Hypopharyngeal Intrabolus Pressure Research Articles

Swallowing biomechanics in tracheostomised critically ill patients compared to age- and gender-matched healthy controls

ObjectiveThe mechanistic effects of a tracheostomy on swallowing are unclear. Pharyngeal high-resolution manometry with impedance (P-HRM-I) is a novel swallow assessment tool providing quantifiable metrics. This study aimed to characterise swallowing biomechanics in tracheostomised critically ill (non-neurological) patients. DesignCohort study. SettingAustralian tertiary hospital intensive care unit. ParticipantsTracheostomised adults, planned for decannulation. Main outcome measuresSwallowing assessment using P-HRM-I, compared to healthy age- and gender-matched controls. ResultsIn this tracheostomised cohort (n = 10), the Swallow Risk Index, a global measure of swallow function, was significantly elevated (p < 0.001). At the upper oesophageal sphincter (UOS), hypopharyngeal intrabolus pressure and UOS integrated relaxation pressure were significantly elevated (control 0.65 mmHg [-1.02, 2.33] v tracheostomy 13.7 mmHg [10.4, 16.9], P < 0.001; control −4.28 mmHg [-5.87, 2.69] v tracheostomy 12.2 mmHg [8.83, 15.6], P < 0.001, respectively). Furthermore, UOS opening extent and relaxation time were reduced (control 4.83 mS [4.60, 5.07] v tracheostomy 4.33 mS [3.97, 4.69], P = 0.002; control 0.52 s [0.49, 0.55] v tracheostomy 0.41 s [0.37, 0.45], P < 0.001, respectively). Total pharyngeal contractility (PhCI) measuring pharyngeal pressure generation was significantly elevated (control 199.5 mmHg cm.s [177.4, 221.6] v tracheostomy 326.5 mmHg cm.s [253.3, 399.7]; P = 0.001). ConclusionIn a critically ill tracheostomised cohort, UOS dysfunction was the prevalent biomechanical feature, with elevated pharyngeal pressures. Pharyngeal weakness is not contributing to dysphagia in this cohort. Instead, elevated pharyngeal pressures may represent a compensatory mechanism to overcome the UOS dysfunction. Further studies to extend these findings may inform the development of timely and targeted rehabilitation.

Cricopharyngeal peroral endoscopic myotomy improves oropharyngeal dysphagia in patients with Parkinson's disease.

Background and study aims Oropharyngeal dysphagia (OPD) is prevalent in patients with Parkinson’s disease (PD). Upper esophageal sphincter (UES) dysfunction is an important pathophysiological factor for OPD in PD. The cricopharyngeus (CP) is the main component of UES. We assessed the preliminary efficacy of cricopharyngeal peroral endoscopic myotomy (C-POEM) as a treatment for dysphagia due to UES dysfunction in PD. Patients and methods Consecutive dysphagic PD patients with UES dysfunction underwent C-POEM. Swallow metrics derived using high-resolution pharyngeal impedance manometry (HRPIM) including raised UES integrated relaxation pressure (IRP), raised hypopharyngeal intrabolus pressure (IBP), reduced UES opening caliber and relaxation time defined UES dysfunction. Sydney Swallow Questionnaire (SSQ) and Swallowing Quality of Life Questionnaire (SWAL-QOL) at before and 1 month after C-POEM measured symptomatic improvement in swallow function. HRPIM was repeated at 1-month follow-up. Results C-POEM was performed without complications in all (n = 8) patients. At 1 month, there was an improvement in both the mean SSQ (from 621.5 to 341.8, mean difference –277.3, 95 %CI [–497.8, –56.7], P = 0.02) and SWAL-QOL (from 54.9 to 68.3, mean difference 9.1, 95 %CI [0.7, 17.5], P = 0.037) scores. Repeat HRPIM confirmed a decrease in both the mean UES IRP (13.7 mm Hg to 3.6 mm Hg, mean difference –10.1 mm Hg, 95 %CI [–16.3, –3.9], P = 0.007) and the mean hypopharyngeal IBP (23.5 mm Hg to 10.4 mm Hg, mean difference –11.3 mm Hg, 95 %CI [–17.2, –5.4], P = 0.003). Conclusions In dysphagic PD patients with UES dysfunction, C-POEM is feasible and enhances UES relaxation and reduces sphincteric resistance to flow during the swallow, thereby improving dysphagia symptoms.

Transient hypopharyngeal intrabolus pressurization patterns: Clinically relevant or normal variant?

In oropharyngeal dysphagia, impaired pharyngoesophageal junction (PEJ) opening is reflected by an elevated hypopharyngeal intrabolus pressure (IBP), quantifiable using pharyngeal high-resolution manometry with impedance (P-HRM-I). Transient intrabolus pressurization (TP) phenomena are not sustained and last for only a brief period. We hypothesized that TP patterns reflect impaired coordination between timing of hypopharyngeal bolus arrival and PEJ relaxation. A retrospective audit was conducted of P-HRM-I datasets; 93 asymptomatic Controls and 214Patients with differing etiological/clinical backgrounds were included. TP patterns were examined during 10ml liquid swallows. TP was defined by a simultaneous, non-sustained, pressurization wave spanning from the velo-/meso-pharynx to PEJ. The coordination between deglutitive pharyngeal bolus distension and PEJ relaxation timing was assessed using timing variables; (i) Distention-Contraction Latency (DCL, s) and (ii) PEJ Relaxation Time (RT, s). Resultant flow resistance was quantified (IBP, mmHg). TP swallows were observed in 87 (28%) cases. DCL was not significantly different in relation to TP, while PEJ relaxation time was shorter, and IBP was higher during TP swallows. In Patients RT-DCL time difference correlated with IBP (r -0.368, p<0.01). Bolus distension and PEJ relaxation were miss-timed during TP swallows, impeding bolus flow and leading to a brief period of pressurization of the pharyngeal chamber by muscular propulsive forces. While TP swallows were identified in both Controls and Patients, increased IBPs were most apparent for Patient swallows indicating that the extent of IBP increase may differentiate pathological TP swallows.

Altered swallowing biomechanics in people with moderate-severe obstructive sleep apnea.

Dysphagia is a common but under-recognized complication of obstructive sleep apnea (OSA). However, the mechanisms remain poorly described. Accordingly, the aim of this study was to assess swallowing symptoms and use high-resolution pharyngeal manometry to quantify swallowing biomechanics in patients with moderate-severe OSA. Nineteen adults (4 female; mean (range) age, 46 ± 26-68 years) with moderate-severe OSA underwent high-resolution pharyngeal manometry testing with 5-, 10-, and 20-mL volumes of thin and extremely thick liquids. Data were compared with 19 age- and sex-matched healthy controls (mean (range) age, 46 ± 27-68 years). Symptomatic dysphagia was assessed using the Sydney Swallow Questionnaire. Swallow metrics were analyzed using the online application swallowgateway.com. General linear mixed model analysis was performed to investigate potential differences between people with moderate-severe OSA and controls. Data presented are means [95% confidence intervals]. Twenty-six percent (5 of 19) of the OSA group but none of the controls reported symptomatic dysphagia (Sydney Swallow Questionnaire > 234). Compared with healthy controls, the OSA group had increased upper esophageal sphincter relaxation pressure (-2 [-1] vs 2 [1] mm Hg, F = 32.1, P < .0001), reduced upper esophageal sphincter opening (6 vs 5 mS, F = 23.6, P < .0001), and increased hypopharyngeal intrabolus pressure (2 [1] vs 7 [1] mm Hg, F = 19.0, P < .05). Additionally, upper pharyngeal pressures were higher, particularly at the velopharynx (88 [12] vs 144 [12] mm Hg⋅cm⋅s, F = 69.6, P < .0001). High-resolution pharyngeal manometry identified altered swallowing biomechanics in people with moderate-severe OSA, which is consistent with a subclinical presentation. Potential contributing mechanisms include upper esophageal sphincter dysfunction with associated upstream changes of increased hypopharyngeal distension pressure and velopharyngeal contractility. Schar MS, Omari TI, Woods CM, etal. Altered swallowing biomechanics in people with moderate-severe obstructive sleep apnea. J Clin Sleep Med. 2021;17(9):1793-1803.

High-Resolution Pharyngeal Manometry and Impedance: Protocols and Metrics-Recommendations of a High-Resolution Pharyngeal Manometry International Working Group.

High-resolution manometry has traditionally been utilized in gastroenterology diagnostic clinical and research applications. Recently, it is also finding new and important applications in speech pathology and laryngology practices. A High-Resolution Pharyngeal Manometry International Working Group was formed as a grass roots effort to establish a consensus on methodology, protocol, and outcome metrics for high-resolution pharyngeal manometry (HRPM) with consideration of impedance as an adjunct modality. The Working Group undertook three tasks (1) survey what experts were currently doing in their clinical and/or research practice; (2) perform a review of the literature underpinning the value of particular HRPM metrics for understanding swallowing physiology and pathophysiology; and (3) establish a core outcomes set of HRPM metrics via a Delphi consensus process. Expert survey results were used to create a recommended HRPM protocol addressing system configuration, catheter insertion, and bolus administration. Ninety two articles were included in the final literature review resulting in categorization of 22 HRPM-impedance metrics into three classes: pharyngeal lumen occlusive pressures, hypopharyngeal intrabolus pressures, and upper esophageal sphincter (UES) function. A stable Delphi consensus was achieved for 8 HRPM-Impedance metrics: pharyngeal contractile integral (CI), velopharyngeal CI, hypopharyngeal CI, hypopharyngeal pressure at nadir impedance, UES integrated relaxation pressure, relaxation time, and maximum admittance. While some important unanswered questions remain, our work represents the first step in standardization of high-resolution pharyngeal manometry acquisition, measurement, and reporting. This could potentially inform future proposals for an HRPM-based classification system specifically for pharyngeal swallowing disorders.

Pathophysiology of swallowing following oropharyngeal surgery for obstructive sleep apnea syndrome.

Uvulopalatopharyngoplasty (UPPP) and coblation channeling of the tongue (CCT) are oropharyngeal surgeries used to treat obstructive sleep apnea syndrome. The extent to which UPPP and CCT affect pharyngeal swallow has not been determined. We therefore conducted a novel case series study employing high-resolution impedance manometry (HRIM) to quantify the swallowing-related biomechanics following UPPP and/or CCT surgery. Twelve patients who underwent UPPP+CCT or CCT only were assessed an average 2.5years postsurgery. Swallow function data were compared with ten healthy controls. All patients completed the Sydney swallow questionnaire (SSQ). Pharyngeal pressure-flow analysis of HRIM recordings captured key distension, contractility and pressure-flow timing swallow parameters testing 5, 10, and 20mL volumes of thin and thick fluid consistencies. Postoperative patients had more dysphagia symptoms with five returning abnormal SSQ scores. Swallowing was biomechanically altered compared to controls, consistent with diminished swallowing reserve, largely driven by elevated hypopharyngeal intrabolus pressure due to a reduced capacity to open the upper esophageal sphincter to accommodate larger volumes. Patients who have undergone UPPP and/or CCT surgery appear to have a deficiency in normal modulation of the swallowing mechanism and a reduced swallowing functional reserve. We speculate that these changes may become relevant in later life with the onset of age-related stressors to the swallowing mechanism. This case series strikes a note of caution that further studies are needed to determine the role of preoperative swallow assessment in patients undergoing UPPP and/or CCT surgery.

Biomechanics of Pharyngeal Deglutitive Function following Total Laryngectomy.

Postlaryngectomy, pharyngeal weakness, and pharyngoesophageal junction (PEJ) restriction are the candidate mechanisms of dysphagia. The aims were, in laryngectomees, whether (1) hypopharyngeal propulsion is reduced and/or PEJ resistance is increased, (2) dilatation improves dysphagia, and (3) whether symptomatic improvement correlates with reduced PEJ resistance. Multidisciplinary cross-sectional study. Tertiary academic hospital. Swallow biomechanics were assessed in 30 laryngectomees. Patients were stratified into severe dysphagia (Sydney Swallow Questionnaire >500) and mild/nil dysphagia (Sydney Swallow Questionnaire ≤500). Average hypopharyngeal peak (contractile) pressure (hPP) and hypopharyngeal intrabolus pressure (hIBP) were measured from high-resolution manometry with concurrent videofluoroscopy based on barium swallows (2.5 and 10 mL). In consecutive 5 patients, measurements were repeated after dilatation. Dysphagia was reported by 87%, and 57% had severe and 43% had mild/nil dysphagia. hIBP increased with larger bolus volumes (P < .0001), while hPP stayed stable and PEJ diameter plateaued at 9 mm. Laryngectomees had lower hPP (110 ± 14 vs 170 ± 15 mm Hg; P = .0162) and higher hIBP (29 ± 5 vs 6 ± 5 mm Hg; P = .156) than controls. There were no differences in hPP between patient groups. However, hIBP was higher in severe than in mild/nil dysphagia (41 ± 10 vs 13 ± 3 mm Hg; P = .02). Predilation hIBP (R(2) = 0.97) and its decrement postdilatation (R(2) = 0.98) well predicted symptomatic improvement. PEJ resistance correlates better with dysphagia severity than peak pharyngeal pressure and is more sensitive to bolus sizes than PEJ diameter. Both baseline PEJ resistance and its decrement following dilatation are strong predictors of treatment outcome. PEJ resistance is vital to detect, as it is reversible and can predict the response to dilatation regimens.

A human model of restricted upper esophageal sphincter opening and its pharyngeal and UES deglutitive pressure phenomena.

Oropharyngeal dysphagia due to upper esophageal sphincter (UES) dysfunction is commonly encountered in the clinical setting. Selective experimental perturbation of various components of the deglutitive apparatus can provide an opportunity to improve our understanding of the swallowing physiology and pathophysiology. The aim is to characterize the pharyngeal and UES deglutitive pressure phenomena in an experimentally induced restriction of UES opening in humans. We studied 14 volunteers without any dysphagic symptoms (7 men, 66 ± 11 yr) but with various supraesophageal reflux symptoms. To induce UES restriction, we used a handmade device that with adjustment could selectively apply 0, 20, 30, or 40 mmHg pressure perpendicularly to the cricoid cartilage. Deglutitive pharyngeal and UES pressure phenomena were determined during dry and 5- and 10-ml water swallows × 3 for each of the UES perturbations. External cricoid pressure against the UES resulted in a significant increase in hypopharyngeal intrabolus pressure and UES nadir deglutitive relaxation pressure for all tested swallowed volumes (P < 0.05). Application of external cricoid pressure increased the length of the UES high pressure zone from 2.5 ± 0.2 to 3.1 ± 0.2, 3.5 ± 0.1, and 3.7 ± 0.1 cm for 20, 30, and 40 mmHg cricoid pressure, respectively (P < 0.05). External cricoid pressure had no significant effect on pharyngeal peristalsis. On the other hand, irrespective of external cricoid pressure deglutitive velopharyngeal contractile integral progressively increased with increased swallowed volumes (P < 0.05). In conclusion, acute experimental restriction of UES opening by external cricoid pressure manifests the pressure characteristics of increased resistance to UES transsphincteric flow observed clinically without affecting the pharyngeal peristaltic contractile function.

841 Variability of Pharyngeal Peristaltic Pressure Parameters Measured by High Resolution Manometry (HRM); A Study of Over 900 Pressure Signatures

Introduction: With the many alluring features of HRM including superior spatial resolution and rapid recording frequency, interest in manometric evaluation of the pharynx during swallowing has been renewed. However, crucial information about the physiologic variability of pharyngeal peristaltic pressure wave parameters is scarce. These data are vital for developing normative data and correct interpretation of pharyngeal manometry results. The aims of the present study were to determine: 1) the variability of pharyngeal peristaltic pressure wave amplitude and duration between swallows at various distances from the upper esophageal sphincter (UES) and 2) Pharyngeal Contractile Integral(PCI),hypo-pharyngeal intra-bolus pressure(IBP) and nadir UES pressure(N-UESP) for a range of swallowed volumes. Methods: We studied seven healthy individuals (age:51±25 years, 6F) in upright head neutral position using a high resolution manometry catheter with 36 recording sites positioned trans-nasally such that pressure was recorded from the entire pharynx, UES and proximal esophagus. In each subject, we tested three repetitions each of dry and room temperature 0.5,5 and 10ml water at 20-30second intervals. Statistical analysis included ANOVA, Kruskal-Wallis Testing, Bartlett's Test of variance, Conover's Squared Rank Test of Variance and the coefficient of variation. Results: Spatial variation of the peak peristaltic pressure wave amplitude showed significant difference in variance across locations 2, 3, 4, 5, 6, 7 and 8cm above the upper margin of the UES high pressure zone (umUESHPZ) for dry(p=0.043), 0.5 (p=0.006) and 5ml (p=0.049)swallows (table). There was significant variability in the peak amplitude between swallows at all sites as seen by the standard deviation bars in the figure (representative example for 5ml swallows). The smallest degree of variability across sites was seen at p6 (6 cm above the umUESHPZ) shown in the figure as circles representing the coefficients of variation. Variance due to volume effects also showed significant differences; however, these difference in variance were confined only to sites 3 (p=0.015), 4 (p=0.020) and 6 (p=0.022) cm above the umUESHPZ. In contrast, PCI and IBP showed similar variability for the tested swallow volumes. Conclusions: 1) Parameters of pharyngeal peristaltic pressure wave vary significantly from one swallow to the other for dry and water swallows,2) this variability is significantly different for different locations across the pharynx. 3) these findings should be taken into account for defining normative data and using pharyngeal manometry for clinical purposes. Supported in part by R01DK025731 and P01DK068051.

842 Pediatric Gastroesophageal Reflux Disease: Acidic and Non-Acidic Gastric Juice Modulates Bronchial Epithelial IL-8 Response

Introduction: With the many alluring features of HRM including superior spatial resolution and rapid recording frequency, interest in manometric evaluation of the pharynx during swallowing has been renewed. However, crucial information about the physiologic variability of pharyngeal peristaltic pressure wave parameters is scarce. These data are vital for developing normative data and correct interpretation of pharyngeal manometry results. The aims of the present study were to determine: 1) the variability of pharyngeal peristaltic pressure wave amplitude and duration between swallows at various distances from the upper esophageal sphincter (UES) and 2) Pharyngeal Contractile Integral(PCI),hypo-pharyngeal intra-bolus pressure(IBP) and nadir UES pressure(N-UESP) for a range of swallowed volumes. Methods: We studied seven healthy individuals (age:51±25 years, 6F) in upright head neutral position using a high resolution manometry catheter with 36 recording sites positioned trans-nasally such that pressure was recorded from the entire pharynx, UES and proximal esophagus. In each subject, we tested three repetitions each of dry and room temperature 0.5,5 and 10ml water at 20-30second intervals. Statistical analysis included ANOVA, Kruskal-Wallis Testing, Bartlett's Test of variance, Conover's Squared Rank Test of Variance and the coefficient of variation. Results: Spatial variation of the peak peristaltic pressure wave amplitude showed significant difference in variance across locations 2, 3, 4, 5, 6, 7 and 8cm above the upper margin of the UES high pressure zone (umUESHPZ) for dry(p=0.043), 0.5 (p=0.006) and 5ml (p=0.049)swallows (table). There was significant variability in the peak amplitude between swallows at all sites as seen by the standard deviation bars in the figure (representative example for 5ml swallows). The smallest degree of variability across sites was seen at p6 (6 cm above the umUESHPZ) shown in the figure as circles representing the coefficients of variation. Variance due to volume effects also showed significant differences; however, these difference in variance were confined only to sites 3 (p=0.015), 4 (p=0.020) and 6 (p=0.022) cm above the umUESHPZ. In contrast, PCI and IBP showed similar variability for the tested swallow volumes. Conclusions: 1) Parameters of pharyngeal peristaltic pressure wave vary significantly from one swallow to the other for dry and water swallows,2) this variability is significantly different for different locations across the pharynx. 3) these findings should be taken into account for defining normative data and using pharyngeal manometry for clinical purposes. Supported in part by R01DK025731 and P01DK068051.

843 Association of Novel High-Resolution Impedance Manometry Parameters (HRIM) With Timed Barium Esophagram Measures and Dysphagia Symptoms in Achalasia Patients

Introduction: With the many alluring features of HRM including superior spatial resolution and rapid recording frequency, interest in manometric evaluation of the pharynx during swallowing has been renewed. However, crucial information about the physiologic variability of pharyngeal peristaltic pressure wave parameters is scarce. These data are vital for developing normative data and correct interpretation of pharyngeal manometry results. The aims of the present study were to determine: 1) the variability of pharyngeal peristaltic pressure wave amplitude and duration between swallows at various distances from the upper esophageal sphincter (UES) and 2) Pharyngeal Contractile Integral(PCI),hypo-pharyngeal intra-bolus pressure(IBP) and nadir UES pressure(N-UESP) for a range of swallowed volumes. Methods: We studied seven healthy individuals (age:51±25 years, 6F) in upright head neutral position using a high resolution manometry catheter with 36 recording sites positioned trans-nasally such that pressure was recorded from the entire pharynx, UES and proximal esophagus. In each subject, we tested three repetitions each of dry and room temperature 0.5,5 and 10ml water at 20-30second intervals. Statistical analysis included ANOVA, Kruskal-Wallis Testing, Bartlett's Test of variance, Conover's Squared Rank Test of Variance and the coefficient of variation. Results: Spatial variation of the peak peristaltic pressure wave amplitude showed significant difference in variance across locations 2, 3, 4, 5, 6, 7 and 8cm above the upper margin of the UES high pressure zone (umUESHPZ) for dry(p=0.043), 0.5 (p=0.006) and 5ml (p=0.049)swallows (table). There was significant variability in the peak amplitude between swallows at all sites as seen by the standard deviation bars in the figure (representative example for 5ml swallows). The smallest degree of variability across sites was seen at p6 (6 cm above the umUESHPZ) shown in the figure as circles representing the coefficients of variation. Variance due to volume effects also showed significant differences; however, these difference in variance were confined only to sites 3 (p=0.015), 4 (p=0.020) and 6 (p=0.022) cm above the umUESHPZ. In contrast, PCI and IBP showed similar variability for the tested swallow volumes. Conclusions: 1) Parameters of pharyngeal peristaltic pressure wave vary significantly from one swallow to the other for dry and water swallows,2) this variability is significantly different for different locations across the pharynx. 3) these findings should be taken into account for defining normative data and using pharyngeal manometry for clinical purposes. Supported in part by R01DK025731 and P01DK068051.

339 Nadir UES Relaxation and Hypopharyngeal Intra Bolus Pressures Are More Sensitive to Consistency and Viscosity Challenge Than Pharyngeal Peristalsis Parameters Measured by High Resolution Manometry

339 Nadir UES Relaxation and Hypopharyngeal Intra Bolus Pressures Are More Sensitive to Consistency and Viscosity Challenge Than Pharyngeal Peristalsis Parameters Measured by High Resolution Manometry

337 Pharyngeal Electrical Stimulation (PES) Expedites Swallowing Recovery in Dysphagia Post-Acute Stroke: a Phase II Double-Blinded Randomised Controlled Trial

Introduction: Human disease models can help to better understand the pathophysiology and systematically characterize its consequences. Upper esophageal sphincter (UES) dysphagia is a common sequela of a number of disorders including CVA, reflux disease and aging. Intrinsic disorders of the UES such as fibrosis and inflammation can result in its diminished distensibility and restrict its opening causing dysphagia. Aim: To characterize the pharyngeal and UES deglutitive pressure phenomena in an experimentally induced restricted UES model in humans. Methods: We studied 15 patients (8 male, age 65±11 years) with various supraesophageal reflux symptoms. To induce UES restriction, we used a handmade simple device comprised of two components that could be comfortably worn around the neck: an elastic band and a cushion (5 X 3 X 2.5 CM). The cushion was placed horizontally at the center of the cricoid cartilage. By adjusting the elastic band, we selectively applied 0, 20, 30, 40 mmHg pressure perpendicular to the cricoid laryngeal structure inducing equivalent resistance against UES opening. In this model, the UES, in addition to relaxation, has to overcome the externally imparted pressure to open. Deglutitive pharyngeal and UES pressure phenomena were determined using high-resolution manometry, which recorded from entire pharynx, UES and proximal esophagus. We tested dry, 5 and 10ml swallows x 3. Results: Application of the external pressure band increased the length of the UES high pressure zone from 2.5 cm without the band to 3.1, 3.5 and 3.7 cm for 20, 30, 40mmHg cricoid restrictive pressure, respectively (p<0.05). Increased restrictive pressure against UES resulted in a significant increase in hypopharyngeal intra-bolus pressure (IBP) during all swallowed volumes (figure). Similarly, increased UES restrictive pressure resulted in increased UES nadir deglutitive relaxation pressure for all swallowed volumes (table, p<0.05). Swallowed volume had no effect on pharyngeal peak pressure, duration or velocity. None of these were affected by restrictive external UES pressures. Deglutitive velopharygeal pressure progressively increased with increased swallowed volume (p<0.05). These pressures were also not affected by UES restrictive external pressure. Conclusions: Acute experimental restriction of UES opening by external cricoid pressure in humans manifests the pressure characteristics of increased resistance to UES trans-sphincteric flow observed in disorders that are accompanied by reduced UES opening. These pressure characteristics include increased hypopharyngeal intra-bolus as well as nadir deglutitive UES relaxation pressures. This model can potentially be helpful in better understanding of UES pathophysiology. The effect of external cricoid (UES restrictive) pressure on UES nadir pressure

338 Maturation and Stimulus-Volumes Modulate Pharyngeal Provocation Induced Pharyngeal Rhythms in Human Premature Infants

Introduction: Human disease models can help to better understand the pathophysiology and systematically characterize its consequences. Upper esophageal sphincter (UES) dysphagia is a common sequela of a number of disorders including CVA, reflux disease and aging. Intrinsic disorders of the UES such as fibrosis and inflammation can result in its diminished distensibility and restrict its opening causing dysphagia. Aim: To characterize the pharyngeal and UES deglutitive pressure phenomena in an experimentally induced restricted UES model in humans. Methods: We studied 15 patients (8 male, age 65±11 years) with various supraesophageal reflux symptoms. To induce UES restriction, we used a handmade simple device comprised of two components that could be comfortably worn around the neck: an elastic band and a cushion (5 X 3 X 2.5 CM). The cushion was placed horizontally at the center of the cricoid cartilage. By adjusting the elastic band, we selectively applied 0, 20, 30, 40 mmHg pressure perpendicular to the cricoid laryngeal structure inducing equivalent resistance against UES opening. In this model, the UES, in addition to relaxation, has to overcome the externally imparted pressure to open. Deglutitive pharyngeal and UES pressure phenomena were determined using high-resolution manometry, which recorded from entire pharynx, UES and proximal esophagus. We tested dry, 5 and 10ml swallows x 3. Results: Application of the external pressure band increased the length of the UES high pressure zone from 2.5 cm without the band to 3.1, 3.5 and 3.7 cm for 20, 30, 40mmHg cricoid restrictive pressure, respectively (p<0.05). Increased restrictive pressure against UES resulted in a significant increase in hypopharyngeal intra-bolus pressure (IBP) during all swallowed volumes (figure). Similarly, increased UES restrictive pressure resulted in increased UES nadir deglutitive relaxation pressure for all swallowed volumes (table, p<0.05). Swallowed volume had no effect on pharyngeal peak pressure, duration or velocity. None of these were affected by restrictive external UES pressures. Deglutitive velopharygeal pressure progressively increased with increased swallowed volume (p<0.05). These pressures were also not affected by UES restrictive external pressure. Conclusions: Acute experimental restriction of UES opening by external cricoid pressure in humans manifests the pressure characteristics of increased resistance to UES trans-sphincteric flow observed in disorders that are accompanied by reduced UES opening. These pressure characteristics include increased hypopharyngeal intra-bolus as well as nadir deglutitive UES relaxation pressures. This model can potentially be helpful in better understanding of UES pathophysiology. The effect of external cricoid (UES restrictive) pressure on UES nadir pressure

336 A Human Model of Restricted UES Opening and Its Characteristic Pharyngeal and UES Deglutitive Pressure Phenomena

Introduction: Human disease models can help to better understand the pathophysiology and systematically characterize its consequences. Upper esophageal sphincter (UES) dysphagia is a common sequela of a number of disorders including CVA, reflux disease and aging. Intrinsic disorders of the UES such as fibrosis and inflammation can result in its diminished distensibility and restrict its opening causing dysphagia. Aim: To characterize the pharyngeal and UES deglutitive pressure phenomena in an experimentally induced restricted UES model in humans. Methods: We studied 15 patients (8 male, age 65±11 years) with various supraesophageal reflux symptoms. To induce UES restriction, we used a handmade simple device comprised of two components that could be comfortably worn around the neck: an elastic band and a cushion (5 X 3 X 2.5 CM). The cushion was placed horizontally at the center of the cricoid cartilage. By adjusting the elastic band, we selectively applied 0, 20, 30, 40 mmHg pressure perpendicular to the cricoid laryngeal structure inducing equivalent resistance against UES opening. In this model, the UES, in addition to relaxation, has to overcome the externally imparted pressure to open. Deglutitive pharyngeal and UES pressure phenomena were determined using high-resolution manometry, which recorded from entire pharynx, UES and proximal esophagus. We tested dry, 5 and 10ml swallows x 3. Results: Application of the external pressure band increased the length of the UES high pressure zone from 2.5 cm without the band to 3.1, 3.5 and 3.7 cm for 20, 30, 40mmHg cricoid restrictive pressure, respectively (p<0.05). Increased restrictive pressure against UES resulted in a significant increase in hypopharyngeal intra-bolus pressure (IBP) during all swallowed volumes (figure). Similarly, increased UES restrictive pressure resulted in increased UES nadir deglutitive relaxation pressure for all swallowed volumes (table, p<0.05). Swallowed volume had no effect on pharyngeal peak pressure, duration or velocity. None of these were affected by restrictive external UES pressures. Deglutitive velopharygeal pressure progressively increased with increased swallowed volume (p<0.05). These pressures were also not affected by UES restrictive external pressure. Conclusions: Acute experimental restriction of UES opening by external cricoid pressure in humans manifests the pressure characteristics of increased resistance to UES trans-sphincteric flow observed in disorders that are accompanied by reduced UES opening. These pressure characteristics include increased hypopharyngeal intra-bolus as well as nadir deglutitive UES relaxation pressures. This model can potentially be helpful in better understanding of UES pathophysiology. The effect of external cricoid (UES restrictive) pressure on UES nadir pressure

Impact of a Laryngectomy and Surgical Closure Technique on Swallow Biomechanics and Dysphagia Severity

The incidence of self-reported dysphagia following a laryngectomy is high (72%). The impact, if any, of a surgical closure technique on swallowing biomechanics and dysphagia severity is not known. To date, there is no recommended standard procedure for pharyngeal reconstruction during laryngectomy surgery. The aim of this study was to determine how laryngectomy surgery alters swallowing biomechanics, pharyngeal peak deglutitive pressure, and hypopharyngeal intrabolus pressures and whether these changes in pressure correlate with specific surgical closure after total laryngectomy or with dysphagia severity. Combined videoradiography and manometry was used to measure peak mid-pharyngeal, tongue, and intrabolus pressures; anatomical derangements; postswallow residue; and pharyngeal dimensions. Radiology Department, St George Hospital, Sydney, Australia. Twenty-four patients following total laryngectomy surgery and age-matched control data. When compared to controls, peak mid-pharyngeal pressures were significantly reduced in laryngectomy patients (P < .001). Hypopharyngeal intrabolus pressures were significantly higher in patients when compared to controls (P < .001). Patients who had undergone mucosa-and-muscle pharyngeal reconstruction had higher peak mid-pharyngeal pressures compared to those who had mucosa-alone closure (P ≤ .04). Combined mucosa-and-muscle closure was also associated with reduced postswallow residue, indicative of a more efficient swallow. Following laryngectomy surgery, pharyngeal pro-pulsive contractile forces are impaired, and there is increased resistance to bolus flow across the pharyngoesophageal segment. These adverse biomechanical effects can be influenced by surgical techniques, providing surgeons with evidence for optimum pharyngeal closure following a laryngectomy to improve swallowing outcomes.

AGA technical review on the clinical use of esophageal manometry

AGA technical review on the clinical use of esophageal manometry

Influence of altered tongue contour and position on deglutitive pharyngeal and UES function.

The potential influence of altered lingual position and contour during the bolus loading phase of the swallow in mediating the swallowed bolus volume-dependent regulation of upper esophageal sphincter (UES) relaxation and opening was studied in 15 healthy volunteers using simultaneous videoradiography and manometry. A maxillary dental splint modulated tongue deformity during the early oral phase of deglutition. We examined the effect of the splint and swallowed bolus density on bolus volume-dependent changes in the timing of events in the swallow sequence and on hypopharyngeal intrabolus and midpharyngeal pressures. Peak mid-pharyngeal pressure (P = 0.001) and hypopharyngeal intrabolus pressure (P = 0.04) were significantly reduced by the splint. The normal volume-dependent earlier onset of sphincter relaxation and opening was preserved with the splint in situ. The splint significantly delayed the onset of hyoid motion and UES relaxation and opening without influencing transit times or total swallow duration. Alterations in tongue contour and position reduce intrabolus pressure and pharyngeal contraction without influencing normal bolus volume-dependent regulation of timing of UES relaxation and opening.

Augmentation of deglutitive upper esophageal sphincter opening in the elderly by exercise.

Earlier studies have shown that the cross-sectional area of the deglutitive upper esophageal sphincter (UES) opening in healthy asymptomatic elderly individuals is reduced compared with healthy young volunteers. The aim of this study was to determine the effect of a head-raising exercise on swallow-induced UES opening and hypopharyngeal intrabolus pressure in the elderly. We studied a total of 31 asymptomatic healthy elderly subjects by videofluoroscopy and manometry before and after real (19 subjects) and sham (12 subjects) exercises. A significant increase was found in the magnitude of the anterior excursion of the larynx, the maximum anteroposterior diameter, and the cross-sectional area of the UES opening after the real exercise (P < 0.05). These changes were associated with a significant decrease in the hypopharyngeal intrabolus pressure studied in 12 (real-exercise) and 6 (sham-exercise) subjects (P < 0.05). A similar effect was not found in the sham-exercise group. In normal elderly subjects, deglutitive UES opening is amenable to augmentation by exercise aimed at strengthening the UES opening muscles. This augmentation is accompanied by a significant decrease in hypopharyngeal intrabolus pressure, indicating a decrease in pharyngeal outflow resistance. This approach may be helpful in some patients with dysphagia due to disorders of deglutitive UES opening.

Influence of surgery on deglutitive upper oesophageal sphincter mechanics in Zenker's diverticulum.

To evaluate the role of upper oesophageal sphincter (UOS) compliance in dysphagia, the functional consequences of surgery were evaluated in eight patients with pharyngeal diverticula. The study examined the hypotheses that hypopharyngeal intrabolus pressure is an indicator of UOS compliance and that UOS opening and intrabolus pressure are normalised by surgery. In eight patients and nine healthy controls, we measured the timing of swallow events, UOS relaxation, maximal UOS dimensions, intrabolus pressure, and trans-sphincteric bolus flow rates by simultaneous videoradiography and pharyngeal manometry. Bolus flow rates were not changed by surgery. Surgery significantly increased UOS opening (p = 0.0001) and reduced hypopharyngeal intrabolus pressure (p = 0.0001). The slope of the relation between sphincter area and intrabolus pressure was steeper in patients than controls and was normalised by surgery. Surgery had minor effects on basal UOS tone and timing of swallow events. Upper oesophageal sphincter compliance is poor in Zenker's diverticulum and is normalised by surgery. Hypopharyngeal intrabolus pressure, which correlates with resistance to trans-sphincteric bolus flow, is a useful indicator of UOS compliance. Intrabolus pressure may be a predictor of outcome after myotomy in pharyngeal dysphagia. Cricopharyngeal myotomy is a mandatory component of surgery for Zenker's diverticulum.