Water Swallows Research Articles

Diagnostic yield of high-resolution manometry with a solid test meal for clinically relevant, symptomatic oesophageal motility disorders: serial diagnostic study

The use of high-resolution manometry (HRM) to diagnose oesophageal motility disorders is based on ten single water swallows (SWS); however, this approach might not be representative of oesophageal function during the ingestion of normal food. We tested whether inclusion of a standardised solid test meal (STM) to HRM studies increases test sensitivity for major motility disorders. Additionally, we assessed the frequency and cause of patient symptoms during STM. Consecutive patients who were referred for investigation of oesophageal symptoms were recruited at Nottingham University Hospitals (Nottingham, UK) in the development study and at University Hospital Zürich (Zürich, Switzerland) in the validation study. HRM was done in the upright, seated position with a solid-state assembly. During HRM, patients ingested ten SWS, followed by a standardised 200 g STM. Diagnosis of oesophageal motility disorders was based on the Chicago Classification validated for SWS (CCv3) and with STM (CC-S), respectively. These studies are registered with ClinicalTrials.gov, numbers NCT02407938 and NCT02397616. The development cohort included 750 patients of whom 360 (48%) had dysphagia and 390 (52%) had reflux or other symptoms. The validation cohort consisted of 221 patients, including 98 (44%) with dysphagia and 123 (56%) with reflux symptoms. More patients were diagnosed with a major motility disorder by use of an STM than with SWS in the development set (321 [43%] patients diagnosed via STM vs 163 [22%] via SWS; p<0·0001) and validation set (73 [33%] vs 49 [22%]; p=0·014). The increase was most evident in patients with dysphagia (241 [67%] of 360 patients on STM vs 125 [35%] patients on SWS in the development set, p<0·0001), but was also present in those referred with reflux symptoms (64 [19%] of 329 patients vs 32 [10%] patients in the development set, p=0·00060). Reproduction of symptoms was reported by nine (1%) of 750 patients during SWS and 461 (61%) during STM (p<0·0001). 265 (83%) of 321 patients with major motility disorders and 107 (70%) of 152 patients with minor motility disorders reported symptoms during the STM (p=0·0038), compared with 89 (32%) of 277 patients with normal motility as defined with CC-S (p<0·0001). The diagnostic sensitivity of HRM for major motility disorders is increased with use of the STM compared with SWS, especially in patients with dysphagia. Observations made during STM can establish motility disorders as the cause of oesophageal symptoms. None.

Pharyngeal swallowing and oesophageal motility during a solid meal test: a prospective study in healthy volunteers and patients with major motility disorders

The factors that determine how people eat when they are healthy or have disease have not been defined. We used high resolution manometry (HRM) to assess pharyngeal swallowing and oesophageal motility during ingestion of a solid test meal (STM) in healthy volunteers and patients with motility disorders. This study was based at University Hospital Zurich (Zürich, Switzerland). Healthy volunteers who responded to an advertisement completed HRM with ten single water swallows (SWS) in recumbent and upright positions followed by a 200 g rice STM in the upright position. Healthy volunteers were stratified for age and sex to ensure a representative population. For comparison, consecutive patients with major motility disorders on SWS and patients with dysphagia but no major motility disorders on SWS (disease controls) were selected from a database that was assembled prospectively; the rice meal data were analysed retrospectively. During STM, pharyngeal swallows were timed and oesophageal contractions were classified as representing normal motility or different types of abnormal motility in accordance with established metrics. Factors that could potentially be associated with eating speed were investigated, including age, sex, body-mass index, and presence of motility disorder. We compared diagnoses based on SWS findings, assessed with the Chicago Classification v3.0, with those based on STM findings, assessed with the Chicago Classification adapted for solids. These studies are registered with ClinicalTrials.gov, numbers NCT02407938 and NCT02397616. Between April 2, 2014, and May 13, 2015, 72 healthy volunteers were recruited and underwent HRM. Additionally, we analysed data from 54 consecutive patients with major motility disorders and 53 with dysphagia but no major motility disorders recruited between April 2, 2013, and Dec 18, 2014. We found important variations in oesophageal motility and eating speed during meal ingestion in healthy volunteers and patients. Increased time between swallows was accompanied by more effective oesophageal contractions (in healthy volunteers, 20/389 [5%] effective swallows at <4 s between swallows vs 586/900 [65%] effective swallows at >11 s between swallows, p<0·0001). Obstructive, spastic, or hypercontractile swallows were rare in healthy volunteers (total <1%). Patients with motility disorders ate slower than healthy volunteers (14·95 g [IQR 11-25] per min vs 32·9 g [25-40] per min, p<0·0001) and pathological oesophageal motility were reproduced when patients consumed the STM. In healthy volunteers, eating speed was associated only with frequency of swallows (slope 2·5 g per min per pharyngeal swallow per min [95% CI 1·1-4·0], p=0·0009), whereas in patients with dysphagia, it was correlated with frequency of effective oesophageal contractions (6·4 g per min per effective contraction per min [4·3-8·5], p<0·0001). Diagnostic agreement was good between the HRM with SWS and rice STM (intra-class correlation coefficient r=0·81, 95% CI 0·74-0·87, p<0·0001). Our results show normative values for pharyngeal swallowing and oesophageal motility in healthy volunteers. Detailed analysis of HRM data acquired during an STM shows that the rate-limiting factor for intake of solids in health is the frequency of pharyngeal swallowing and not oesophageal contractility. The reverse is true in patients with oesophageal motility disorders, in whom the frequency of effective oesophageal contractions determines eating speed. University Hospital Zurich.

Sa1657 - Achalasia Despite Normal Integrated Relaxation Pressure with 5ml Water Swallows

Introduction Resistance to bolus flow across the lower esophageal sphincter (LES) is a hallmark of achalasia. Presently the gold standard of diagnosis is by high-resolution manometry (HRM) demonstration of raised integrated relaxation pressure (IRP) following ten 5 mL water swallows; however, this does not replicate normal swallowing behaviour. It has been demonstrated that the addition of adjunctive tests improves sensitivity of identifying relevant dysmotility. Such tests include multiple water swallows (MWS; 200 mL water drunk freely) and solid swallows. In addition, the timed barium esophagram (TBE) measures esophageal emptying. This study describes a cohort of patients who have been treated as having achalasia based on resistance to flow not exhibited with single water swallows. Method Inclusion criteria were all patients between October 2014–2016 with normal mean and median IRP with 5 mL water swallows but considered to have achalasia due to resistance to flow demonstrated by pan-esophageal pressurisation (PEP) during MWS or solid swallows and/or a persistent column at 5 min during TBE. Outcome post-treatment was based on Eckardt score (ES). Results 14 patients (9 male) fulfilled inclusion criteria. 7 were treatment-naive and 7 treatment-experienced (3 myotomy, 4 dilatation). Mean resting LES pressure was 14.6±7.4 mmHg. In all patients, mean and median IRP values for ten 5 mL water swallows were non-raised (mean 9.1±4.3 and 8.7±4.5 mmHg respectively). Of the 7 treatment-naive patients, 5 demonstrated PEP on MWS, 3 on solid swallows and 6 had a positive TBE at 5 min. In treatment-experienced patients, 5 had PEP on MWS, 1 on solid swallows and all had a positive TBE. Of the 13 who had resistance to flow on TBE, 10 (77%) also had resistance demonstrated during MWS and/or solid swallows. Mean height of the 5 min column of barium at baseline was 16.5±8.9 cm. 8 patients underwent therapy based on these findings; one POEM and 7 pneumatic dilatations. Median baseline ES was 7.5 (IQR 5–8). Median ES at minimum 3 months following treatment was 1 (IQR 0–2.5; p Conclusion A normal IRP for water swallows does not preclude a diagnosis of achalasia. The addition of free drinking/solids during HRM or the TBE can identify pathology that might have been missed with standard 5 mL water swallows alone. Patients treated based on this algorithm exhibit excellent treatment outcomes, validating this approach. Disclosure of Interest None Declared

Pharyngeal peristaltic pressure variability, operational range, and functional reserve

The present understanding of pharyngeal motor function remains incomplete. Among the remaining gaps of knowledge in this regard is the magnitude of variability of pharyngeal peristaltic pressure amplitude. Although variability can pose difficulty in interpretation of manometric findings, its magnitude can inform the operational range and reserve of the pharyngeal contractile function. We aimed to define the intra- and intersubject and intersession variability of select pharyngeal manometric parameters and, using this information, determine the number of swallow repetitions for acquiring reliable pharyngeal manometric data. We recorded pharyngeal peristalsis in 10 healthy subjects (age: 50 ± 25 yr, 5 women) by high-resolution manometry during two separate sessions of 20 sequences of 0.5-ml water swallows. Two-way ANOVA showed significant variation in the mean peak peristaltic pressure value across sites (P < 0.0001) as well as within the data at each site (P < 0.0001). Similarly, the pharyngeal contractile integral exhibited significant inter- (P = 0.003) and intrasubject (P < 0.001) variability. The Shapiro-Wilk normality test showed mixed results, in that some sites showed normally distributed data, whereas others did not. A robust Monte Carlo simulation showed that the nominal sample size was different for various tested metrics. For a power of 0.8, commonly accepted as an adequate threshold for acceptable statistical power, the optimal sample size for various peristaltic parameters ranged between 3 and 15. There is significant intra- and intersubject variability in site-specific and integrated parameters of pharyngeal peristalsis. The observed variance indicates a significant operational range and reserve in pharyngeal contractile function while necessitating parameter-specific sample size for reliable results.NEW & NOTEWORTHY Intra- and intersubject variability are significant and different at various sites within the contractile pharynx. In addition, significant swallow-to-swallow and subject-to-subject variability exists in pharyngeal contractile integral. The range of intrasubject variability indicates the existence of broad operational range and reserve. Lastly, our variability studies informed Monte Carlo and power analyses, yielding estimates of sample size that would ensure accurate representation of pressure metric variability.

Functional connectivity patterns of normal human swallowing: difference among various viscosity swallows in normal and chin-tuck head positions

Consuming thicker fluids and swallowing in the chin-tuck position has been shown to be advantageous for some patients with neurogenic dysphagia who aspirate due to various causes. The anatomical changes caused by these therapeutic techniques are well known, but it is unclear whether these changes alter the cerebral processing of swallow-related sensorimotor activity. We sought to investigate the effect of increased fluid viscosity and chin-down posture during swallowing on brain networks. 55 healthy adults performed water, nectar-thick, and honey thick liquid swallows in the neutral and chin-tuck positions while EEG signals were recorded. After pre-processing of the EEG timeseries, the time-frequency based synchrony measure was used for forming the brain networks to investigate whether there were differences among the brain networks between the swallowing of different fluid viscosities and swallowing in different head positions. We also investigated whether swallowing under various conditions exhibit small-world properties. Results showed that fluid viscosity affects the brain network in the Delta, Theta, Alpha, Beta, and Gamma frequency bands and that swallowing in the chin-tuck head position affects brain networks in the Alpha, Beta, and Gamma frequency bands. In addition, we showed that swallowing in all tested conditions exhibited small-world properties. Therefore, fluid viscosity and head positions should be considered in future swallowing EEG investigations.

Rapid Drink Challenge in high-resolution manometry: an adjunctive test for detection of esophageal motility disorders.

The Chicago Classification for diagnosis of esophageal motility disorders by high-resolution manometry (HRM) is based on single water swallows (SWS). Emerging data suggest that a "Rapid Drink Challenge" (RDC) increases sensitivity for motility disorders. This study establishes normal values and diagnostic thresholds for RDC in clinical practice. Two cohort studies were performed in patients with dysphagia or reflux symptoms (development and validation sets). Healthy subjects and patient controls provided reference values. Ten SWS and two 200-mL RDC were performed. Primary diagnosis for SWS was established by the Chicago Classification. Abnormal RDC was defined by impaired esophagogastric junction (EGJ) function (elevated integrated relaxation pressure during RDC [IRP-RDC]); incomplete inhibition of contractility during and ineffective contraction after RDC. Diagnostic thresholds identified in the development set were prospectively tested in the validation set. Normal values were determined in healthy (n=95; age 37.8±12) and patient controls (n=44; age 46.4±15). Development and validation sets included 178 (54±17years) and 226 (53±16years) patients, respectively. Integrated relaxation pressure during RDC was higher for SWS than RDC in all groups (overall P<.001), except achalasia. Rapid Drink Challenge suppressed contractility, except in achalasia type III, spasm, and hypercontractile motility disorders (P<.001). An effective after-contraction was present more often in health than disease (P<.001). Optimal diagnostic thresholds identified in the development set (IRP-RDC ≥12mmHg achalasia, IRP-RDC ≥8mmHg "all cause" EGJ dysfunction), were confirmed in the validation set (both, sensitivity ~85%, specificity >95%). Rapid Drink Challenge contributes clinically relevant information to routine HRM studies, especially in patients with EGJ dysfunction.

OC-071 Dysphagia Patients with Normal Oesophageal High Resolution Manometry: Assessing The Diagnostic Value of Bread Swallows

Introduction High resolution manometry (HRM) is currently the gold standard technique to investigate oesophageal motility in patients with dysphagia. However, with routine HRM procedure and use of Chicago classification, a group of patients with dysphagia are considered as being normal and dysphagia remains unexplained. The aim of this study is to assess the diagnostic value of solid bolus swallows in patients with dysphagia and normal HRM. Methods Patients having dysphagia and normal HRM studies during January-October 2015 were selected. Solid bolus swallows of bread (1cm 3 single bread swallows and/or a sandwich meal) followed the routine water swallows on HRM. Patients with a double high pressure zone, oesophageal diverticulum or history of antireflux surgery were excluded. The patients were categorised to symptomatic and asymptomatic groups based on having dysphagia reproduced on bread swallows. Hospital odynophagia and dysphagia questionnaire (HODQ) score, integrated relaxation pressure (IRP), distal contractile integration (DCI), distal latency (DL) and peristaltic abnormality during water swallows were investigated and compared between groups. ROC curve was used to identify the optimum level of sensitivity and specificity of the significant parameters in identifying patients who have a meaningful abnormality on bread swallows. Student t-test is used to compare significance of differences. P value Results 72 patients referred with dysphagia and diagnosed with normal HRM were selected. In the asymptomatic group, 7/22 patients showed abnormality on bread swallows and in the symptomatic group, 45/50 showed abnormal motility (P = 0.0001). ROC analysis showed that having >33.3% abnormal bread swallows has sensitivity of 72%, specificity of 90.91% and likelihood ratio of 7.9 to detect patients who may have abnormal motility and dysphagia on bread swallows. Analysis of water swallow parameters comparing the asymptomatic group against the symptomatic group with abnormal motility on bread swallows did not reveal any significant difference in HODQ score (P = 0.2), IRP (P = 0.17), DL (P = 0.3) and peristaltic abnormalities (P = 0.4). Conclusion Performing solid swallows on HRM can explain dysphagia in a considerable number of patients with dysphagia and normal routine HRM. This complementary test is readily available, and avoids the need for Barium swallowing and radiation exposure. Disclosure of Interest None Declared

Esophageal motility after peroral endoscopic myotomy for achalasia.

Peroral endoscopic myotomy (POEM) has been introduced as a novel endoscopic treatment for achalasia. The aim of this work is to assess the changes in esophageal motility caused by POEM in patients with achalasia. Forty-one patients with achalasia underwent POEM from September 2012 to November 2014. Esophageal motility of all patients was evaluated preoperatively and 1 month after POEM utilizing high-resolution manometry, which was performed with ten water swallows, ten steamed bread swallows, and multiple rapid swallows (MRS). In single swallows, including liquid swallows and bread swallows, all the parameters of lower esophagus sphincter resting pressure (LESP), 4-s integrated relaxation pressure (4sIRP), and intra-bolus pressure (IBP) were decreased between pre- and post-POEM patients (all p < 0.05). Postoperatively, the trend of distal contractile integral (DCI) and distal esophageal peristaltic amplitude declined in subtype II and subtype III (subtype II: p < 0.05; subtype III: p > 0.05), but increased in subtype I (subtype I: p > 0.05). In liquid swallows, the Eckardt score of subtype II patients decreased with DCI, and distal esophageal peristaltic amplitude after POEM was significantly lower compared with those showing increased values of those two parameters (p < 0.05). In MRS, the rate of LES relaxation increased from 66.67 to 95.24%, but without normal response in all achalasia patients. POEM reduces LES pressure in achalasia, and partly restores esophageal motility. POEM displayed varying effect on esophageal motility in patients with different patterns of swallowing. In addition, the changes in parameters associated with esophageal peristalsis correlated with decreases in Eckardt score.

Effects of Aging and Acid Reflux on Esophageal Motility

Introduction: It is generally thought that esophageal motility decreases with age, however a decrease in esophageal motility may also be caused by esophagitis. The aim of this study is to investigate the effects of aging and acid reflux on esophageal motility. Methods: 40 young (under 45) healthy subjects (HS) and 40 elderly (over 65) HS, with neither reflux symptoms nor reflux esophagitis (RE), and 40 elderly patients with mild RE (elderly RE), underwent esophageal high resolution manometry with a 21-lumen perfused assembly, which monitored pressure in the pharynx, the upper esophageal sphincter, the esophageal body, the lower esophageal sphincter (LES) and the proximal stomach. An infusion port, located 18cm above the distal side hole, was used to inject air and expiratory basal LES pressure was referenced to end expiratory intragastric pressure. Primary peristalsis was tested with 5ml water swallows, each swallow separated by a 30 second interval and the process repeated 10 times. Secondary peristalsis was triggered by esophageal distention, using a 20ml bolus of air, which was injected rapidly, by hand, into the middle esophagus. After 20 seconds each stimulus was followed by a dry swallow to clear any of the residual air and then repeated 5 times. Results: There was no difference in the LES pressure and also in the success rate of primary peristalsis between young and elderly HS or between elderly HS and RE. There was no difference in the distal contractile integral (DCI) of primary peristalsis and secondary peristalsis between the young and elderly HS, but in the elderly RE, it was significantly lower than in the elderly HS. There was no difference in the success rate of secondary peristalsis between elderly HS and RE, but in elderly HS it was significantly lower than in young HS. Conclusion: Aging may cause a decrease in the success rate of secondary peristalsis, and acid reflux itself may cause a decrease of the DCI in primary and secondary peristalsis.

Audio-based detection and evaluation of eating behavior using the smartwatch platform

In recent years, smartwatches have emerged as a viable platform for a variety of medical and health-related applications. In addition to the benefits of a stable hardware platform, these devices have a significant advantage over other wrist-worn devices, in that user acceptance of watches is higher than other custom hardware solutions. In this paper, we describe signal-processing techniques for identification of chews and swallows using a smartwatch device׳s built-in microphone. Moreover, we conduct a survey to evaluate the potential of the smartwatch as a platform for monitoring nutrition. The focus of this paper is to analyze the overall applicability of a smartwatch-based system for food-intake monitoring. Evaluation results confirm the efficacy of our technique; classification was performed between apple and potato chip bites, water swallows, talking, and ambient noise, with an F-measure of 94.5% based on 250 collected samples.

Swallowing accelerometry signal feature variations with sensor displacement

Dual-axis accelerometry has recently shown promise as a non-invasive method for detecting swallowing impairment using signal processing and pattern classification algorithms. However, it is unknown whether variations in sensor placement alter signal characteristics, threatening the accuracy of signal processing classifiers for aspiration detection. To address this question, water swallows were recorded in 14 healthy adults using a dual-axis accelerometer in 13 different positions (baseline, and 2, 4, 6 and 8 mm above, below and to the right of baseline). The baseline position was midline, immediately below the thyroid cartilage during quiet breathing. After segmentation and pre-processing, signal features were extracted in multiple domains (time, frequency, time-frequency). The effect of sensor position on signal feature distributions was examined with non-parametric statistical analysis. The analysis showed that the sensor could be displaced by as much as 4 mm inferior and lateral to the baseline position and by up to 6 mm above the baseline location without significantly altering time-frequency features. In other words, when considering the baseline position as the origin, the admissible region for sensor placement spans 10 mm in the superior-inferior axis and 8 mm in the medial-lateral direction. Results of this study suggest that time-frequency representations of accelerometry signals are most robust to sensor placement variations around the baseline position. The implication of this finding is that a swallowing accelerometry classifier based on time-frequency features can likely tolerate small variations in sensor location without degradation in classification performance.

Investigation of Dysphagia After Antireflux Surgery by High-resolution Manometry: Impact of Multiple Water Swallows and a Solid Test Meal on Diagnosis, Management, and Clinical Outcome

Management of patients with dysphagia, regurgitation, and related symptoms after antireflux surgery is challenging. This prospective, case-control study tested the hypothesis that compared with standard high-resolution manometry (HRM) with single water swallows (SWS), adding multiple water swallows (MWS) and a solid test meal increases diagnostic yield and clinical impact of physiological investigations. Fifty-seven symptomatic and 12 asymptomatic patients underwent HRM with SWS, MWS, and a solid test meal. Dysphagia and reflux were assessed by validated questionnaires. Diagnostic yield of standard and full HRM studies with 24-hour pH-impedance monitoring was compared. Pneumatic dilatation was performed for outlet obstruction on HRM studies. Clinical outcome was assessed by questionnaires and an analogue scale with "satisfactory" defined as at least 40% symptom improvement requiring no further treatment. Postoperative esophagogastric junction pressure was similar in all groups. Abnormal esophagogastric junction morphology (double high pressure band) was more common in symptomatic than in control patients (13 of 57 vs 0 of 12, P= .004). Diagnostic yield of HRM was 11 (19%), 11 (19%), and 33 of 57 (58%), with SWS, MWS, and solids, respectively (P < .001); it was greatest for solids in patients with dysphagia (19 of 27, 70%). Outlet obstruction was present in 4 (7%), 11 (19%), and 15 of 57 patients (26%) with SWS, MWS, and solids, respectively (P < .009). No asymptomatic control had clinically relevant dysfunction on solid swallows. Dilatation was performed in 12 of 15 patients with outlet obstruction during the test meal. Symptom response was satisfactory, good, or excellent in 7 of 12 (58%) with no serious complications. The addition of MWS and a solid test meal increases the diagnostic yield of HRM studies in patients with symptoms after fundoplication and identifies additional patients with outlet obstruction who benefit from endoscopic dilatation.

Tu1413 Relationship Between Esophageal Pressure Changes in Different Body Positions and Bolus Dynamics at the Esophago-Gastric Junction

Background: The Chicago classification is useful to classify esophageal motility disorders; however, the clinical importance of some diagnoses such as esophago-gastric junction (EGJ) outflow obstruction should be clarified. There are several cases in which it is difficult to determine if a high integral relaxation pressure (IRP) value in the supine position (supine IRP) has causes dysphagia because IRP in the sitting position (sitting IRP) is lower. Although the relationship between EGJ pressure and bolus dynamics at the EGJ has been assessed, the relationship between esophageal pressure and bolus dynamics at the EGJ is not fully understood.Aim: To clarify the relationship between esophageal pressure changes in different body positions and bolus dynamics at the EGJ. Material and Methods: High resolution manometry (HRM) was performed using ManoScan® in 43 patients with esophageal symptoms such as dysphagia, chest pain or heartburn. Ten 5-ml water swallows were performed in the supine position to evaluate esophageal motility, followed by at least five 5-ml water swallows were repeated in the sitting position. Moreover, an esophagogram in the upright position was performed in all patients. Pressure values were calculated by ManoView® and esophageal motility disorders were diagnosed by the Chicago classification criteria. Barium bolus dynamics were classified into 4 types: i) bolus passed smoothly at the EGJ (type 1), ii) bolus was pooled in the esophagus and then cleared by peristalsis (type 2), iii) bolus passed at the EGJ with minor pooling in the esophagus (type 3), and iv) most of bolus was pooled in the esophagus (type 4). The Mann-Whitney test or the Kruskal-Wallis test was used to compare pressure values.Results: The patient diagnoses, IRP, and intrabolus pressure (IBP) values in different body positions, and the bolus dynamics at the EGJ are shown in the Table. Although the IRP was similar in different body positions in patients with achalasia, the sitting IRP was significantly lower than the supine IRP in patients with other abnormalities or normal peristalsis. Bolus dynamics varied according to esophageal motility abnormalities. The bolus was pooled in the esophagus (type 3 or 4) in all patients with achalasia and absent peristalsis, and in some patients with weak or frequent failed peristalsis. The type 2 bolus dynamics were observed in all, but one patients with EGJ outflow obstruction. The sitting IRP in patients with type 2 or 4 bolus dynamics was significantly higher than that in patients with type 1 or 3 bolus dynamics (median 9.4 vs. 4.4 mmHg, respectively, p<0.01). Conclusions: Both EGJ relaxation and esophageal peristalsis are important for esophageal

Tu1184 High Resolution Manometry With Multiple Water Swallows: A Complementary Role in the Detection of Esophageal Pathology

Tu1184 High Resolution Manometry With Multiple Water Swallows: A Complementary Role in the Detection of Esophageal Pathology

Normwerte für die Hochauflösungsmanometrie von Pharynx und oberem Ösophagussphinkter

High resolution manometry (HRM) can provide information about the muscular contraction of the pharynx and the upper esophageal sphincter (UES) and represents an important tool in the diagnostics of dysphagia. To compare the results of swallowing studies interindividually and to identify pathological swallows, normative data are necessary. Normative data for the use of an HRM-probe with a large diameter has already been published. As previously has been shown these probes can influence the normal contraction of the pharynx and the UES. In this study comprehensive normal values are presented for small HRM-probes in diameter (2 mm), that only minimally affect pharyngeal and UES contractions. 29 healthy volunteers underwent pharyngeal and upper esophageal HRM. All subjects performed 10 water swallows of 2 ml in an upright position. Pressure and time dependent parameters of the velopharyngeal region, the tongue base and the UES have been evaluated. Mean and median values and different percentile ranges were calculated. The normative values for the key parameters were (mean±SD): maximum velopharyngeal pressure 269.9±113.1 mmHg, maximum tongue base pressure 278±93.6 mmHg, maximum UES pressure 205.8±64.0 mmHg, UES resting pressure 42.5±18.7 mmHg and relaxation time of the UES 681.6±86.8 ms. Further parameters have been measured. Time dependent values are comparable to those already published. Especially in the UES lower pressures can be measured when a small HRM-probe is used. The normative data established in this study might help to distinguish pathological from physiological swallows using HRM.

Smartphone-Based Real-time Assessment of Swallowing Ability From the Swallowing Sound.

Dysphagia can cause serious challenges to both physical and mental health. Aspiration due to dysphagia is a major health risk that could cause pneumonia and even death. The videofluoroscopic swallow study (VFSS), which is considered the gold standard for the diagnosis of dysphagia, is not widely available, expensive and causes exposure to radiation. The screening tests used for dysphagia need to be carried out by trained staff, and the evaluations are usually non-quantifiable. This paper investigates the development of the Swallowscope, a smartphone-based device and a feasible real-time swallowing sound-processing algorithm for the automatic screening, quantitative evaluation, and the visualisation of swallowing ability. The device can be used during activities of daily life with minimal intervention, making it potentially more capable of capturing aspirations and risky swallow patterns through the continuous monitoring. It also consists of a cloud-based system for the server-side analyzing and automatic sharing of the swallowing sound. The real-time algorithm we developed for the detection of dry and water swallows is based on a template matching approach. We analyzed the wavelet transformation-based spectral characteristics and the temporal characteristics of simultaneous synchronised VFSS and swallowing sound recordings of 25% barium mixed 3-ml water swallows of 70 subjects and the dry or saliva swallowing sound of 15 healthy subjects to establish the parameters of the template. With this algorithm, we achieved an overall detection accuracy of 79.3% (standard error: 4.2%) for the 92 water swallows; and a precision of 83.7% (range: 66.6%–100%) and a recall of 93.9% (range: 72.7%–100%) for the 71 episodes of dry swallows.

The effect of water bolus temperature on esophageal motor function as measured by high-resolution manometry.

Ingestion of cold fluids may induce pain in patients with esophageal motility disorders. Hot fluids, on the other hand, may help to relieve pain. We studied changes in esophageal motility as a variable of water bolus temperature using high-resolution manometry (HRM) in healthy human. Thirty-two healthy subjects were recruited at Kosin University Hospital. HRM was performed in a sitting position, with room temperature (RT, 25 °C), hot (45 °C), and cold (2 °C) water swallowed in that order. This exam included single swallowing (10 swallows of 5 mL water, 30 s intervals) and multiple water swallows (MWS; 100 mL water within 30 s). In the single swallowing, hot water caused a decrease in lower esophageal sphincter (LES) residual pressure (5.87 ± 4.20 mmHg vs 7.45 ± 4.17 mmHg (RT), p = 0.001) and duration of esophageal body (EB) contraction (3.01 ± 0.80 s vs 3.15 ± 1.16 s (RT), p = 0.009). Cold water caused an increase in the duration of EB contraction (3.52 ± 0.87 s vs 3.15 ± 1.16 s (RT), p = 0.001) and a decrease in contractile front velocity (CFV) (4.43 ± 1.50 cm/s vs 4.90 ± 2.53 cm/s (RT), p = 0.007). Similarly, in the MWS, hot water caused a decrease in the duration of EB contraction (12.95 ± 5.02 s vs 16.33 ± 5.94 s (RT), p = 0.024) and an increase in the amplitude of EB contraction (114.27 ± 83.36 mmHg vs 82.70 ± 46.77 mmHg (RT), p = 0.007). Cold water caused an increase in the duration of EB contraction (27.38 ± 2.89 s vs 16.33 ± 5.94 s (RT), p = 0.03) and a decrease in the amplitude of EB contraction (51.68 ± 33.94 mmHg vs 82.70 ± 46.77 mmHg (RT), p = 0.001). This study showed changes in esophageal motility to be dependent on water temperature. Especially, MWS showed clear changes in esophageal motility at different temperatures of water.

Comparison of High Resolution Pressure Topography and High Resolution Impedance Manometry in Patients With Non-obstructive Dysphagia

Introduction: High resolution pressure topography (HRPT) facilitates better characterization of esophageal peristalsis than conventional waveforms (CW), including recognition of ineffective esophageal motility (IEM). Likewise, high resolution impedance manometry (HRIM) provides information regarding bolus transit. It is not known if HRIM confers a diagnostic advantage over HRPT in the assessment of peristalsis in patients with non-obstructive dysphagia (NOD). Methods: Patients with NOD were evaluated with a 36-pressure and 18-impedance solid-state esophageal probe. Failed, weak and normal peristalses were identified with HRPT, HRIM and CW, independently by two assessors. Abnormal and normal peristalses were compared between the techniques. ROC curve analysis was used to determine area under the curve (AUC), sensitivity and specificity for a diagnosis of IEM using HRIM at cut-offs of 50% (HRIM50%) and 30% (HRIM30%) with CW50% and HRPT50% as references. Results: 81/111 screened patients (F/M = 57/24; mean age 53 years) were evaluated. With HRPT, IEM was seen in 28.0±3.6 % of water swallows, of which failed peristalses were seen in 11.0±2.7 % and weak peristalses in 17.0 ± 2.4 %. Of those ineffective swallows, 8.8±1.8 % were large breaks, 10.5±1.1% were small breaks and 35.4±4.0 % had transition zone defects (TZDs) (mean length 3.1±0.3 cm). Less than a third of subjects had a mean distal contractile integral (DCI)<450 mmHg-s-cm. With HRIM, IEM was seen in 35.1±4.0 %, of which 17.2 ± 3.1 % were failed peristalses and 17.9 ± 2.7% were weak peristalses. The mean distal baseline impedance was 1.3±0.1Ω. TZDs with impaired bolus clearance were seen in 19.4±3.2%. Comparing HRIM vs. HRPT, more failed peristalses (1.8±0.3 vs. 1.2±0.3, P=0.02) were identified, but weak peristalses (1.8±0.3 vs. 1.8±0.3, P=1.0) and normal peristalses (6.1±0.4 vs. 6.0±0.4,P =0.8) were similar. Using ROC curve analysis, the % of AUCs, sensitivities and specificities for HRIM50% (63.2, 48.4 and 78.0 respectively) and HRPT50% (68.2, 48.4 and 88.0 respectively) were both better than CW50% (both P<0.05). Compared with HRPT50%, the % of AUCs, sensitivities and specificities were equally better with HRIM30% (69.8, 76.2 and 63.3 respectively, P=0.007) and HRIM50% (73.3, 66.7 and 80.0 respectively, P=0.002). Conclusion: HRIM is more likely to identify peristaltic defects than HRPT, and therefore is a better test for the assessment of NOD. To diagnose IEM, HRIM30% and HRIM50% were both equally better than HRPT50% and CW50%, and should be the preferred approach. Disclosure - Dr. Rao is supported by a grant from National Institutes of Health NIH grant RO1 DK 57100-05NIHRO-1.

Inter-observer agreement for diagnostic classification of esophageal motility disorders defined in high-resolution manometry.

High-resolution esophageal manometry (HRM) is a recent development used in the evaluation of esophageal function. Our aim was to assess the inter-observer agreement for diagnosis of esophageal motility disorders using this technology. Practitioners registered on the HRM Working Group website were invited to review and classify (i) 147 individual water swallows and (ii) 40 diagnostic studies comprising 10 swallows using a drop-down menu that followed the Chicago Classification system. Data were presented using a standardized format with pressure contours without a summary of HRM metrics. The sequence of swallows was fixed for each user but randomized between users to avoid sequence bias. Participants were blinded to other entries. (i) Individual swallows were assessed by 18 practitioners (13 institutions). Consensus agreement (≤ 2/18 dissenters) was present for most cases of normal peristalsis and achalasia but not for cases of peristaltic dysmotility. (ii) Diagnostic studies were assessed by 36 practitioners (28 institutions). Overall inter-observer agreement was 'moderate' (kappa 0.51) being 'substantial' (kappa > 0.7) for achalasia type I/II and no lower than 'fair-moderate' (kappa >0.34) for any diagnosis. Overall agreement was somewhat higher among those that had performed >400 studies (n = 9; kappa 0.55) and 'substantial' among experts involved in development of the Chicago Classification system (n = 4; kappa 0.66). This prospective, randomized, and blinded study reports an acceptable level of inter-observer agreement for HRM diagnoses across the full spectrum of esophageal motility disorders for a large group of clinicians working in a range of medical institutions. Suboptimal agreement for diagnosis of peristaltic motility disorders highlights contribution of objective HRM metrics.

Variations in tongue-palate swallowing pressures when swallowing xanthan gum-thickened liquids.

Thickened liquids are frequently recommended to reduce the risk of aspiration in patients with oropharyngeal dysphagia. Although it has previously been reported that tongue-palate pressures increase when swallowing spoon-thick and semi-solid consistencies compared to thin liquids, relatively little is known about how swallowing behaviors differ when swallowing liquids of nectar- or honey-thick consistency. Furthermore, previous studies have primarily used starch-based thickeners, and little is known about swallowing behaviors with xanthan gum-thickened liquids, which have recently been introduced for dysphagia management. In this study, we measured variations in tongue-palate pressures during the swallowing of liquids thickened to apparent viscosities of 190, 250, and 380 mPa s at 50/s using increasing concentrations of xanthan gum (0.5, 0.63 and 0.87 w/w%). The viscosity differences between these nectar- and honey-thick stimuli were confirmed to exceed sensory perceptual discrimination thresholds. Data were collected from 78 healthy adults in two sex-balanced age-groups (young; mature) and compared to reference values obtained during water swallowing. The results confirm that increased amplitudes of tongue-palate pressure were used when swallowing the thickened liquid stimuli, compared to swallows of water, and for the honey-thick liquid compared to the two nectar-thick liquids. Age-related reductions were seen in tongue strength but not in swallowing pressures, which fell below 40 % of maximum isometric pressure values. Thus, the use of xanthan gum-thickened liquids is unlikely to tax the swallowing system in terms of tongue pressure generation requirements, even in seniors with reduced maximum isometric tongue pressure measures.