Pharyngoesophageal Segment Research Articles

Dilation of the Upper Esophageal Sphincter

The upper esophageal sphincter (UES) is a 3 to 5 cm long multiplicitous high-pressure zone that connects the hypopharynx to the cervical esophagus. Due to its anatomic location between the arbitrary anatomic boundaries of numerous subspecialties, this region has often been referred to as “no man’s land.” Recent evidence confirming that the UES is not round suggests that conventional dilators designed to distend the cylindrical esophagus may be inappropriate to treat disorders of this region. This has led to the development of devices specifically designed to dilate the kidney shaped UES. The purpose of this manuscript is to review the anatomy and physiology of the UES, educate the reader on the most common indications for UES dilation, and describe the contemporary technique of state-of-the-art dilation of the UES with a novel device designed specifically to treat disorders of the pharyngo-esophageal segment.

Respiratory-swallow patterning and oropharyngeal swallowing impairment in patients undergoing evaluation for lung transplant.

Although swallowing impairment is prevalent following lung transplantation, baseline respiratory and swallowing characteristics are often overlooked. Respiratory disease processes may predispose lung transplant candidates to altered respiratory-swallow patterning and swallowing impairment. This cross-sectional study included patients referred for a Modified Barium Swallow Study during lung transplant evaluation. Swallowing impairment was measured using the Modified Barium Swallow Impairment Profile and Penetration-Aspiration Scale. Respiratory plethysmographic signals synchronized with videofluoroscopy were analyzed to determine phase patterning, pause duration, and rate. Mixed-effects logistic regression was used to identify linkages between respiratory and swallowing measures. Fifty patients were included and demonstrated delayed swallow initiation (49/50), oral residue (37/50), incomplete pharyngoesophageal segment opening (35/50), and esophageal retention (43/50). Airway invasion occurred infrequently (10/50). Atypical respiratory patterning was significantly associated with impairment in pharyngeal swallow initiation (OR [95% CI] = 1.76 [1.16, 2.68], p = 0.009), laryngeal elevation (OR [95% CI] = 1.45 [1.01, 2.07], p = 0.044), and laryngeal vestibular closure (OR [95% CI] = 2.57 [1.48, 4.46], p < 0.001). Increased pause duration was associated with impaired initiation (OR [95% CI] = 2.24 [1.20, 4.16], p = 0.011), laryngeal elevation (OR [95% CI] = 1.18 [1.03, 1.36], p = 0.018), laryngeal closure (OR [95% CI] = 1.28 [1.9, 1.50], p = 0.003), and tongue base retraction (OR [95% CI] = 1.33 [1.13, 1.56], p < 0.001). Patients undergoing evaluation for lung transplant demonstrated impaired swallowing and phase patterning. Preliminary findings implicate the need for further evaluation of respiratory-swallow coordination and its potential role in swallowing impairment before and after lung transplantation.

Inter-rater reliability and clinical relevance of subjective and objective interpretation of videofluoroscopy findings.

Dysphagia is commonly evaluated using videofluoroscopy (VFS). As its ratings are usually subjective normal-abnormal ratings, objective measurements have been developed. We compared the inter-rater reliability of the usual VFS ratings to the objective measurement VFS ratings and evaluated their clinical relevance. Two blinded raters analyzed the subjective normal-abnormal ratings of 77 patients' VFS. Two other blinded raters analyzed the objective measurements of pharyngeal aerated area with bolus held in the oral cavity (PAhold), the pharyngeal area of residual bolus during swallowing (PAmax), the pharyngeal constriction ratio (PCR), the maximum pharyngoesophageal segment opening (PESmax), pharyngoesophageal segment opening duration (POD), airway closure duration (ACD), and total pharyngeal transit time (TPT). We evaluated the inter-rater agreement in the subjective ratings and the objective measurements. Clinical utility analysis compared the measurements with the VFS findings of pharyngeal phase abnormality, penetration/aspiration, and cricopharyngeal relaxation. In the pharyngeal findings, the subjective analysis inter-rater agreement was mainly moderate to strong. The strongest agreements were on the pharyngeal residues and penetration/aspiration findings. The objective measurements had fair to good inter-rater agreement. Clinical utility analysis found statistically significant connections between TPT and pharyngeal phase abnormality, normal PCR and lack of penetration/aspiration, and normal PESmax and normal cricopharyngeal relaxation. The subjective analysis had moderate to strong inter-rater agreement in the pharyngeal VFS findings, especially concerning pharyngeal residues and penetration/aspiration detection, reflecting the efficacy and safety of swallowing. The objective measurements had fair to good inter-observer reproducibility and could thus improve the reliability of VFS diagnostics. 4.

Effortful Swallow Maneuver and Modifications on Swallow Dynamics in Healthy Adults

Introduction: Effortful swallow (ES) is a widely used technique in dysphagia management, believed to strengthen oropharyngeal muscles and enhance swallowing safety and efficiency. Although its impact on the oral phase of swallowing is well documented, its effects on pharyngeal swallowing physiology remain inconsistent. This study aimed to elucidate the effects of ES on swallowing kinematics and timing, addressing existing inconsistencies in the literature. Methods: This study involved 22 healthy adults using archived videofluoroscopic swallowing studies. Participants performed three swallow trials of 10 mL puree under regular conditions and with the ES maneuver. The outcome measures comprised swallow timing and kinematic measures. Swallow timing parameters included time to maximum hyoid and laryngeal excursion, laryngeal vestibule closure (LVC) reaction and duration, pharyngeal constriction duration, pharyngoesophageal segment (PES) opening duration, and swallow duration. Swallow kinematic parameters encompassed hyoid and laryngeal excursions, pharyngeal constriction ratio, and maximum PES width. All variables were analyzed via videofluoroscopy. Paired t tests were used to examine the effect of ES on each outcome measure, with a significance threshold set at p < 0.004. Results: The ES maneuver significantly increased the duration of LVC, pharyngeal constriction, PES opening, and overall swallow duration. It also improved the pharyngeal constriction ratio. However, there were no significant changes in hyoid and laryngeal excursions. Submental muscle activity showed a notable increase during ES. Conclusion: The study demonstrates that ES can effectively modify certain temporal and kinematic aspects of swallowing, particularly by prolonging key phases and enhancing pharyngeal constriction. These findings suggest the potential utility of ES in dysphagia rehabilitation, especially in cases that require prolonged pharyngeal constriction, LVC, and PES opening. However, the limited impact on hyoid and laryngeal excursions along with LVC reaction time indicates that ES may not address all aspects of dysphagia. The findings highlight the need for tailored therapeutic approaches in dysphagia management, considering individual physiological impairment profiles.

Investigating Parkinson's disease with dual high resolution pharyngeal manometry with impedance and videofluoroscopy.

To characterize pharyngeal function in people with Parkinson's Disease using both high resolution impedance manometry (HRIM) and videofluoroscopy (VFSS) and to explore correlations between VFSS and HRIM metrics. All participants received both VFSS and HRIM within 24 h-time window. A standard VFSS protocol (IDDSI 0: 1 mL, 3 mL, 20 mL, and 100 mL) was performed. A solid-state unidirectional catheter (36 pressure sensors) was used to acquire manometric data for triplicate swallows (IDDSI 0: 5 mL, 10 mL, 20 mL), quantitative swallow analysis was completed through Swallowtail™ and SwallowGateway™. Parameters were compared to published norms and statistical tests explored correlational associations (p < 0.05). Twenty-one participants (76% male; mean age 70 years, SD7.16) with mild-moderate severity PD were recruited with 73% reporting Eating Assessment Tool (EAT-10) scores ≥3 indicating swallow impairment. Compared to normal metrics, one third of participants had abnormally elevated hypopharyngeal contractile integral (HPCI), hypopharyngeal peak pressure, upper esophageal sphincter (UES) integrated relaxation pressure (UES IRP), and reduced UES maximum admittance. Five participants showed compromised swallow safety (Penetration-Aspiration Scale score ≥6). One third of participants had abnormal VFSS values for pharyngoesophageal segment (PES) opening duration, maximum PES opening distance, and maximum hyoid displacement measures. Some HRIM metrics had a strong correlation with pharyngeal VFSS measures (r > 0.60, p < 0.05). This study identifies early manometric signs of pharyngeal dysfunction in people with PD. The congruence of the VFSS and HRIM measures confirms the hypothesis of insidious early decline in swallow function in PD despite maintenance of airway safety (i.e., low aspiration rates).

Objective evaluation of the pharyngoesophageal segment as a source of substitute phonation in patients after total laryngectomy

The study aimed to identify objective predictors of the successful voice rehabilitation after total laryngectomy to select the optimal method of voice restoration.Material and Methods. The study included 60 laryngectomized male patients who were stratified into 2 equal groups depending on the patient’s choice of voice restoration: tracheoesophageal puncture or esophageal voice. A comprehensive assessment of the qualitative and quantitative parameters of the pharyngoesophageal segment was carried out using the diagnostic procedures, such as: fiberoptic endoscopic evaluation of swallowing, high-speed video endoscopy, and high-resolution pharyngoesophageal manometry. The results of examination of the pharyngoesophageal segment were compared with the results of voice rehabilitation.Results. A significant difference in the resting pressure in the pharyngoesophageal segment between patients with successful and unsuccessful voice rehabilitation was found. The resting pressure in the pharyngoesophageal segment was higher in patients with unsuccessful voice rehabilitation than in patients with successful voice rehabilitation. Among patients with failed voice rehabilitation, 64 % had pseudodiverticula, 25 % had cicatricial strictures and 11 % had pharyngospasm. Pseudodiverticula were found only in patients who underwent vertical or apparatus pharyngeal closure. We described vibrating patterns of substitute phonation in laryngectomized patients and identified 5 different types of pseudoglottis. No significant differences between the methods of substitute phonation were found.Conclusion. The state of pharyngoesophageal segment is an objective predictor of successful substitute phonation and depends on the surgical technique of pharyngeal closure, the volume of cancer treatment and the course of the postoperative period. A comprehensive assessment of the qualitative and quantitative parameters of the pharyngoesophageal segment using fiberendoscopic, fuoroscopic studies and highresolution pharyngoesophageal manometry allows prediction of voice rehabilitation outcomes.

High-Resolution Manometry Contributions to the Physiology of Phonation

High-resolution manometry (HRM) is a motility diagnostic system that measures intraluminal pressure of the gastrointestinal tract using a series of closely spaced pressure sensors. The topographic plot generated by HRM software makes it possible to visualize phonation pressures at the pharynx, UES, and body of the esophagus in real time, indicating pressure intensity by color, which permits easy data interpretation. It has been largely used for swallowing study and dysphagia diagnosis. Due to the proximity of the pharyngoesophageal and laryngeal structures, this technology instigated voice researchers. Despite the few studies published so far, high-resolution manometry has yet proven to be an extremely useful tool in obtaining entire pharyngoesophageal segment pressure measurements during phonation. It also allows natural voice production not interfering with the mouth area. HRM data already brought light to subglottic pressure, vertical laryngeal excursion, cricopharyngeal muscle activation, air flow, muscle tension associated with vocalization and pressure variations associated with different phonatory stimuli.

Flexible Zenker's Per-oral Endoscopic Myotomy

Zenker's diverticulum is a pulsion-type pseudodiverticulum of the pharyngoesophageal segment. Endoscopic surgery is primarily directed at dividing the common wall between the esophagus and diverticulum. Rigid exposure with diverticuloscopes have allowed for common wall division with staplers, lasers, and advanced energy sealers, however not all patients can be successfully treated with rigid instrumentation. As a result, flexible endoscopic surgery provides another option for patients. This technique employs various instrumentation through the working channel of a gastroscope to not only divide the common wall but seal the incision, which if done appropriately, results in a symptom resolution with complication rates comparable to rigid techniques. Flexible endoscopic surgery requires the surgeon to perform technically challenging submucosal dissection through a gastroscope as well as possess expertise with advanced energy delivery systems and instrumentation. However, with time, surgeons can build these skills to offer the breadth of surgical options tailored to the individual patient.

Longitudinal Analysis of Dysphagia and Factors Related to Postoperative Pneumonia in Patients Undergoing Esophagectomy for Esophageal Cancer

AbstractFew studies have quantified longitudinal changes in swallowing in patients undergoing esophagectomy for esophageal cancer. This study longitudinally analyzed the changes in the Modified Barium Swallow Study Impairment Profile (MBSImP™) scores, swallowing kinematic measurements, and swallowing-related symptoms in patients undergoing esophagectomy. We also examined the association between identified swallowing impairment and aspiration pneumonia after surgery. We included consecutive patients who underwent esophagectomy and completed laryngoscopy and videofluoroscopy before, two weeks, and three months after surgery. We analyzed physiological impairments using the MBSImP. We also assessed the swallowing kinematics on a 5 mL thickened liquid bolus at three time points. Vocal fold mobility was assessed using a laryngoscope. Repeated measures were statistically examined for longitudinal changes in swallowing function. The association between the significant changes identified after esophagectomy and aspiration pneumonia was tested. Twenty-nine patients were included in this study. Preoperative swallowing function was intact in all participants. The timing of swallowing initiation and opening of the pharyngoesophageal segment remained unchanged after surgery. Tongue base retraction and pharyngeal constriction ratio worsened two weeks after surgery but returned to baseline levels three months after surgery. Three months after surgery, hyoid displacement and vocal fold immobility did not fully recover. Aspiration pneumonia occurred in nine patients after surgery and was associated with postoperative MBSImP pharyngeal residue scores. Decreased hyoid displacement and vocal fold immobility were observed postoperatively and persisted for a long time. The postoperative pharyngeal residue was associated with pneumonia and thus should be appropriately managed after surgery.

Impact of Varying Transcutaneous Electrical Stimulation Pulse Frequency on Swallow Timing Measures in Healthy Adults.

The impaired swallow timing subsequent to dysphagia or aging can potentially endanger swallowing safety and efficiency. Preliminary evidence has suggested that transcutaneous electrical stimulation (TES) may have the potential to affect swallow timing. However, limited knowledge exists regarding which TES parameters can optimize swallow timing. Pulse frequency is one of the primary TES parameters that can affect the quality of muscle contraction. Yet, no clear information exists regarding how changing pulse frequency impacts the timing of swallowing events. This study aimed to investigate the varying effects of submental TES pulse frequency on swallowing events during and post-15-min TES administration. Twenty-six healthy individuals between the ages of 20 and 54 participated in this study and were assigned to high pulse frequency (HPF) (80 Hz) or low pulse frequency (LPF) (30 Hz) groups. Videofluoroscopic swallowing study (VFSS) was used to record swallowing. Three trials of 10mL pureed mixed with barium sulfate were presented under three different conditions, including pre-TES, during TES, and post-TES, in which measures were taken following 15min of TES delivery. The swallow timing events that were measured in each condition were time to maximum hyoid elevation, time to maximum laryngeal elevation, laryngeal vestibule closure reaction time (LVCrt), laryngeal vestibule closure duration (LVCd), time to maximum pharyngeal constriction, and pharyngoesophageal segment (PES) opening duration. No significant pulse frequency effect was found on any swallow timing measures during or after 15min of TES. Both protocols decreased the duration of some swallowing events during TES including time to maximum hyoid elevation [p < 0.017, ηp2 = 0.185], LVCrt [p < 0.032, ηp2 = 0.158], and time to maximum pharyngeal constriction [p < 0.034, ηp2 = 0.155]. None of the significant TES effects were continued when TES ceased after 15min. Overall, both protocols have comparable immediate effects on shortening the duration of some swallowing events during TES. Future clinical trials should examine whether these physiologic timing changes can lead to safer and more efficient swallows in patients with dysphagia.

An experimental model of the pharyngoesophageal segment in tracheoesophageal phonation.

Tracheoesophageal (TE) speech is an important method of speech rehabilitation for those who undergo a total laryngectomy. Despite the many advantages over other methods, there is still room for improvement in terms of the overall quality of the TE voice as well as its success rate. These points could be greatly assisted by an improved knowledge on the mechanics of TE speech. Here, an experimental model of the pharyngoesophageal segment (PES), based on the idea of a collapsible tube, is proposed. To implement the model, considerable simplifications had to be made, most notably in the use of a thin flexible tube to represent the PES. The model was used to assess the minimum amount of tonicity required for the onset of phonation in terms of the flow rate and longitudinal tension. Additionally, comparisons with a mathematical model [Tourinho, da Silva, dos Santos, Thomaz, and Vieira, J. Acoust. Soc. Am. 149, 1979-1988 (2021)] have been made, yielding similar trends for sufficiently large flow rates. The measurements also suggest that the phonation frequency is most affected by the tonicity of the PES, which highlights the question of which physiological mechanism is responsible for the control of the fundamental frequency of phonation.

Objective Fluoroscopic Outcomes After Endoscopic Staple Versus Laser Zenker's Diverticulotomy.

Endoscopic Zenker's diverticulotomy (EZD) is typically performed via stapling (endoscopic staple diverticulotomy; ESD) or CO2 laser (endoscopic laser diverticulotomy; ELD). Conflicting reports exist on which approach provides optimal outcomes. This investigation compared objective fluoroscopic data between ESD and ELD. A retrospective review of all patients undergoing primary EZD at a tertiary center between January 1, 2014 and January 10, 2022 was performed. Patients undergoing ESD and ELD were matched by preoperative diverticulum size. Primary outcome measures were postoperative diverticulum size and change in diverticulum size from pre- to postoperative swallowing fluoroscopy. Secondary outcome measures were the Eating Assessment Tool (EAT-10) score, penetration aspiration scale (PAS), pharyngeal constriction ratio (PCR), and pharyngoesophageal segment opening (PESo). Thirteen matched pairs with complete fluoroscopic data were identified. The mean (±SD) age of the cohort was 74.0 (±8.5) years. There were no age or gender differences between groups (p > 0.05). The mean pre-operative ZD size was 1.98 (±0.69) cm for ESD and 1.97 (±0.72) cm for ELD; the mean postoperative size was 0.84 (±0.62) cm for ESD and 0.34 (±0.27) cm for ELD (p < 0.05). Mean diverticulum size improved by 1.14 (±0.59) cm after ESD and 1.62 (±0.59) cm after ELD (p < 0.05). There were no significant differences in postoperative EAT-10, PAS, PCR, or PESo between groups. The data suggest that endoscopic laser Zenker's diverticulotomy results in a greater improvement in diverticulum size than endoscopic staple diverticulotomy. The data did not suggest a difference in postoperative dysphagia symptom scores or other objective fluoroscopic parameters between staple and laser diverticulotomy. Level 3 Laryngoscope, 133:3057-3060, 2023.

Impact of Quantitative Videofluoroscopic Swallowing Measures on Clinical Interpretation and Recommendations by Speech-Language Pathologists

Quantitative measures are available for adult videofluoroscopic swallow study (VFSS) analysis but are yet to be seen routinely in clinical practice. This study explores agreement between traditional observational analysis and quantitative analysis, and the impact of analytical approaches on subsequent diagnosis and recommendations. One hundred adults referred for VFSSs with swallowing concerns were administered a standardised VFSS protocol. All VFSSs were analysed using three approaches: (1) a traditional observational analysis typically used by treating speech-language pathologists (SLPs), (2) quantitative analysis by two independent raters, and (3) binary subjective analysis by 11 independent raters. Three metrics were focussed on; pharyngeal constriction (PC), hyoid displacement (Hmax) and pharyngoesophageal segment opening (PESmax). All raters were blinded to others’ ratings. Treating SLPs using traditional observational analysis were provided with no instructions. Quantitative analysis used published Leonard and Kendall digital displacement measures. Binary subjective analysis involved rating each VFSS as normal versus impaired for the three metrics above. Treating SLPs using traditional observational analysis and quantitative analysis raters independently provided diagnostics and treatment plans. PC, Hmax and PESmax achieved fair agreement (Kappa = 0.33–0.36) between binary subjective analysis compared to substantial agreement (ICC = 0.77–0.94) for quantitative analysis. Reports of impairment were significantly lower in the traditional observational and binary subjective analyses compared with studies rated using the quantitative analysis (p < 0.05). Consequently, this resulted in significantly less rehabilitation recommendations when traditional observational analysis was used in comparison to the quantitative analysis. Quantitative measures to analyse VFSSs can be used in clinical practice producing increased inter-rater agreement and supporting more targeted rehabilitation recommendations than using a traditional observational VFSS analysis alone.

Has Esophageal Speech Returned as an Increasingly Viable Postlaryngectomy Voice and Speech Rehabilitation Option?

The literature on postlaryngectomy voice and speech rehabilitation is long-standing. Although multiple rehabilitation options have existed over the years, the acquisition and use of esophageal speech (ES) has decreased significantly over the past 40 years. This reduction coincides with the increased application of tracheoesophageal puncture (TEP) voice restoration. The literature suggests that voice acquisition failures observed secondary to TEP may represent a similar phenomenon that led to ES acquisition failures. A comprehensive review of the literature on ES and TEP voice/speech was conducted. Specific attention was directed toward information on ES and TEP speech failures. Information on pharyngoesophageal segment (PES) spasm in the context of ES and TEP voicing failures was of specific importance. Similarities between voicing failures with both ES and TEP were identified. In order to resolve spasm in TEP speech, proactive efforts to eliminate it were undertaken, and regardless of the method used, voicing improvements were observed. These data suggest that both ES and TEP speech acquisition failures may be related to the same control mechanisms influencing the PES. The elimination of PES spasm provides evidence that justifies the reconsideration of ES. Consequently, ES may return as an increasingly viable postlaryngectomy voice and speech rehabilitation option.

Bolus Clearance Ratio Elevated in Patients With Neurogenic Dysphagia Compared With Healthy Adults: A Measure of Pharyngeal Efficiency.

Postswallow pharyngeal residue is a risk factor for aspiration, implies swallowing inefficiency, and increases the work of eating. The Bolus Clearance Ratio (BCR) is a derived metric that relates quantities of bolus material observed in the pharynx at two different points: before and after a swallow. The ratio provides a percentage estimate of bolus clearance. In healthy adults, mean BCR is < .05; that is, less than 5% of an ingested bolus is retained in the pharynx. The aim of this study was to compare BCR measures from patients referred for videofluoroscopic swallow studies with concerns related to stroke (n = 100) or other neurological conditions (n = 131, including Parkinson's disease and dementia) with BCRs for 139 healthy adults across the age range. BCR for a 20 ml of thin liquid barium bolus was measured. Additional metrics included age, penetration-aspiration scale (PAS) score, and quantitative measures of timing and displacement. Correlations were explored between BCR and pharyngeal constriction ratio (PCR), pharyngoesophageal segment opening (PESmax), maximum hyoid displacement (HMax), and total pharyngeal transit time (TPT). BCR values for patients with stroke (Mdn = 9%, interquartile range [IQR]: 19%, range: 0%-73%) and other neurological conditions (Mdn = 9%, IQR: 16%, range: 0%-96%) were significantly higher than in healthy norms (Mdn = 2%, IQR: 4%, range: 0%-16%, p < .001). BCR was significantly correlated with age (R s = .23, p < .01), TPT (R s = .20, p < .01), PCR (R s = .55, p < .01), PESmax (R s = -.17, p < .01), HMax (R s = -.16, p < .01), and PAS (R s = .38, p < .01). BCR was elevated in patients with neurogenic dysphagia in comparison with healthy norms and was significantly associated with increased aspiration severity (i.e., PAS). BCR was also correlated with pharyngeal timing and displacement parameters, with the strongest correlation with pharyngeal constriction-a measure of pharyngeal strength. The BCR offers clinicians a simple, quantitative measure of bolus residue and, therefore, pharyngeal efficiency and may be used to assess change in patients over time and with treatment.

Effects of Presbyphagia on Oropharyngeal Swallowing Observed during Modified Barium Swallow Studies.

Understanding how aging impacts swallowing can help differentiate typical from atypical behaviors. This study aimed to quantify age-related swallowing alterations observed during a modified barium swallow study. Cross-sectional study. Adult fluoroscopy suite in a metropolitan hospital at an academic center. 195 healthy adults distributed across 3 age categories: 21-39; 40-59; 60+ years. 17 physiologic components of swallowing across three functional domains (oral, pharyngeal, esophageal), including summed composite scores (Oral Total [OT] and Pharyngeal Total [PT]), from the validated and standardized Modified Barium Swallow Impairment Profile. Most components (65%) demonstrated no impairment (scores of "0"). The odds of a worse (higher) score increased significantly with age for: Tongue Control during Bolus Hold, Hyolaryngeal Movement, Laryngeal Closure, Pharyngeal Contraction, and Pharyngoesophageal Segment Opening. OT and PT scores for 40-59-year-olds were worse than the youngest group (p=.01 and p <.001, respectively). Adults 60+ years had significantly worse PT scores among all groups (p-values <.01). Oropharyngeal swallowing physiology evolves as healthy adults age and should be considered during clinical decision-making.

Determining Swallowing Biomechanics Underlying Modified Barium Swallow Impairment Profile Scoring Using Computational Analysis of Swallowing Mechanics.

The elements of impaired swallowing biomechanics are visually assessed and scored by clinicians using a standardized and validated tool for assessing type and severity of physiological impairments using the Modified Barium Swallow Impairment Profile (MBSImP). However, the functional anatomical correlates that underly noted impairments using MBSImP scoring have not been measured. The purpose of this study was to determine whether differences in MBSImP component scores represent differences in underlying swallowing mechanics as measured by computational analysis of swallowing mechanics (CASM) to better define underlying mechanisms of impairment. A retrospective analysis of modified barium swallow studies from physician-referred adult patients with dysphagia was scored using the MBSImP for laryngeal elevation, anterior hyoid excursion, epiglottic movement, pharyngoesophageal segment opening, and tongue base retraction. A canonical variate analysis (CVA) was performed to determine the movement of anatomical landmarks associated with MBSImP component scores using the CASM method. Mahalanobis distances (D) were then used to detect differences among MBSImP scores for each component assessed. CVA showed significant differences (p < .0001) in Mahalanobis distance (D > 1) between MBSImP component scores of 0-1, 0-2, 0-3, or 0-4, as applicable, depending on the component. Discriminant function analyses revealed concomitant increase/worsening in MBSImP score with changes in anatomical positioning of structures. Ratings of swallowing impairment and physiology using the MBSImP have distinct biomechanical correlates with anatomical movements of swallowing. These data further demonstrate how swallowing mechanics are highly interrelated. Understanding these linkages between anatomical and physiological movement within impaired swallowing biomechanics is essential in more specific characterization and treatment of dysphagia. https://doi.org/10.23641/asha.20816788.

The upper esophageal sphincter: anatomy and physiology

: The upper esophageal sphincter (UES), also known as the pharyngoesophageal segment (PES), is a 4-cm segment of the digestive tract that separates the esophagus from the pharynx and larynx. This narrative review represents an overview of the anatomy and physiology of this critical component of the airway protective mechanism. The structure is bounded anteriorly by the larynx, posterolaterally by the pharyngoesophageal muscles, superiorly by the pharynx and inferiorly by the esophagus. Guarding the entrance of the esophagus, the UES controls inflow and outflow through the region, preventing aerophagia in the anterograde direction as well as regurgitation in the retrograde. Although the cricopharyngeus muscle (CPM) is often considered synonymous with the UES, in reality it is but one component of the complicated anatomy. In fact, relaxation of the CPM is not the primary contributor to UES opening. During the act of swallow, the relaxation of the CPM, elevation of the larynx and propulsion of the food bolus by the pharynx coordinate to open the UES and facilitate deglutition. An understanding of the anatomy of the region in addition to the phases of UES opening facilitates more refined therapeutic interventions for patients with pharyngoesophageal swallow impairment and dysphagia.

Global Dysphagia Scale Detects Swallowing Disorder Following a Clinical Dose of Buprenorphine

Opioid use is associated with increased risk of chest infection due to opioid suppression of immune function, ventilation, cough, and secretion mobilization. Buprenorphine is a highly lipophilic, semi‐synthetic partial agonist of the mu opioid receptor. Intramuscular buprenorphine is commonly used for post‐operative analgesia at a dose range of 0.01‐0.04 mg/kg in the cat. While buprenorphine is considered to have a low side effect profile, its effects on the pharyngeal phase of swallow are unknown. We hypothesized that administration of opioid would result in clinically meaningful decline of pharyngeal swallow function. Experiments were performed on healthy adult cats (12 months old). Animals were administered intramuscular buprenorphine (0.015 mg/kg) q12 hours for 48 hours. One hour after the last dose was given, videofluoroscopic swallow studies were performed to evaluate the effects of the drug on swallow function. Animals were presented with 40% by volume barium sulfate in tuna water mixed to a thin consistency, and all animals ate voluntarily. Images were recorded in the lateral plane at 30 frames/second and compared to control feeding assessments using the Global Dysphagia Scale (GDS), a novel tool developed to rate swallow function in the cat. The GDS consists of an Airway Invasion Scale (AIS) and relevant components of the Modified Barium Swallow Impairment Profile (MBSImP), a standardized protocol for swallow assessment. The AIS is a 10‐point scale where scores of 0‐1 are normal, scores of 2‐4 indicate laryngeal penetration, and scores of 5‐9 indicate tracheobronchial aspiration. Four components of the MBSImP were included: Initiation of the pharyngeal swallow, pharyngeal stripping wave, pharyngoesophageal segment opening, and pharyngeal residue. The GDS rating was derived by adding the AIS and MBSImP sub‐totals. During control assessments mean GDS was 5.5 ± 1.3, and aspiration was not detected in any animal. On buprenorphine, mean GDS was 11.25 ± 4.2, and 50% of animals exhibited large volume tracheobronchial aspiration. In conclusion, after 48 hours on buprenorphine, airway protection during swallow failed without appreciable response in 50% of animals (no cough, throat clear, or cessation of eating). Our success in producing dysphagia (significant but varying by animal) with relatively small doses of opioid has potential implications for predicting aspiration pneumonia in post‐surgical clinical cases.

An experimental model for the study of tracheoesophageal phonation

Tracheoesophageal speech is the most widely used method of speech rehabilitation for those who have undergone a total laryngectomy. Despite its high success rate, the interplay between different factors may inhibit voice production. Among these factors, the amount of muscle contraction in the pharyngoesophageal segment is the most significant one. The present work is aimed at studying the effect of muscle contraction on tracheoesophageal voice production. An experimental model has been developed, in which a silicone tube, acting as the pharyngoesophageal segment, is connected at both ends to rigid tubes representing the pharynx and the esophagus. The effect of the musculature of the pharyngoesophageal segment has been included in the model by two different components. The first one, modeling the tendency of the muscle layer to close the pharyngoesophageal segment, has been taken into account by placing the tube inside a pressurized chamber. The second, modeling the stretching caused by longitudinal muscle fibers, has been included by means of a sliding device in one of the terminations of the silicone tube. The necessary parameters for self-sustained oscillations to occur were measured and compared with predictions made by a mathematical model [Tourinho et al., J. Acoust. Soc. Am. 149, 1979–1988 (2021)].