Swallowing Pressure Variability as a Function of Pharyngeal Region, Bolus Volume, Age, and Sex

Normative High-Resolution Pharyngeal Manometry: Impact of Age, Size of System, and Sex on Primary Metrics and Pressure Stability

There have been many reports of normative pharyngeal swallowing pressures using high-resolution pharyngeal manometry, but there is a fair amount of between-subject variance in reported pressure parameters. The purpose of this study was to put forward normative pharyngeal high-resolution manometry measures across the lifespan and investigate the effects of age, size of system, and sex. High-resolution pharyngeal manometry was performed on 98 healthy adults (43 males) between the ages 21 and 89. Pressure duration, maxima, integral, and within-individual variability metrics were averaged over 10 swallows of 10-ml thin liquid. Multiple linear and logistic regressions with model fitting were used to examine how pharyngeal pressures relate to age, pharyngeal size, and sex. Age was associated with tongue base maximum pressure, tongue base maximum variability, and upper esophageal sphincter-integrated relaxation pressure (F3,92 = 6.69; p < 0.001; adjusted R2 = 0.15). Pharyngeal area during bolus hold was associated with velopharynx integral (F1,89 = 5.362; p = 0.02; adjusted R2 = 0.05), and there was no significant model relating pharyngeal pressures to C2-C4 length (p < 0.05). Sex differences were best described by tongue base integral and hypopharynx maximum variability (χ2 = 10.27; p = 0.006; pseudo R2 = 0.14). Normative data reveal the distribution of swallow pressure metrics which need to be accounted for when addressing dysphagia patients, the importance of pressure interactions in normal swallow, and address the relative stability of swallow metrics with normal aging.

Videofluoroscopy of the aerodigestive tract in Phoca vitulina: reshaping perspectives on translational medicine

Thousands of rescued harbor seals (Phoca vitulina) require rehabilitation worldwide. Many require resource intensive gavage feeding due to abandonment soon after birth. Little is known about seal swallowing, therefore, our primary objective was to determine the feasibility of conducting videofluoroscopic swallowing studies (VFS) on seal pups prior to their release. Secondarily, we propose swallowing phase descriptions. We adapted a VFS approach used in humans and our feasibility parameters included: bolus detection and consumption, and number of analyzable swallowing events. Unrestrained seals were imaged in a dry environment using a Siemens mobile c-arm fluoroscopy unit. Oral boluses were thawed herring injected with liquid barium suspension (105% w/v). Two independent raters described swallows using a standardized approach with results summarized descriptively. We successfully completed freely-behaving VFS with two infant seals (1 male: 8 wks, 3 d; 1 female: 5 wks, 3 d). Both consumed five boluses with six fully analyzable swallowing events. We describe four swallow phases: preparatory, prehension, oropharyngeal and esophageal. Airway protection likely occurs in two ways: (1) during the preparatory phase through modified corniculate cartilage contact with the glottis and (2) with soft palate contact to the base of tongue prior to swallow initiation. We have conducted a unique VFS approach on rehabilitated seals, prior to their release. We have described airway protection and suggest that swallowing is initiated earlier in the feeding process than described previously. This protocol success will afford: (1) collection of normative swallowing data, and (2) future knowledge translation from humans to seals.

Normal Variations in Upper Esophageal Sphincter Function During Deglutition: A Secondary Analysis of Videofluoroscopic Data

OBJECTIVE

Cricopharyngeal dysfunction is a common potential cause of pharyngoesophageal dysphagia. Contextual factors (i.e., personal demographics and bolus properties) appear to impact upper esophageal sphincter (UES) function but have yet to be assessed collectively in a large-scale study using psychometrically sound swallow task procedures. Using a standardized and validated videofluoroscopic approach, we investigated the collective effects of age, sex, and swallow task on UES opening duration (UESOdur) and UES maximum distension (UESmax) in a large sample of healthy adults.

METHODS

UESOdur and UESmax data were analyzed from existing videofluoroscopic images of 195 healthy adults (21-89 years old) across seven swallow tasks (thin liquid to viscous liquids, puree, and a solid). Generalized estimating equation modeling captured the effects of the aforementioned contextual factors (α = 0.05).

RESULTS

UESOdur significantly increased with age, while UESmax had an inverse relationship. Females had significantly wider UESmax. UESOdur of 5 mL thin liquid was significantly shorter than all other liquid swallow tasks, while solid had an inverse effect. Compared to 5 mL thin liquid, all other swallow tasks resulted in significantly wider UESmax. Mildly and moderately thick liquid significantly increased UESOdur when isolating viscosity. UESmax was significantly wider with mildly and moderately thick liquid and puree than thin liquid. When isolating volume, cup sip thin liquid increased both measures significantly relative to 5 mL.

CONCLUSION

Age, sex, and swallow task can influence the normal timing and extent of UES movement. These collective effects contribute to normal variability in UES function and should be considered for clinical decision-making.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:2306-2315, 2024.

A Systematic Review of Pharyngeal High-Resolution Manometry Normative Data

PURPOSE

The utilization of high-resolution pharyngeal manometry (HRPM) in the evaluation of pharyngeal dysphagia has been increasing; however, standardization of its use has lagged behind. Without standardization using normative values, it is difficult for clinicians to adopt this emerging technology into meaningful use. Our goal is to map and compare the published normative values for common HRPM metrics in order to help establish consensus reference values.

METHOD

A systematic review was conducted on prospective and retrospective studies that included HRPM metrics, defined by an international working group consensus, in healthy adult populations. Data on the following variables were extracted when available: contractile integrals of the pharynx (PhCI), velopharynx, mesopharynx, and hypopharynx, as well as the upper esophageal sphincter (UES) integrated relaxation pressure (IRP), relaxation time (RT), maximum admittance, and hypopharyngeal intrabolus pressure.

RESULTS

Thirty studies were included. Significant variation existed in the technique and equipment used to perform procedures between the different studies. Lower PhCIs and UES IRPs were seen in younger compared to older individuals. Higher UES RTs were found in individuals in the upright position compared to the supine position and in those using larger boluses sizes or smaller catheters.

CONCLUSIONS

Due to the wide variety of protocols, catheter configurations, manufacturers, and software used in the existing literature, it is difficult to formulate consensus on HPRM normative values using pooled data. Prospective studies adhering to standardized HRPM protocols for specific catheter configurations and manufacturers with larger cohorts of normal individuals are necessary to establish proper reference values for HRPM metrics.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24843753.

High-resolution manometry with impedance for the study of pharyngeal motility and the upper esophageal sphincter: Keys for its use in the study of the pathophysiology of oropharyngeal dysphagia

Oropharyngeal dysphagia (OD) is a pathology with a high prevalence in different patient phenotypes. High-resolution pharyngoesophageal manometry (HRPM) with impedance (HRPM-I) has become in recent years a fundamental technique for better understanding the pathophysiology of pharynx and upper oesophageal sphincter (UES) dysfunctions in patients with OD. Various groups of experts have proposed a methodology for the practice of the HRPM-I and for the standardization of the different metrics for the study of pharyngeal motility and UES dysfunctions based on the quantification of 3main phenomena: relaxation of the UES, resistance to flow through the UES and propulsion of the bolo through the pharynx into the oesophagus. According to the alterations of these metrics, 3patterns of dysfunction are proposed that allow a specific therapeutic approach: (a) UES flow restriction with normal pharyngeal propulsión; (b) UES flow restriction with ineffective pharyngeal propulsion, and (c) ineffective pharyngeal contraction with normal relaxation of the UES. We present a practical review of the methodology and metrics used by the main working groups together with the description of the main patterns of dysfunction according to our experience to highlight the usefulness of the HRPM-I in the study of the pathophysiology and selection of a specific treatment in patients with OD.

Age-related sex differences in tongue strength and muscle morphometry in a rat model

OBJECTIVE

To investigate potential effects of sex on voluntary tongue strength, evoked twitch and tetanic tension, speed of contraction, and muscle fiber cross-sectional area in the muscles of the rat tongue. Additionally, we aimed to determine whether estrous cycle stage impacts any of the dependent variables as a pilot investigation into the use of female rats in a model of tongue exercise and aging.

DESIGN

Fischer 344-Brown Norway male and female rats in two age groups (16 middle-aged, 16 young-adult) were trained to use a tongue force operandum. Tongue muscle contraction, myosin heavy chain (MyHC) composition, and cross section area of the genioglossus and styloglossus muscles were examined. Vaginal lavage determined estrous cycle stage of the female rats daily.

RESULTS

The female group had significantly lower evoked twitch and tetanic tension, longer contraction times, and a smaller proportion of MyHC type IIa and MyHC type IIx in the styloglossus muscle. There was no significant sex effect in maximal voluntary tongue force (MVTF) despite a significant weight difference between the male and female groups. There were no significant age or sex effects in the genioglossus. Estrous cycle stage did not have a significant effect on any of the dependent variables.

CONCLUSIONS

Sex and age both have a significant effect on tongue muscle structure and physiology. While the female group showed reduced contraction speed and maximal twitch and tetanic tension relative to the male group, differences in muscle morphology appeared to vary by muscle.

A Novel Risk Model for Predicting Dysphagia after Tongue Reconstruction: A Retrospective Multicenter Study in Japan

BACKGROUND

There is no consensus on the postoperative outcomes of tongue reconstruction. Therefore, the authors developed a novel risk model for predicting dysphagia after tongue reconstruction.

METHODS

This retrospective study was conducted by the Oral Pharyngeal Esophageal Operation and Reconstruction Analytical, or OPERA, group across 31 cancer centers and university hospitals in Japan. A total of 532 patients [390 (73.3%) men and 142 (26.7%) women; median age at surgery, 60 years (range, 15 to 88 years)] who were diagnosed with oral tongue squamous cell carcinoma and underwent tongue reconstruction following glossectomy between 2009 and 2013 were included. Independent risk factors were identified using univariate regression analysis and converted to a binary format for multivariate analysis. An integer value was assigned to each risk factor to calculate a total score capable of quantifying the risk of feeding tube dependence.

RESULTS

Overall, 54 patients (10.2%) required a feeding tube at the time of evaluation. Predictive factors for feeding tube dependence were advanced age, lower American Society of Anesthesiologists physical status, low body mass index, lower serum albumin, comorbid hypertension and diabetes, extended tongue defect, resection beyond the tongue, laryngeal suspension, postoperative radiation therapy, and no functional teeth. In multivariate logistic regression analysis, age greater than or equal to 58.5 years, postoperative radiation therapy, wider tongue defect, and body mass index less than 21.27 kg/m 2 earned 6, 4, 3, and 2 points, respectively, for a maximum total score of 15.

CONCLUSION

The authors' risk model provides a mathematical tool for estimating the individual risk of postoperative feeding tube dependence before tongue reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

The Natural Swallow: Factors Affecting Subject Choice of Bolus Volume and Pharyngeal Swallow Parameters in a Self-selected Swallow

Predetermined volumes are used extensively throughout clinical assessment of swallowing physiology, but bolus volumes selected by an individual in their natural swallow can vary greatly from those used in structured assessment. This study aims to identify factors influencing self-selected volume and how the mechanics of self-selected volume swallows differ from predetermined volume swallows. We used pharyngeal high-resolution manometry (HRM) with simultaneous videofluoroscopy to measure swallowing pressures in the velopharynx, hypopharynx, and upper esophageal sphincter (UES). Data were collected from 95 healthy adults during thin liquid swallows of 10 mL and a self-selected comfortable volume. An intraclass correlation coefficient (ICC) was calculated to analyze within-subject self-selected volume reliability. Linear mixed effects regression models were used to examine the association of subject characteristics with self-selected swallow volume and of self-selected volumes on pharyngeal swallowing pressures and timing events. Mean self-selected volume was 16.66 ± 7.70 mL. Increased age (p = 0.002), male sex (p = 0.021), and increased pharyngeal hold area (p = 0.007) were significantly associated with increase in self-selected bolus volume. There was good reliability between subjects' individual swallow volumes (ICC = 0.80). Velopharyngeal maximum pressure and pressure integral, tongue base duration and maximum pressure, UES pre- and post-swallow maximum pressure, and overall pharyngeal contractile integral decreased significantly with self-selected boluses. Understanding a patient's natural swallow volume, and how their natural swallow functions, will be important for designing clinical evaluations that place stress on the patient's natural swallowing mechanics in order to assess for areas of dysfunction.

Pharyngeal Pressure Variability During Volitional Swallowing Maneuvers

PURPOSE

Within-individual pharyngeal swallowing pressure variability differs among pharyngeal regions in healthy individuals and increases with age. It remains unknown if pharyngeal pressure variability is impacted by volitional swallowing tasks. We hypothesized that pressure variability would increase during volitional swallowing maneuvers and differ among pharyngeal regions depending on the type of swallowing task being performed.

METHOD

Pharyngeal high-resolution manometry was used to record swallowing pressure data from 156 healthy participants during liquid (5 cc) or saliva swallows, and during volitional swallowing tasks including effortful swallow, Mendelsohn maneuver, Masako maneuver, or during postural adjustments. The coefficient of variation was used to determine pressure variability of velopharynx, tongue base, hypopharynx, and upper esophageal sphincter regions. Repeated-measures analysis of variance was used on log-transformed data to examine effects of pharyngeal region and swallowing tasks on swallow-to-swallow variability.

RESULTS

There was a significant main effect of task with greater pressure variability for the effortful swallow (p = .002), Mendelsohn maneuver (p < .001), Masako maneuver (p = .002), and the head turn (p = .006) compared with normal effort swallowing. There was also a significant main effect of region (p < .01). In general, swallowing pressure variability was lower for the tongue base and upper esophageal sphincter regions than the hypopharynx. There was no significant interaction of task and region (effortful, p = .182; Mendelsohn, p = .365; Masako, p = .885; chin tuck, p = .840; head turn, p = .059; and inverted, p = .773).

CONCLUSIONS

Pharyngeal swallowing pressure variability increases in healthy individuals during volitional swallowing tasks. Less stable swallow patterns may result when tasks are less automatic and greater in complexity. These findings may have relevance to swallowing motor control integrity in healthy aging and individuals with neurogenic dysphagia.

Use of Pharyngeal High-Resolution Manometry to Evaluate Dysphagia in Adults with Motor Neurone Disease: A Scoping Review

There has been a recent shift towards proactive dysphagia intervention in motor neurone disease (MND) to maintain physiological reserve. Pharyngeal high-resolution manometry (PHRM) can quantify swallowing pathophysiology to inform and evaluate proactive dysphagia intervention. This study aims to explore the current use of PHRM as a dysphagia evaluation in adults with MND. A scoping review based on the Joanna Briggs Framework was completed. Four electronic databases (PubMed, EMBASE, CINAHL and Web of Science core) were searched (inception to March 2021) by two independent researchers. Data were analysed according to (i) PHRM protocol and analysis methods and the feasibility of same, (ii) swallow biomechanics data and (iii) dysphagia intervention effects as measured by PHRM. Six studies with 78 people with MND (PwMND) were included. There was considerable variation in PHRM protocol and analysis methods. Five studies reported a 100% completion rate and three studies reported no adverse events. Swallow biomechanics data were reported across all studies. The effects of sensory stimulation, increased bolus consistency, effortful swallow and cricopharyngeal myotomy were evaluated using PHRM with 20 PwMND across four studies with varying effects. Literature on the use of PHRM in PwMND is limited. Variability in PHRM methods restricts comparison of metrics. PHRM appears to be a feasible tool for PwMND. PHRM can provide novel swallow physiology data in PwMND and quantify discrete effects of compensatory and surgical dysphagia interventions not detectable by videofluoroscopy or FEES. Further research on the effects of proactive dysphagia intervention as measured by PHRM is required.

Swallowing biomechanics pre-multi-level and post-multi-level upper airway surgery for obstructive sleep apnea

STUDY OBJECTIVES

The effect of contemporary multi-level upper airway surgery for obstructive sleep apnea (OSA) on swallowing is unclear. This study assessed the biomechanical swallowing function in participants with OSA pre- and post-modified uvulopalatopharyngoplasty and coblation channeling of the tongue (mUPPP+CCT).

METHODS

In this prospective, longitudinal study adults diagnosed with moderate-severe OSA who underwent mUPPP+CCT surgery had swallowing biomechanics assessed using high-resolution pharyngeal manometry (HRPM) and analyzed with swallowgateway.com. Symptomatic swallowing difficulty was evaluated using the Sydney Swallow Questionnaire (SSQ ≥234). General linear mixed model analysis was conducted to evaluate the difference pre- and post-mUPPP+CCT. Data presented as mean [95% confidence intervals].

RESULTS

HRPM assessments were conducted in 10 participants (7 male; median age 50 [IQR 36-65]) pre- and repeated post-operatively at 9 months [IQR 6-13]. Self-reported dysphagia was unchanged following surgery (SSQ 149 [53, 447] to 168 [54, 247]; P =0.093). HRPM outcomes indicated reduced mesopharyngeal pressures (148 [135, 161] to 124 [112, 137] mm Hg.s.cm; P =0.011), reduced hypopharyngeal pressures (113 [101, 125] to 93 [84, 102] mm Hg.s.cm; P =0.011) and reduced upper esophageal sphincter relaxation pressure (5 [4, 6] to 2 [1,3] mm Hg; P =0.001) but no change to velopharyngeal pressures (135 [123, 147] to 137 [117, 157] mm Hg.s.cm; P =0.850) post-surgery.

CONCLUSIONS

mUPPP may have less implications on the swallow mechanism than previously suspected. In contrast, the reduction in mesopharyngeal contractile pressures associated with CCT, although within normal limits, may effect bolus propulsion. Biomechanical alterations were insufficient to worsen self-reported swallowing function.