The effects of tegaserod on oesophageal function and bolus transport in healthy volunteers: studies using concurrent high-resolution manometry and videofluoroscopy

Tegaserod: What's Old Is New Again

Irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) are common gastrointestinal disorders imposing considerable impact on the quality of life and well-being of affected individuals. A paucity of evidence-based treatment options exist for CIC and IBS-C sufferers. Tegaserod, a 5-HT₄ agonist, has a substantial body of preclinical and clinical study evidence to support its beneficial role in modulating sensorimotor function of the luminal gastrointestinal tract. Tegaserod was first approved for use by the U.S. Food and Drug Administration for the management of IBS-C and CIC in 2002 and 2004, respectively. Tegaserod enjoyed a successful uptake in the management of these disorders during its first several years of availability in the United States, but was later withdrawn from the market in 2007 over concerns related to adverse cardiovascular events. Since then, additional safety data has been generated, and following a resubmission and review by the Food and Drug Administration, in April 2019, tegaserod was once again approved for use in IBS-C under a more restricted labeling, confining use to women under 65 years of age without heart disease or additional cardiovascular risk factors. This review summarizes the regulatory journey of tegaserod and details the existing pharmacokinetic, physiologic, clinical, and safety data of tegaserod generated over the last 2 decades. The discussion also examines the future of tegaserod in the treatment of these constipation disorders, as well as its potential role in other related disorders of brain-gut interaction.

High-Resolution Manometry-Observations After 15 Years of Personal Use-Has Advancement Reached a Plateau?

PURPOSE OF REVIEW

In the absence of mucosal or structural disease, the aim of investigating the oesophagus is to provide clinically relevant measurements of function that can explain the cause of symptoms, identify pathology and guide effective management. One of the most notable recent advances in the field of oesophageal function has been high-resolution manometry (HRM). This review explores how innovation in HRM has progressed and has far from reached a plateau.

RECENT FINDINGS

HRM technology, methodology and utility continue to evolve; simple additions to the swallow protocol (e.g. eating and drinking), shifting position, targeting symptoms and adding impedance sensors to the HRM catheter have led to improved diagnoses, therapeutic decision-making and outcomes. Progress in HRM persists and shows little sign of abating. The next iteration of the Chicago Classification of motor disorders will highlight these advances and will also identify opportunities for further research and innovation.

Normative Values for Esophageal Motility Assessed in the Physiological Seated Position for 16-Channel Water Perfused High-resolution Esophageal Manometry System and Postural Variations in Healthy Volunteers

Background/Aims

Consensus guidelines for performance and analysis of high-resolution esophageal manometry (HREM) recommend use of equipment, population and posture specific normative values. To provide normative values for Chicago classification (CC) metrics in the physiological seated position for a 16-channel water perfused system (Dentsleeve HREM catheter, Advanced Manometry Systems, Melbourne, Australia) widely used in India and other countries with limited access to solid-state equipment. The results are compared with published CC metrics in supine position done using the same system and volunteers.

Methods

HREM tracings of ten 5 mL water swallows in sitting posture were acquired in healthy volunteers and normative values for CC version 3.0 metrics calculated. Individual swallows were paired with previously reported supine swallows for postural variations (Wilcoxon sign rank test) and concordance of CC diagnoses (Pearson coefficient).

Results

Analysis of 530 sitting posture water swallows (53 subjects) and comparison with their supine data revealed significantly higher integrated relaxation pressure (IRP; median 6.7 mmHg vs 6.1 mmHg) but lower distal latency (DL; mean 6.3 seconds vs 6.8 seconds) and distal contractile integral (DCI; mean 1224 mmHg sec cm vs 1456 mmHg sec cm). Sitting posture normal was defined as: IRP < 13.9, DL > 4.5, and DCI = 115–4500 (absent contractility: DCI < 30). CC diagnoses concordance using posture-specific cut-offs was moderate (k = 0.47).

Conclusions

This paper provides normative values for the Advanced Manometry Systems 16-channel water perfused system in the physiological seated position for CC metrics. Our findings of higher IRP and lower DCI in sitting posture than previously reported supine CC cut-offs, confirm the need to use posture-specific cut-offs for reporting HREM tracings.

Effects of Posture and Swallow Volume on Esophageal Motility Morphology and Probability of Bolus Clearance: A Study Using High-Resolution Impedance Manometry

The Chicago classification diagnostic criteria of esophageal motility disorders are based on 5-ml water swallows in the supine position and have not been analyzed for the correlation between the morphology and bolus transit in the upright position and larger volume swallow conditions. This study aimed to evaluate the effect of posture and swallow volume on peristaltic morphology and the probability of bolus clearance in patients with nonspecific esophageal disorder. A total of 139 patients (4,214 swallows) were included for high-resolution impedance manometry analysis in the right lateral recumbent and upright positions, as well as 5- and 10-ml liquid swallows. Intact peristalses were more frequent in the right lateral recumbent position than in the upright position. No difference was reported on failed peristalsis between both positions. Breaks were more frequent in the upright position. A 20 mmHg isobaric contour (compared with 30 mmHg) was associated with decreased bolus clearance. Bolus clearance probability with 10-ml swallows is greater than that with 5-ml swallows. There was no significant difference in the total bolus clearance comparing between the right lateral recumbent and upright positions. The right lateral recumbent position was associated with a higher intact peristalsis. The volume of swallow did not affect the integrality of esophageal peristalsis but did improve the bolus clearance.

Opioid Treatment and Excessive Alcohol Consumption Are Associated With Esophagogastric Junction Disorders

Background/Aims

The influence of external factors such as opioids and alcohol has been extensively investigated for various segments of the gastrointestinal tract. However, the association between their use and the development of esophagogastric junction outflow obstruction disorders (EGJOODs) is unknown. Therefore, the aim of this study is to analyze prevalence and clinical relevance of opioids and alcohol intake in patients with EGJOODs.

Methods

In this single-center, retrospective study, we reviewed clinical and pharmacological data of 375 consecutive patients who had undergone high resolution impedance manometry for EGJOODs. EGJOODs were classified according to the Chicago classification version 3.0 and to recently published normal values for test meals. Demographics, manometric data, and symptoms were compared between different groups using Pearson’s chi-squared test, Fisher’s exact test, and multivariate analysis. A P < 0.05 was considered significant.

Results

EGJOOD was found in 30.7% (115/375) of all analyzed patients. The prevalence of opioids (14.8% vs 4.2%, P = 0.026) was significantly higher in patients with EGJOODs compared to patients without EGJOODs. Additionally, excessive alcohol consumption (12.2% vs 3.5%, P = 0.011) was associated with EGJOODs. Excessive alcohol consumption was especially frequent in the non-achalasia esophagogastric junction outflow obstruction subgroup (16.2%) and opioid use in the achalasia type III subgroup (20.0%).

Conclusions

We found a significant association between EGJOODs and opioid as well as excessive alcohol consumption. This underlines the importance of detailed history taking regarding medication and ethanol consumption in patients with dysphagia. Further prospective studies on mechanisms undelaying esophagogastric junction dysfunction due to opioids or alcohol are warranted.

The role of oesophageal physiological testing in the assessment of noncardiac chest pain

Oesophageal physiology testing plays an important role in the diagnosis of noncardiac chest pain (NCCP) after cardiac, structural and mucosal abnormalities have been ruled out. Endoscopy can establish the presence of structural causes of chest pain such as cancer, oesophageal webs and diverticula. Even if macroscopically normal, eosinophilic oesophagitis is a common cause of chest pain and needs to be ruled out with an adequate biopsy regimen. In the remaining cases, diagnosis is focused on the identification of often subtle mechanisms that lead to NCCP. The most common oesophageal aetiologies for NCCP are gastro-oesophageal reflux disease (GORD), oesophageal dysmotility and functional chest pain. Ambulatory pH studies (with or without impedance or wireless measurements) can establish the presence of GORD, nonerosive reflux as well any association with symptoms of chest pain. High-resolution manometry, particularly with the inclusion of adjunctive testing, can rule out major motility disorders such as spasm, hypercontraction or achalasia. The EndoFLIP device can help define disorders with reduced distensibility, not easily appreciated with endoscopy or manometry. When all tests remain negative, a diagnosis of oesophageal hypersensitivity is normally made and therapy is shifted from targeting a disease to treating symptoms and patient affect.

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

BACKGROUND AND AIM

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.

METHODS

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.

RESULTS

Prucalopride significantly increased primary peristaltic wave amplitude (68.1 ± 10.0 vs 55.5 ± 8.8 mmHg, P = 0.02). The threshold volume for triggering secondary peristalsis was significantly decreased by prucalopride during slow (9.3 ± 0.8 vs 12.0 ± 0.8 mL; P = 0.04) and rapid air injection (4.9 ± 0.3 vs 7.1 ± 0.1 mL; 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 ± 13.8 mmHg; P = 0.19) or pressure wave amplitudes during rapid air injection (84.2 ± 8.6 vs 69.5 ± 12.9 mmHg; P = 0.09).

CONCLUSIONS

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.

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

BACKGROUND

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.

METHODS

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.

FINDINGS

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).

INTERPRETATION

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.

FUNDING

University Hospital Zurich.

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

BACKGROUND/AIMS

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.

METHODS

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.

RESULTS

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 ± 17 years) and 226 (53 ± 16 years) 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 ≥12 mmHg achalasia, IRP-RDC ≥ 8mmHg "all cause" EGJ dysfunction), were confirmed in the validation set (both, sensitivity ~85%, specificity >95%).

CONCLUSIONS

Rapid Drink Challenge contributes clinically relevant information to routine HRM studies, especially in patients with EGJ dysfunction.

Ineffective esophageal motility and the vagus: current challenges and future prospects

Ineffective esophageal motility (IEM) is characterized by low to very low amplitude propulsive contractions in the distal esophagus, hence primarily affecting the smooth muscle part of the esophagus. IEM is often found in patients with dysphagia or heartburn and is commonly associated with gastroesophageal reflux disease. IEM is assumed to be associated with ineffective bolus transport; however, this can be verified using impedance measurements or evaluation of a barium coated marshmallow swallow. Furthermore, water swallows may not assess accurately the motor capabilities of the esophagus, since contraction amplitude is strongly determined by the size and consistency of the bolus. The “peristaltic reserve” of the esophagus can be evaluated by multiple rapid swallows that, after a period of diglutative inhibition, normally give a powerful peristaltic contraction suggestive of the integrity of neural orchestration and smooth muscle action. The amplitude of contraction is determined by a balance between intrinsic excitatory cholinergic, inhibitory nitrergic, as well as postinhibition rebound excitatory output to the musculature. This is strongly influenced by vagal efferent motor neurons and this in turn is influenced by vagal afferent neurons that send bolus information to the solitary nucleus where programmed activation of the vagal motor neurons to the smooth muscle esophagus is initiated. Solitary nucleus activity is influenced by sensory activity from a large number of organs and various areas of the brain, including the hypothalamus and the cerebral cortex. This allows interaction between swallowing activities and respiratory and cardiac activities and allows the influence of acute and chronic emotional states on swallowing behavior. Interstitial cells of Cajal are part of the sensory units of vagal afferents, the intramuscular arrays, and they provide pacemaker activity to the musculature that can generate peristalsis in the absence of innervation. This indicates that a low-amplitude esophageal contraction, observed as IEM, can be caused by a multitude of factors, and therefore many pathways can be potentially explored to restore normal esophageal peristalsis.

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

BACKGROUND & AIMS

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Buspirone, a new drug for the management of patients with ineffective esophageal motility?

Ineffective esophageal motility (IEM) is the most frequently encountered esophageal motility disorder. Patients may present with a variety of symptoms, such as dysphagia, heartburn, odynophagia, and regurgitation. Over the past years, the landscape of esophageal motility testing has been revolutionized; however, our current treatment options for IEM still remain limited. Previous studies have suggested that buspirone, a serotonin receptor agonist, enhances esophageal peristalsis and lower esophageal sphincter (LES) function. Recent work provides the first evidence that buspirone may influence LES resting pressure in patients with systemic sclerosis. Future research should evaluate whether the beneficial effects of buspirone also apply to the broad clinical entity of esophageal dysphagia patients with IEM.

The effect of position on esophageal structure and function determined with solid-state high-resolution manometry

OBJECTIVE

To investigate the influence of posture on the anatomy and function of esophageal sphincters using solid-state high-resolution manometry.

METHODS

Fifty individuals underwent esophageal manometry with a 36-channel solid-state catheter in the supine and upright positions. The length and pressure of the esophageal sphincters, as well as the esophageal and intra-abdominal lengths of lower esophageal sphincter (LES), were recorded. The residual pressure of the upper esophageal sphincter (UES) and the 4-s integrated relaxation pressure were also measured when the participants swallowed 10 consecutive servings of water (5 mL each). The Bland-Altman plot was used to assess agreement between these parameters in the supine and upright positions.

RESULTS

The LES resting pressure was significantly decreased in the upright position compared with the supine position (13.85 ± 5.90 mmHg vs 18.09 ± 7.80 mmHg, P = 0.000). Weaker integrated relaxation pressures were observed when the participants were in the upright position (5.66 ± 3.33 mmHg vs 7.80 ± 3.25 mmHg, P = 0.000). Compared with the supine position, the upright esophageal length was longer (P = 0.004) and the upper border of the LES was lower (P = 0.050) when the individuals were in the upright position. The agreement between the two positions was acceptable for the esophageal length, LES upper border location and LES pressure measurements.

CONCLUSIONS

Body position exerts a greater influence on the LES than on the UES. Thus, it is necessary to establish normal values for the LES basal pressure and residual pressure in different positions.

Beneficial effect of the 5-HT1A receptor agonist buspirone on esophageal dysfunction associated with systemic sclerosis: A pilot study

BACKGROUND

Esophageal involvement in systemic sclerosis (SSc) carries significant morbidity and is empirically managed with domperidone, albeit with questionable efficacy. The oral 5-HT1A receptor agonist buspirone may enhance esophageal peristalsis and lower esophageal sphincter (LES) function in healthy volunteers.

AIM

We aimed to test the hypothesis that buspirone may exert a beneficial acute effect on esophageal motor dysfunction in symptomatic patients with SSc.

METHODS

Twenty consecutive patients with SSc reporting esophageal symptoms underwent high-resolution manometry before and 30 minutes after administration of buspirone (10 mg). Ten other patients received domperidone (10 mg) and served as control group. Changes in LES resting and residual pressure, amplitude, duration, and velocity of distal esophageal body contractions were examined.

RESULTS

Esophageal hypomotility and hypotensive LES was found in 63% and 67% of patients, respectively. Demographic and clinical characteristics, including baseline manometric parameters, were comparable between groups. Resting pressure of LES increased after buspirone from 9.42 ± 2.6 to 11.53 ± 3.4 mmHg (p = 0.0002 by paired t-test), but not after domperidone; a trend for increase of amplitude of contractions was also observed after buspirone (p = 0.09). Comparison of the individual changes revealed that buspirone was superior to domperidone in enhancing LES pressure ( + 2.11 ± 2.0 versus -0.45 ± 2.3 mmHg, p = 0.006). No significant effects of either drug were noted on other examined parameters of esophageal function.

CONCLUSION

The beneficial acute effect of buspirone on impaired LES function associated with SSc suggests a role of 5-HT1A receptor-mediated interactions in these patients. Prospective studies to examine whether buspirone is of long-term therapeutic value for SSc-associated esophageal disease are warranted.

Influence of everyday bolus consistencies in different body positions on high-resolution esophageal pressure topography (HREPT) parameters

The standard protocol for esophageal manometry involves placing the patient in the supine position with head turned to left (supine head left [SHL]) while evaluating liquid bolus swallows. Routinely, semisolid or solid boluses are not evaluated. Currently, the daily American diet includes up to 40% solid or semisolid texture. Thus far, the data on the effect of different bolus on high-resolution esophageal pressure topography (HREPT) parameters are scarce. This study aims to evaluate the effect of every day bolus consistencies in different body positions on HREPT variables. HREPT was performed on healthy volunteers with a modified protocol including liquid swallows in the SHL position followed by applesauce (semisolid), cracker (solid), and marshmallow (soft solid) in three different positions (SHL, sitting, and standing). A total of 38 healthy adult subjects (22 males and 16 females, median age = 27, and mean body mass index = 25) were evaluated. The resting upper esophageal sphincter pressure was significantly different while subjects swallowed crackers, applesauce, and marshmallows in most positions compared with liquid SHL (P < 0.05). The lower esophageal sphincter, contractile front velocity, and distal contractile integral pressures did not differ in all different consistencies compared with SHL. The integrated relaxation period was significantly higher with solid bolus compared with liquid bolus only in SHL position. The intrabolus pressure was significantly different with solid and soft solid boluses in all postures compared to liquid SHL. The American diet consistency affects upper esophageal sphincter pressure and partially integrated relaxation period and intrabolus pressure in various positions. Semisolid bolus swallows do not cause substantial pressure changes and are safe for evaluation and maintaining adequate caloric intake in patients with dysphagia who cannot tolerate solids.

Randomised clinical trial: the 5-HT4 agonist revexepride in patients with gastro-oesophageal reflux disease who have persistent symptoms despite PPI therapy

BACKGROUND

A substantial proportion of patients with gastro-oesophageal reflux disease (GERD) have only a partial response to proton pump inhibitor (PPI) therapy. Prokinetic drugs may improve reflux symptoms by enhancing oesophageal motility and gastric emptying.

AIM

To evaluate the effect of revexepride, a novel prokinetic 5-hydroxytryptamine type 4 (5-HT4 ) receptor agonist, compared with placebo, in patients with GERD who have a partial response to PPIs.

METHODS

A phase 2b, double-blind, parallel-group study was conducted, in which patients were randomised to one of three revexepride treatment groups (0.1, 0.5 and 2.0 mg three times daily) or placebo (1:1:1:1 ratio). Daily e-diary data captured patients' symptoms over an 8-week treatment period. The primary efficacy outcome was the weekly percentage of regurgitation-free days in the second half of the study (weeks 5-8).

RESULTS

In total, 480 patients were randomised and 477 received treatment (mean age 47.9 years; 61% women). The mean percentage of regurgitation-free days increased from baseline (range, 15.0-18.8%) to week 8 (62.3-70.5%) in all four study arms; however, there were no statistically significant differences in this change between placebo and the three treatment arms. No dose-dependent relationship in treatment effect was observed for any of the study endpoints. The incidence of treatment-emergent adverse events (TEAEs) was revexepride dose-dependent. Only one serious TEAE occurred and none resulted in death.

CONCLUSIONS

Revexepride was no more effective than placebo in controlling regurgitation in patients with GERD symptoms partially responsive to PPIs. Revexepride was well tolerated. ClinicalTrials.gov Identifier: NCT01472939.

Randomized clinical trial: effect of the 5-HT4 receptor agonist revexepride on reflux parameters in patients with persistent reflux symptoms despite PPI treatment

BACKGROUND

Approximately, 20-30% of patients with gastro-esophageal reflux disease (GERD) experience persistent symptoms despite treatment with proton pump inhibitors (PPIs). These patients may have underlying dysmotility; therefore, targeting gastric motor dysfunction in addition to acid inhibition may represent a new therapeutic avenue. The aim of this study was to assess the pharmacodynamic effect of the prokinetic agent revexepride (a 5-HT4 receptor agonist) in patients with GERD who have persistent symptoms despite treatment with a PPI.

METHODS

This was a phase II, exploratory, multicenter, randomized, placebo-controlled, double-blind, parallel-group study in patients with GERD who experienced persistent symptoms while taking a stable dose of PPIs (ClinicalTrials.gov identifier: NCT01370863). Patients were randomized to either revexepride (0.5 mg, three times daily) or matching placebo for 4 weeks. Reflux events and associated characteristics were assessed by pH/impedance monitoring and disease symptoms were assessed using electronic diaries and questionnaires.

KEY RESULTS

In total, 67 patients were enrolled in the study. There were no significant differences between study arms in the number, the mean proximal extent or the bolus clearance times of liquid-containing reflux events. Changes from baseline in the number of heartburn, regurgitation, and other symptom events were minimal for each treatment group and no clear trends were observed.

CONCLUSIONS & INFERENCES

No clear differences were seen in reflux parameters between the placebo and revexepride groups.

Treatment of esophageal motility disorders based on the chicago classification

OPINION STATEMENT

The Chicago Classification divides esophageal motor disorders based on the recorded value of the integrated relaxation pressure (IRP). The first group includes those with an elevated mean IRP that is associated with peristaltic abnormalities such as achalasia and esophagogastric junction outflow obstruction. The second group includes those with a normal mean IRP that is associated with esophageal hypermotility disorders such as distal esophageal spasm, hypercontractile esophagus (jackhammer esophagus), and hypertensive peristalsis (nutcracker esophagus). The third group includes those with a normal mean IRP that is associated with esophageal hypomotility peristaltic abnormalities such as absent peristalsis, weak peristalsis with small or large breaks, and frequent failed peristalsis. The therapeutic options vary greatly between the different groups of esophageal motor disorders. In achalasia patients, potential treatment strategies comprise medical therapy (calcium channel blockers, nitrates, and phosphodiesterase 5 inhibitors), endoscopic procedures (botulinum toxin A injection, pneumatic dilation, or peroral endoscopic myotomy) or surgery (Heller myotomy). Patients with a normal IRP and esophageal hypermotility disorder are candidates for medical therapy (nitrates, calcium channel blockers, phosphodiesterase 5 inhibitors, cimetropium/ipratropium bromide, proton pump inhibitors, benzodiazepines, tricyclic antidepressants, trazodone, selective serotonin reuptake inhibitors, and serotonin-norepinephrine reuptake inhibitors), endoscopic procedures (botulinum toxin A injection and peroral endoscopic myotomy), or surgery (Heller myotomy). Lastly, in patients with a normal IRP and esophageal hypomotility disorder, treatment is primarily focused on controlling the presence of gastroesophageal reflux with proton pump inhibitors and lifestyle modifications (soft and liquid diet and eating in the upright position) to address patient's dysphagia.

High-resolution Impedance Manometry Criteria in the Sitting Position Indicative of Incomplete Bolus Clearance

BACKGROUND/AIMS

We used high-resolution impedance manometry (HRIM) to determine the length of breaks on the isobaric contour which would predict incomplete bolus clearance in patients in the sitting position.

METHODS

In total, 651 swallows in 71 patients with esophageal symptoms were studied using a solid-state HRIM system in the sitting position. Each swallow was classified as complete or incomplete bolus clearance by impedance criteria and peristaltic integrity was evaluated using 20- and 30-mmHg pressure topography isobaric contours. Correlations between the lengths of the breaks for 20- and 30-mmHg were analyzed.

RESULTS

Complete bolus clearance was observed in 83.3% (542/651) of swallows. Breaks of 3 and 7 cm or less were associated with a bolus clearance of 96.8% on the 20-mmHg and 94.7% on the 30-mmHg isobaric contour, respectively (P < 0.001). The areas under the ROC curves for the 20 and 30 mmHg isobaric contours were 0.900 and 0.950, respectively. The sensitivity and specificity for complete bolus clearance were 75.6% and 89.3% for breaks 3 cm or less on the 20-mmHg isobaric contour and 87.9% and 78.7% for breaks 7 cm or less on the 30-mmHg contour (P < 0.001).

CONCLUSIONS

Breaks of < 3 cm in the 20-mmHg isobaric contour or < 7 cm in the 30-mmHg isobaric contour were associated with com-plete bolus clearance. The threshold for breaks in the sitting position was greater than previous reports using the supine posi-tion and longer breaks predicted incomplete bolus clearance.(J Neurogastroenterol Motil 2014;20:491-496).

Regionally dependent neuromuscular functions of motilin and 5-HT₄ receptors in human isolated esophageal body and gastric fundus

BACKGROUND

Motilin agonists promote human gastric motility and cholinergic activity, but excitatory and inhibitory actions are reported in the esophagus. The effect of 5-HT₄ agonists in esophagus is also unclear. Perhaps the use of drugs with additional actions explains the variation. The aim, therefore, was to examine how motilin and prucalopride, selective motilin and 5-HT₄ receptor agonists, modulate neuromuscular functions in human esophagus and gastric fundus.

METHODS

Electrical field stimulation (EFS) evoked nerve-mediated contractions of circular and longitudinal muscle from human esophageal body and circular muscle from gastric fundus.

KEY RESULTS

In esophageal circular muscle EFS evoked brief contraction, followed by another contraction on termination of EFS, each prevented by atropine. Nitric oxide synthase inhibition facilitated contraction during EFS and the overall contraction became monophasic. In esophagus longitudinal muscle and gastric fundus, EFS evoked cholinergically mediated, monophasic contractions, attenuated by simultaneous nitrergic activation. Motilin (100-300 nM) reduced esophagus circular muscle contractions during EFS, unaffected by L-NAME or apamin. Motilin 300 nM also reduced EFS-evoked contractions of longitudinal muscle. Similar concentrations of motilin facilitated cholinergic activity in the fundus and increased baseline muscle tension. Prucalopride facilitated EFS-evoked contractions in esophagus (tested at 30 μM) and fundus (0.1-30 μM).

CONCLUSIONS & INFERENCES

Selective motilin and 5-HT₄ agonists have different, region-dependent abilities to modulate human esophageal and stomach neuromuscular activity, exemplified by weak inhibition (motilin) or excitation (5-HT₄) in esophageal body and excitation for both in stomach. In different patients with motility dysfunctions, motilin and 5-HT₄ agonists may reduce gastro-esophageal reflux in different ways.

Prucalopride decreases esophageal acid exposure and accelerates gastric emptying in healthy subjects

BACKGROUND

The 5-HT4 receptor agonist prucalopride is a prokinetic drug which improves colonic motility. Animal data and in vitro studies suggest that prucalopride also affects gastric and esophageal motor function. We aimed to assess the effect of prucalopride on gastric emptying, esophageal motility, and gastro-esophageal reflux in man.

METHODS

In this double-blind, placebo-controlled, randomized, crossover study, we included 21 healthy volunteers who received 4 mg prucalopride or placebo per day for 6 days. We performed high-resolution manometry (HRM) followed by 120-min HRM-pH-impedance monitoring after a standardized meal, ambulatory 24-h pH-impedance monitoring, and gastric emptying for solids.

KEY RESULTS

Prucalopride decreased (median [IQR]) total acid exposure time (3.4 [2.5-5.6] vs 1.7 [0.8-3.5] %, p < 0.05). The total number of reflux events was unaffected by prucalopride, however, the number of reflux events extending to the proximal esophagus was reduced by prucalopride (15.5 [9.8-25.5] vs 10.5 [5.3-17.5], p < 0.05). Furthermore, prucalopride improved acid clearance time (77.5 [47.8-108.8] vs 44.0 [30.0-67.8] s, p < 0.05). Prucalopride did not affect the number of transient lower esophageal sphincter (LES) relaxations or their association with reflux events. Esophageal motility and basal pressure of the LES were not affected by prucalopride. Prucalopride increased gastric emptying (T1/2 ; 32.7 [27.9-44.6] vs 49.8 [37.7-55.0] min, p < 0.05) and decreased residue after 120 min (8.8 [4.4-14.8] vs 2.7 [1.3-5.4] %, p < 0.05).

CONCLUSIONS & INFERENCES

Prucalopride reduces esophageal acid exposure and accelerates gastric emptying in healthy male volunteers. These findings suggest that the drug could be effective for treatment of patients with reflux disease and functional dyspepsia.

Sensation of stasis is poorly correlated with impaired esophageal bolus transport

BACKGROUND

It is common belief that symptoms of patients with non-obstructive dysphagia are the result of impaired bolus clearance in the esophagus, usually caused by esophageal motility disorders. We therefore investigated the relationship between transit of swallowed boluses and the symptom dysphagia.

METHODS

Twenty healthy volunteers and 20 patients with dysphagia underwent videofluoroscopy. Success of bolus transport was graded on a 7-point scale. Each subject swallowed five liquid and five solid barium boluses.

KEY RESULTS

For liquids, patients reported dysphagia during 1 [0-3] of the five swallows, while controls reported no dysphagia (median 0 [0-0]; p = 0.003). For solids, patients reported dysphagia during 3 [2-4] of five swallows, while controls reported dysphagia in 0.5 [0-2] of five swallows (p = 0.001). When correlating dysphagia to ineffective clearance (score ≥ 3), in 3 [2-4] of five liquids, the subjects perception of clearance was related to the clearance result on fluoroscopy in patients and also 3 [1-5] were correctly perceived in controls (p = 0.6). For solids, in 4 [3-5] of five swallows, the subjects perception of clearance was related to the clearance result on fluoroscopy in patients, but only 2 [1-3] of five swallows were correctly perceived by controls, the difference being statistically significant.

CONCLUSIONS & INFERENCES

Patients very frequently report dysphagia when bolus clearance is successful. Therefore, the major underlying problem in patients with non-obstructive dysphagia is disordered perception and increased sensitivity to physiological bolus stasis. Treatment should therefore be directed at reducing increased sensitivity rather than at improving motility.

Assessment of esophageal dysfunction and symptoms during and after a standardized test meal: development and clinical validation of a new methodology utilizing high-resolution manometry

BACKGROUND

In the absence of major dysmotility, esophageal manometry with water swallows rarely explains the causes of esophageal symptoms and disease. This methodology development study assessed esophageal function and symptoms during a test meal in patients with reflux symptoms and asymptomatic controls. The impact of this approach on manometric diagnosis and clinical outcome was reviewed.

METHODS

18 patients with reflux symptoms and 10 healthy volunteers underwent high resolution manometry (HRM) with 5 mL water swallows, 200 mL water drink, and standardized solid test meal followed by 10 min postprandial observation. The number of symptoms associated with esophageal dysfunction (SAD) divided by total symptoms (dysfunction symptom index [D-SI]) was calculated. Ambulatory reflux pH-monitoring was performed. Final diagnosis and clinical outcome were documented at 2 years.

KEY RESULTS

Meal intake took longer in patients than controls (552 vs 339 s) and this was associated with a higher number of ineffective swallows in this group (51% vs 28%; p < 0.001). No swallowing problems occurred with water swallows but 12/18 (66%) patients had SAD during either the meal or postprandial observations with D-SI >50% in 9/12 (75%). Compared with water swallows, manometric classification was altered in 12/18 (67%) and clinical diagnosis was altered in 7/18 (39%) patients due to test meal observations.

CONCLUSIONS & INFERENCES

A novel methodology for the detection of symptomatic dysmotility during a test meal and postprandial observation is presented. This technique increased the diagnostic yield of esophageal dysfunction in patients presenting with reflux symptoms. Long-term follow-up indicated that these observations can guide effective clinical management.

Effect of mosapride combined with esomeprazole improves esophageal peristaltic function in patients with gastroesophageal reflux disease: a study using high resolution manometry

BACKGROUND

Whether addition of prokinetics to proton pump inhibitors improves esophageal peristalsis and symptoms in patients with gastroesophageal reflux disease (GERD) remains unknown.

AIM

We evaluated the effect of mosapride, a 5-HT4 agonist, and PPI cotherapy in patients with GERD on esophageal motility using high-resolution manometry (HRM).

METHOD

This study was designed as a double-blind, randomized, placebo-controlled trial. Patients with GERD were allocated to a group either taking 40 mg esomeprazole plus 30 mg mosapride or taking esomeprazole plus placebo. Symptom assessment and the HRM study were conducted before drug treatment and after 4 weeks.

RESULTS

Of 50 patients enrolled, 24 in the mosapride group (49 years old, 15 males) and 19 in the placebo group (43 years old, nine males) completed the study. Approximately 79 % of the patients had normal peristaltic function. Treatment response was not different between the two groups (79 vs. 68 %). Mosapride cotherapy tended to yield better response in patients with dyspepsia than those without dyspepsia (92 vs. 67 %). Lower esophageal sphincter pressure didn't change in both groups. Intrabolus pressure decreased in the mosapride group (3.4 ± 3.5 mmHg to 1.4 ± 4.1 mmHg, P < 0.05). Distal esophageal amplitude increased in the mosapride group and not in the placebo group (81 ± 34 to 89 ± 29 mmHg vs. 82 ± 32 to 83 ± 31 mmHg).

CONCLUSION

Adding mosapride on esomeprazole improved esophageal contractability and lowered intrabolus pressure in patients with GERD. Mosapride and esomeprazole cotherapy tended to yield better response in patients with concomitant dyspepsia.

Evaluation of esophageal motor function in clinical practice

Esophageal motor function is highly coordinated between central and enteric nervous systems and the esophageal musculature, which consists of proximal skeletal and distal smooth muscle in three functional regions, the upper and lower esophageal sphincters, and the esophageal body. While upper endoscopy is useful in evaluating for structural disorders of the esophagus, barium esophagography, radionuclide transit studies, and esophageal intraluminal impedance evaluate esophageal transit and partially assess motor function. However, esophageal manometry is the test of choice for the evaluation of esophageal motor function. In recent years, high-resolution manometry (HRM) has streamlined the process of acquisition and display of esophageal pressure data, while uncovering hitherto unrecognized esophageal physiologic mechanisms and pathophysiologic patterns. New algorithms have been devised for analysis and reporting of esophageal pressure topography from HRM. The clinical value of HRM extends to the pediatric population, and complements preoperative evaluation prior to foregut surgery. Provocative maneuvers during HRM may add to the assessment of esophageal motor function. The addition of impedance to HRM provides bolus transit data, but impact on clinical management remains unclear. Emerging techniques such as 3-D HRM and impedance planimetry show promise in the assessment of esophageal sphincter function and esophageal biomechanics.

Effect of buspirone, a 5-HT1A receptor agonist, on esophageal motility in healthy volunteers

There are limited data concerning the effects of 5-HT(1A) receptor activation on esophageal motility. Sumatriptan, a 5-HT(1A) receptor agonist, was recently reported to enhance esophageal peristalsis after intravenous administration. Buspirone, an orally available 5-HT(1A) receptor agonist, was shown to modulate gastroduodenal motor function. Our aim was to evaluate the effect of buspirone on esophageal motility of healthy volunteers. On two separate visits, 20 healthy volunteers aged 21-29 years (nine women) underwent esophageal manometry before and 10, 30, and 60 minutes after the administration of buspirone 20-mg or placebo capsule, according to a double-blind crossover design. At each time point, we compared buspirone and placebo effects on: resting pressure of the lower esophageal sphincter (LES); residual pressure and duration of LES relaxation; amplitude, duration, and onset velocity of esophageal body contractions, during 10 swallows of 5 mL of water. Significant analysis of variance differences (P < 0.05) are presented as mean ± standard deviation. Buspirone significantly increased mean distal esophageal wave amplitude (151 vs. 87 mmHg, P < 0.05) and duration (6.1 vs. 4.2 seconds, P < 0.05). Similarly, buspirone significantly increased mean LES resting pressure (26 vs. 21 mmHg, P < 0.05) and mean residual LES pressure (7.9 vs. 2 mmHg, P < 0.05), whereas reduced mean LES relaxation duration (7.2 vs. 8.0 seconds, P < 0.05) and mean distal onset velocity (7.6 vs. 14.7 cm/second, P < 0.05). Buspirone enhances esophageal peristalsis and LES function in healthy volunteers. Further study is warranted on the effects of buspirone on esophageal function and symptoms in patients with ineffective esophageal motility.

Future directions in esophageal motility and function - new technology and methodology

BACKGROUND

Symptom based diagnosis is not reliable in patients with swallowing problems, heartburn, and other dyspeptic complaints. The aim of investigation is to provide clinically relevant measurements of gastrointestinal structure and function that explain the cause of symptoms, identify pathology, and guide effective management. Current practice rarely meets these ideals.

PURPOSE

This review considers recent advances in technology such as high-resolution manometry (HRM) with esophageal pressure topography (EPT), HRM with impedance, high frequency ultrasound, and endoscopic functional luminal impedance planimetry (Endo-FLIP) that provide new opportunities to identify the pathophysiologic basis of esophageal symptoms and disease. As experience with these new devices increases researchers are developing new methodologies that maximize their utility in clinical practice. For example, application of HRM to assess motility and function during and after a test meal can identify the causes of swallowing problems, reflux and other postprandial symptoms and intra-operative application of Endo-FLIP may help surgeons perform antireflux surgery. These examples illustrate the potential of physiologic measurement to direct rational and effective clinical management for individual patients.

Weak and absent peristalsis

BACKGROUND

Weak and absent esophageal peristalsis are frequently encountered esophageal motility disorders, which may be associated with dysphagia and which may contribute to gastroesophageal reflux disease. Recently, rapid developments in the diagnostic armamentarium have taken place, in particular, in high-resolution manometry with or without concurrent intraluminal impedance monitoring.

PURPOSE

This article aims to review the current insights in the terminology, pathology, pathophysiology, clinical manifestations, diagnostic work-up,and management of weak and absent peristalsis.

Chicago classification criteria of esophageal motility disorders defined in high resolution esophageal pressure topography

BACKGROUND

The Chicago Classification of esophageal motility was developed to facilitate the interpretation of clinical high resolution esophageal pressure topography (EPT) studies, concurrent with the widespread adoption of this technology into clinical practice. The Chicago Classification has been an evolutionary process, molded first by published evidence pertinent to the clinical interpretation of high resolution manometry (HRM) studies and secondarily by group experience when suitable evidence is lacking.

PURPOSE

This publication summarizes the state of our knowledge as of the most recent meeting of the International High Resolution Manometry Working Group in Ascona, Switzerland in April 2011. The prior iteration of the Chicago Classification was updated through a process of literature analysis and discussion. The major changes in this document from the prior iteration are largely attributable to research studies published since the prior iteration, in many cases research conducted in response to prior deliberations of the International High Resolution Manometry Working Group. The classification now includes criteria for subtyping achalasia, EGJ outflow obstruction, motility disorders not observed in normal subjects (Distal esophageal spasm, Hypercontractile esophagus, and Absent peristalsis), and statistically defined peristaltic abnormalities (Weak peristalsis, Frequent failed peristalsis, Rapid contractions with normal latency, and Hypertensive peristalsis). The Chicago Classification is an algorithmic scheme for diagnosis of esophageal motility disorders from clinical EPT studies. Moving forward, we anticipate continuing this process with increased emphasis placed on natural history studies and outcome data based on the classification.

New pharmacologic approaches in gastroesophageal reflux disease

This article highlights current and emerging pharmacological treatments for gastroesophageal reflux disease (GERD), opportunities for improving medical treatment, the extent to which improvements may be achieved with current therapy, and where new therapies may be required. These issues are discussed in the context of current thinking on the pathogenesis of GERD and its various manifestations and on the pharmacologic basis of current treatments.

Distal esophageal spasm in high-resolution esophageal pressure topography: defining clinical phenotypes

BACKGROUND

The manometric diagnosis of distal esophageal spasm (DES) uses "simultaneous contractions" as a defining criterion, ignoring the concept of short latency distal contractions as an important feature. Our aim was to apply standardized metrics of contraction velocity and latency to high-resolution esophageal pressure topography (EPT) studies to refine the diagnosis of DES.

METHODS

Two thousand consecutive EPT studies were analyzed for contractile front velocity (CFV) and distal latency to identify patients potentially having DES. Normal limits for CFV and distal latency were established from 75 control subjects. Clinical data of patients with reduced distal latency and/or rapid CFV were reviewed.

RESULTS

Of 1070 evaluable patients, 91 (8.5%) had a high CFV and/or low distal latency. Patients with only rapid contractions (n = 186 [17.4%] using conventional manometry criteria; n = 85 [7.9%] using EPT criteria) were heterogeneous in diagnosis and symptoms, with the majority ultimately categorized as weak peristalsis or normal. In contrast, 96% of patients with premature contraction had dysphagia, and all (n = 24; 2.2% overall) were ultimately managed as spastic achalasia or DES.

CONCLUSIONS

The current DES diagnostic paradigm focused on "simultaneous contractions" identifies a large heterogeneous set of patients, most of whom do not have a clinical syndrome suggestive of esophageal spasm. Incorporating distal latency into the diagnostic algorithm of EPT studies improves upon this by isolating disorders of homogeneous pathophysiology: DES with short latency and spastic achalasia. We hypothesize that prioritizing measurement of distal latency will refine the management of these disorders, recognizing that outcomes trials are necessary.

Treatment approaches of gastrointestinal dysfunction in Parkinson's disease, therapeutical options and future perspectives

Gastrointestinal (GI) dysfunction is a common but underestimated feature in Parkinson's disease (PD). Out of the multimodal spectrum of treatment options, there currently are only a few pharmacological treatments available to improve gastrointestinal motility and symptoms. Because enteric nervous function is mainly regulated by transmitters different from those involved in the brain, dopamine replacement is not a treatment option in PD patients. This article focuses on the known regulative mechanism of GI function and presents known and upcoming treatment options for GI dysfunction in PD.

Normative values and inter-observer agreement for liquid and solid bolus swallows in upright and supine positions as assessed by esophageal high-resolution manometry

BACKGROUND

High-resolution manometry (HRM) with spatiotemporal representation of pressure data is a recent advance in esophageal measurement. At present, normal values are available for 5mL water swallows in the supine position. This study provides reference values for liquid and solid bolus swallows in the upright seated and supine positions.

METHODS

A total of 23 asymptomatic volunteers (11M:12F, age 20-56) underwent HRM (Manoscan 360; Sierra Scientific Instruments) with 5mL water and 1cm3 bread swallows in the upright and supine positions. Normal values for primary parameters associated with effective bolus transport [proximal transition zone length (PTZ, assesses peristaltic coordination], contraction front velocity (CFV), distal contractile index (DCI) and integrated relaxation pressure (IRP)] are presented. For each parameter, median values along with the 5-95th percentile range are reported. Inter-observer agreement between independent observers is reported using the intra-class correlation coefficient.

KEY RESULTS

A higher proportion of swallows were peristaltic for liquids than solids in both the upright and supine positions (both P<0.05). As workload increases with solid bolus and on moving from the upright to the supine position the esophageal contractile response resulted in a shorter PTZ, a slower CFV, and a more vigorous DCI. Also IRP increased during solid bolus transit (all P<0.01). There was significant agreement between independent observers for HRM parameters.

CONCLUSIONS & INFERENCES

Normative values for esophageal function for solids as well as liquids and in the 'physiologic', upright position will optimize the utility of HRM studies. The high level of inter-observer agreement indicates that these can be applied as reference values in clinical practice.

Failure to respond to physiologic challenge characterizes esophageal motility in erosive gastro-esophageal reflux disease

BACKGROUND

Non-specific esophageal dysmotility with impaired clearance is often present in patients with gastro-esophageal reflux disease (GERD), especially those with erosive disease; however the physio-mechanic basis of esophageal dysfunction is not well defined.

METHODS

Retrospective assessment of patients with erosive reflux disease (ERD; n=20) and endoscopy negative reflux disease (ENRD; n=20) with pathologic acid exposure on pH studies (>4.2% time/24 h) and also healthy controls (n=20) studied by high resolution manometry. Esophageal motility in response to liquid and solid bolus swallows and multiple water swallows (MWS) was analyzed. Peristaltic dysfunction was defined as failed peristalsis, spasm, weak or poorly coordinated esophageal contraction (>3cm break in 30 mmHg isocontour).

KEY RESULTS

Peristaltic dysfunction was present in 33% of water swallows in controls, 56% ENRD and 76% ERD respectively (P<0.023 vs controls, P=0.185 vs ENRD). The proportion of effective peristaltic contractions improved with solid compared to liquid bolus in controls (18%vs 33%, P=0.082) and ENRD (22%vs 54%, P=0.046) but not ERD (62%vs 76%, P=0.438). Similarly, MWS was followed by effective peristalsis in 83% of controls and 70% ENRD but only 30% ERD patients (P<0.017 vs controls and P<0.031 vs ENRD). The association between acid exposure and dysmotility was closer for solid than liquid swallows (r=0.52 vs 0.27).

CONCLUSIONS & INFERENCES

Peristaltic dysfunction is common in GERD. ERD patients are characterized by a failure to respond to the physiologic challenge of solid bolus and MWS that is likely also to impair clearance following reflux events and increase exposure to gastric refluxate.

New pharmacologic approaches in gastroesophageal reflux disease

This article highlights current and emerging pharmacological treatments for gastroesophageal reflux disease (GERD), opportunities for improving medical treatment, the extent to which improvements may be achieved with current therapy, and where new therapies may be required. These issues are discussed in the context of current thinking on the pathogenesis of GERD and its various manifestations and on the pharmacologic basis of current treatments.

Does body position modify the results of oesophageal high resolution manometry?

BACKGROUND Oesophageal motility classification using high resolution manometry (HRM) has been established in the supine position. Nevertheless, examination in the sitting position is more physiological. Our aim was to determine if body position modifies oesophago-gastric junction (OGJ) morphology and oesophageal motility. METHODS A total of 100 patients (47 males, mean age 51 years) were included in this study. The oesophageal HRM protocol included examination in supine and sitting positions. Recordings were reviewed by two different operators. Amplitude, duration, velocity, Distal Contractile Integral (DCI) and Pressurization Front Velocity of oesophageal waves induced by swallowing were recorded. KEY RESULTS The lower oesophageal sphincter resting pressure was not significantly changed by body position. The sitting position modified the OGJ classification in 12 patients. The inter-observer agreement to classify OGJ was moderate (kappa = 0.54 and 0.46, in the supine and sitting positions respectively) while it was good to diagnose motility disorders (kappa = 0.72 and 0.83). The percentage of normal waves was lower in the sitting position in comparison with the supine position (56%vs 67%, P < 0.01). The DCI was also lower in the sitting position (1125 mmHg.s.cm vs 1639, P < 0.01) as well as the amplitude of oesophageal waves. Finally the diagnosis was concordant in both positions in 72 patients. CONCLUSIONS & INFERENCES Body position can affect OGJ morphology and oesophageal motility assessment by HRM in some patients. Normal values in the sitting position should thus be determined. Inter-observer variation for the proposed classification of OGJ morphology must also be taken into account.

High-resolution esophageal manometry: using technical advances for clinical advantages

BACKGROUND

High-resolution manometry (HRM) is a new technique to investigate the motor function of the esophagus. It differs from conventional manometry in recording pressures by solid state microtransducers at 12 points around the circumference at every centimeter of esophageal length, and displaying the data in pseudo-three-dimensional format using a topographic plot, where esophageal pressures within a given range are represented by different colors.

RATIONALE

The large amount of data and the capacity to analyze and display it intuitively has afforded many new insights into esophageal dysfunction. Among these insights are the ability to distinguish three different subtypes of achalasia and predict their response to therapy, better understanding of the relationship between the lower esophageal sphincter (LES) and the crural diaphragm, the development of novel quantitative parameters to understand the nature of the dysfunction in non-specific esophageal motor disorders, and the elucidation of a newly described motility disorder characterized by failure of peristalsis at the transitional zone between the upper skeletal muscle and the more distal smooth muscle portion of the esophagus. It is also ideally suited to analysis of the effect of prokinetic medications. The method is quicker and less uncomfortable for patients and the analysis is visually appealing and intuitively comprehensible.

CONCLUSION

Despite these potential advantages, there are currently no data to demonstrate a clinical advantage in treatment. The results of such studies will be crucial to the acceptance of this novel technology.

Development and evaluation of a pH-dependent sustained release tablet for irritable bowel syndrome

The overall objective of this study was to develop a pH-dependent sustained release tablet formulation of a model drug, tegaserod maleate (TM), which is a poorly water soluble and acid labile drug in gastric milieu. The formulation's goal was to allow the dosage form to pass through the stomach intact, start disintegrating in the upper small intestine and slowly release the active in a controlled manner. Partition coefficient, contact angle and drug-excipient compatibility were investigated as part of the preformulation studies. A pH-dependent sustained release tablet was prepared using a combination of Eudragit L100 and Eudragit S100. The effects of solubilizer, disintegrant, binder, coating polymer concentration, pore former, and plasticizer on the drug release rate were determined. The results demonstrated that approximately 90% of the drug was released in a sustained release manner in the pH 6.8 phosphate buffer within 12 h while no drug was detected when subjected to drug release studies in 0.1 mol/L hydrochloric acid for 2 h. The drug release mechanism involved stress points and/or pore formation in the coated film. The coated tablets were stable at 40 degrees C/75% RH for 3 months. These results highlighted the feasibility of this coated tablet system containing TM, which may contribute to the successful treatment of irritable bowel syndrome.

Role of the multichannel intraluminal impedance technique in infants and children

Recently, multichannel intraluminal impedance (MII) was added to the repertoire of tests available to study esophageal (patho)physiology in children. MII has since been used in 2 major areas. First, it has been used as a diagnostic test for gastroesophageal reflux disease (GERD). The main advantage over traditional pH monitoring is its ability to detect both acid and nonacid gastroesophageal reflux (GER) and to discern between liquid and gas GER.Although feasible with multiple pH sensors, the MII technique routinely detects the proximal extent of a GER episode. When a pH sensor is added to the MII-catheter, important information about the acidity of a GER event can be gathered.The second area in which the role of MII has been investigated is that of esophageal function testing. Manometry classically reveals information about esophageal pressure patterns and sphincter function, but does not inform us about bolus flow. MII not only detects the presence of esophageal flow but also adds information on the direction of flow, duration of bolus presence, completeness of bolus clearance, and composition of a bolus.The combination of MII with manometry enables determination of the relationship between esophageal pressures and flow and, therefore, enhances evaluation of esophageal function in terms of assessment of mechanisms of esophageal volume clearance. In addition, this technique will improve our understanding of (patho)physiological mechanisms in pediatric GERD and other esophageal motility disorders.

Esophageal motility testing: impedance-based transit measurement and high-resolution manometry

Esophageal function tests are widely used, not only to obtain insight into esophageal physiology and pathophysiology in a research setting, but also to diagnose esophageal motor disorders in patients with symptoms such as dysphagia and chest pain. While esophageal function testing has long been considered almost synonymous with manometry, recently new techniques such as impedance measurement and high-resolution manometry have emerged. With impedance monitoring the transit of a bolus through the esophagus can be studied without the use of ionizing radiation. High-resolution manometry offers a highly detailed and comprehensive view of esophageal pressure patterns. Multichannel high resolution manometry with color plotting facilitates positioning of the catheter and interpretation of the tracings. In this article the development, clinical usefulness, and indications of these new tests are discussed.

Oesophageal peristaltic transition zone defects: real but few and far between

This study analysed the association between oesophageal transition zone (TZ) defects [characterized by a delay and/or spatial gap between the terminus of the proximal oesophageal (striated muscle) contraction and the initiation of the distal oesophageal (smooth muscle) contraction] and dysphagia in a large patient cohort. Four hundred consecutive patients (178 with dysphagia) and 75 controls were studied with 36-channel high-resolution manometry (HRM). The resultant pressure topography plots were first analysed for impaired oesophagogastric junction (OGJ) relaxation, distal segment contractile abnormalities, and proximal contractile abnormalities using normal values from the 75 controls. If these aspects of oesophageal motility were deemed normal, the TZ was characterized by length and duration between the proximal and distal contractions using a 20 mmHg isobaric contour to establish the segment boundaries. Patients were then classified according to whether or not they exhibited TZ defects (spatial separation or delay) and the occurrence of unexplained dysphagia. Of the 400 patients, 267 were suitable for TZ analysis and of these 55 had a spatial or temporal TZ measurement exceeding the 95th percentile of the controls (2 cm, 1 s). Exactly 34.6% of the patients (n = 19) with spatial and/or temporal TZ defects had unexplained dysphagia, which was significantly more than seen with normal TZ dimensions (19.8%). Although far less common than distal peristaltic or OGJ abnormailites, TZ defects may be related to dysphagia in a minority of patients (<4% in this series) and should be considered a distinct oesophageal motility disorder.

Physiology of the oesophageal transition zone in the presence of chronic bolus retention: studies using concurrent high resolution manometry and digital fluoroscopy

Distinct contraction waves (CWs) exist above and below the transition zone (TZ) between the striated and smooth muscle oesophagus. We hypothesize that bolus transport is impaired in patients with abnormal spatio-temporal coordination and/or contractile pressure in the TZ. Concurrent high resolution manometry and digital fluoroscopy were performed in healthy subjects and patients with reflux oesophagitis; a condition associated with ineffective oesophageal contractility and clearance. A detailed analysis of space-time variations in bolus movement, intra-bolus and intra-luminal pressure was performed on 17 normal studies and nine studies in oesophagitis patients with impaired bolus transit using an interactive computer based system. Compared with normal controls, oesophagitis patients had greater spatial separation between the upper and lower CW tails [median 5.2 cm (range 4.4-5.6) vs 3.1 cm (2.2-3.7)], the average relative pressure within the TZ region (TZ strength) was lower [30.8 mmHg (28.3-36.5) vs 45.8 mmHg (36.1-55.7), P < 0.001], and the risk of bolus retention was higher (90%vs 12%; P < 0.01). The presence of bolus retention was associated with a wider spatial separation of the upper and lower CWs (>3 cm, the upper limit of normal; P < 0.002), independent of the presence of oesophagitis. We conclude that bolus retention in the TZ is associated with excessively wide spatial separation between the upper and lower CWs and lower TZ muscle squeeze. These findings provide a physio-mechanical basis for the occurrence of bolus retention at the level of the aortic arch, and may underlie impaired clearance with reflux oesophagitis.

Advances in roles of prokinetic agents in the treatment of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is characterized by the reflux of gastric content into esophagus with or without histological changes. Pathogenesis of GERD is lower esophageal sphincter (LES) dysfunction, abnormal clearing capacity of refluxed materials, delayed gastric emptying and abnormal resistance of esophageal mucosa to gastric acid, but the primary upper gastrointestinal motility dysfunction is regarded as the most important factor in general. Therefore, prokinetic agents which can restore gastric motility with increasing of LES and esophageal motility have been developed and used frequently in the treatment of GERD. There are several prokinetic agents such as metoclopramide, domperidone, cisapride and mosapride that facilitate acetylcholine release from the enteric cholinergic neurons through a selective 5-HT₄ receptor agonistic action. It is considered that prokinetic agents have the same effect as H2 blocker in the treatment of patients with mild GERD. Additionally, it was reported that a combination therapy with prokinetic agents and proton pump inhibitors (PPI) or H2 receptor antagonists (H2RAs) is more effective than monotherapy in patients with severe GERD. This article reviews the recent advances in the role of prokinetic agents in the treatment of gastroesophageal reflux disease.

High-resolution manometry

Recently, high-resolution oesophageal manometry was added to the armamentarium of researchers and gastroenterologists. Current studies suggest that the yield of high-resolution oesophageal manometry is higher than that of conventional pull-through manometry and is at least comparable to that of sleeve sensor manometry. Probably the most important advantage of solid-state high-resolution manometry is that it makes oesophageal manometry faster and easier to perform. Topographic plotting of high-resolution manometry signals facilitates their interpretation. It is concluded that high-resolution manometry is a promising technique for the evaluation of oesophageal motor function. Further studies will have to determine whether high-resolution manometry is superior to conventional manometry in the diagnostic work-up of patients with oesophageal symptoms.

Segmental characteristics of oesophageal peristalsis in paediatric patients

High-resolution manometry (HRM) in adults identifies a sequential chain of pressure segments that together form normal oesophageal peristalsis. HRM was performed in 40 neonates, infants/toddlers and children (age 1 day-14 years) to see if a similar segmental pattern could be identified in paediatric subjects. A chain of three pressure segments was found with inter-segmental troughs at 27.4 +/- 1.1%, 62.6 +/- 1.3% and 94.9 +/- 0.8% oesophageal length. The first and second pressure troughs were similarly distributed along the oesophagus across age groups; the third was 7.6-8.9% oesophageal length further from the lower oesophageal sphincter in neonates (P < 0.05 compared with other age groups). There were no significant differences in trough locations between subjects with or without oesophageal disease, controlling for age. Consistent presence of all three segments was less common in neonates, primarily because of fewer swallows demonstrating the first (proximal) and third (distal) segments compared with children. HRM in paediatric patients demonstrates, from neonates to children, the distinctive chain of pressure events that also characterizes oesophageal peristalsis in adults. The segmental character to oesophageal peristalsis should be taken into consideration in manometric investigation of all age groups - for example, in testing pharmacological responses and evaluating clearance mechanisms.

Esophagopharyngeal reflux

Objective

Laryngopharyngeal reflux (LPR) is the disorder caused by the regurgitation of gastric contents into the laryngopharynx. Many persons diagnosed with LPR who fail medical therapy regurgitate contents from the proximal esophagus into the laryngopharynx (esophagopharyngeal reflux or EPR) on cinefluoroscopy.

Study Design

Retrospective review.

Subjects and Methods

The charts of consecutive adult patients with findings of EPR on cinefluoroscopy were reviewed.

Results

Twenty patients met the diagnostic criteria for EPR (mean age, 50 years of age; 60% female). Most common symptoms were cough (40%), dysphagia (35%), dysphonia (25%), and chronic throat clearing (25%). Eighty-five percent had a prior diagnosis of acid reflux disease (LPR or GER) and were unsuccessfully treated with proton pump inhibitors and/or anti-reflux surgery; 15% had fluoroscopic oropharyngeal abnormalities; all patients had fluoroscopic esophageal abnormalities.

Conclusion

EPR is characterized by regurgitation of proximal esophageal contents into the laryngopharynx. The symptoms are similar to LPR. EPR appears to be caused by a disorder of volume clearance and esophageal dysmotility not acid and peptic injury.

High-resolution manometry of the esophagus: more than a colorful view on esophageal motility?

Since the introduction of pressure measurement of the esophagus, there has been a stepwise improvement in manometric techniques and the recognition of esophageal manometry as a useful tool to evaluate esophageal function in clinical practice. The newest development in this field is high-resolution manometry of the esophagus. In this review, we will briefly discuss the indications for esophageal manometry and we will focus on the development of the technique of high-resolution manometry and the new insights that were obtained by using this emerging tool. We conclude that high-resolution esophageal manometry with spatiotemporal plotting of signals is a valuable research tool. Clinically, the solid-state high-resolution technique is attractive because it makes it easy to perform a high-quality manometric test. However, future studies will have to determine whether the yield of the technique is higher than that of conventional manometry.