correlated with EAT-10 scores. Maximum UES opening size was predictive of severity of swallowing dysfunction in patients with ZD. Size of ZD and the angle of bolus entry in patients with ZD are not predictive of swallowing dysfunction. Understanding the predictors of swallowing dysfunction will assist in counseling patients on postoperative expectations.

Aspects of the assessment and management of pharyngoesophageal dysphagia.

Swallowing complaints are common and may have significant consequences for nutrition and pulmonary health. Etiology varies and different aspects of the deglutitive system may be affected. A thorough assessment from the oral cavity to the stomach will provide physiologic information that enables specific targeted management plans to be devised. Although the swallow trajectory bridges anatomic areas, there has previously been a tendency to compartmentalize assessment and treatment by arbitrary anatomic boundaries. It is now clear that this approach fails to appreciate the complexity of swallow mechanics and that systems (oral, pharyngeal, esophageal, and pulmonary) are intertwined and codependent. Swallowing specialists from different backgrounds and with complementary skill sets form a multidisciplinary team that can provide insight and address multiple areas of management. With the advent of new tools for instrumental evaluation, such as manometry, targeted rehabilitative strategies can be informed by physiology, increased in precision and breadth, and assessed quantitatively. Surgical approaches have evolved toward endoscopic techniques, and food technology is expanding options in dietary management. The multidisciplinary team is core to managing this varied and often neglected patient population. This review is for clinicians treating swallowing disorders and will explore the selected aspects of the assessment and management of pharyngoesophageal swallowing disorders.

Building an integrated multidisciplinary swallowing disorder clinic: considerations, challenges, and opportunities.

Dysphagia is a complex condition with numerous causes, symptoms, and treatments. As such, patients with dysphagia commonly require a multidisciplinary approach to their evaluation and treatment. Integrated multidisciplinary clinics provide an optimal format for a collaborative approach to patient care. In this manuscript, we will discuss considerations for teams looking to build a multidisciplinary dysphagia clinic, including what professionals are typically involved, what patients benefit most from this approach, what tests are most appropriate for which symptoms, financial issues, and traversing interpersonal challenges.

Proximal reflux: biochemical mediators, markers, therapeutic targets, and clinical correlations.

Airway reflux is implicated in the pathophysiology of a wide range of adult and pediatric upper and lower airway diseases. However, the diagnosis of proximal reflux-associated disease remains challenging due to evolving clinical criteria and institutional and regional variances in diagnostic practices. Evidence suggests that nonacidic contents of reflux may serve as both pathologic mediators of and biomarkers for reflux in the upper airway. Furthermore, they offer potential pharmaceutical and surgical intervention targets and are the focus of novel clinical diagnostic tools currently under investigation.

Retrospective review of dosing trends in botulinum toxin injections for the treatment of adductor spasmodic dysphonia in a long-term cohort.

BACKGROUND: Botulinum toxin A (BT) is the gold standard treatment for adductor spasmodic dysphonia (AdSD) with established use for greater than thirty years. The spasmodic dysphonia (SD) literature would benefit from additional long-term cohort data, especially in the Canadian population. The goals of this study were to evaluate whether BT dosage required to achieve acceptable voice shifts over time and to elucidate differences in the subgroups of patients receiving unilateral vocal fold (UVF) injections. METHODS: Patient records were retrospectively reviewed at the regional tertiary Voice Clinic for AdSD patients from 1996 to 2017 to identify AdSD patients treated with serial BT injections. Descriptive statistics, paired t-tests for time between treatments and ANOVA tests were used to evaluate trends in subgroup age. RESULTS: One-hundred and twenty-six patients (61% female, mean age = 53 ± 15.5 years) met inclusion criteria and received laryngeal EMG-guided BT injections for up to twenty-two years and as many as 79 treatments. The mean total BT dosage for our population was 1.54 ± 0.35 Units per side. The majority of subjects had decreasing doses over time with a small subgroup having slowly increasing doses. Comparing treatment dosages between unilateral and bilateral injection groups, injection dosage per vocal fold was 1.65 ± 0.62 with time between injections was significantly shorter for the unilateral injection group (mean = 105 days, SD ± 19.8 days, p = 0.005) compared to the bilateral injection subgroup (137 ± 35.7 days, p < 0.005). The mean age of the unilateral injection population as younger at 42.4 ± 11.8 years (p = 0.004). CONCLUSION: The majority of patients in this study had decreasing BT injection dosages over time, with a smaller proportion having slowly increasing doses, thought to be likely relating to disease severity. The unilateral vocal fold injections were well tolerated despite needing more frequent injections, and found to be more prevalent in the younger age group.

Volumetric changes in pharyngeal structures following head and neck cancer chemoradiation therapy.

OBJECTIVES/HYPOTHESIS: To determine the volumetric changes in pharyngeal structures in patients with head and neck squamous cell carcinoma (HNSCC) treated with curative chemoradiation therapy (CRT). Patients treated with CRT for esophageal carcinoma (EC), where pharyngeal structures were not part of the radiation treatment fields, were controlled for dysphagia-associated weight loss. We hypothesize that tissue volume alteration is a contributing factor of post-CRT dysphagia. STUDY DESIGN: Case series. METHODS: This study measured pre- and 1-year posttreatment volumes of the base of tongue (BOT), parapharyngeal spaces, posterior pharyngeal constrictors (PCs), and retropharyngeal space (RPS) in patients undergoing CRT for HNSCC or EC treated January 1, 2012 to December 31, 2015. All HNSCC patients were treated to doses of 66 to 70 Gy in 30 to 33 fractions using intensity-modulated radiotherapy techniques. RESULTS: Our cohort included 49 HNSCC and 11 EC patients. Within the HNSCC cohort, the PCs volume increased 1.55 cm3 (95% confidence interval [CI]: 0.77 to 2.34 cm3 , P = .0002), RPS increased 1.22 cm3 (95% CI: 0.67 to 1.77 cm3 , P < .0001), and BOT decreased 2.29 cm3 (95% CI: -0.20 to 4.79 cm3 , P = .070). The EC cohort showed no significant volumetric changes for any anatomic space, with combined PCs and RPS volume changes statistically less than the HNSCC cohort (P = .031). There was no difference in mean body mass index reduction between groups (P = .10). CONCLUSIONS: Volumetric changes following CRT may play a role in posttreatment dysphagia. Our findings support loss of physiologic function from posterior pharynx tissue thickening combined with reduced pharyngeal constriction capacity, and BOT atrophy secondary to radiation effects contribute to dysphagia. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:597-602, 2020.

Three-dimensional analysis of the human pharyngoesophageal sphincter.

OBJECTIVES: Dysfunction of the pharyngoesophageal segment (PES) is a common cause of oropharyngeal dysphagia. Surgical dilation of the PES uses cylindrical dilators that expand radially in a circular shape. Animal studies, however, suggest that the PES is kidney-shaped. The purpose of this investigation was to evaluate the 3D shape of the human PES with a novel casting method. METHODS: A platinum-cured liquid silicone polymer was infused under pressure into the upper aerodigestive tract of nine fresh human cadavers to construct 3D casts of the maximally distended PES. Cross-sectional and volumetric analysis were performed using computed tomography and serial sectioning of the models. Canonical variate analysis was used to identify the shape features that best distinguishes the PES from the cervical esophagus. RESULTS: The mean age of the cadavers was 77.9 (SD ± 10.6) years, with 67% women. Analysis of the casts confirms that the human PES possesses a kidney-shaped structure at maximal distention, which is discretely different from the adjacent esophagus (P < 0.001). The posterior body of the cricoid cartilage formed the anterior wall of the PES, which provided a rigid structure responsible for preservation of the kidney shape during distention. The diameter of the maximally distended PES at the cricopharyngeus was highly variable (range = 0.86-4.68 cm2 ; SD = 1.33 cm2 ). CONCLUSION: The data suggest that the human PES is not round and that targeted expansion at the level of the cricopharyngeus with an eccentrically shaped dilator may provide improved distention. LEVEL OF EVIDENCE: 4 Laryngoscope, 2019.

High elevation training mask as a respiratory muscle strength training tool for dysphagia.

BACKGROUND: Expiratory muscle strength training (EMST) is a treatment for swallowing dysfunction due to its activation of the suprahyoid muscles. Current EMST devices have numerous limitations. OBJECTIVE: The purpose was to evaluate the utility of elevation training mask as an alternative respiratory muscle strength training (RMST) device. METHODS: A closed system, simulating expiration was designed. Air was delivered through a pressure gauge with a measurement range of 0-15 psi. The EMST150TM and the Elevation Training Mask 2.0® (ETM) maximal resistance levels were measured and compared. RESULTS: EMST150 produced increasing expiratory resistance pressures of 0.3, 0.6, 1.2, 1.9 and 2.1 psi, which correspond to its indicator of 30, 60, 90, 120 and 150 cmH2O. The ETM resistance pressure produced expiratory resistance pressures of 0.1 and 0.2 psi at simulated altitudes of 3000 and 6000 feet, respectively. A stable expiratory resistance pressure of 0.25 psi was measured at simulated altitudes of 9000, 12,000, 15,000 and 18,000 feet. CONCLUSION: ETM provides adjustable expiratory muscle strength resistance pressures. Further investigation is necessary to evaluate safety, compliance and clinical efficacy in patients with swallowing dysfunction. SIGNIFICANCE: ETM can serve as an effective treatment modality for pulmonary dysfunction and swallowing disorders through RMST.