Amplitude Of Peristaltic Waves Research Articles

The effect of peristalsis on dispersion in Casson fluid flow

The present study examines the peristaltic flow of a non-Newtonian (Casson) fluid and solute transport through a flexible tube. Using the long-wavelength approximation, an analytical solution for the Casson fluid velocity is obtained in the axial and radial directions. Then, a numerical solution to the solute concentration is computed using the standard Galerkin finite element method (FEM) for the case of solutal convection-diffusion and the Discontinuous Galerkin FEM for the pure convection case. Graphical results are presented for the axial and local solute concentrations, and the influence of peristaltic wave amplitude, volumetric flow rate, modified Péclet number, time, yield stress, and pertinent initial condition parameters were investigated.

Catalytic effects on peristaltic flow of Jeffrey fluid through a flexible porous duct under oblique magnetic field: Application in biomimetic pumps for hazardous materials

Homogenous and heterogeneous reactions play an essential role in polymer production, combustion, ceramic production, catalysis, distillation, and biochemical procedures. As a result of this advancement, a mathematical model is developed to examine the role of catalytic chemical reaction effects on the magneto-hydrodynamic peristaltic transport in a flexible divergent duct containing a non-deformable porous medium as a model for complex hazardous waste bio-inspired pumping mechanisms. The Jeffrey model is utilized to simulate strong non-Newtonian characteristics. Additional multi-physical features included in the model are heat generation, thermal radiation, Hall current, and complaint wall properties along with an inclined (oblique) magnetic field. The long wavelength and low Reynolds number approximations are deployed to transform the primitive conservation equations from a moving boundary problem to a fixed frame. Appropriate transformations are then utilized to render the model dimensionless. The exact solutions are obtained for stream function and velocity. Further, the R-K-Fehlberg integration scheme is applied to solve the energy and concentration equations. Velocity, temperature, concentration, skin friction, and Nusselt number profiles are visualized graphically. Streamline patterns are also included to capture bolus dynamics. Validation with previous simpler studies has been included. A detailed appraisal of key control parameters on transport characteristics is conducted. It is found that velocity is suppressed with elevation in the damping force parameter while it is enhanced with an increment in regime permeability i. e. Darcy number. Both homogeneous and heterogeneous reactions are observed to exert a significant impact on the species concentration. The volume of the trapped fluid bolus size is shown to be an increasing function of the peristaltic wave amplitude ratio. The present work generalizes existing studies to consider catalytic effects on dissipative peristaltic pumping of the Jeffrey fluid with heat generation and radiative flux, aspects which have been neglected in a single model previously. The simulations are relevant to better characterize the complex transport phenomena in nuclear reactor waste transport via biologically inspired pumping designs.

Intraoesophageal pressure in patients receiving proximal gastrectomy with hinged double flap method for gastric cancer: a retrospective cohort study

Background: Objective functional assessment of esophagogastric anastomosis in patients who underwent proximal gastrectomy with the hinged double flap method for gastric cancer has not been well investigated. This study aimed to perform a functional analysis of reconstruction using high-resolution impedance manometry (HRIM). Materials and methods: The authors enroled 25 patients who underwent proximal gastrectomy for gastric cancer between May 2015 and April 2020 and subsequently underwent HRIM postoperatively. Eligible questionnaires [Postgastrectomy Syndrome Assessment Scale-37 (PGSAS-37)] were retrieved from 16 patients. The association between HRIM data and PGSAS-37 was analyzed. Results: The amplitudes of distal oesophageal peristaltic waves, contractile front velocity, and distal latency assessed by HRIM were almost normal after surgery. Most patient’s lower oesophageal sphincter (LES) resting pressure created by the hinged double flap was within normal limits. Conversely, LES residual pressure values during swallowing-induced relaxation were abnormally high in most patients, and the lower the values, the more severe the reflux and diarrhoea symptoms (P=0.038, P=0.041, respectively). In addition, even when the integrated relaxation pressure (IRP) was normal, lower values corresponded to more severe reflux symptoms (P=0.020). The required LES pressure may be higher after proximal gastrectomy because of the relatively higher intragastric pressure due to the reduced volume of the remnant stomach. This also suggests that swallowing-induced relaxation of the LES was considered a trigger for oesophageal reflux in post-proximal gastrectomy patients. Conclusion: LES residual pressure and IRP values in HRIM correlated with reflux symptoms in patients after proximal gastrectomy.

Transcutaneous auricular vagus nerve stimulation influences gastric motility: A randomized, double-blind trial in healthy individuals

BackgroundTranscutaneous auricular vagus nerve stimulation (taVNS) has been investigated regarding its therapeutic properties in several several conditions such as epilepsy, migraine and major depressive disorder and was shown to access similar neural pathways as invasive vagus nerve stimulation. While the vagus nerve's role in gut motility is physiologically established, the effect of taVNS has scarcely been investigated in humans and yielded conflicting results. Real-time gastric magnetic resonance imaging (rtMRI) is an established reproducible method to investigate gastric motility non-invasively. ObjectiveTo investigate the influence of taVNS on gastric motility of healthy participants using rtMRI. MethodsWe conducted a randomized, double-blind study using high-frequency (HF) stimulation at 25Hz or low-frequency (LF) taVNS at 1Hz after ingestions of a standardized meal in 57 healthy participants. The gastric motility index (GMI) was determined by measuring the amplitude and velocity of the peristaltic waves using rtMRI. ResultsAfter HF taVNS, GMI was significantly higher than after LF stimulation (p = 0.005), which was mainly attributable to a higher amplitude of the peristaltic waves (p = 0.003). ConclusionWe provide evidence that 4-h of taVNS influences gastric motility in healthy human participants for the first time using rtMRI. HF stimulation is associated with higher amplitudes of peristaltic waves in the gastric antrum compared to LF stimulation. Further studies are needed to investigate the effect of different frequencies of taVNS and its therapeutic properties in conditions with impaired gastric motility.

Effect of prucalopride on sildenafil-induced inhibition of esophageal peristalsis in healthy adults.

Prucalopride, a high-affinity 5-hydroxytryptamine 4 receptor agonist, promotes esophageal peristalsis, while phosphodiesterase type 5 inhibitor sildenafil inhibits esophageal peristalsis. The present study was aimed to evaluate whether prucalopride would augment esophageal peristalsis subsequent to the application of sildenafil. Seventeen healthy adults underwent high-resolution manometry by a catheter with one injection port located in the mid-esophagus. Secondary peristalsis was assessed by rapid air injections after water swallows. Two sessions were randomly performed including acute administration of sildenafil 50mg after pretreatment with prucalopride or the placebo. The frequency of primary peristalsis subsequent to the administration of sildenafil was significantly increased by prucalopride (P=0.02). Prucalopride also significantly increased distal contractile integral of primary peristalsis subsequent to the administration of sildenafil (P=0.03). No difference in the frequency of secondary peristalsis subsequent to the administration of sildenafil for air injects of 10mL (P=0.14) or 20mL (P=0.21) was found between prucalopride and placebo. Prucalopride did not change distal contractile integral of secondary peristalsis subsequent to the administration of sildenafil for air injections of 10mL (P=0.09) or 20mL (P=0.12). Prucalopride modulates sildenafil-induced inhibition of primary peristalsis by increasing its effectiveness and peristaltic wave amplitude. Our findings suggest that activation of 5-hydroxytryptamine 4 receptors plays a role in mediating sildenafil-induced inhibition of esophageal primary peristalsis rather than secondary peristalsis.

Esophageal Peristalsis Disorders in ALS Patients with Dysphagia.

To detect the variations of esophageal peristalsis in amyotrophic lateral sclerosis (ALS) patients with predominantly bulbar or predominantly pseudobulbar clinical presentation by using esophageal manometry (EM). Fifteen ALS patients with pseudobulbar clinical presentation (PBP) and 13 patients with bulbar presentation (BP), fulfilling WFN Criteria, were studied. EM was performed in all subjects using a flexible catheter with solid-state transducers. Swallowing was initiated with 5 to 10 mL of water (wet swallows) and saliva (dry swallows) and repeated at 30 s intervals. The manometric parameters were measured automatically and visualized by the computer system. The tracings were analyzed using Synectics software. In PBP patients, an increase of resting pressure value in the upper esophageal sphincter (UES) >45 mmHg, a wave-like course of resting pressure, and toothed peristaltic waves were observed. In BP patients, a low amplitude of peristaltic waves <30 mmHg (mean: 17 ± 5) was recorded, without signs of esophageal motility disturbance at onset or during progression. EM procedure allows objectively distinguishing dysphagia in ALS patients due to bulbar syndrome from the dysphagia due to pseudobulbar syndrome. It is important to identify PBP patients because of their high risk of aspiration.

Fluid transport with suspended particles by means of dilating peristaltic waves

In the present study, transport of a Newtonian fluid containing uniformly distributed tiny particles moving in a cylindrical tube is investigated when the peristaltic wave amplitude dilates exponentially. Long wavelength approximation is used to get rid of non-linear inertia terms. It is observed that dilation of wave-amplitude during propagation enhances pressure but reduces it with rising concentration of particulate suspension. Pressure rises with the amplitude dilation parameter in case solid particles are suspended in the fluid. Pressure is also observed to increase in the distal part of the tube.

Bifurcations of stagnation points in a micropolar fluent media under the influence of an asymmetric peristaltic movement

In the present analysis, the effects of an asymmetric peristaltic movement on the bifurcations of stagnation points have been investigated. An exact analytic solution for a flow of an incompressible micropolar fluid has been established under long wavelength and vanishing Reynolds number assumptions in a moving frame of reference. The stagnation points are located through a system of autonomous differential equations. The behavior and bifurcations of these stagnation points and corresponding streamline patterns have been epitomized through dynamical system methods. Different flow situations manifesting in the flow are characterized as follows: backward flow and trapping and augmented flow. Two possible bifurcations encountered in the flow because of the transitions between these flow regions, where nonhyperbolic degenerate points appear and heteroclinic connections between saddles are conceived. The micropolar parameter, coupling number, amplitude ratios, and phase difference have significant impacts on the bifurcations of the stagnation points and the ranges of the flow rate, which are explored graphically by local bifurcation diagrams. The backward flow region is observed to shrink by increasing the micropolar parameter up to an optimal value, and later an opposite trend is found. Furthermore, the increment in the coupling number causes the trapping region to expand. A reduction in the trapping phenomenon is encountered by enlarging the phase difference, while the augmented flow region becomes smaller for large amplitudes of peristaltic waves propagating along the walls of the channel. At the end, global bifurcation diagrams are used to summarize the obtained results.

Assessment of abdominal organ motion using cine magnetic resonance imaging in different gastric motilities: a comparison between fasting and postprandial states

This study assessed abdominal organ motion induced by gastroduodenal motilities in volunteers during fasting and postprandial states, using cine magnetic resonance imaging (cine-MRI). Thirty-five volunteers underwent cine-MRI while holding their breath in the fasting and postprandial states. Gastric motility was quantified by the amplitude and velocity of antral peristaltic waves. Duodenal motility was evaluated as the change of duodenal diameter. Abdominal organ motion was measured in the liver, pancreas and kidneys. Motion was quantified by calculating maximal organ displacement in the left–right, antero–posterior and caudal–cranial directions. Median antral amplitude and velocity in the fasting and postprandial states were 7.7 and 15.1 mm (P < 0.01), and 1.3 and 2.5 mm/s (P < 0.01), respectively. Duodenal motility did not change. Median displacement for all organs ranged from 0.9 to 2.9 mm in the fasting state and from 1.0 to 2.9 mm in the postprandial state. Significant increases in abdominal organ displacement in the postprandial state were observed in the right lobe of the liver, pancreatic head and both kidneys. Differences in the median displacement of these organs between the two states were all <1 mm. Although the motion of several abdominal organs increased in the postprandial state, the difference between the two states was quite small. Thus, our study suggests that treatment planning and irradiation need not include strict management of gastric conditions, nor the addition of excess margins to compensate for differences in the intra-fractional abdominal organ motion under different gastric motilities in the fasting and postprandial states.

Endoscopic Variceal Sequential Ligation Does Not Increase Risk of Gastroesophageal Reflux Disease in Cirrhosis Patients

BackgroundEndoscopic variceal sequential ligation (EVSL) is currently endorsed in our hospital, as the preferred endoscopic treatment for prevention of variceal rebleeding and achieving adequate hemostasis. There is currently a lack of consensus surrounding EVSL-induced changes in esophageal motor function and abnormal reflux.AimsTo explore alterations in esophageal motor function and risk of abnormal gastroesophageal reflux in liver cirrhosis patients with esophageal varices, after EVSL.MethodsTwenty-one liver cirrhosis patients with esophageal varices were studied using manometry and 24-h pH monitoring 1 day prior to and 1 month following EVSL. The EVSL consisted of performing esophageal variceal ligation using a multi-band ligator, which was repeated every 4 weeks until the varices were eradicated.ResultsThe amplitude and duration of peristaltic contraction waves and the percentage of abnormal esophageal contraction waveforms were unaltered in both the proximal (P > 0.05) and the distal (P > 0.05) esophagus after EVSL. However, the lower esophageal sphincter pressure was decreased following EVSL (16.1 ± 7.9 mmHg vs 21.1 ± 6.3 mmHg (P < 0.05)). Various quantitative parameters including percentage of total monitoring time with pH < 4.0, total number of reflux episodes, number of reflux episodes > 5 min, and DeMeester scores were not increased in post-EVSL patients. Abnormal reflux monitored by 24-h pH monitoring occurred in ten (47.6%) pre-EVSL patients and 11 (52.4%) post-EVSL patients.ConclusionsAlthough EVSL affects esophageal motility by relatively decreasing LES pressure, it does not induce substantial motor abnormalities nor increase risk of abnormal gastroesophageal reflux disease in cirrhosis patients.

Effects of esophageal acid infusion vs mosapride on distension-induced secondary peristalsis in humans.

Secondary peristalsis contributes to the clearance of the refluxate from the esophagus. Acute administration of 5-hydroxytryptamine 4 (5-HT4 ) receptors agonist, mosapride or esophageal infusion of hydrochloric acid (HCl) facilitates secondary peristalsis. The aim of this study was to determine whether esophageal acid infusion and administration of mosapride had different effects on secondary peristalsis. Secondary peristalsis was performed with esophageal distension with rapid and slow air injections in 16 healthy subjects. We performed two separate sessions with HCl (0.1 N) and 40 mg oral mosapride to compare their influence on secondary peristaltic parameters. The threshold volume of secondary peristalsis was significantly lower with HCl infusion than mosapride (P = 0.01) by slow air injections. The threshold volume to generate secondary peristalsis was significantly lower with HCl infusion than mosapride (P = 0.002) by rapid air injections. More secondary peristalsis was trigged by rapid air injections after HCl infusion than mosapride (P = 0.003). Infusion of HCl or mosapride administration has similar effects on peristaltic wave amplitude and duration of primary and secondary peristalsis. Acute esophageal acid infusion can induce greater mechanosensitivity to distension-induced secondary peristalsis than 5-HT4 receptors agonist mosapride. The data suggest that acid-sensitive afferents are more likely to contribute to sensory modulation of esophageal secondary peristalsis; however, the motility aspects of secondary peristalsis are comparable between acute esophageal acidification and 5-HT4 receptors activation via mosapride.

Effects of coagulation on the two-phase peristaltic pumping of magnetized prandtl biofluid through an endoscopic annular geometry containing a porous medium

In this article, motivated by more accurate simulation of electromagnetic blood flow in annular vessel geometries in intravascular thrombosis, a mathematical model is developed for elucidating the effects of coagulation (i.e., a blood clot) on peristaltically induced motion of an electrically-conducting (magnetized) Prandtl fluid physiological suspension through a non-uniform annulus containing a homogenous porous medium. Magnetohydrodynamics is included owing to the presence of iron in the hemoglobin molecule and also the presence of ions in real blood. Hall current which generates a secondary (cross) flow at stronger magnetic field is also considered in the present study. A small annular tube (endoscopic) with sinusoidal peristaltic waves traveling along the inner and outer walls at constant velocity with a clot present is analyzed. The governing conservation equations which comprise the continuity and momentum equations for the fluid phase and particle phase are simplified under lubrication approximations (long wavelength and creeping flow conditions). The moving boundary value problem is normalized and solved analytically (with appropriate wall conditions) for the fluid phase and particle phase using the homotopy perturbation method (HPM) with MATHEMATICA software. Validation is conducted with MAPLE numerical quadrature. A parametric study of the influence of clot height (δ), particle volume fraction (C), Prandtl fluid material parameters (α, β), Hartmann number (M), Hall parameter (m), permeability parameter (k), peristaltic wave amplitude (φ) and wave number (δ¯) on pressure difference and wall shear (friction forces) is included. Pressure rise is elevated with clot height, medium permeability and Prandtl rheological material parameters whereas it is reduced with increasing particle volume fraction and magnetic Hartmann number. Friction forces on the outer and inner tubes of the endoscope annulus are enhanced with clot height and particle volume fraction whereas they are decreased with Prandtl rheological material parameters, Hall parameter and permeability parameter. The simulations provide a good benchmark for more general computational fluid dynamics studies of magnetic endoscopic multi-phase peristaltic pumping.

Three-layered electro-osmosis modulated blood flow through a microchannel

Electrokinetic peristaltic multi-layered transport is considered in a micro-channel under the action of an axial electrical field. Three different layers i.e. the core layer, intermediate layer and peripheral layer are simulated with three different viscosities for each fluid layer. The unsteady two-dimensional conservation equations for mass and momentum with electrokinetic body forces, are transformed from the wave frame to the laboratory frame and the electrical field terms are rendered into electrical potential terms via the Poisson–Boltzmann equation, Debye length approximation and ionic Nernst–Planck equation. The dimensionless emerging linearized electrokinetic boundary value problem is solved using integral methods. Closed-form expressions are derived for stream functions in the core, intermediate and peripheral layers. Expressions are also derived for the core–intermediate interface shape and the intermediate–peripheral interface shape. Maximum pressures are also computed. To study bolus migration, the range of the trapping limit is also determined in the peripheral layer. It is found that in the core layer larger boluses are computed in the case of lower intermediate layer viscosity relative to peripheral layer viscosity although the number of boluses is greater when the intermediate layer viscosity exceeds the peripheral layer viscosity. Furthermore, in the intermediate layer, stronger concentration of streamlines is computed in the lower half space with positive Helmholtz–Smoluchowski velocity. Also negative Helmholtz–Smoluchowski velocity reduces the core layer (H1) interface shape whereas it enhances the peripheral layer (H) and intermediate layer (H2) shapes. At lower values of volume flow rate ratio, hydromechanical efficiency is maximum for positive Helmholtz–Smoluchowski velocity whether intermediate layer viscosity is less or greater than peripheral layer viscosity. Finally, greater with greater peristaltic wave amplitude and also for positive Helmholtz–Smoluchowski velocity there is an increase in time-averaged flow rate, whether intermediate layer viscosity is less or greater than peripheral layer viscosity. The analysis is relevant to electro-kinetic hemodynamics and bio-micro-fluidics.

Influence of prucalopride on esophageal secondary peristalsis in reflux patients with ineffective motility.

Ineffective esophageal motility (IEM) is associated with gastroesophageal reflux disease. Secondary peristalsis contributes to esophageal clearance. Prucalopride promotes secondary peristalsis by stimulating 5-hydroxytrypatamine 4 receptors in the esophagus. We aimed to determine whether prucalopride would augment secondary peristalsis in gastroesophageal reflux disease patients with IEM. After a baseline recording of primary peristalsis, secondary peristalsis was stimulated by slow and rapid mid-esophageal injections of air in 15 patients with IEM. Two separate sessions with 4-mg oral prucalopride or placebo were randomly performed. Prucalopride significantly increased primary peristaltic wave amplitude (68.1±10.0 vs 55.5±8.8mmHg, P=0.02). The threshold volume for triggering secondary peristalsis was significantly decreased by prucalopride during slow (9.3±0.8 vs 12.0±0.8mL; P=0.04) and rapid air injection (4.9±0.3 vs 7.1±0.1mL; P=0.01). Secondary peristalsis was triggered more frequently after application of prucalopride (55% [43-70%]) than placebo (45% [33-50%]) (P=0.008). Prucalopride did not change pressure wave amplitudes during slow air injection (84.6±8.1 vs 57.4±13.8mmHg; P=0.19) or pressure wave amplitudes during rapid air injection (84.2±8.6 vs 69.5±12.9mmHg; P=0.09). Prucalopride enhances primary peristalsis and mechanosensitivity of secondary peristalsis with limited impact on secondary peristaltic activities in IEM patients. Our study suggests that prucalopride appears to be useful in augmenting secondary peristalsis in patients with IEM only via sensory modulation of esophageal secondary peristalsis.

Swallowing of Casson fluid in oesophagus under the influence of peristaltic waves of varying amplitude

The experimentally verified fact that there is a high pressure zone in the lower part of the oesophagus has established that the earlier models fall short of representing the realistic swallowing process in the oesophagus. Since the high pressure is created by gradually increasing amplitudes of peristaltic waves, swallowing of Casson fluid in oesophagus is mathematically remodeled. It is revealed that in the case of exponentially increasing amplitude, pressure is non-uniformly distributed for different cycles. Pressure increases along the entire length of the oesophagus; and finally toward the end of the oesophageal flow, it increases quite significantly, probably to ensure delivery into the stomach. This is a similar observation for Newtonian as well as non-Newtonian fluids but Casson fluids need more pressure; and hence more efforts are required by the oesophagus to transport the fluid forward. When wave amplitude is small, flow rates are small. In such a case, Casson fluid requires higher flow rates for reflux to occur in comparison to Newtonian fluid. This tendency gradually diminishes with increasing amplitude. For a particular value of amplitude, there is no difference; and beyond that the trends are quite opposite. Thus, Casson fluid is found to be less prone to reflux near the wall. It is also concluded that for the Newtonian fluid as well as for the non-Newtonian Casson fluid, reflux is more likely to occur with increasing amplitude and it is further augmented by the addition of amplifying parameter.

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.

Mathematica numerical simulation of peristaltic biophysical transport of a fractional viscoelastic fluid through an inclined cylindrical tube

This paper studies the peristaltic transport of a viscoelastic fluid (with the fractional second-grade model) through an inclined cylindrical tube. The wall of the tube is modelled as a sinusoidal wave. The flow analysis is presented under the assumptions of long wave length and low Reynolds number. Caputo's definition of fractional derivative is used to formulate the fractional differentiation. Analytical solutions are developed for the normalized momentum equations. Expressions are also derived for the pressure, frictional force, and the relationship between the flow rate and pressure gradient. Mathematica numerical computations are then performed. The results are plotted and analysed for different values of fractional parameter, material constant, inclination angle, Reynolds number, Froude number and peristaltic wave amplitude. It is found that fractional parameter and Froude number resist the flow pattern while material constant, Reynolds number, inclination of angle and amplitude aid the peristaltic flow. Furthermore, frictional force and pressure demonstrate the opposite behaviour under the influence of the relevant parameters emerging in the equations of motion. The study has applications in uretral biophysics, and also potential use in peristaltic pumping of petroleum viscoelastic bio-surfactants in chemical engineering and astronautical applications involving conveyance of non-Newtonian fluids (e.g. lubricants) against gravity and in conduits with deformable walls.

Detailed esophageal function and morphological analysis shows high prevalence of gastroesophageal reflux disease and Barrett's esophagus in patients with cervical inlet patch

Although the pathogenesis of cervical inlet patch (CIP) is not fully understood, most authors consider it as a congenital abnormality, whereas others surmise it to be related to gastroesophageal reflux disease (GERD). We aimed to evaluate esophageal function and the prevalence of GERD and Barrett's esophagus in patients with CIP. GERD is defined by the presence of erosive esophagitis or an abnormal pH monitoring. Seventy-one consecutive patients with endoscopic and histological evidence of CIP were prospectively evaluated. Esophageal symptom analysis, 24-hour simultaneous biliary reflux and double-channel pH-monitoring, and esophageal manometry were carried out in 65/71 (92%) patients and in 25 matched controls. Six patients were not suitable for testing and were, therefore, excluded. The histological evaluation of the heterotopic islands showed cardia and/or oxyntic mucosa in 64/65 (98%) patients and specialized intestinal metaplasia (SIM) in one patient (2%). The cardia and/or oxyntic mucosa was accompanied by focally appearing pancreatic acinar metaplasia and pancreatic ductal metaplasia in 7/64 (11%) and in 1/64 (2%), superficial mucous glands in 6/64 (9%), and SIM in 2/64 (3%) cases. In total, SIM was present in three patients (5%), and one of them had low-grade dysplasia. At the gastroesophageal junction, 28 (43%) patients had columnar metaplasia, including nine (14%) patients with SIM. Erosive esophagitis was present in 37 (57%) cases. Thirty-two patients (49%) had abnormal acid reflux in the distal and 25 (38%) in the proximal esophagus. Abnormal biliary reflux was present in 25 (38%) cases. On the basis of endoscopic and pH studies, GERD was established in 44/65 (68%) patients. Typical reflux symptoms were common (33/65, 51%). The combined 24-hour biliary and double-channel pH-monitoring detected significantly more significant acidic reflux at both measurement points and significantly longer bile exposure time in the distal esophagus in patients with CIP. Acid secretion in the CIP was detected in three (5%) cases. Esophageal manometry revealed decreased LES pressure and prolonged relaxation with decreased peristaltic wave amplitude, and an increased number of simultaneous contractions in the esophageal body. The detailed evaluation of the esophageal morphology and function in subjects with CIP showed a high prevalence of GERD and Barrett's esophagus. Further studies are needed to evaluate whether combined acidic and biliary reflux is able to promote similar histomorphological changes in the CIP, as it is shown distally in patients with Barrett's esophagus.