Esophageal body motor response to reflux events: secondary peristalsis

Disorders of secondary peristalsis are associated with the development of esophagitis

BACKGROUND

Disorders of primary peristalsis are associated with a higher percent time pH <4 in the esophagus suggesting poor acid clearance. However, there are no studies of secondary peristalsis and its relationship to microscopic or erosive esophagitis. The goal of this study was to determine the relationship between secondary peristalsis using functional luminal imaging probes (EndoFLIP) and the presence or absence of esophagitis.

METHODS

We reviewed the endoscopic and EndoFLIP 2.0 tracings for 103 consecutive patients including those with a history of upper gastrointestinal surgery undergoing upper endoscopy. Esophagogastric junction (EGJ) distensibility and diameter, repetitive antegrade contraction (RACs) presence and frequency, and occlusive diameters were measured. Measurements were then compared between patients with and without microscopic and/or erosive esophagitis. Means were compared using t-tests. Proportions were compared using Chi-Squared analyses.

KEY RESULTS

One hundred and three patients were included (mean age: 14.4 + 6.4 years). Ten patients had erosive esophagitis and 28 patients had microscopic esophagitis. Erosive and microscopic esophagitis were associated with abnormal or absent of RACs (p < 0.001). Occlusive diameters were higher in patients with esophagitis compared to those without (p < 0.001). There was no relationship between EGJ distensibility and the presence of erosive or microscopic esophagitis (p = 0.4). The absence of RACs was the only independent predictor of esophagitis (erosive and microscopic), after controlling for age, proton pump inhibitors (PPI) use and EGJ distensibility (p < 0.001).

CONCLUSIONS & INFERENCES

Abnormal secondary peristalsis is associated with microscopic and gross esophagitis, suggesting that EndoFLIP should be part of the diagnostic algorithm for esophagitis.

Influence of Menthol Infusion on Esophageal Peristalsis in Patients With Ineffective Esophageal Motility

Background/Aims

Activation of the cold receptor, transient receptor potential melastatin 8 (TRPM8) by menthol inhibits esophageal secondary peristalsis in healthy adults. Ineffective esophageal motility (IEM) is common. This study is to evaluate the effects of acute infusion of menthol on esophageal peristalsis in patients with IEM.

Methods

Twenty patients with IEM (males 11, mean age 36) were studied for esophageal peristalsis using high-resolution manometry. All participant had primary peristalsis performed with 10 water swallows and secondary peristalsis generated with 10 rapid air injections of 20 mL via mid-esophageal infusion port. Two different sessions by randomly performing acute administration of placebo or menthol (3 mM) were used for testing their effects on esophageal peristalsis.

Results

Menthol infusion had no effects on distal contractile integral (P = 0.471), distal latency (P = 0.58), or complete peristalsis (P = 0.251). Menthol infusion did not change basal lower esophageal sphincter pressure (P = 0.321), esophagogastric junction contractile integral (P = 0.758), or integrated relaxation pressure (P = 0.375) of primary peristalsis, but reduced upper esophageal sphincter pressure (P = 0.037). Infusion of menthol significantly reduced the frequency of secondary peristalsis for air injects of 20 mL (P = 0.002), but did not affect distal contractile integral of secondary peristalsis for air injections of 20 mL.

Conclusion

This work has suggested that activation of TRPM8 by menthol can attenuate mechanosensitivity of secondary peristalsis in response to rapid air distension regardless of the presence of IEM.

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

BACKGROUND AND AIM

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.

METHODS

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 50 mg after pretreatment with prucalopride or the placebo.

RESULTS

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 10 mL (P = 0.14) or 20 mL (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 10 mL (P = 0.09) or 20 mL (P = 0.12).

CONCLUSIONS

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.

Risk of Squamous Cell Carcinoma and Adenocarcinoma of the Esophagus in Patients With Achalasia: A Long-Term Prospective Cohort Study in Italy

INTRODUCTION

Epidemiological studies assessing relative risk and incidence rate of esophageal cancer in patients with achalasia are scarce. We performed a long-term prospective cohort study to evaluate the risk of both squamous cell carcinoma and adenocarcinoma of the esophagus in these patients.

METHODS

Between 1973 and 2018, patients with primary achalasia were followed by the same protocol including upper endoscopy with esophageal biopsies. Standardized incidence ratios (SIRs) with 95% confidence interval (CI) were used to estimate the relative risk of esophageal cancer in patients with achalasia compared with the sex- and age-matched general population.

RESULTS

A cohort of 566 patients with achalasia (46% men, mean age at diagnosis: 48.1 years) was followed for a mean of 15.5 years since the diagnosis of achalasia. Overall, 20 patients (15 men) developed esophageal cancer: 15 squamous cell carcinoma and 5 adenocarcinoma. The risk of esophageal cancer was significantly greater than the general population (SIR 104.2, 95% CI 63.7-161), and this for both squamous cell carcinoma (SIR 126.9, 95% CI 71.0-209.3) and adenocarcinoma (SIR 110.2, 95% CI 35.8-257.2). The excess risk was higher in men than women. Annual incidence rate of esophageal cancer was only 0.24% and was higher for squamous cell carcinoma (0.18%) than adenocarcinoma (0.06%).

DISCUSSION

Patients with achalasia have an excess risk of developing both squamous cell carcinoma and adenocarcinoma of the esophagus; however, this prospective cohort study confirms that the annual incidence of esophageal cancer is rather low. These findings may have implications for endoscopic surveillance of patients with achalasia.

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

BACKGROUND AND AIM

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.

METHODS

Secondary peristalsis was performed with intra-esophageal slow and rapid air injections in 13 healthy subjects. Direct esophageal infusion of 0.1 N HCl following pretreatment with placebo or baclofen was randomly performed at least 1 week apart. Symptom intensity, distension thresholds, and peristaltic parameters were determined and compared between each study protocol.

RESULTS

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).

CONCLUSIONS

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.

Pediatric Esophageal Disorders: Diagnosis and Treatment of Reflux and Eosinophilic Esophagitis

Gastroesophageal reflux (GER) occurs frequently in infants, generally at its worst at 4 months of age, with approximately two-thirds of infants spitting up daily. GER typically improves after 7 months of age, with only ∼5% of infants continuing to have reflux at 1 year of age. The diagnosis can often be made based on clinical symptoms. Upper GI (UGI) study has low sensitivity and specificity and should not be ordered as a diagnostic test for reflux. UGI study is best for evaluating other anatomic causes of vomiting. GER becomes problematic gastroesophageal reflux disease (GERD) when complications are present, including feeding difficulties and poor weight gain. Conservative treatment and thickened formula can be helpful for treating GERD. Proton pump inhibitors (PPIs) are frequently prescribed for treating reflux. However, studies do not show a definite benefit in infants, and there are potential side effects. Older children with GERD may present with regurgitation, heartburn, chest discomfort, dysphagia, abdominal pain, vomiting, poor appetite, or poor weight gain. Upper endoscopy is considered for children with concerning symptoms, persistent symptoms despite treatment, and relapse of symptoms after treatment. Other esophageal disorders can have a similar clinical presentation as GERD, notably eosinophilic esophagitis (EoE). EoE is a chronic immune-mediated disorder of the esophagus, which may present as dysphagia, food impaction, heartburn, vomiting, abdominal pain, feeding difficulties, or failure to thrive. Diagnosis is made histologically by the presence of esophageal eosinophilia on endoscopic biopsies in the correct clinical setting.

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.

Influence of GABA-B Agonist Baclofen on Capsaicin-Induced Excitation of Secondary Peristalsis in Humans

OBJECTIVES

Esophageal instillation of capsaicin enhances secondary peristalsis, but the γ-aminobutyric acid receptor type B (GABA-B) agonist baclofen inhibits secondary peristalsis. This study aimed to investigate whether baclofen could influence heartburn perception and secondary peristalsis subsequent to capsaicin infusion in healthy adults.

METHODS

Secondary peristalsis was performed by slow and rapid mid-esophagus air injections in 15 healthy subjects. Two different sessions including esophageal infusion of capsaicin-containing red pepper sauce (0.84 mg) following pre-treatment with placebo or baclofen were randomly performed to test the effects on heartburn perception and secondary peristalsis.

RESULTS

The intensity of heartburn symptom subsequent to capsaicin infusion was significantly greater after pre-treatment of baclofen as compared with the placebo (P=0.03). Baclofen significantly increased the threshold volume of secondary peristalsis to slow air injections subsequent to esophageal capsaicin infusion (P<0.001). Baclofen significantly increased the threshold volume of secondary peristalsis to rapid air injections subsequent to esophageal capsaicin infusion (P<0.01). The frequency of secondary peristalsis subsequent to capsaicin infusion was significantly decreased with baclofen as compared with the placebo (P<0.002). Baclofen had no effect on any of the peristaltic parameters of secondary peristalsis subsequent to capsaicin infusion.

CONCLUSIONS

The GABA-B agonist baclofen appears to attenuate the esophagus to capsaicin-induced excitation of secondary peristalsis in healthy adults. Our study suggests the inhibitory modulation for GABA-B receptors on capsaicin-sensitive afferents mediating secondary peristalsis in human esophagus.

Relevance of sleep disturbance to the integrity and characteristics of secondary peristalsis in patients with gastroesophageal reflux disease

OBJECTIVE

Sleep disturbance is common in patients with gastroesophageal reflux disease (GERD). Secondary peristalsis is important for clearance of the refluxate from the esophagus. We aimed to test the hypothesis whether secondary peristalsis is impaired in GERD patients with sleep disturbance.

METHODS

Secondary peristalsis was stimulated with slow and rapid air injections into mid-esophagus in 8 age-matched health controls and 41 patients with GERD. Sleep disturbance was assessed by the Pittsburg Sleep Quality Index (PSQI). Objective sleep measures were assessed by ambulatory actigraphy.

RESULTS

The threshold volume for inducing secondary peristalsis during slow air injection was significantly higher in GERD patients with sleep disturbance than healthy controls (14.3 ± 1.2 vs. 8.9 ± 0.5 mL, p < .05). GERD patients with sleep disturbance had higher threshold volume of secondary peristalsis during rapid air injection than GERD patients without sleep disturbance (5.1 ± 0.4 vs. 3.9 ± 0.2 mL, p < .05) and healthy controls (5.1 ± 0.4 vs. 3.6 ± 0.2 mL, p < .05). There was a negative correlation between PSQI score and peristaltic frequency during rapid air injection (r = -.39, p = .01). Secondary peristaltic amplitude during rapid air injection was negatively correlated with wake after sleep onset (r = -.34, p = .04).

CONCLUSIONS

Sleep disturbance is associated with secondary peristaltic response to distension-induced esophageal stimulation in patients with GERD. Our study suggests that sleep disturbance per se may adversely influence the effectiveness of esophageal peristalsis and bolus clearance during sleep in patients with GERD.

Influence of capsaicin infusion on secondary peristalsis in patients with gastroesophageal reflux disease

AIM

To determine whether capsaicin infusion could influence heartburn perception and secondary peristalsis in patients with gastroesophageal reflux disease (GERD).

METHODS

Secondary peristalsis was performed with slow and rapid mid-esophageal injections of air in 10 patients with GERD. In a first protocol, saline and capsaicin-containing red pepper sauce infusions were randomly performed, whereas 2 consecutive sessions of capsaicin-containing red pepper sauce infusions were performed in a second protocol. Tested solutions including 5 mL of red pepper sauce diluted with 15 mL of saline and 20 mL of 0.9% saline were infused into the mid-esophagus via the manometric catheter at a rate of 10 mL/min with a randomized and double-blind fashion. During each study protocol, perception of heartburn, threshold volumes and peristaltic parameters for secondary peristalsis were analyzed and compared between different stimuli.

RESULTS

Infusion of capsaicin significantly increased heartburn perception in patients with GERD (P < 0.001), whereas repeated capsaicin infusion significantly reduced heartburn perception (P = 0.003). Acute capsaicin infusion decreased threshold volume of secondary peristalsis (P = 0.001) and increased its frequency (P = 0.01) during rapid air injection. The prevalence of GERD patients with successive secondary peristalsis during slow air injection significantly increased after capsaicin infusion (P = 0.001). Repeated capsaicin infusion increased threshold volume of secondary peristalsis (P = 0.002) and reduced the frequency of secondary peristalsis (P = 0.02) during rapid air injection.

CONCLUSION

Acute esophageal exposure to capsaicin enhances heartburn sensation and promotes secondary peristalsis in gastroesophageal reflux disease, but repetitive capsaicin infusion reverses these effects.

Effects of prucalopride on esophageal secondary peristalsis in humans

Objectives:

Prucalopride, a high-affinity 5-hydroxytrypatamine 4 (5-HT₄) receptors agonist, has been shown to improve colon motility in adults. Secondary peristalsis helps the clearance of retained food bolus and refluxate from the esophagus, but the effects of prucalopride on esophageal secondary peristalsis are unknown. We aimed to assess the effects of prucalopride on distension-induced secondary peristalsis in healthy adults.

Methods:

Two separate sessions with prucalopride and placebo were performed in 11 healthy adults to test the effects on secondary peristalsis. Secondary peristalsis was performed with slow and rapid mid-esophageal injections of air after a baseline recording of esophageal motility.

Results:

Prucalopride significantly decreased the threshold volume to generate secondary peristalsis during slow air injection (9.8±1.4 vs. 14.4±0.9 ml, P=0.005) and rapid air injection (3.9±0.3 vs. 5.2±0.4 ml, P=0.008). Secondary peristalsis was generated more frequently after application of prucalopride (80% (70–100%) vs. 70% (60–73%), P=0.01). Prucalopride increased the wave amplitude of distal esophagus during slow air injection (147.9±28.5 vs. 104.2±16.8 mm Hg, P=0.048) and rapid air injection (128.0±13.3 vs. 105.7±12.3 mm Hg, P=0.016). Primary peristaltic amplitudes were also significantly increased by the application of prucalopride.

Conclusions:

Acute administration of prucalopride enhances mechanosensitivity of distension-induced secondary peristalsis and promotes esophageal contractility in healthy adults. Whether prucalopride could be a therapeutic option for the treatment of subjects with esophageal hypomotility needs further study.

Esophageal Acid Clearance During Random Swallowing Is Faster in Patients with Barrett's Esophagus Than in Healthy Controls

Background/Aims

Impaired esophageal acid clearance may be a contributing factor in the pathogenesis of Barrett’s esophagus. However, few studies have measured acid clearance as such in these patients. In this explorative, cross-sectional study, we aimed to compare esophageal acid clearance and swallowing rate in patients with Barrett’s esophagus to that in healthy controls.

Methods

A total of 26 patients with histology-confirmed Barrett’s esophagus and 12 healthy controls underwent (1) upper endoscopy, (2) an acid clearance test using a pH-impedance probe under controlled conditions including controlled and random swallowing, and (3) an ambulatory pH-impedance measurement.

Results

Compared with controls and when swallowing randomly, patients cleared acid 46% faster (P = 0.008). Furthermore, patients swallowed 60% more frequently (mean swallows/minute: 1.90 ± 0.74 vs 1.19 ± 0.58; P = 0.005), and acid clearance time decreased with greater random swallowing rate (P < 0.001). Swallowing rate increased with lower distal esophageal baseline impedance (P = 0.014). Ambulatory acid exposure was greater in patients (P = 0.033), but clearance times assessed from the ambulatory pH-measurement and acid clearance test were not correlated (all P > 0.3).

Conclusions

More frequent swallowing and thus faster acid clearance in Barrett’s esophagus may constitute a protective reflex due to impaired mucosal integrity and possibly acid hypersensitivity. Despite these reinforced mechanisms, acid clearance ability seems to be overthrown by repeated, retrograde acid reflux, thus resulting in increased esophageal acid exposure and consequently mucosal changes.

Prevalence of dental erosion among people with gastroesophageal reflux disease in China

STATEMENT OF PROBLEM

Gastroesophageal reflux disease (GERD) is typically diagnosed based on symptoms of regurgitation and heartburn, although it may also manifest as asthma-like symptoms, laryngitis, or dental erosion.

PURPOSE

The purpose of this prospective, cross-sectional study was to assess the prevalence of dental erosion in people with GERD and to evaluate the association between GERD and dental erosion.

MATERIAL AND METHODS

The presence, severity, and pattern of dental erosion was assessed in 51 participants with GERD and 50 participants without GERD using the Smith and Knight tooth wear index. Medical, dietary, and dental histories were collected by questionnaire. Factors potentially related to dental erosion, including GERD, were evaluated by logistic regression.

RESULTS

Dental erosion was observed in 31 (60.8%) participants with GERD and 14 (28%) participants without GERD. Bivariate analysis revealed that participants with GERD were more likely to experience dental erosion (crude odds ratio [cOR]: 2.74; 95% CI: 1.19, 6.32) than participants without GERD. Multivariate analysis also revealed that participants with GERD had a higher risk of dental erosion (adjusted odds ratio [aOR]: 3.97; 95% CI: 1.45, 10.89). Consumption of grains and legumes, the most frequently consumed foods in China, did not correlate with dental erosion. However, carbonated beverage consumption was significantly associated with GERD and dental erosion (aOR: 3.34; 95% CI: 1.01, 11.04; P=.04).

CONCLUSIONS

GERD was positively correlated with dental erosion. Carbonated beverage consumption can increase the risk of both GERD and dental erosion.

Esophageal Bolus Transit in Newborns with Gastroesophageal Reflux Disease Symptoms: A Multichannel Intraluminal Impedance Study

PURPOSE

The aim of this study was to evaluate bolus transit during esophageal swallow (ES) and gastroesophageal reflux (GER) events and to investigate the relationship between the characteristics of ES and GER events in a population of term and preterm newborns with symptoms of gastroesophageal reflux disease (GERD).

METHODS

The study population consisted of term and preterm newborns referred to combined multichannel intraluminal impedance (MII) and pH monitoring for GERD symptoms. The frequency and characteristics of ES and GER events were assessed by two independent investigators. Statistical significance was set at p<0.05.

RESULTS

Fifty-four newborns (23 preterm) were included in the analyses. Median bolus head advancing time corrected for esophageal length (BHATc) was shorter during mealtime than during the postprandial period (median, interquartile range): 0.20 (0.15-0.29) s/cm vs. 0.47 (0.39-0.64) s/cm, p<0.001. Median bolus presence time (BPT) was prolonged during mealtime: 4.71(3.49-6.27) s vs. 2.66 (1.82-3.73) s, p<0.001. Higher BHATc (p=0.03) and prolonged BPT (p<0.001) were observed in preterm newborns during the postprandial period. A significant positive correlation between BHATc and bolus clearance time was also observed (ρ=0.33, p=0.016).

CONCLUSION

The analysis of ES and GER events at the same time by MII provides useful information to better understand the physiopathology of GERD. In particular, the analysis of BHATc during the postprandial period could help clinicians identify newborns with prolonged esophageal clearance time due to impaired esophageal motility, which could allow for more accurate recommendations regarding further tests and treatment.

Relevance of ineffective esophageal motility to secondary peristalsis in patients with gastroesophageal reflux disease

BACKGROUND AND AIMS

The study aimed to investigate the hypothesis whether the presence of Ineffective esophageal motility would affect physiological characteristics of secondary peristalsis.

METHODS

Secondary peristalsis was performed with slow and rapid air injections into mid-esophagus of 18 ineffective esophageal motility patients and 15 age-matched controls. Severity of ineffective esophageal motility was defined by the application of combined multichannel intraluminal impedance and manometry.

RESULTS

Ineffective esophageal motility patients included 11 patients without impedance abnormality and seven patients with impedance abnormality during liquid and/or viscous swallowing. The prevalence of failed secondary peristaltic response during slow air injection was significantly greater in ineffective esophageal motility patients without impedance abnormality (3/11 [27%], P < 0.001) and with impedance abnormality (4/7 [57%], P = 0.04) than healthy subjects. The threshold volume for inducing secondary peristalsis during rapid air injection was significantly greater in ineffective esophageal motility patients with impedance abnormality (6.1 ± 0.3 mL) than healthy subjects (4.6 ± 0.3 mL, P < 0.05) and ineffective esophageal motility patients without impedance abnormality (4.1 ± 0.4 mL, P < 0.05). The frequency of peristaltic response during rapid air injection was significantly lower in ineffective esophageal motility patients with impedance abnormality (40% [20-50%] than healthy subjects (90% [90-100%], P < 0.05).

CONCLUSIONS

Defective activation of secondary peristalsis is present in ineffective esophageal motility patients with impedance abnormality. Our study indicates that increased ineffective esophageal motility severity associated with defective triggering of secondary peristalsis may contribute to impaired esophageal clearance in patients with gastroesophageal reflux disease.

Weak peristalsis with large breaks is associated with higher acid exposure and delayed reflux clearance in the supine position in GERD patients

OBJECTIVES

Ineffective esophageal motility is frequently observed in gastroesophageal reflux disease (GERD) patients but its clinical relevance remains controversial. In healthy subjects and in patients with nonobstructive dysphagia, it has been demonstrated, by means of high-resolution manometry (HRM), that long breaks of esophageal peristalsis predict delayed bolus clearance.

METHODS

HRM and 24-h multichannel impedance-pH (MI-pH) monitoring were performed in 40 GERD patients with no evidence of hiatal hernia. Total bolus clearing time (BCT) in upright and supine position and acid exposure time (AET) were calculated.

RESULTS

Of the 40 patients, 23 showed a pathological AET and 15 erosive reflux disease (ERD). Patients with a pathological number of large breaks were characterized by a significantly lower BCT value in the supine position and higher AET. In all, 10/15 ERD patients (67%) and 5/25 nonerosive reflux disease patients (20%) were characterized by an abnormal number of small or large breaks (P<0.05). ERD patients were characterized by significantly higher AET and BCT in the supine position.

CONCLUSIONS

GERD patients with a pathological number of large breaks, assessed by HRM, are characterized by a significantly prolonged reflux clearance in the supine position and higher AET. ERD patients display a higher number of esophageal breaks that might explain the development of erosions.

Pathophysiology of gastroesophageal reflux disease

The gastroesophageal junction is structurally complex and functionally designed to ensure the acid secreted by the most proximal gastric mucosa flows towards the stomach and not up onto the oesophageal squamous mucosa. The pattern and mechanism of reflux vary with the severity of reflux disease and this probably represents different ends of a spectrum rather than distinct pathophysiological mechanisms. Nearly all patients with severe reflux disease have hiatus hernia, however, a substantial proportion of patients with mild reflux disease do not, and this may be a result of intermittent or partial hiatus hernia undetectable by current available tools. The acid pocket is an area of post-prandial unbuffered gastric acidity immediately distal to the gastroesophageal junction and which is enlarged in patients with hiatus hernia. The acid pocket provides a reservoir of acid available to reflux when the intrinsic sphincter fails. Central obesity is an important factor in the aetiology of reflux and does this by the increased abdomino-thoracic pressure gradient inducing hiatus hernia and increasing the rate of flow of reflux when sphincter opens. Central obesity also induces short segment intrasphincteric reflux and thereby columnar metaplasia of the most distal oesophagus.

Effects of mosapride on esophageal secondary peristalsis in humans

BACKGROUND

Secondary peristalsis is important for the clearance of refluxate or retained food bolus from the esophagus. Mosapride is a prokinetic agent that enhances GI motility by stimulating 5-hydroxytrypatamine(4) (5-HT(4) ) receptors, but its effects on secondary peristalsis are yet unclear in humans. We aimed to investigate the effect of a 5-HT(4) agonist mosapride on esophageal distension-induced secondary peristalsis in normal subjects.

METHODS

After a baseline recording esophageal motility, secondary peristalsis was generated by slow and rapid mid-esophageal injections of air in 15 healthy subjects. Two separate sessions with 40mg oral mosapride or placebo were randomly performed to test their effects on esophageal secondary peristalsis.

KEY RESULTS

Mosapride decreased the threshold volume for triggering secondary peristalsis during rapid air distension (4.5±0.3 vs 5.3±0.4mL; P=0.04) but not slow air distension (14.3±1.2 vs 13.3±1.3mL; P=0.41). Secondary peristalsis was triggered more frequently in response to rapid air distension after application of mosapride [100% (90-100%) vs 90% (80-100%); P=0.02]. Mosapride significantly increased pressure wave amplitudes of secondary peristalsis during slow (135.4±13.8 vs 105.0±12.9mmHg; P=0.001) and rapid air distensions (124.0±11.6 vs 95.9±14.0mmHg; P=0.002).

CONCLUSIONS & INFERENCES

Mosapride enhances sensitivity to distension-induced secondary peristalsis and facilitates secondary peristaltic contractility. These data provide an evidence for modulation of esophageal secondary peristalsis by the 5-HT(4) agonist mosapride, as well support for its clinical utility.

Does impaired gallbladder function contribute to the development of Barrett's esophagus and esophageal adenocarcinoma?

INTRODUCTION

Esophageal adenocarcinoma is aetiologically associated with gastro-esophageal reflux, but the mechanisms responsible for the metaplasia-dysplasia sequence are unknown. Bile components are implicated. Impaired gallbladder function may contribute to duodenogastric reflux (DGR) and harmful GERD.

AIMS

This study aims to compare gallbladder function in patients with Barrett's esophagus, adenocarcinoma, and controls.

METHODS

Three groups of patients, all free of gallstone disease, were studied. Group 1: (n = 15) were normal controls. Group 2: (n = 15) were patients with >3-cm-long segment of Barrett's esophagus. Group 3: (n = 15) were patients with esophageal adenocarcinoma. Using real-time ultrasonography unit, gallbladder volume was measured in subjects following a 10-h fast. Ejection fraction was calculated before and after standard liquid meal and compared between the groups.

RESULTS

The mean percentage reduction in gallbladder volume was 50% at 40 min in the adenocarcinoma group compared with 72.4% in the control group (p < 0.001). At 60 min, gallbladder filling had recommenced in the control group to 64.1% of fasting volume while continuing to empty with further reduction to 63% in the Barrett's group and to 50.6% (p = 0.008) in the adenocarcinoma group. The mean gallbladder ejection fraction decreased progressively from controls to Barrett's to adenocarcinoma and was significantly lower in Barrett's group (60.9%; p = 0.019) and adenocarcinoma group (47.9%; p < 0.001) compared with normal controls (70.9%).

CONCLUSION

Gallbladder function is progressively impaired in Barrett's esophagus and adenocarcinoma. Gallbladder malfunction increases duodenogastric reflux, exposing the lower esophagus to an altered chemical milieu which, in turn, may have a role in promoting metaplasia-dysplasia-neoplasia sequence in the lower esophageal mucosa.

Nocturnal gastroesophageal reflux revisited by impedance-pH monitoring

Background/Aims

Impedance-pH monitoring allows detailed characterization of gastroesophageal reflux and esophageal activity associated with reflux. We assessed the characteristics of nocturnal reflux and esophageal activity preceding and following reflux.

Methods

Impedance-pH tracings from 11 healthy subjects and 76 patients with gastroesophageal reflux disease off acid-suppressive therapy were analyzed. Characteristics of nocturnal supine reflux, time distribution and esophageal activity seen on impedance at 2 minute intervals preceding and following reflux were described.

Results

Patients had more nocturnal reflux events than healthy subjects (8 [4-12] vs 2 [1-5], P = 0.002), with lower proportion of weakly acidic reflux (57% [35-78] vs 80% [60-100], P = 0.044). Nocturnal reflux was mainly liquid (80%) and reached the proximal esophagus more often in patients (6% vs 0%, P = 0.047). Acid reflux predominated in the first 2 hours (66%) and weakly acidic reflux in the last 3 hours (70%) of the night. Most nocturnal reflux was preceded by aboral flows and cleared by short lasting volume clearance. In patients, prolonged chemical clearance was associated with less esophageal activity.

Conclusions

Nocturnal weakly acidic reflux is as common as acid reflux in patients with gastroesophageal reflux disease, and predominates later in the night. Impedance-pH can predict prolonged chemical clearance after nocturnal acid reflux.

Risk of esophageal adenocarcinoma in achalasia patients, a retrospective cohort study in Sweden

OBJECTIVES

Achalasia is a motor disorder of the lower esophageal sphincter, which fails to relax on swallowing. Although a greater risk of esophageal squamous cell carcinoma among achalasia patients is fairly well established, no epidemiological study has evaluated the risk of esophageal adenocarcinoma in these patients.

METHODS

We compiled a cohort of 2,896 patients recorded with a discharge diagnosis of achalasia between 1965 and 2003 in the Swedish Inpatient Register. The cohort was followed through 2003 via record linkages with essentially complete registers of cancer, causes of death, and migration. Standardized incidence ratios (SIRs) were used to estimate the relative risk of esophageal cancer in achalasia patients compared to the age-, sex-, and calendar period-matched Swedish population. We further estimated SIRs for esophageal cancer among patients treated with esophagomyotomy.

RESULTS

After excluding the first year of follow-up, we observed excess risks for both squamous cell carcinoma (SIR 11.0, 95% confidence interval [CI] 6.0-18.4) and adenocarcinoma (SIR 10.4, 95% CI 3.8-22.6) of the esophagus. Notwithstanding similar numbers of men and women in our achalasia cohort, 20 of 22 esophageal cancers developed in men (SIRs for adenocarcinoma and squamous cell carcinoma were 8.4 and 13.1, respectively). Increased SIRs among operated patients pertained mainly to esophageal squamous cell carcinoma. We found no evidence that surgical esophagomyotomy increases the risk of esophageal adenocarcinoma.

CONCLUSIONS

Male achalasia patients have substantially greater risks for both squamous cell carcinoma and adenocarcinoma of the esophagus. Small numbers preclude a firm conclusion about the risk among women.

Lower esophageal sphincter relaxation reflex kinetics: effects of peristaltic reflexes and maturation in human premature neonates

We defined the sensory-motor characteristics of the lower esophageal sphincter relaxation (LESR) (stimulus threshold volume, response onset, and relaxation period, relaxation magnitude, nadir) during maturation in human neonates. We hypothesized that LESR kinetics differs during maturation and with peristaltic reflex type. Basal and adaptive esophageal motility testing was performed (N = 20 premature neonates) at 34.7 and 39.1 wk (time 1 and time 2). Effects of midesophageal provocation with graded stimuli (N = 1,267 stimuli, air and liquids) on LESR kinetics during esophagodeglutition response (EDR) and secondary peristalsis (SP) were analyzed by mixed models. Frequency of LESR with basal primary peristalsis were different during maturation (P = 0.03). During adaptive responses with maturation, 1) the frequencies of peristaltic reflexes and LESR were similar; 2) liquid stimuli resulted in a shorter LESR response latency and LESR nadir and greater LESR magnitude (all P < 0.05); 3) media differences were noted with LESR response latency (air vs. liquids, P < 0.02); and 4) infusion flow rate-LESR were different (P < 0.01 for air and liquids). Mechanistically, 1) frequency of LESR was greater during peristaltic reflexes at both times (vs. none, P < 0.0001); 2) LESR response latency, duration, and time to complete LESR were longer with EDR (all P < 0.05, vs. SP at time 2); and 3) graded stimulus volume LESR were different for air and liquids (P < 0.01). In conclusion, sensory-motor characteristics of LESR depend on the mechanosensitive properties of the stimulus (media, volume, flow), type of peristaltic reflex, and postnatal maturation. Maturation modulates an increased recruitment of inhibitory pathways that favor LESR.

The prokinetic effect of mosapride citrate combined with omeprazole therapy improves clinical symptoms and gastric emptying in PPI-resistant NERD patients with delayed gastric emptying

BACKGROUND

Previous studies have shown that non-erosive reflux disease (NERD) patients are less sensitive to proton pump inhibitor (PPI) treatment than patients with erosive reflux disease. The aim of this study was to investigate whether treatment with prokinetics in addition to omeprazole therapy would improve clinical symptoms, gastric emptying and esophageal peristalsis in PPI-resistant NERD patients with or without delayed gastric emptying.

METHODS

Subjects were 64 consecutive patients presenting with typical symptoms of PPl-resistant NERD (n = 44) and 20 healthy volunteers. PPI-resistant NERD patients underwent mosapride citrate (15 mg/day) and omeprazole (20 mg/day) co-therapy for 12 weeks. We evaluated the clinical symptoms as well as gastric emptying and esophageal manometry before and after combined therapy. We measured both acylated- and des-acylated plasma ghrelin levels by the ELISA method. The primary endopoint was to investigate whether co-administration of mosapride citrate and omeprazole would improve clinical symptoms and gastric emptying in PPI-resistant NERD patients with delayed gastric emptying.

RESULTS

T (max) value in PPI-resistant NERD patients was significantly higher than in healthy volunteers. Combination therapy with the prokinetic agent mosapride citrate and omeprazole significantly improved reflux symptoms and T (max) value in T (max) > 65 min NERD patients. Co-therapy also significantly reduced des-acylated-ghrelin levels in NERD patients with delayed gastric emptying.

CONCLUSIONS

Administration of mosapride citrate in addition to omeprazole improved gastro-esophageal reflux and gastric emptying in PPI-resistant NERD patients with delayed gastric emptying.

Upregulation of the esophago-UES relaxation response: a possible pathophysiological mechanism in suspected reflux laryngitis

BACKGROUND

Inappropriate or excessive, non-swallow related, reflexive relaxation of the upper esophageal sphincter (UES) in response to esophageal distension may be the principal mechanism permitting retrograde trans-sphincteric flow during acid regurgitation. The neural pathways mediating reflexive UES relaxation in the human have received little attention. Patients with laryngitis demonstrate an increased acid reflux in the proximal esophagus. Such events, combined with an increased tendency for UES relaxation, might precipitate regurgitation into the pharynx. The aim was to determine whether the esophago-UES relaxation reflex induced by rapid esophageal distension is upregulated in patients with posterior laryngitis.

METHODS

In 21 healthy volunteers and 14 patients with posterior laryngitis, UES responses to rapid air insufflation were examined. UES responses were monitored with perfused manometry catheter with a oval sleeve sensor.

KEY RESULTS

The probability of triggering UES relaxation in response to the rapid esophageal air distension, for all volumes of insufflation, was higher in laryngitis (45%) than in health (17%). The minimum distension volume required to elicit an UES relaxation response was significantly lower in laryngitis patients when compared with controls. Patients who demonstrated a laryngoscopic response to a trial of omeprazole, were less likely to generate a distension-induced UES contractile response (5%) than patients who did not respond (23%).

CONCLUSIONS & INFERENCES

The threshold for esophageal distension-induced UES relaxation is reduced in patients with laryngitis when compared with controls. This finding supports the hypothesis that in this population, a hypersensitive belch-like response may be one contributory mechanism of regurgitation when triggered by an abrupt spontaneous gastro-esophageal reflux event.

Mechanisms of bolus clearance in patients with laparoscopic adjustable gastric bands

BACKGROUND

The components of esophageal function important to success with laparoscopic adjustable gastric banding (LAGB) are not well understood. A pattern of delayed, however, successful bolus transit across the LAGB is observed.

METHODS

Successful LAGB patients underwent a high-resolution video manometry study in which bolus clearance, flow, and intraluminal pressures were recorded. Liquid and semi-solid swallows and stress barium (a combination of semi-solid swallows and liquid barium) were performed. A new measurement, the lower esophageal contractile segment (LECS), was defined and evaluated.

RESULTS

Twenty patients participated (mean age 48.3 +/- 12.0 years, four men, %excess weight loss 65.6 +/- 18.0). During semi-solid swallows, two patterns of esophageal clearance were observed: firstly, a native pattern (n = 10) similar to that which is expected in non-LAGB patients; secondly, a lower esophageal sphincter-dependent pattern (n = 7), where flow only occurred when the intrabolus pressure increased during the lower esophageal sphincter (LES) aftercontraction. In both patterns, if there was incomplete bolus clearance, reflux was observed and was usually followed by another swallow. A mean of 4.5 +/- 2.9 contractions were required to clear the semi-solid bolus. Contractions with an intact LECS demonstrated longer flow duration: 7.1 +/- 3.8 vs.1.6 +/- 3.2 s, p < 0.005. During the stress barium, an intrabolus pressure of 44.5 +/- 16.0 mm Hg leads to cessation of intake.

CONCLUSIONS

In LAGB patients, normal esophageal peristaltic contractions transition to a LES aftercontraction, producing trans-LAGB flow. Repeated contractions are required to clear a semi-solid bolus. Incorporating measurements of the LECS into assessments of esophageal motility in LAGB patients may improve the usefulness of this investigation.

Manometric findings in patients with isolated distal gastroesophageal reflux

AIM: To analyze manometric abnormalities in patients with isolated distal reflux and compare these findings in patients with erosive and non-erosive disease.

METHODS: Five hundred and fifty patients who presented to the outpatient clinic of Turkiye Yuksek Ihtisas Hospital with gastroesophageal reflux disease-like symptoms were enrolled. Each individual was evaluated with esophageal manometry, 24-h ambulatory pH monitoring, and upper gastrointestinal endoscopy. Manometric findings for the patients with isolated distal reflux were compared to findings in controls who were free of reflux disorders or hypersensitive esophagus. Findings for isolated distal reflux patients with and without erosive reflux disease were also compared.

RESULTS: Of the 550 subjects enrolled, 97 (17.6%, mean age 48 years) had isolated distal reflux and 100 had no abnormalities on ambulatory pH monitoring (control group, mean age 45 years). There were no significant differences between the isolated distal reflux group and control group with respect to age, body mass index, and esophageal body contraction amplitude (EBCA). Mean lower esophageal sphincter pressure was significantly higher in the control group (12.7 ± 10.3 mmHg vs 9.6 ± 7.4 mmHg, P = 0.01). Fifty-five (56.7%) of the 97 patients with isolated distal reflux had erosive reflux disease. There were no statistical differences between the erosive reflux disease and non-erosive reflux disease subgroups with respect to mean EBCA, lower esophageal sphincter pressure, or DeMeester score. However, 13% of patients with gastroesophageal reflux disease had distal wave amplitudes ≤ 30 mmHg, whereas none of the patients with non-erosive reflux disease had distal wave amplitudes in this low category.

CONCLUSION: Patients with erosive and non-erosive disease present with similar manometric abnormalities. The only striking difference is the observation of very low EBCA exclusively in patients with erosive disease.

Effect of postnatal maturation on the mechanisms of esophageal propulsion in preterm human neonates: primary and secondary peristalsis

OBJECTIVES

The changes in esophageal propulsive characteristics during maturation are not known. Our aim was to define the effects of postnatal maturation on esophageal peristaltic characteristics in preterm human neonates. We tested the hypotheses that: (i) maturation modifies esophageal bolus propulsion characteristics, and (ii) the mechanistic characteristics differ between primary and secondary peristalsis.

METHODS

Esophageal motility in 10 premature neonates (mean 27.5 weeks gestational age) was evaluated twice at 33.8 weeks (time 1, earlier study) and 39.2 weeks (time 2, later study) mean postmenstrual age. Esophageal manometry waveform characteristics (amplitude and duration, peristaltic velocity, and intrabolus pressure domains) were analyzed during spontaneous primary peristalsis and infusion-induced secondary peristalsis. Repeated-measures and unstructured variance-covariance or compound symmetry matrixes were used for statistical comparison. Values stated as least squares means+/-s.e.m. or percent.

RESULTS

A total of 200 primary peristalsis and 227 secondary peristalsis events were evaluated. Between time 1 and time 2: (i) proximal esophageal waveform amplitude increased (P<0.02), with primary peristalsis (38+/-6 vs. 48+/-7 mm Hg) and with secondary peristalsis (34+/-6 vs. 46+/-5 mm Hg); (ii) distal esophageal waveform amplitude was similar (P=NS), with primary peristalsis (42+/-4 vs. 43+/-4 mm Hg) and secondary peristalsis (29+/-3 vs. 32+/-4 mm Hg); (iii) proximal esophageal waveform onset to peak duration decreased (P=0.02) with primary (2.6+/-0.3 vs. 1.9+/-0.1 s, P<0.003) and with secondary peristalsis (2.2+/-0.2 vs. 1.8+/-0.1 s); (iv) distal esophageal waveform onset to peak duration decreased (P=0.01) with primary (2.4+/-0.3 vs. 1.8+/-0.1 s) and with secondary peristalsis (1.9+/-0.2 vs. 1.5+/-0.1 s); (v) effects of identical stimulus volume on intrabolus pressure were similar (P=NS); however, greater infusion volumes (2 vs. 1 ml) generated higher intrabolus pressure at both time 1 and time 2 (both Ps<0.05). Between primary and secondary peristalsis (mechanistic variable): (i) no differences were noted at either period, with proximal esophageal waveform amplitudes (P=NS); (ii) differences were noted with distal esophageal waveform amplitudes at each time period (P=0.0002); (iii) no differences were noted with both esophageal waveforms duration at either period (P=NS); (iv) peristaltic velocity was faster with secondary peristalsis than with primary peristalsis at either period (at earlier study, 7.9+/-1.4 vs. 2.5+/-1.4 cm/s and at later study 6.2+/-1.6 vs. 1.2+/-1.5 cm/s, both Ps<0.01).

CONCLUSIONS

In preterm neonates, longitudinal maturation modulates the characteristics of primary and secondary peristalsis. Differences in proximal striated muscle and distal smooth muscle activity during peristalsis are evident. Peristaltic velocity is faster with secondary peristalsis. These findings may represent maturation of central and peripheral neuromotor properties of esophageal bolus propulsion in healthy preterm human neonates.

[Modern esophageal surgery and late functional results as equations with several unknowns--Hungarian Academy of Sciences Doctoral Thesis]

Using the same surgical method and anatomically ideal primary healing, the functional results could even be different later. Trying to identify various factors being responsible for the above differences, 637 patient's data, who underwent previous oesophago-gastric surgery between 1985-2005, were analyzed. Biochemical, histological and electrophysiological examinations had been evaluated. Developing hypertrophy-like metabolic changes and enteric ganglionitis as morphological alternations of LES muscles induced by GERD may be reasons for complaints after antireflux surgery. The marking of Z-line with endoscopic clips followed by an immediately upright contrast study and substractional evaluation is appropriate for detecting true short esophagus. Open surgical procedures are justified even in the new millennium in cases when the patient already underwent previous upper abdominal operations - due to an increased risk of injury because of adhesions - in cases of primarily recurrent paraesophageal hernias after an unsuccessful open and/or laparoscopic reconstruction, as well as in cases of reflux with complications. When adenocarcinomas of the gastro-oesophageal junction are examined preoperatively, the ratio of the performed catabolic - AMAN, CB, and DPP I - enzymatic activity of the tissue sample from the tumour and adjacent intact mucosa within 2 cm of the tumour may have a prognostic value even in the preoperative examination period, and neo-adjuvant treatment should be considered in these group of patients. The patients' post-operative complaints and symptoms change during the post-operative period and correlate with the parameters of the myoelectric and contractile activities of the "Akiyama stomach". Tachygastria seems to be the major pathogenetic factor involved in the contractile dysfunction. Gastro-jejuno-duodenal interposition represents an adequate 'second-best' method of choice if technical difficulties emerge with jejunal or colon interposition following limited resection of the oesophagus performed due to early Barrett's carcinoma or non-dilatable peptic stricture.

Gastro-oesophageal reflux disease in Asia : birth of a 'new' disease?

Gastro-oesophageal reflux disease (GORD) is one of the most common gastrointestinal diseases in the Western world and imposes a heavy burden on society. Although its prevalence in Asia is much lower, there is evidence that this is rapidly rising in Asia. The reported population prevalence of GORD in Eastern Asia ranges from 2.5% to 6.7% for at least weekly symptoms of heartburn and/or acid regurgitation. In general, Asians tend to have a milder spectrum of the disease. Most Asian patients have non-erosive GORD; erosive oesophagitis is less commonly seen than in the Western population. Complicated GORD, such as oesophageal stricture and Barrett's oesophagus, is seldom encountered. The mechanisms of GORD may be different in the Chinese population compared with the Western population. Chest pain is the most predominant extra-oesophageal manifestation of GORD in China, whereas an association with asthma has been shown in Japanese patients. The prevalence of GORD appears to be increasing and possible factors for GORD in Asian populations include Helicobacterpylori infection, obesity and increasing dietary fat intake. The adoption of a Western lifestyle in many developing Asian countries may account for the increasing prevalence of GORD. Proton pump inhibitors remain the most effective medical treatment for GORD. GORD will undoubtedly be a great challenge to clinicians both in primary care and in gastroenterology practice in the Asia-Pacific region in the coming years.

Continuing medical education questions

If you wish to receive credit for this activity, please refer to the Web site: http://www.acg.gi.org/journalcme/. Article Title: Drug Interactions in Inflammatory Bowel Disease.

Defective triggering of secondary peristalsis in patients with non-erosive reflux disease

BACKGROUND AND AIM

The pathophysiology of non-erosive reflux disease is poorly understood. Triggering of secondary peristalsis is impaired in patients with erosive esophagitis but data in patients with non-erosive reflux disease are lacking. The aim of this study was to evaluate the difference in esophageal motility between patients with non-erosive reflux disease and healthy subjects.

METHODS

Twenty patients with non-erosive reflux disease, with reflux symptoms occurring more than twice per week, and 20 healthy subjects of comparable age and sex underwent esophageal manometry. Primary peristalsis was tested with 10 swallows of a 5-mL water bolus. Secondary peristalsis was triggered by esophageal distention using a 20-mL air bolus, which was injected rapidly into the mid-esophagus. After 20 s, each stimulus was followed by a dry swallow to clear any residual air and then each stimulus was repeated five times.

RESULTS

Basal lower esophageal sphincter pressure, pressure wave amplitude in the upper, middle and lower esophagus, wave velocity and the rates of successful primary peristalsis were similar in non-erosive reflux disease patients and controls. The rate of triggering of secondary peristalsis in patients with non-erosive reflux disease (median 20%, interquartile range 0-40%) was significantly lower (P < 0.0001) than that in healthy subjects (90%, 70-100%). When secondary peristalsis occurred in patients with non-erosive reflux disease, however, there were no differences in the amplitude and velocity of secondary peristalsis between the groups.

CONCLUSIONS

Triggering of secondary peristalsis is defective in non-erosive reflux disease. This could lead to prolongation of the contact time between refluxed gastric acid and esophageal mucosa thereby leading to symptoms.

Relevance of mild ineffective oesophageal motility (IOM) and potential pharmacological reversibility of severe IOM in patients with gastro-oesophageal reflux disease

BACKGROUND

Several studies showed high prevalence of ineffective oesophageal motility (IOM) in gastro-oesophageal reflux disease (GERD) and suggested an important role for ineffective oesophageal motility in increased acid exposure. However, impedance-manometric studies proposed that only severe ineffective oesophageal motility might affect oesophageal clearance.

OBJECTIVES

(i) To re-assess the relevance of mild IOM in GERD and (ii) to test the reversibility of IOM.

METHODS

Oesophageal motility, clearance and acid exposure were assessed in 191 GERD patients: 99 without IOM; 58 with mild IOM (30-80% ineffective contractions) and 34 with severe IOM (>80% ineffective contractions). In 30 patients with oesophagitis, the potential reversibility of IOM was evaluated with edrophonium intravenously.

RESULTS

Patients with mild IOM had identical oesophageal clearance and acid exposure in comparison with those without IOM. Patients with severe IOM had a higher probability of prolonged supine clearance and acid exposure [odds ratio: 2.88 (1.16-7.17); 2.48 (0.99-6.17)]. This effect was independent of the presence of hiatal hernia and male sex. Severe IOM could be transiently reverted in 55% of patients.

CONCLUSIONS

Mild IOM does not affect oesophageal clearance. Only severe IOM is associated with prolonged clearance and acid exposure, particularly in supine periods. The edrophonium test might be useful to predict severe IOM response to prokinetic medications.

Modulation of activity in swallowing motor cortex following esophageal acidification: a functional magnetic resonance imaging study

Esophageal acid exposure induces sensory and motility changes in the upper gastrointestinal tract; however, the mechanisms involved and the effects on activity in the brain regions that control swallowing are unknown. The aim of this study was to examine functional changes in the cortical swallowing network as a result of esophageal acidification using functional magnetic resonance imaging (fMRI). Seven healthy volunteers (3 female, age range=20-30 years) were randomized to receive either a 0.1 M hydrochloric acid or (control) saline infusion for 30 min into the distal esophagus. Postinfusion, subjects underwent four 8 min blocks of fMRI over 1 h. These alternated between 1 min swallowing water boluses and 1 min rest. Three-dimensional cluster analysis for group brain activation during swallowing was performed together with repeated-measures ANOVA for differences between acid and saline. After acid infusion, swallowing-induced activation was seen predominantly in postcentral gyrus (p<0.004). ANOVA comparison of acid with saline showed a significant relative reduction in activation during swallowing of the precentral gyrus (M1) BA 4 (p<0.008) in response to acid infusion. No areas of increased cortical activation were identified with acid vs. saline during swallowing. Esophageal acidification inhibits motor and association cortical areas during a swallowing task, probably via changes in vagal afferent or nociceptive input from the esophagus. This mechanism may play a protective role, facilitating acid clearance by reduced descending central motor inhibition of enteric/spinal reflexes, or by preventing further ingestion of injurious agents.

Non-achalasic motor disorders of the oesophagus

Motor abnormalities of the oesophagus are characterised by a chronic impairment of the neuromuscular structures that co-ordinate oesophageal function. The best-defined entity is achalasia, which is discussed in a separate chapter. Other motor disorders with clinical relevance include diffuse oesophageal spasm, oesophageal dysmotility associated with scleroderma, and ineffective oesophageal motility. These non-achalasic motor disorders have variable prevalence but they could be associated with invalidating symptoms such as dysphagia, chest pain and gastro-oesophageal reflux disease. New oesophageal diagnostic techniques, including high-resolution manometry, high-frequency intraluminal ultrasound and intraluminal impedance, allow (1) better definition of peristalsis and sphincter function, (2) assessment of changes in oesophageal wall thickness, and (3) evaluation of pressure gradients within the oesophagus and across the sphincters that can produce normal or abnormal patterns of bolus transport. This chapter discusses recent advances in physiology, pathophysiology, diagnosis and treatment of non-achalasic oesophageal motor disorders.

Distinct clinical characteristics between patients with nonerosive reflux disease and those with reflux esophagitis

BACKGROUND & AIMS

It has been postulated that nonerosive reflux disease (NERD) and erosive reflux disease (ERD) are 2 distinct entities of gastroesophageal reflux disease. The aim of this study was to compare the clinical characteristics between patients with NERD and those with ERD.

METHODS

We prospectively recruited consecutive patients presenting with weekly attacks of heartburn or acid regurgitation. Exclusion criteria included gastric surgery, recent use of nonsteroidal anti-inflammatory drug or proton pump inhibitor, and peptic ulcer disease. Concomitant functional dyspepsia, irritable bowel syndrome, and psychological disorders were documented. Endoscopy, esophageal manometry, acid perfusion test, and 24-hour ambulatory pH monitoring were performed. Risk factors of NERD were determined by multivariate analysis.

RESULTS

Two hundred fourteen patients (NERD, 113; ERD, 111) were studied. NERD patients were characterized by higher prevalence of Helicobacter pylori (36.3% vs 18%, P = .005), functional dyspepsia (64.6% vs 42.3%, P = .003), irritable bowel syndrome (44.2% vs 15.3%, P < .001), psychological disorders (9% vs 0.9%, P = .04), and positive acid perfusion test (40.7% vs 19.8%, P = .004). ERD patients had more hiatal hernias (35.1% vs 17.1%, P = .009), higher esophageal acid exposure (total time esophageal pH <4, 4.2% +/- 2.1% vs 5.9% +/- 2.3%; P = .01), and esophageal dysmotility (P < .05). With multivariate analysis, H pylori (odds ratio, 1.8; 95% confidence interval [CI], 1.1-3.2), irritable bowel syndrome (odds ratio, 2.8; 95% CI, 1.6-5.3), and positive acid perfusion test (odds ratio, 1.9; 95% CI, 1.4-2.8) were independent risk factors for NERD.

CONCLUSIONS

Patients with NERD and ERD have distinct differences in clinical characteristics. NERD is characterized by higher prevalence of functional gastrointestinal disorders and esophageal acid hypersensitivity.

Primary and secondary esophageal contractions in patients with gastroesophageal reflux disease

We studied the primary and secondary esophageal peristalsis in 36 patients with heartburn and acid regurgitation and in 14 asymptomatic volunteers. Primary peristalsis was elicited by ten swallows of a 5-mL bolus of water and secondary peristalsis was elicited by intra-esophageal infusion of 5, 10, and 15 mL water, 0.1 N hydrochloric acid and air. Esophageal contractions were measured by an 8-lumen manometric catheter assembly incorporating a 6-cm sleeve device. Contractions were registered at 3, 9, and 15 cm from the upper margin of the sleeve and the infusion was done through a side hole located at 12 cm. Twenty patients had normal endoscopic esophageal examination, 10 with normal (group I) and 10 with abnormal pH-metric examination (group II), and 16 had esophagitis (group III). The amplitude of contractions after swallows was lower (97.8 +/- 10.0 mmHg) in the distal esophagus of group III patients than in controls (142.3 +/- 14.0 mmHg). Patients of group III had fewer secondary contractions (water: 25% of infusion) than patients of the other groups and controls (67% of infusion). Patients of group III also had a lower amplitude of secondary peristalsis in the distal esophagus (water: 70.1 +/- 9.6 mmHg) than controls (129.2 +/- 18.2 mmHg). We conclude that patients with esophagitis have an impairment of primary and secondary peristalsis in the distal esophagus.

Influence of sleep stages on esophago-upper esophageal sphincter contractile reflex and secondary esophageal peristalsis

BACKGROUND & AIMS

Airways are most vulnerable to aspiration during sleep. Esophago-upper esophageal sphincter (UES) contractile reflex (EUCR) and secondary peristalsis (2P) have been proposed to protect the airway by reflexively contracting the UES and clearing the esophagus of refluxate, respectively. Our aim was to study EUCR and 2P elicitation in "awake" state, stage II, slow-wave (stage III/IV), and rapid eye movement (REM) sleep.

METHODS

Thirteen healthy volunteers were studied in the supine position using concurrent UES and esophageal manometry and polysomnography. Threshold volume (Tvol) to trigger EUCR and 2P and changes in sleep stages were recorded during injection of 2.7 mL/min water into the proximal esophagus after sleep stages were confirmed.

RESULTS

UES pressure progressively declined with deeper stages of sleep. Tvol for EUCR and 2P elicitation was not significantly different between the stage II and "awake" state (EUCR: 4.0 +/- 1.8 mL vs 6.1 +/- 3.6 mL stage II; 2P: 5.8 +/- 2.2 mL vs 8.0 +/- 4.0 mL stage II). Tvol for EUCR and 2P elicitation during REM sleep were significantly lower than during the stage II and "awake" state (REM EUCR: 2.2 +/- 1.1 mL; 2P: 3.5 +/- 1.2 mL). Arousal and cough preempted development of EUCR and 2P during slow-wave sleep.

CONCLUSIONS

(1) EUCR/2P can be elicited in stage II and REM but is preempted by arousal in slow-wave sleep. (2) Tvol for EUCR/2P elicitation is significantly lower in REM, compared with the stage II and "awake" state, suggesting a heightened sensitivity of these reflexes during REM sleep. (3) Although UES pressure progressively declines with deeper stages of sleep, it can still reflexively contract during REM sleep, despite generalized hypotonia.

Relationship between the mechanism of gastro-oesophageal reflux and oesophageal acid exposure in patients with reflux disease

This study investigated the relationship between the oesophageal acid exposure time and the underlying manometric motor events in patients with gastro-oesophageal reflux disease (GORD). In 31 patients, 3-hour oesophageal motility and pH were measured after a test meal. Ten patients underwent 24-hour ambulatory manometry and pH recording. In the 3-hour postprandial study, of 367 reflux episodes 79% was associated with a transient lower oesophageal sphincter relaxation (TLOSR), 14% with absent basal lower oesophageal sphincter (LOS) pressure and the remaining 7% with other mechanisms, representing 62, 28 and 10% of the acid exposure time, respectively. Acid reflux duration per motor mechanism was longer for absent basal LOS pressure than for TLOSR (189 +/- 23 s and 41 +/- 5 s, respectively, P < 0.001). In the 24-hour ambulatory study, the contribution of TLOSRs to reflux frequency vs acid exposure time were 65 vs 54% interprandially and 74 vs 53% after the meal. During the night, absence of basal LOS pressure accounted for 36% of reflux events representing 71% of acid exposure time. In conclusion, the duration of oesophageal acid exposure following a TLOSR is shorter than reflux during absent basal LOS pressure. TLOSRs are, the major contributor to oesophageal acid exposure during the day. At night, however, reflux during absent basal LOS pressure is the major contributor to acid exposure.

Saliva transport to the distal esophagus

OBJECTIVE

During esophageal acid clearance, saliva should reach the most distal esophagus. The mechanisms responsible for saliva transport are not completely understood but it is assumed that normal peristalsis plays a significant role. The aim of this study was to assess the role of esophageal peristalsis and gravity in saliva transport to the distal esophagus.

MATERIAL AND METHODS

Esophageal transit and presence times of a 2-ml bolus of radiolabeled artificial saliva were assessed using concurrent scintigraphy and manometry in 10 healthy volunteers in the upright and supine positions before and after disruption of esophageal motility with sildenafil (50 mg).

RESULTS

With normal peristalsis, there was no difference in saliva transit to the distal esophagus between supine and upright positions 3.9 (1.5- >60.0) versus 3.3 s (1.3-8.3). Low amplitude contractions did not affect saliva transit but the disappearance of contractions after sildenafil was associated with prolonged saliva transit in supine position 7.4 (1.0- >60.0). Saliva presence time was significantly prolonged in both the upright and supine positions by esophageal dysmotility.

CONCLUSIONS

Saliva transport to the distal esophagus does not require complete normal peristalsis or gravity and mainly depends on an efficient pharyngeal pump. However, subjects in supine position with severe esophageal dysmotility might have both impaired volume clearance and delayed saliva transport, leading to abnormal acid clearance and esophagitis.

Pathophysiology of gastroesophageal reflux diseases in Chinese--role of transient lower esophageal sphincter relaxation and esophageal motor dysfunction

BACKGROUND AND AIMS

Transient lower esophageal sphincter relaxation (TLESR) is the major mechanism for gastroesophageal reflux in the Western population. The major reflux mechanism in Chinese patients with GERD has not been studied before.

METHODS

Fifty-four patients with GERD and 28 controls underwent stationary baseline manometry and the 24-h ambulatory esophageal pH monitoring. TLESRs were measured before and after an 850 kcal meal in the supine position. Primary peristalsis, secondary peristalsis, and esophageal acid clearance were measured by esophageal manometry.

RESULTS

Total time esophageal pH </= 4 (7.3 vs 1.5, p= 0.001) was significantly higher in patients with GERD when compared to controls. Majority of acid reflux episodes was due to TLESR in both patients with GERD and controls. The frequency of TLESRs after meal was similar between patients with GERD and controls (1.0 vs 1.3/h, p= 0.34). There was no difference in the distribution of reflux mechanism between patients with GERD and controls. However, patients with GERD had a significantly lower successful primary peristalsis (59%vs 70%, p= 0.043) when compared to controls.

CONCLUSION

The frequency of TLESRs was similar between patients with GERD and controls during stationary manometry. Primary peristalsis was impaired in Chinese patients with GERD. Esophageal motor dysfunction may contribute to the pathophysiology of GERD in the Chinese population.

Esophageal Acid clearance: more volume-dependent than motility-dependent in healthy piglets

BACKGROUND/AIMS

The present study investigates manometrically in healthy piglets whether esophageal clearance after distension with different volumes of acid is volume-dependent.

METHODS

Sedated, non-intubated piglets (n = 22) underwent stationary manometry of the esophagus with a 4-probe perfused assembly after successive injection of 1, 2, and 3 mL of saline and acid. Simultaneous pH metering allowed assessment of acid clearance. Wave features and clearance times after saline and acid were compared by paired non-parametric tests and Friedman analysis of variance. The linearity of the relationships between the clearance times and the volumes of acid infused were tested after square root transformations by one-way ANOVA repeated measures. The significance level was set at < 0.05.

RESULTS

The motor response was identical after distension with saline and acid except for the largest amount of acid used, which elicited more waves during the first 5 minutes after infusion. Time elapsed until regaining pH4 was longer after higher amounts of acid, but not significantly, whereas that necessary to regain baseline pH was significantly longer after such challenge. Esophageal motility was practically identical after 1 and 2 mL of acid, but it was slightly less effective in the first minute after the 3 mL challenge. There was a linear correlation between clearance times and volumes of acid infused.

CONCLUSIONS

Up to a certain volume, the motor responses of the healthy esophagus to distension with neutral or acid fluids were similar. Acid clearance was more a function of the amount of acid present than of the motor response elicited by its presence. Only when the amount of acid was large, esophageal motor response was worse than that elicited after equivalent volumes of neutral fluid. The present evidence suggests that long episodes of reflux in pH tracings might reflect large volumes of refluxate as well as disturbed motor function.

Mechanisms of gastroesophageal reflux and gastroesophageal reflux disease

Gastroesophageal reflux is a physiological phenomenon, occurring with different severity and duration in different individuals. Reflux occurs when this normal event results in the occurrence of symptoms/signs or complications. The pathophysiology of gastroesophageal reflux is complex and diverse, since it is influenced by factors that are genetic, environmental (e.g., diet smoking), anatomic, hormonal, and neurogenic. However, many mechanisms remain incompletely understood. Future research should focus on a better understanding of the physiology of the upper and lower esophageal sphincters, and of gastric motility. The afferent and efferent neural pathways and neuropharmacologic mediators of transient lower esophageal sphincter relaxations and gastric dysmotility require further study. The role of anatomic malformations such as hiatal hernia in children has been underestimated. While therapeutic possibilities are greater in number and largely improved, the outcomes of some treatments are far from satisfactory in many cases. In addition to development of new forms of treatment, research should address better use of currently available medical and surgical treatments.

Gastric emptying and duodeno-gastro-oesophageal reflux in gastro-oesophageal reflux disease

BACKGROUND

Previous studies present conflicting results regarding relationship between gastric emptying and gastro-oesophageal reflux disease. Reflux of duodenal content to oesophagus is generally considered to be associated with more severe disease.

AIM

To assess presence of a gastric emptying disorder in persons with reflux of duodenal contents to oesophagus and to identify any correlation with gastric emptying and oesophageal motility.

METHODOLOGY

A total of 15 subjects with (B+) and 15 subjects without (B-) bile reflux to oesophagus determined by 24-hour bilirubin monitoring were studied with scintigraphic solid gastric emptying and 24-hour oesophageal manometry.

RESULTS

There was no difference in lag phase [median 23.7 (range 10.8-44.0) vs 24.6 (8.1-40.1) min], half emptying time [74.6 (48.0-93.6) vs 82.8 (54.4-153.9) min] or emptying rate [0.89 (0.59-1.34) vs 0.83 (0.36-1. 15)%/min] for B- and B+ subjects, respectively. In addition, there was no difference in emptying rate of gastric fundus between B- and B+ subjects. Subjects with bile reflux had less effective oesophageal contractions of oesophageal body [9.4(3.3-37)%] compared to subjects without bile reflux [32(19-47)%, p = 0.002]. However, there was no correlation between oesophageal motility and gastric emptying.

CONCLUSION

Results suggest that a gastric emptying disorder is a less likely contributing cause of bile reflux to the oesophagus, but bile reflux is associated with less effective oesophageal motility.

Gastroesophageal reflux induced by white wine: the role of acid clearance and "rereflux"

OBJECTIVES

White wine has been demonstrated to induce gastroesophageal reflux (GER) in healthy people and GER patients. This GER is characterized by reflux episodes of prolonged duration. Our aim was to explore the pathogenesis of the prolonged reflux duration.

METHODS

Twelve healthy volunteers received in a randomized order 300 ml of white wine and tap water together with a standardized meal. Esophageal pH and motility were continuously monitored by a glass pH electrode and a strain gauge manometry probe (four measuring points in the esophagus and one in the pharynx to register swallowing) for 90 min after ingestion. Blinded to the ingested beverage, we calculated the fraction of time esophageal pH was <4, the number of reflux episodes and their duration, the swallowing and contraction rate, the contraction amplitude, and the distribution of primary, secondary, simultaneous, and nonpropagated contractions. The motility analysis was separately performed for periods with and without GER. During GER, the time until occurrence of the first contraction, its type, the type of the contraction that raises pH to >4, and the number of peristaltic contractions necessary to raise pH to >4 were also determined. The percentage of GER episodes with simultaneous contractions and failed peristalsis (nontransmitted swallows and nonpropagated contractions) as calculated. The percentage of GER episodes with signs of "rereflux" (further pH drop, common cavity phenomenon in the motility trace) into the acidic esophagus was also determined. The mean reflux duration and the number of peristaltic contractions needed to raise pH to >4 were recalculated by taking the rereflux events into account.

RESULTS

White wine significantly increased the fraction of time esophageal pH was <4, reflux frequency, and reflux duration compared to water. During periods without GER, no differences in the motility data were observed between wine and water. During GER, the contraction rate after white wine was significantly lower because of an increase in nontransmitted swallows. The time until occurrence of the first contraction after GER was significantly prolonged after white wine. Primary peristalsis was the main first and clearance contraction type. The percentage of GER episodes with simultaneous contractions and with failed peristalsis was significantly increased with wine. Similarly, the percentage of GER episodes with rereflux was significantly increased. The "corrected" mean reflux duration was still prolonged relative to water, but the difference was no longer significant. The numbers of peristaltic contractions necessary to raise pH to >4, which significantly differed for conventionally defined GER episodes between wine and water, were similar when counted only from onset of the latest rereflux event until pH rose to >4.

CONCLUSIONS

The pathogenesis of white wine-induced GER episodes of long duration is 2-fold. First, white wine provokes a disturbed esophageal clearance due to an increase in simultaneous contractions and in failed peristalsis. The second mechanism is the occurrence of repeated reflux events into the esophagus when pH is still acidic from a previous reflux episode.

[Aspects of sleep effects on the digestive tract]

BACKGROUND

During sleep the gastrointestinal system function is markedly reduced most of the time.

OBJECTIVES

In this revision we described the effect of sleep on the digestive system. Salivation, swallowing rate, upper esophageal sphincter pressure and number of primary esophageal contractions have all been shown to be reduced during sleep.

DATA SOURCES

Gastric emptying is slow during sleep but the REM sleep is associated with faster gastric emptying. During the night we have a more regular intestinal motility than during the day. During sleep, phase II of the migrating motor complex cycle is virtually absent, both during diurnal or nocturnal sleep. The nocturnal velocity of migrating motor complex propagation in the proximal small bowel is slower than the diurnal velocity. The colon has a decrease in tonus and contractions. The anal canal pressure is lower and rectum activity is higher during sleep than during the awake state, but the anal pressure is still higher than the rectum pressure and the rectum contractions are most frequently retrograde.

DATA SYNTHESIS

Transient lower esophageal sphincter relaxation is the most frequent cause of gastroesophageal reflux. The frequency of this transient relaxation is very low during sleep. Gastroesophageal reflux during sleep is more frequently associated with a low lower esophageal sphincter pressure.

CONCLUSIONS

In this situation the disease is worse because the patient is in the supine position, so gravity does not help the acid esophageal clearance, salivation is decreased and the primary esophageal contraction is not frequent, a fact causing a prolongation of acid clearance during sleep. The right lateral position during sleep causes more reflux episodes than the left lateral position. The gastroesophageal reflux may be associated with nocturnal wheezing, chronic nocturnal cough and sleep apnea.

Practical approaches to dysphagia caused by Esophageal motor disorders

Dysphagia is a common symptom with which patients present. This review focuses primarily on the esophageal motor disorders that result in dysphagia. Following a brief description of the normal swallowing mechanisms and the messengers involved, more specific motor abnormalities are discussed. The importance of achalasia, as the only pathophysiologically defined esophageal motor disorder, is discussed in some detail, including recent developments in pathogenesis and treatment options. Other esophageal spastic disorders are described, with relevant manometric tracings included. In recent years, the importance of gastroesophageal reflux as a primary cause of esophageal dysmotility has been recognized, and this is also discussed. In addition, the motility disturbances that develop after surgical fundoplication are reviewed.