Bolus Flow Time Research Articles

Sa1972 Bolus Flow Time Calculated From High-Resolution Impedance and Manometry (HRIM) Data Correlates With Timed Barium Esophagram Measures

Example of esophageal impedance topography (EIT) plot showing the method for deriving EIT parameters Z1, Z2 and the Z2/Z1 ratio from a HRIM study. The pressure contours at 20 mmHg intervals (black solid lines) are overlaid with the enhanced impedance data (purple colorization) with the same resolution as pressure data in both time and spatial domain after interpolation. A region of interest (ROI, red dashed rectangle) is selected and the swallow event is divided into two sections by the contractile wave defined by the pressure isobaric contour. The impedance clearance contour (white curve) defines an impedance value of 50% drop from the mean baseline impedance to the mean nadir impedance and these white contours are superimposed on the EIT plot within the ROI for calculation of EIT parameters including bolus area in zone 1 (Z1), bolus area in zone 2 (Z2), and a ratio of Z2/ Z1, calculated to define the percentage of bolus that is retained in the esophagus after the swallow.

Mo1895 Bolus Flow Time Through Esophagogastric Junction (EGJ) Derived During High-Resolution Impedance-Manometry (HRIM) Studies: A Novel Parameter for Assessment of Esophageal Bolus Transit

Mo1895 Bolus Flow Time Through Esophagogastric Junction (EGJ) Derived During High-Resolution Impedance-Manometry (HRIM) Studies: A Novel Parameter for Assessment of Esophageal Bolus Transit

Oesophageal pressure-flow metrics in relation to bolus volume, bolus consistency, and bolus perception.

The utility of combined oesophageal pressure-impedance recording has been enhanced by automation of data analysis. To understand how oesophageal function as measured by automated impedance manometry (AIM) pressure-flow analysis varies with bolus characteristics and subjective perception of bolus passage. Oesophageal pressure-impedance recordings of 5 and 10 ml liquid or viscous swallows and 2 and 4 cm solid swallows from 20 healthy control subjects (five male; 25-73 years) were analysed. Metrics indicative of bolus pressurization (intrabolus pressure and intrabolus pressure slope) were derived. Bolus flow resistance, the relationship between bolus pressurization and flow timing, was assessed using a pressure-flow index. Bolus retention was assessed using the ratio of nadir impedance to peak pressure impedance (impedance ratio). Subjective perception of bolus passage was assessed swallow by swallow. Viscosity increased the bolus flow resistance and reduced bolus clearance. Responses to boluses of larger volume and more viscous consistency revealed a positive correlation between bolus pressurization and oesophageal peak pressure. Flow resistance was higher in subjects who perceived bolus hold up of solids. Bolus volume and bolus type alter oesophageal function and impact AIM analysis metrics descriptive of oesophageal function. Perception of bolus transit was associated with heightened bolus pressurization relative to bolus flow.

Characterization of esophageal pressure‐flow abnormalities in patients with non‐obstructive dysphagia and normal manometry findings

Patients with non-obstructive dysphagia (NOD) report symptoms of impaired esophageal bolus transit without evidence of bolus stasis. In such patients, manometric investigation may diagnose esophageal motility disorders; however, many have normal motor patterns. We hypothesized that patients with NOD would demonstrate evidence of high flow-resistance during bolus passage which in turn would relate to the reporting of bolus hold up perception. Esophageal pressure-impedance recordings of 5 mL liquid and viscous swallows from 18 NOD patients (11 male; 19-71 years) and 17 control subjects (9 male; 25-60 years) were analyzed. The relationship between intrabolus pressure and bolus flow timing in the esophagus was assessed using the pressure flow index (PFI). Bolus perception was assessed swallow by swallow using standardized descriptors. NOD patients were characterized by a higher PFI than controls. The PFI defined a pressure-flow abnormality in all patients who appeared normal based on the assessment esophageal motor patterns and bolus clearance. The PFI was higher for individual swallows during which subjects reported perception of bolus passage. Bolus flow-resistance is higher in NOD patients compared with controls as well as higher in relation to perception of bolus transit, suggesting the presence of an esophageal motility disorder despite normal findings on conventional analysis.

529 Esophageal Contraction Wave Abnormalities on High Resolution Manometry (HRM) Not Meeting Chicago Classification Criteria: Are They Clinically Relevant?

Introduction: The subjective perception of solid bolus hold up during swallowing is a common reason for referral for manometric investigation, yet standardmeasures of esophageal function relate poorly to patient perception and a large proportion of patients with dysphagia demonstrate no apparent abnormality on routine diagnostic testing for esophageal dysfunction. The utility of combined esophageal pressure-impedance recording has been recently enhanced by automated impedance manometry pressure-flow analysis (AIM analysis) and newmetrics have been conceived that better describe the interactions between bolus transport and pressure generation. In this study we undertook to assess whether these new esophageal pressure-flow metrics were altered when subjects perceived solid bolus hold up. Methods: Esophageal high-resolution pressure-impedance recordings of 5ml/10ml liquid/viscous swallows and 2cm/4cm solid swallows from 20 control subjects (29-73 years) were analysed. Two solid state pressure(P)/impedance(Z) catheter configurations were used; 32 1cm P/16 2cm Z (Sandhill Scientific) and 36 1cm P/18 2cm Z (Given Imaging). Bolus flow resistance, the relationship between bolus compression and bolus flow timing, was assessed using the pressure flow index (PFI) (Myers et al Neurogastro. Mot. 2012; Nguyen et al Neurogastro. Mot. 2012). Heightened perception of bolus hold up was assessed on a swallow by swallow basis using a 6 point scale (1 = no perception, 2 = awareness of bolus transit, 3-6 = bolus hold up). Results: On a swallow by swallow analysis, heightened perception of solid boluses (swallows with scores 3+) was associated with a higher PFI (distal esophagus Odds Ratio for score 3+ 1.001 [1.000 1.002], p = 0.021). A significant correlation was observed between the maximum subject reported perception score and the average PFI for solids (distal esophagus Pearson's r = 0.690, p,0.001). Grouping of subjects in relation to bolus perception revealed that the PFI was elevated for solids and viscous boluses, but not liquids, in subjects reporting bolus hold up (Figure). Esophageal peak pressures and iso-contour defect size were not significantly related to bolus perception. Conclusion: We report novel findings in relation to mechanical factors during bolus transport that may enhance bolus perception. This study shows that heightened perception of a swallowed bolus relates to subtle differences in flow resistance, which suggests higher levels of muscle tension during the transition phase from a bolus-containing to a lumen-occluded esophageal segment.

528 The Mechanics of Esophageal Bolus Transport Are Altered in Subjects Reporting Perception of Solid Bolus Hold up

Introduction: The subjective perception of solid bolus hold up during swallowing is a common reason for referral for manometric investigation, yet standardmeasures of esophageal function relate poorly to patient perception and a large proportion of patients with dysphagia demonstrate no apparent abnormality on routine diagnostic testing for esophageal dysfunction. The utility of combined esophageal pressure-impedance recording has been recently enhanced by automated impedance manometry pressure-flow analysis (AIM analysis) and newmetrics have been conceived that better describe the interactions between bolus transport and pressure generation. In this study we undertook to assess whether these new esophageal pressure-flow metrics were altered when subjects perceived solid bolus hold up. Methods: Esophageal high-resolution pressure-impedance recordings of 5ml/10ml liquid/viscous swallows and 2cm/4cm solid swallows from 20 control subjects (29-73 years) were analysed. Two solid state pressure(P)/impedance(Z) catheter configurations were used; 32 1cm P/16 2cm Z (Sandhill Scientific) and 36 1cm P/18 2cm Z (Given Imaging). Bolus flow resistance, the relationship between bolus compression and bolus flow timing, was assessed using the pressure flow index (PFI) (Myers et al Neurogastro. Mot. 2012; Nguyen et al Neurogastro. Mot. 2012). Heightened perception of bolus hold up was assessed on a swallow by swallow basis using a 6 point scale (1 = no perception, 2 = awareness of bolus transit, 3-6 = bolus hold up). Results: On a swallow by swallow analysis, heightened perception of solid boluses (swallows with scores 3+) was associated with a higher PFI (distal esophagus Odds Ratio for score 3+ 1.001 [1.000 1.002], p = 0.021). A significant correlation was observed between the maximum subject reported perception score and the average PFI for solids (distal esophagus Pearson's r = 0.690, p,0.001). Grouping of subjects in relation to bolus perception revealed that the PFI was elevated for solids and viscous boluses, but not liquids, in subjects reporting bolus hold up (Figure). Esophageal peak pressures and iso-contour defect size were not significantly related to bolus perception. Conclusion: We report novel findings in relation to mechanical factors during bolus transport that may enhance bolus perception. This study shows that heightened perception of a swallowed bolus relates to subtle differences in flow resistance, which suggests higher levels of muscle tension during the transition phase from a bolus-containing to a lumen-occluded esophageal segment.

Susceptibility to dysphagia after fundoplication revealed by novel automated impedance manometry analysis

Conventional measures of esophageal pressures or bolus transport fail to identify patients at risk of dysphagia after laparoscopic fundoplication. Liquid and viscous swallows were evaluated with impedance/manometry in 19 patients with reflux disease before and after surgery. A new method of automated impedance manometry (AIM) analysis correlated esophageal pressure with impedance data and automatically calculated a range of pressure and bolus movement variables. An iterative analysis determined whether any variables were altered in relation to dysphagia. Standard measures of esophago-gastric junction pressure, bolus presence time, and total bolus transit time were also evaluated. At 5 months postop, 15 patients reported some dysphagia, including 7 with new-onset dysphagia. For viscous boluses, three AIM-derived pressure-flow variables recorded preoperatively varied significantly in relation to postoperative dysphagia. These were: time from nadir esophageal impedance to peak esophageal pressure (TNadImp-PeakP), median intra-bolus pressure (IBP, mmHg), and the rate of bolus pressure rise (IBP slope, mmHgs(-1) ). These variables were combined to form a dysphagia risk index (DRI=IBP×IBP_slope/TNadImp-PeakP). DRI values derived from preoperative measurements were significantly elevated in those with postoperative dysphagia (DRI=58, IQR=21-408 vs no dysphagia DRI=9, IQR=2-19, P<0.02). A DRI >14 was optimally predictive of dysphagia (sensitivity 75% and specificity 93%). Before surgery, a greater and faster compression of a swallowed viscous bolus with less bolus flow time relates to postoperative dysphagia. Thus, susceptibility to postfundoplication dysphagia is related to a pre-existing sub-clinical variation of esophageal function.

Defining and Measuring Dysphagia Following Stroke

To continue the development of a quantified, standard method to differentiate individuals with stroke and dysphagia from individuals without dysphagia. Videofluoroscopic swallowing studies (VFSS) were completed on a group of participants with acute stroke (n = 42) and healthy age-matched individuals (n = 25). Calibrated liquid volumes of 3, 5, 10, and 20 ml were administered during the VFSS. Six measures in 3 domains of bolus flow (timing, direction, and clearance) were measured. Values of these measures obtained from the control group were used to classify dysphagia within the participants. The use of a single measure or single liquid volumes to classify dysphagia did not distinguish between healthy adults and individuals following stroke with and without dysphagia. Abnormality on more than 1 measure across multiple volumes appears to be a more robust method in defining dysphagia for liquids. Our findings indicate that the definition of dysphagia is critical in determining whether persons are classified with disordered swallowing. The definition is dependent on materials and measures evaluated. Each measure provides independent aspects to the evaluation. Determining the level of importance of each depends on the purpose of the evaluation.

The Effects of Intraoral Pressure Sensors on Normal Young and Old Swallowing Patterns

Lingual pressure generation plays a crucial role in oropharyngeal swallowing. To more discretely study the dynamic oropharyngeal system, a 3-bulb array of pressure sensors was designed with the Kay Elemetrics Corporation (Lincoln Park, NJ). The influence of the device upon normal swallowing mechanics and boluses representative of flow relative to age and bolus condition was the focus of this study. Twelve healthy adults in two age groups (31 +/- 5 years, 2 males and 4 females, and 78 +/- 7 years, 2 males and 4 females) participated. Each subject was instructed to swallow four boluses representative of conditions with and without three pressure sensors affixed to the hard palate. Post-swallow residue at four locations, Penetration/Aspiration Scale scores, and three bolus flow timing measures were assessed videofluoroscopically with respect to age and bolus condition. The only statistically significant influences attributable to the presence of the pressure sensors were slight increases in residue in the oral cavity and upper esophageal sphincter with some bolus consistencies, 8% more frequent trace penetration of the laryngeal vestibule predominantly with effortful swallowing, and variances in oral clearance duration. We conclude that the presence of the pressure sensors does not significantly alter normal swallowing patterns of healthy individuals.