Peristaltic Amplitude Research Articles

Therapeutic effect of Wendan Decoction combined with mosapride on gastroesophageal reflux disease after esophageal cancer surgery.

Gastroesophageal reflux disease (GERD) is a common complication of esophageal cancer surgery that can affect quality of life and increase the risk of esophageal stricture and anastomotic leakage. Wendan Decoction (WDD) is a traditional Chinese herbal formula used to treat various gastrointestinal disorders, such as gastritis, functional dyspepsia, and irritable bowel syndrome. Mosapride, a prokinetic agent, functions as a selective 5-hydroxytryptamine 4 agonist, enhancing gastrointestinal motility. To evaluate the therapeutic effects of WDD combined with mosapride on GERD after esophageal cancer surgery. Eighty patients with GERD were randomly divided into treatment (receiving WDD combined with mosapride) and control (receiving mosapride alone) groups. The treatment was conducted from January 2021 to January 2023. The primary outcome was improved GERD symptoms as measured using the reflux disease questionnaire (RDQ). The secondary outcomes were improved esophageal motility (measured using esophageal manometry), gastric emptying (measured using gastric scintigraphy), and quality of life [measured via the Short Form-36 (SF-36) Health Survey]. The treatment group showed a notably reduced RDQ score and improved esophageal motility parameters, such as lower esophageal sphincter pressure, peristaltic amplitude, and peristaltic velocity compared to the control group. The treatment group showed significantly higher gastric emptying rates and SF-36 scores (in both physical and mental domains) compared to the control group. No serious adverse effects were observed in either group. WDD combined with mosapride is an effective and safe therapy for GERD after esophageal cancer surgery. It can improve GERD symptoms, esophageal motility, gastric emptying, and the quality of life of patients. Further studies with larger sample sizes and longer follow-up periods are required to confirm these findings.

Insight into the synergistic effects of surface microstructures and wall peristalsis on glucose production in a bionic microreactor

The enzymatic hydrolysis stage is regarded as a key step in the production of biofuels derived from lignocellulosic biomass, but the elevated production expenses and limited conversion efficiency are still not favorable for practical applications. In this study, inspired by the efficient degradation of cellulose in the termite gut, a cellulase-loaded flexible microreactor model with bionic surface structures was first proposed for the production of fermentable glucose. In such a system, the fold-like structures can provide more enzyme loading sites, and villus-like structures can not only increase enzyme loading but also improve radial transfer in the microreactor. These two structures synergized well and resulted in a 58.5% increase in glucose production compared to the control. Applying peristalsis can further enhance mass transfer by the formation of backflow and vortex, and reducing the peristaltic period is more effective than increasing the peristaltic amplitude for glucose production enhancement. The glucose concentration obtained by the synergistic enhancement of peristalsis and surface structure was 2.3 times of the control. Moreover, for reactions with higher intrinsic reaction rates, the system is in a mass transfer-limited state and peristaltic enhancement is more effective. These results give insight into the design of the bionic flexible microreactor for efficient glucose production.

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.

The profound effect of heat transfer on magnetic peristaltic flow of a couple stress fluid in an inclined annular tube

In this study, we explore the analysis of peristaltic flow with heat transfer occurring within the gap between coaxial inclined tubes. The inner tube’s wall is rigid, while the outer tube’s wall features a sinusoidal wave propagating through it. The cylindrical system is employed to formulate the problem. The flow is characterized using continuity, momentum, and energy equations. We apply the assumption of long wavelength and the low Reynolds number approximation to simplify the nonlinear governing equation, subsequently solving it through perturbation techniques. We investigate the impact of crucial parameters, such as the magnetic field, porous media, slipping conditions, and others, on the peristaltic flow of a couple stress fluid. Our focus lies on assessing their influence on axial velocity, pressure gradient, and flow streamlines. The outcomes are visually presented through graphical representations. Notably, an increase in the slipping parameter results in a reduction of fluid velocity, attributed to the reverse slipping of the flow. The introduction of a magnetic field leads to an augmentation of the pressure gradient. Moreover, elevating the peristaltic amplitude and heat source induces the formation of a vortex within the flow. The presence of porous media leads to an increase in the pressure difference of the fluid flow. The primary objective of this research is to enhance our understanding of the peristaltic motion of non-Newtonian fluid dynamics, specifically incorporating a couple stress fluid. This contributes to a deeper understanding of crucial fluids, such as blood, within the human circulatory system. The implications extend to biological and industrial applications like magnetic resonance imaging (MRI) and radiosurgery, advancing our scholarly understanding of fluid behavior, especially in non-Newtonian scenarios.

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.

Peristalsis prevents ureteral dilation.

The etiology of ureteral dilation in primary nonrefluxing, nonobstructing megaureters is still not well understood. Impaired ureteral peristalsis has been theorized as one of the contributing factors. However, ureteral peristalsis and its "normal" function is not well defined. In this study, using mathematical modeling techniques, we aim to better understand how ureteral peristalsis works. This is the first model to consider clinically observed, back-and-forth, cyclic wall longitudinal motion during peristalsis. We hypothesize that dysfunctional ureteral peristalsis, caused by insufficient peristaltic amplitudes (e.g., circular muscle dysfunction) and/or lack of ureteral wall longitudinal motion (e.g., longitudinal muscle dysfunction), promotes peristaltic reflux (i.e., retrograde flow of urine during an episode of peristalsis) and may result in urinary stasis, urine accumulation, and consequent dilation. Based on lubrication theory in fluid mechanics, we developed a two-dimensional(planar) model of ureteral peristalsis. In doing so, we treated ureteral peristalsis as an infinite train of sinusoidal waves. We then analyzed antegrade and retrograde flows in the ureter under different bladder-kidney differential pressure and peristalsis conditions. There is a minimum peristaltic amplitude required to prevent peristaltic reflux. Ureteral wall longitudinal motion decreases this minimum required amplitude, increasing the nonrefluxing range of peristaltic amplitudes. As an example, for a normal bladder-kidney differential pressure of 5 cmH2 O, ureteral wall longitudinal motion increases nonrefluxing range of peristaltic amplitude by 65%. Additionally, ureteral wall longitudinal motion decreases refluxing volumetric flow rates. For a similar normal bladder pressure example of 5 cmH2 O, refluxing volumetric flow rate decreases by a factor of 18. Finally, elevated bladder pressure, not only increases the required peristaltic amplitude for reflux prevention but it increases maximum refluxing volumetric flow rates. For the case without wall longitudinal motion, as bladder-kidney differential pressure increases from 5 to 40 cmH2 O, minimum required peristaltic amplitude to prevent reflux increases by 40% while the maximum refluxing volumetric flow rate increases by approximately 100%. The results presented in this study show how abnormal ureteral peristalsis, caused by the absence of wall longitudinal motion and/or lack of sufficient peristaltic amplitudes, facilitates peristaltic reflux and retrograde flow. We theorize that this retrograde flow can lead to urinary stasis and urine accumulation in the ureters, resulting in ureteral dilation seen on imaging studies and elevated infection risk. Our results also show how chronically elevated bladder pressures are more susceptible to such refluxing conditions that could lead to ureteral dilation.

MP70-04 URETERAL PERISTALSIS LONGITUDINAL MOTION MINIMIZES REFLUX

You have accessJournal of UrologyCME1 Apr 2023MP70-04 URETERAL PERISTALSIS LONGITUDINAL MOTION MINIMIZES REFLUX Kourosh Kalayeh, Haotian Xie, J. Brian Fowlkes, William W. Schultz, and Bryan S. Sack Kourosh KalayehKourosh Kalayeh More articles by this author , Haotian XieHaotian Xie More articles by this author , J. Brian FowlkesJ. Brian Fowlkes More articles by this author , William W. SchultzWilliam W. Schultz More articles by this author , and Bryan S. SackBryan S. Sack More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003338.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Lack of sufficient ureteral peristalsis is theorized as one of the mechanisms contributing to ureteral dilation in vesicoureteral reflux (VUR) and non-obstructing megaureters. To help understand the phathophysiologic mechanism for these disorders, we first need to understand the dynamics of normal ureteral peristalsis, which results in near complete clearance of urine from the ureter (i.e., non-dilated). We hypothesize that the clinically observed ureteral wall longitudinal motion is crucial to prevent and/or limit peristaltic reflux (i.e., retrograde flow of urine during an episode of peristalsis). METHODS: To examine this hypothesis, based on the lubrication theory in fluid mechanics, we modeled ureteral peristalsis mathematically as an infinite train of sinusoidal waves and analyzed the antegrade and retrograde flows in the ureter. In doing so, we accounted for ureteral wall longitudinal motion by imposing a periodic Gaussian longitudinal velocity on the wall, Figure 1 (a) and (b), inspired by videos of ureteral operations. RESULTS: Effects of wall longitudinal motion on peristaltic reflux and performance are shown in Figure 1 (c) & (d), and Figure 2 (a) & (b), respectively. The results are shown as an example for a typical clinical case with discharge rate of 1.62 mL/min and peristaltic amplitude of 80 % of lumen diameter. As shown, by considering wall longitudinal motion, the range of urine flow rates resulting in peristaltic reflux drops substantially. The minimum required flow rate to prevent peristaltic reflux drops by 50% when including the wall longitudinal motion effect, Figure 2 (a). Similarly, the required flow rate to limit the reflux volume fraction below a critical value of 2% (chosen as an example, based on clinical expertise) drops by 70%, Figure 2 (b). CONCLUSIONS: This computational model is the first to include longitudinal wall motion, which aligns with our hypothesis that it is important for minimizing peristaltic reflux. This supports the clinical observation of normal ureters having high emptying ability and helps direct further investigations to understand ureteral disorders. Source of Funding: This research has been partially supported by grants from the Michigan Institute for Clinical and Health Research (MICHR), and the Departments of Urology and Radiology at the University of Michigan © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1004 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kourosh Kalayeh More articles by this author Haotian Xie More articles by this author J. Brian Fowlkes More articles by this author William W. Schultz More articles by this author Bryan S. Sack More articles by this author Expand All Advertisement PDF downloadLoading ...

Effects of peristaltic amplitude and frequency on gastric emptying and mixing: a simulation study.

The amplitude and frequency of peristaltic contractions are two major parameters for assessing gastric motility. However, it is not fully understood how these parameters affect the important functions of the stomach, such as gastric mixing and emptying. This study aimed to quantify the effects of peristaltic amplitude and frequency on gastric mixing and emptying using computational fluid dynamics simulation of gastric flow with an anatomically realistic model of the stomach. Our results suggest that both the increase and decrease in peristaltic amplitude have a significant impact on mixing strength and emptying rate. For example, when the peristaltic amplitude was 1.2 times higher than normal, the emptying rate was 2.7 times faster, whereas when the amplitude was half, the emptying rate was 4.2 times slower. Moreover, the emptying rate increased more than proportionally with the peristaltic frequency. The nearest contraction wave to the pylorus and the subsequent waves promoted gastric emptying. These results suggest the importance of maintaining parameters within normal ranges to achieve healthy gastric function.

Study on the effect of wall structures and peristalsis of bionic reactor on mixing

Little is known so far about the effects of different inner wall’s structures and peristalsis modes of bionic reactors on fluid mixing. In this study, the small intestine model reactors (SIMR) with different structures of the inner wall are proposed and simulated. The results showed that the mixing level of the fluid in the SIMR with villi or villi plus folds is the highest. The dimensionless villi spacing of 0.014 and height of 0.1 for villi are optimal for mixing intensification. The symmetric peristalsis is more advantageous to the mixing intensification compared to the asymmetric peristalsis. In addition, both the peristalsis modes show much better mixing performance than convection and diffusion. It was also found that the mixing effects of fluids highly depend on the peristaltic velocity, amplitude, and position. The results give insight for the design and optimization of bionic reactors and dynamic in vitro digestion models.

Intensifying biofuel production using a novel bionic flow-induced peristaltic reactor: biodiesel production as a case study

Intensification of biofuel production processes could play a critical role in boosting the economic and environmental features of the whole process. A novel bionic flow-induced peristaltic reactor with a high conversion rate is constructed to realize efficient biofuel production from high-concentration high-viscosity fluids. It is experimentally verified through biodiesel production from soybean oil. Experimental results show that the conversion efficiency is up to 89.9% at 10 s in the peristaltic reactor, which is 38.4% higher than that in the rigid tube reactor. Furthermore, a three-dimensional peristaltic model is conducted to understand the mechanism of heat and mass transfer enhancement. The simulation results show that an increase in peristaltic amplitude strengthens the mixing of the bionic peristaltic reactor by 92.5-100.8%. The temperature distribution in the bionic peristaltic reactor is more uniform than in the traditional rigid tube reactor. The results demonstrate that the conversion rate of soybean oil in the bionic flow-induced peristaltic reactor is 528.82% min-1, which is 17-60 times higher than other intensified reactors operating in either continuous or batch modes.

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.

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.

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.

Gamma-aminobutyric acid receptor type B agonist baclofen inhibits acid-induced excitation of secondary peristalsis but not heartburn sensation.

Acute esophageal acid infusion promotes distension-induced secondary peristalsis. The gamma-aminobutyric acid receptor type B (GABA-B) receptors activation inhibits secondary peristalsis. This study aimed to test the hypothesis whether acid excitation of secondary peristalsis can be influenced by baclofen. Secondary peristalsis was performed with intra-esophageal slow and rapid air injections in 13 healthy subjects. Direct esophageal infusion of 0.1N HCl following pretreatment with placebo or baclofen was randomly performed at least 1week apart. Symptom intensity, distension thresholds, and peristaltic parameters were determined and compared between each study protocol. The intensity of heartburn symptom in response to esophageal acid infusion was significantly greater with baclofen than the placebo (P=0.002). The threshold volume of secondary peristalsis during slow air injections in response to acid infusion was significantly greater with baclofen than the placebo (P=0.001). Baclofen significantly increased the threshold volume of secondary peristalsis during rapid air injections in response to acid infusion (P=0.001). The frequency of secondary peristalsis in response to acid infusion was significantly decreased by baclofen as compared with the placebo (P=0.001). Baclofen significantly decreased peristaltic amplitudes in response to acid infusion during rapid air injections (P=0.007). Gamma-aminobutyric acid receptor type B agonist baclofen inhibits acid excitation of secondary peristalsis in human esophagus, which is probably mediated by both muscular and mucosal mechanoreceptors. This work supports the evidence of potential involvement of GABA-B receptors in negative modulation of acid excitation of esophageal perception as well as secondary peristalsis.

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.

A randomized double‐blind placebo‐controlled crossover‐style trial of buspirone in functional dysphagia and ineffective esophageal motility

Studies suggest that Ineffective Esophageal Motility (IEM) is the manometric correlate of Functional Dysphagia (FD). Currently, there is no accepted therapy for either condition. Buspirone is a serotonin modulating medication and has been shown to augment esophageal peristaltic amplitude in healthy volunteers. We aimed to determine if buspirone improves manometric parameters and symptoms in patients with overlapping IEM/FD. We performed a prospective, double-blind, placebo-controlled, crossover-style trial of 10 patients with IEM/FD. The study consisted of two 2-week treatment arms with a 2-week washout period. Outcomes measured at baseline, end of week 2, and week 6 include high resolution esophageal manometry (HREM), the Mayo Dysphagia Questionnaire-14 (MDQ-14), and the GERD-HRQL. The mean age of our 10 patients was 53±9years and 70% were female. After treatment with buspirone, 30% of patients had normalization of IEM on manometry; however, there was 30% normalization in the placebo group as well. Comparing buspirone to placebo, there was no statistically significant difference in the HREM parameters measured. There was also no statistically significant difference in symptom outcomes for buspirone compared to placebo. Of note, patients had a statistically significant decrease in the total GERD-HRQL total score when treated with placebo compared to baseline levels. Despite previous data demonstrating improved esophageal motility in healthy volunteers, our study shows no difference in terms of HREM parameters or symptom scores in IEM/FD patients treated with buspirone compared to placebo. Further research is necessary to identify novel agents for this condition.

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.

Esophageal motility dysfunction and Type 2 Diabetes Mellitus: Indian scenario

Introduction: Diabetes mellitus (DM) is a metabolic disorder which affects multiple systems of the body including gastrointestinal (GI) system. A number of researchers have studied the effect of type 2 DM on esophageal motility function in western population, but there are no such studies on Indian population. Objectives: Assessment of esophageal motility functions in patients of type 2 DM and its correlation with duration of diabetes, blood sugar, and glycated hemoglobin (HbA1c). To explore the correlation of GI symptoms with abnormal esophageal motility findings. Materials and Methods: The study was conducted on 42 patients. History of three common GI symptoms was recorded. Esophageal motility functions were assessed using high-resolution GI manometry assembly. Blood sugar (Fasting and Post Prandial) and HbA1c were measured. Results: In the present study, the mean duration of diabetes was 6.21 ± 4.55 year and the mean body mass index of the patients was 25.80 ± 4.93 kg/m2. Twenty-nine patients gave a history of GI symptoms. The mean HbA1Cwas 7.86 ± 1.49 and 62% patients had HbA1Cvalues >7%. Contractile front velocity (CFV) and basal lower esophageal sphincter pressure (BLESP) were the main esophageal motility parameters found to be affected in the study. About 26.19% patients had CFV more than 9 cm/s and 26% patients had abnormal BLESP. Only 5% patient had raised peristaltic amplitude. Conclusion: CFV and BLESP were the main esophageal motility parameters which were affected in the diabetic patients. The association between GI symptoms and CFV was significant. The duration of diabetes negatively correlated with peristaltic amplitude and HbA1Cvalues. Larger studies, especially in India, would be of significance to the clinicians for better symptomatic management of the disease in India.