Upper sphincter function during transient lower oesophageal sphincter relaxation (tLOSR); it is mainly about microburps

Wake up to gastro-oesophageal reflux disease: The interplay between arousal and night-time reflux

This review examines the temporal association between nocturnal gastro-oesophageal reflux and sleep-arousal cycles. Most nocturnal gastro-oesophageal reflux events occur during the awake cycle, and arousals precede most nocturnal gastro-oesophageal reflux events, indicating that arousal from sleep predisposes to nocturnal gastro-oesophageal reflux. This sheds light on the complex relationship between nocturnal gastro-oesophageal reflux and sleep, and has implications for managing nocturnal gastro-oesophageal reflux symptoms. The appearance of symptoms and the pathophysiology of nocturnal gastro-oesophageal reflux are influenced by sleep hygiene, sleep disturbances and the misalignment of circadian rhythms. Nocturnal gastro-oesophageal reflux and its related sleep disorders are prevalent and negatively impact the quality of life. There is conflicting evidence on whether nocturnal gastro-oesophageal reflux and sleep disturbances are causally linked, and whether sleep disturbances drive nocturnal gastro-oesophageal reflux. Poor sleep quality increases oesophageal hypersensitivity and overall acid exposure. The nocturnal gastro-oesophageal reflux is linked to the more severe forms of gastro-oesophageal reflux disease, especially with atypical/extra-oesophageal manifestations and complications of mucosal damage such as oesophagitis and stricture, Barret's oesophagus, and oesophageal adenocarcinoma. This review highlights the role of sleep problems in presenting nocturnal gastro-oesophageal reflux, and the potential benefits of treating sleep disturbances in enhancing patient care and quality of life.

Retrograde Cricopharyngeal Dysfunction: A Review

Retrograde cricopharyngeal dysfunction (RCPD), also referred to as retrograde cricopharyngeus dysfunction, is a condition characterized by the inability to burp. The pathophysiology of this condition is thought to result from failure of cricopharyngeal sphincter relaxation during periods of esophageal distension, which leads to patients' bothersome symptoms. RCPD negatively impacts patients' quality of life and is associated with bloating, gurgling, avoidance of carbonation, self-imposed dietary and lifestyle changes designed to minimize discomfort, and flatulence. Complaints often start during adolescence, and many patients search for a diagnosis for years before obtaining treatment. A recent increase in awareness through patient-led social media discussion boards describing the 'no burp' syndrome is leading to an increasing incidence of presentations, often with patients making a self-diagnosis. The increased incidence of RCPD is fueling a larger case series investigating treatment options and outcomes. In this review, we discuss what is known about the pathophysiology of this condition, the otolaryngologic perspective on diagnosis and treatment, the patients' lived experience of this condition, and the influence of social media on RCPD.

The Role of Empirical Treatment with Proton Pump Inhibitor as a Diagnostic Tool in Laryngopharyngeal Reflux

The presentations of laryngopharyngeal reflux (LPR) are diverse and include chronic hoarseness, sensation of foreign body in the throat, sore throat etc. 24 h pH monitoring considered the gold standard of investigation for LPR is costly, cumbersome and not readily available at all centers. Empirical trial of Proton pump inhibitor (PPI) as a diagnostic tool after assessment by Reflux Symptom Index (RSI) and Reflux Findings Score (RFS) is a cheaper, simple and readily available alternative. The objectives of the study were to determine clinical manifestations in patients presenting with LPR and to evaluate the role of empirical treatment with PPI as a diagnostic tool in LPR. 100 patients were divided into experimental group (RSI ≥ 13 and RFS ≥ 7) and control group (RSI < 13 and RFS < 7). Omeprazole trial was given to experimental group and assessed for RSI and RFS at 04 and 08 weeks. Statistical analysis was done within the group and between the groups. (1) The response rate to Omeprazole at 04 and 08 weeks interval (RSI<13 and/or RFS<7) was 60% and 76% respectively. (2) The response to Omeprazole given to the experimental group with RSI≥13 and RFS≥7 was significant at 04 weeks and 08 weeks duration (P<0.0001). RSI and RFS are good clinical tools to assess and diagnose patients with Laryngopharyngeal reflux. Based on the clinical diagnosis an empirical trial of a proton pump inhibitor (PPI) can be given to patients for duration of 02 months resulting in a good response.

Retrograde upper esophageal sphincter function… and dysfunction

Upper esophageal sphincter (UES) function has been extensively studied in the context of swallowing and antegrade bolus transit, but relatively little attention has been paid to its retrograde function to facilitate belching. Indeed, prior to 2019, there were only three case reports in the world literature of individuals with a physiologically demonstrated inability to belch due to failure of the UES to relax after gas venting from the stomach and ensuing low-pressure esophageal distention. In this minireview, that disorder is termed retrograde UES dysfunction (R-UESD). The associated symptom complex includes some combination of chest pain, gurgling noises in the chest, bloating, nausea, hiccups, and flatulence. The obscurity of R-UESD has recently been challenged by two large series published in the ENT literature of circumstantially demonstrated R-UESD that was resolved by botulinum toxin (BT) injection to the cricopharyngeus. The field has now further advanced with the publication in this issue of the Journal by Oude Nijhuis et al. of 8 cases of R-UESD demonstrated by high-resolution impedance manometry (HRIM) with a provocative challenge of carbonated water. These individuals were also treated with BT and at 3-month follow-up had both an encouraging symptomatic response and HRIM demonstrated resolution of R-UESD.

Characteristics of symptomatic belching in patients with belching disorder and patients who exhibit gastroesophageal reflux disease with belching

Background/Aims

Belching disorder (BD) is clinically distinct from gastroesophageal reflux disease (GERD) with belching. Supragastric belching (SGB) is closely associated with reflux episodes. This study investigates belch characteristics in association with reflux, compared between patients with BD and those who had GERD with belching.

Methods

Impedance pH monitoring data from 10 patients with BD and 10 patients with GERD who exhibited belching were retrospectively analyzed. Belches were considered "isolated" or "reflux-related" and acidic/non-acidic. Belch characteristics were compared between patients with BD and those with GERD.

Results

Symptomatic belches were more frequent in patients with BD than in patients with GERD (median, 160.5 vs 56.0, P < 0.05). SGB was the most common type in both groups; common subtypes comprised "isolated" in patients with BD and "isolated during the reflux period" in patients with GERD. Reflux-related SGB was more common in patients with GERD than in BD (78.3% vs 45.2%, P < 0.005). Both "preceding belching" including the reflux period and acidic SGB were more common in patients with GERD than in BD (31.8% vs 8.6% and 38.1% vs 8.9%, both P < 0.05). Supragastric belch number positively correlated with all reflux episodes in patients with GERD (adjusted R² = 0.572, P = 0.007).

Conclusions

BD is characterized by more belching, compared to GERD. SGB is more frequently associated with reflux in GERD than in BD; acidity may be related to GERD. In BD, SGB is typically non-acidic and unrelated to reflux. Distinct SGB characteristics may reflect different pathogenic mechanisms of reflux and associated symptoms.

Belching in Gastroesophageal Reflux Disease: Literature Review

Belching is a common phenomenon. However, it becomes bothersome if excessive. Impedance–pH monitoring can classify the belching into two types: gastric belching and supragastric belching (SGB). The former is a physiological mechanism to vent swallowed air from the stomach, whereas the latter is a behavioral disorder. Gastroesophageal reflux disease (GERD) is the most relevant condition in both types of belching. Recent findings have raised awareness that excessive SGB possibly sheds light on the pathogenesis of a part of proton pump inhibitor (PPI) refractoriness in GERD. SGB could cause typical reflux symptoms such as heartburn, regurgitation or chest pain in two ways: SGB-induced gastroesophageal reflux or SGB-induced esophageal distension. In PPI-refractory GERD, it is important to detect hidden SGB as a cause of reflux symptoms since SGB requires psychological treatment instead of high dose PPIs or pain modulators. In the case of PPI-refractory GERD with excessive SGB, recent studies imply that the combination of a psychological approach and conventional treatment can improve treatment outcome.

Influence of Acid Swallows on the Dynamics of the Upper Esophageal Sphincter

Mechanisms of the upper esophageal sphincter (UES) when exposed to acid are still incompletely understood. The presented work investigated the reaction of the UES to acid exposure during swallowing. Ten healthy individuals swallowed ten 2 ml neutral water boli of pH 7, followed by 10 swallows each of different levels of acidity (pH 1.8, pH 3 and pH 5). Effects were analyzed by high-resolution manometry (HRM) for the primary parameter Restitution Time, as well as Resting Pressures, maximal, minimal pressures and time intervals. Restitution Times measured mean values of 12.67 s (SD ± 7.03 s) for pH 1.8, pH 7 = 8.69 s (SD ± 2.72 s), pH 3 = 7.56 s (SD ± 2.23 s) and pH 5 = 7.29 s (SD ± 2.55 s), showing prolonged Restitution Times in the UES when exposed to strong bolus acidity. This difference was significant towards the neutral bolus, but also to less acidic boli (pH 5: p = 0.006, pH 3: p = 0.009, pH 7: p = 0.038). Considerable differences of mean values were found for Post-Swallow Maximum and Period of Sphincter Activity. Also, Pre-Swallow Maximum values were found to be highest with the strongest acid. Relaxation Times showed a slight trend of prolongation for the highest bolus acidity. Prolonged Restitution Times may represent a reflexive protective mechanism triggered by receptors in the pharyngeal mucosa or the UES preventing regurgitation of acid into the pharynx and larynx, besides representing ongoing attempts of acid clearance. Exposure to high levels of acidity by a swallowed bolus does influence UES functions during swallowing.

Deglutition in Patients With Hypernasality Associated With Unilateral Cleft Lip and Palate Evaluated With High-Resolution Manometry

Objective:

To evaluate pharyngeal pressure profiles during swallowing in patients with unilateral cleft lip and palate (UCLP) and identify compensation mechanisms.

Design:

Prospective experimental study.

Setting:

University Hospital and Medical School.

Participants:

Ten volunteers and 10 patients with nonsyndromic repaired UCLP with hypernasality (age: 19-27 years, 5 females and 5 males per group) were included.

Interventions:

All participants swallowed 2 and 10 mL of water and underwent high-resolution manometry (HRM).

Main Outcome Measures:

Pharyngeal and upper esophageal sphincter (UES) parameters were measured using HRM. Student t test was used for statistical intergroup comparisons. Additionally, the Sydney Swallowing Questionnaire (SSQ) was used as a subjective measure.

Results:

Patients exhibited reduced velopharyngeal closing pressure and velopharyngeal and tongue base (TB) region contraction times, compared to volunteers ( P < .05). The UES opening and closing functions did not change. The SSQ revealed nasal regurgitation in some patients.

Conclusions:

In patients with UCLP, velopharyngeal region alterations are caused by impaired muscle force and function. The reduced TB contraction time may be a compensation mechanism allowing bolus transportation without nasal regurgitation. However, deglutition is not completely altered since UES function remains normal. Future studies will need to reveal at which point a decrease in velopharyngeal closing pressure will result in velopharyngeal insufficiency.

Effects of esophageal acidification on esophageal reflexes controlling the upper esophageal sphincter

Esophageal acid exposure can alter upper esophageal sphincter (UES) function, but the mechanism is unknown. The aim of this study was to determine the effects of esophageal acid exposure on esophago-UES relaxation (EURR) and contractile (EUCR) reflexes. Cats, decrebrate ( n = 27) or chronic ( n = 4), were implanted with electromyographic electrodes on pharynx, larynx, and esophagus. The esophagus was infused with either NaCl (0.9%) or HCl (0.1 N). The EUCR was activated by balloon distension in acute cats and slow air injection in chronic cats, and the EURR was activated by rapid air injection in both sets of cats. We found that NaCl infused for 15 or 30 min had no effect on EUCR or EURR in acute cats. HCl infused for 15, 30, or 45 min significantly ( P < 0.05) decreased the sensitivity to activate EUCR. HCl infused for 15 min significantly ( P < 0.05) increased and for 45 min significantly ( P < 0.05) decreased sensitivity to activate EURR. In chronic cats, HCl infused for 15 min/day increased sensitivity to activate EURR and decreased ( P < 0.05) sensitivity to activate EUCR after 4 days of infusion. EURR occurred spontaneously during HCl infusions on the 3rd and 4th ( P < 0.05) days of HCl infusion. We conclude that esophageal acid exposure initially sensitizes the esophagus to activation of EURR and desensitizes to activation of EUCR, but with longer exposure desensitizes to both. The alteration in sensitivity to activate EURR and EUCR caused by gastroesophageal reflux may play a role in the generation of supraesophageal reflux. NEW & NOTEWORTHY In acute studies, short-term esophageal acid exposure sensitizes esophagus to activation of esophago-upper esophageal sphincter relaxation response (EURR), whereas longer-term exposure inhibits EURR. Short- or long-term esophageal acid exposure decreases sensitivity to activation of esophago-upper esophageal sphincter contractile response (EUCR). In chronic studies, short-term esophageal acid exposure has the same effects on EURR and EUCR as occur acutely, but these effects take days to develop. Alteration in EURR and EUCR caused by gastroesophageal reflux may play a role in reflux disease.

What Is the Impact of High-Resolution Manometry in the Functional Diagnostic Workup of Gastroesophageal Reflux Disease?

International guidelines agree that high-resolution esophageal manometry (HRM) is an integral part of the diagnostic evaluation of patients with refractory reflux symptoms and should be performed before antireflux surgery. Its most important goal is to explore differential diagnoses, in particular major esophageal motility disturbances, that may be responsible for symptoms. HRM additionally provides insights into all relevant pathomechanisms of gastroesophageal reflux disease (GERD): It can reveal important information on the morphology and function of the esophagogastric junction (EGJ), the presence of a hiatus hernia, transient lower esophageal sphincter relaxations, and dysmotility of the esophageal body. To obtain this information, a 3-step hierarchical system has been proposed for the algorithmic characterization of esophageal motor function. The first step is to investigate the morphology and contractility of the EGJ, the second to monitor esophageal body motor patterns in response to water swallows, and the third to determine the contraction reserve in patients with abnormal esophageal motor function using provocation tests. Observations made with HRM can not only explain the cause of symptoms in GERD patients but may also have the potential to direct specific treatment.

Sleep and Nocturnal Gastroesophageal Reflux: An Update

Nocturnal gastroesophageal reflux has been associated with poor sleep quality. Normal physiological adaptations of the aerodigestive system to sleep prolong and intensify nocturnal reflux events. This occurrence leads to sleep disruption, as well as to esophageal, laryngeal, and laryngopharyngeal reflux. Controversy exists on whether OSA and nocturnal reflux are causally linked or merely associated because of shared risk factors. Advances in diagnostic technology have provided new insights into gastroesophageal reflux and the mechanisms of nocturnal reflux during sleep. This update reviews new data on causal links between sleep and gastroesophageal reflux disease.

Validation of criteria for the definition of transient lower esophageal sphincter relaxations using high-resolution manometry

BACKGROUND

Criteria for transient lower esophageal sphincter relaxations (TLESRs) are well-defined for Dentsleeve manometry. As high-resolution manometry (HRM) is now the gold standard to assess esophageal motility, our aim was to propose a consensus definition of TLESRs using HRM.

METHODS

Postprandial esophageal HRM combined with impedance was performed in 10 patients with gastroesophageal reflux disease. Transient lower esophageal sphincter relaxations identification was performed by 17 experts using a Delphi process. Four investigators then characterized TLESR candidates that achieved 100% agreement (TLESR events) and those that achieved less than 25% agreement (non-events) after the third round. Logistic regression and decision tree analysis were used to define optimal diagnostic criteria.

KEY RESULTS

All diagnostic criteria were more frequently encountered in the 57 TLESR events than in the 52 non-events. Crural diaphragm (CD) inhibition and LES relaxation duration >10 seconds had the highest predictive value to identify TLESR. Based on decision tree analysis, reflux on impedance, esophageal shortening, common cavity, upper esophageal sphincter relaxation without swallow and secondary peristalsis were alternate diagnostic criteria.

CONCLUSION & INFERENCES

Using HRM, TLESR might be defined as LES relaxation occurring in absence of swallowing, lasting more than 10 seconds and associated with CD inhibition.

The Physiology of Eructation

Eructation is composed of three independent phases: gas escape, upper barrier elimination, and gas transport phases. The gas escape phase is the gastro-LES inhibitory reflex that causes transient relaxation of the lower esophageal sphincter, which is activated by distension of stretch receptors of the proximal stomach. The upper barrier elimination phase is the transient relaxation of the upper esophageal sphincter along with airway protection. This phase is activated by stimulation of rapidly adapting mechanoreceptors of the esophageal mucosa. The gas transport phase is esophageal reverse peristalsis mediated by elementary reflexes, and it is theorized that this phase is activated by serosal rapidly adapting tension receptors. Alteration of the receptors which activate the upper barrier elimination phase of eructation by gastro-esophageal reflux of acid may in part contribute to the development of supra-esophageal reflux disease.

Impaired upper esophageal sphincter reflexes in patients with supraesophageal reflux disease

BACKGROUND & AIMS

Normal responses of the upper esophageal sphincter (UES) and esophageal body to liquid reflux events prevent esophagopharyngeal reflux and its complications, however, abnormal responses have not been characterized. We investigated whether patients with supraesophageal reflux disease (SERD) have impaired UES and esophageal body responses to simulated reflux events.

METHODS

We performed a prospective study of 25 patients with SERD (age, 19-82 y; 13 women) and complaints of regurgitation and supraesophageal manifestations of reflux. We also included 10 patients with gastroesophageal reflux disease (GERD; age, 32-60 y; 7 women) without troublesome regurgitation and supraesophageal symptoms and 24 healthy asymptomatic individuals (controls: age, 19-49 y; 13 women). UES and esophageal body pressure responses, along with luminal distribution of infusate during esophageal rapid and slow infusion of air or liquid, were monitored by concurrent high-resolution manometry and intraluminal impedance.

RESULTS

A significantly smaller proportion of patients with SERD had UES contractile reflexes in response to slow esophageal infusion of acid than controls or patients with GERD. Only patients with SERD had abnormal UES relaxation responses to rapid distension with saline. Diminished esophageal peristaltic contractions resulted in esophageal stasis in patients with GERD or SERD.

CONCLUSIONS

Patients with SERD and complaints of regurgitation have impaired UES and esophageal responses to simulated liquid reflux events. These patterns could predispose them to esophagopharyngeal reflux.

[Physiology of the upper esophageal sphincter]

The upper esophageal sphincter (UES) forms a barrier between the pharynx and the esophagus. When opened, the UES allows the food bolus to pass into the esophagus, as well as permitting emesis and eructation. The basal sphincter tone constitutes a barrier function which serves to prevent reflux and passive aerophagia in the case of deep breathing. Basal sphincter tone is dependent on several influencing factors; during swallowing, sphincter opening and closure follow a complex multiphase pattern. This article presents an overview of the current understanding of UES physiology.

Mechanism of UES relaxation initiated by gastric air distension

The aim of this study was to determine the mechanism of initiation of transient upper esophageal sphincter relaxation (TUESR) caused by gastric air distension. Cats (n = 31) were decerebrated, EMG electrodes were placed on the cricopharyngeus, a gastric fistula was formed, and a strain gauge was sewn on the lower esophageal sphincter (n = 8). Injection of air (114 ± 13 ml) in the stomach caused TUESR (n = 18) and transient lower esophageal sphincter relaxation (TLESR, n = 6), and this effect was not significantly (P > 0.05) affected by thoracotomy. Free air or bagged air (n = 6) activated TLESR, but only free air activated TUESR. Closure of the gastroesophageal junction blocked TUESR (9/9), but not TLESR (4/4), caused by air inflation of the stomach. Venting air from distal esophagus during air inflation of the stomach prevented TUESR (n = 12) but did not prevent air escape from the stomach to the esophagus (n = 4). Rapid injection of air on the esophageal mucosa always caused TUESR (9/9) but did not always (7/9) cause an increase in esophageal pressure. The time delay between the TUESR and the rapid air pulse was significantly more variable (P < 0.05) than the time delay between the rapid air pulse and the rise in esophageal pressure. We concluded that the TUESR caused by gastric air distension is dependent on air escape from the stomach, which stimulates receptors in the esophagus, but is not dependent on distension of the stomach or esophagus, or the TLESR. Therefore, the TUESR caused by gastric air distension is initiated by stimulation of receptors in the esophageal mucosa.

Impact of Neuromuscular Electrical Stimulation on Upper Esophageal Sphincter Dynamics

Objectives:

Beside traditional dysphagia therapy, neuromuscular electrical stimulation (NMES) has been proposed to treat patients with dysphagia. Considering the complexity of the nerve-muscle interaction during swallowing, the underlying physiology of NMES remains unclear. Here, we addressed the question of whether NMES can modify upper esophageal sphincter (UES) dynamics.

Methods:

In a prospective study, 26 healthy volunteers performed water swallows with and without NMES. The stimulus was applied in a participant- and operator-initiated stimulation above, near, and below the motor threshold. Swallowing parameters were measured using high-resolution manometry.

Results:

The UES relaxation time was found to be extended by 10%, indicating a modification in UES dynamics.

Conclusions:

The chosen NMES paradigm influenced the involuntary swallowing phase by extending relaxation time, providing more time for bolus passage into the esophagus. Future studies will have to evaluate if this effect can be found in patients with dysphagia and whether it is beneficial for treatment.

The spectrum of achalasia: lessons from studies of pathophysiology and high-resolution manometry

High-resolution manometry and recently described analysis algorithms, summarized in the Chicago Classification, have increased the recognition of achalasia. It has become apparent that the cardinal feature of achalasia, impaired lower esophageal sphincter relaxation, can occur in several disease phenotypes: without peristalsis, with premature (spastic) distal esophageal contractions, with panesophageal pressurization, or with peristalsis. Any of these phenotypes could indicate achalasia; however, without a disease-specific biomarker, no manometric pattern is absolutely specific. Laboratory studies indicate that achalasia is an autoimmune disease in which esophageal myenteric neurons are attacked in a cell-mediated and antibody-mediated immune response against an uncertain antigen. This autoimmune response could be related to infection of genetically predisposed subjects with herpes simplex virus 1, although there is substantial heterogeneity among patients. At one end of the spectrum is complete aganglionosis in patients with end-stage or fulminant disease. At the opposite extreme is type III (spastic) achalasia, which has no demonstrated neuronal loss but only impaired inhibitory postganglionic neuron function; it is often associated with accentuated contractility and could be mediated by cytokine-induced alterations in gene expression. Distinct from these extremes is progressive plexopathy, which likely arises from achalasia with preserved peristalsis and then develops into type II achalasia and then type I achalasia. Variations in its extent and rate of progression are likely related to the intensity of the cytotoxic T-cell assault on the myenteric plexus. Moving forward, we need to integrate the knowledge we have gained into treatment paradigms that are specific for individual phenotypes of achalasia and away from the one-size-fits-all approach.

Specific movement of esophagus during transient lower esophageal sphincter relaxation in gastroesophageal reflux disease

Background/Aims

Transient lower esophageal sphincter relaxation (TLESR) is the main mechanism of gastroesophageal reflux disease (GERD). The aim of this study was to investigate the characteristics of transient lower esophageal sphincter movement in patients with or without gastroesophageal reflux by high-resolution manometry (HRM).

Methods

From June 2010 to July 2010, we enrolled 9 patients with GERD (GERD group) and 9 subjects without GERD (control group), prospectively. The manometry test was performed in a semi-recumbent position for 120 minutes following ingestion of a standardized, mixed liquid and solid meal. HRM was used to identify the frequency and duration of TLESR, esophageal shortening length from incomplete TLESR, upper esophageal sphincter (UES) response, and the related esophageal motor responses during TLESR.

Results

TLESR occurred in 33 in the GERD group and 34 in the control group after 120 minutes following food ingestion. Duration of TLESR and length of esophageal shortening did not differ between 2 groups. UES pressure increase during TLESR was mostly detected in patients with GERD, and UES relaxation was observed frequently in the control group during TLESR. TLESR-related motor responses terminating in TLESR were predominantly observed in the control group.

Conclusions

Increased UES pressure was noted frequently in the GERD group, suggesting a mechanism for preventing harmful reflux, which may be composed mainly of fluid on the larynx or pharynx. However, patients with GERD lacked the related motor responses terminating in TLESR to promote esophageal emptying of refluxate.

Digestive and respiratory tract motor responses associated with eructation

We studied the digestive and respiratory tract motor responses in 10 chronically instrumented dogs during eructation activated after feeding. Muscles were recorded from the cervical area, thorax, and abdomen. The striated muscles were recorded using EMG and the smooth muscles using strain gauges. We found eructation in three distinct functional phases that were composed of different sets of motor responses: gas escape, barrier elimination, and gas transport. The gas escape phase, activated by gastric distension, consists of relaxation of the lower esophageal sphincter and diaphragmatic hiatus and contraction of the longitudinal muscle of the thoracic esophagus and rectus abdominis. All these motor events promote gas escape from the stomach. The barrier elimination phase, probably activated by rapid gas distension of the thoracic esophagus, consists of relaxation of the pharyngeal constrictors and excitation of dorsal and ventral upper esophageal sphincter distracting muscles, as well as rapid contraction of the diaphragmatic dome fibers. These motor events allow esophagopharyngeal air movement by promoting retrograde airflow and opening of the upper esophageal sphincter. The transport phase, possibly activated secondary to diaphragmatic contraction, consists of a retrograde contraction of the striated muscle esophagus that transports the air from the thoracic esophagus to the pharynx. We hypothesize that the esophageal reverse peristalsis is mediated by elementary reflexes, rather than a coordinated peristaltic response like secondary peristalsis. The phases of eructation can be activated independently of one another or in a different manner to participate in physiological events other than eructation that cause gastroesophageal or esophagogastric reflux.

Airway reflux, cough and respiratory disease

It is increasingly accepted that the effects of gastro-oesophageal reflux are not limited to the gastrointestinal tract. The adjacent respiratory structures are also at risk from material ejected from the proximal oesophagus as a result of the failure of anatomical and physiological barriers. There is evidence of the influence of reflux on several respiratory and otorhinological conditions and although in many cases the precise mechanism has yet to be elucidated, the association alone opens potential novel avenues of therapy to clinicians struggling to treat patients with apparently intractable respiratory complaints. This review provides a description of the airway reflux syndrome, its effects on the lung and current and future therapeutic options.

[High-resolution manometry of the upper esophageal sphincter]

BACKGROUND

High-resolution manometry (HRM) represents a valuable tool for the evaluation of peristalsis in the oesophagus. Due to the wide spacing of the pressure transducers, however, examination of the upper oesophageal sphincter's relaxation period has not proved satisfactory as yet.

DESIGN

A feasibility study was carried out to clarify whether evaluation of the upper oesophageal sphincter's behaviour during swallows is possible using a catheter with very closely spaced pressure transducers.

SETTING

University hospital.

PROCEDURE

Healthy subjects were analysed using a specially developed catheter as well as a modified software to evaluate whether swallow-associated behaviour could be verified.

RESULTS

Interpreting pressure profiles in terms of resting pressure, residual pressure, relaxation time and maximum peristaltic pressure proved to be feasible. The present analysis supports the existence of distinct dynamic swallow-associated phases, which conform to the phases that had previously been postulated. An additional initial phase, however, should be added.

CONCLUSION

This newly created catheter design in combination with the modified software enable a very detailed evaluation of the sphincter's swallow-associated behaviour and represent a valuable, minimally invasive tool with no exposure to radiation for dysphagia diagnosis as well as treatment planning.

Physiology of the LES

The purpose of this review is to consider the neuromuscular mechanism of LES contractility both by itself and in relation to the esophagogastric junction (EGJ) complex in order to appreciate the intricacies of EGJ valvular function.

Response of the upper esophageal sphincter to esophageal distension is affected by posture, velocity, volume, and composition of the infusate

BACKGROUND & AIMS

Studies of the pressure response of the upper esophageal sphincter (UES) to simulated or spontaneous gastroesophageal reflux have shown conflicting results. These discrepancies could result from uncontrolled influence of variables such as posture, volume, and velocity of distension. We characterized in humans the effects of these variables on UES pressure response to esophageal distension.

METHODS

We studied 12 healthy volunteers (average, 27 ± 5 years old; 6 male) using concurrent esophageal infusion and high-resolution manometry to determine UES, lower esophageal sphincter, and intraesophageal pressure values. Reflux events were simulated by distal esophageal injections of room temperature air and water (5, 10, 20, and 50 mL) in individuals in 3 positions (upright, supine, and semisupine). Frequencies of various UES responses were compared using χ(2) analysis. Multinomial logistical regression analysis was used to identify factors that determine the UES response.

RESULTS

UES contraction and relaxation were the overriding responses to esophageal water and air distension, respectively, in a volume-dependent fashion (P < .001). Water-induced UES contraction and air-induced UES relaxation were the predominant responses among individuals in supine and upright positions, respectively (P < .001). The prevalence of their respective predominant response significantly decreased in the opposite position. Proximal esophageal dp/dt significantly and independently differentiated the UES response to infusion with water or air.

CONCLUSIONS

The UES response to esophageal distension is affected by combined effects of posture (spatial orientation of the esophagus), physical properties, and volume of refluxate, as well as the magnitude and rate of increase in intraesophageal pressure. The UES response to esophageal distension can be predicted using a model that incorporates these factors.

Cricopharyngeal Muscle Electromyography Findings in Patients with Gastroesophageal Reflux Disease

Objective

To analyze the grade of reflux and the behavior of the cricopharyngeal muscle (CPM) in patients with gastroesophageal reflux (GER) by means of electromyographic (EMG) analysis of CPM.

Study Design

Prospective clinical study.

Setting

Istanbul Training and Research Hospital.

Subject and Methods

Motor unit potential (MUP) recordings and kinesiological recordings of CPM were performed using a concentric needle electrode during dry material swallowing and 3-, 5-, and 10-mL water swallowing. Twenty-four patients with GER were compared with 21 healthy volunteers.

Results

GER was mild in 15 patients and moderate-to-severe in 9 patients. MUP recordings were normal in both groups during the preswallowing/postswallowing periods. Kinesiological investigations revealed that the number of patients who did not show a preswallow EMG burst had a positive correlation with the severity of reflux and the amount of liquid swallowed. Rebound bursts were observed in the patient and the control groups. Duration of preswallow and rebound bursts was similar in all groups. Duration of swallowing was shorter in mild GER patients compared with healthy volunteers and moderate-to-severe GER patients. Piecemeal deglutition during 10-mL liquid swallowing was higher in moderate-to-severe GER patients. We also found a positive correlation between the number of swallows and the severity of reflux.

Conclusion

Needle EMG of the upper esophageal sphincter was normal in GER patients. Kinesiological evaluations showed increased piecemeal deglutition and number of swallows that correlated positively with the severity of GER.

The lower esophageal sphincter

The lower esophageal sphincters (LES) together with the crural diaphragm are the major antireflux barriers protecting the esophagus from reflux of gastric content. However, reflux of gastric contents into the esophagus is a normal phenomenon in healthy individuals occurring primarily during episodes of transient lower esophageal sphincter relaxation (TLESR), defined as LES relaxation in the absence of a swallow. Transient lower esophageal sphincter relaxation is also the dominant mechanism of pathologic reflux in gastroesophageal reflux disorder (GERD) patients. Frequency of TLESR does not differ significantly between healthy individuals and those with GERD, but TLESRs are more likely to be associated with acid reflux in GERD patients. Understanding the mechanisms responsible for elicitation of a TLESR, using recently introduced novel technology is an area of intense interest. Pharmacologic and non-pharmacologic manipulation of receptors involved in the control of TLESR has recently emerged as a potential target for GERD therapy.

High resolution manometry to detect transient lower oesophageal sphincter relaxations: diagnostic accuracy compared with perfused-sleeve manometry, and the definition of new detection criteria

BACKGROUND

Inhibition of transient lower oesophageal sphincter relaxations (tLESRs) has become one of the most relevant therapeutic objectives in patients with reflux symptoms resistant to proton pump inhibitors. tLESRs are currently detected by oesophageal perfused-sleeve manometry (PSM), but oesophageal high resolution manometry (HRM), which combines closely spaced pressure sensors and oesophageal pressure topography plots, may prove to be a better tool.

AIM

To evaluate the efficacy, reproducibility and interobserver agreement of HRM for the detection of tLESRs, in comparison with PSM.

METHODS

Twenty-four healthy volunteers underwent HRM alone and on a separate occasion with PSM simultaneously. LES pressure was monitored for 1 h during fasting and 2 h postprandial. Criteria for tLESRs were defined by characterising spontaneous LES relaxation associated with common cavity and then applied to all spontaneous LES relaxations. Interobserver agreement and the rates of tLESRs detected by HRM and PSM were compared.

RESULTS

New HRM criteria for the detection of tLESRs have been established. A similar number of tLESRs were identified during the two HRM recordings (median per subject 15 and 13 (P = 0.07) and less with PSM (median per subject 11, P < 0.01). The overall concordance rate between the two procedures was substantial (kappa = 0.61). The interobserver agreement was almost perfect (kappa = 0.83) with HRM and only fair (kappa = 0.38) with PSM.

CONCLUSIONS

High resolution manometry is reproducible and more sensitive than PSM to detect tLESRs. HRM provides a better interobserver agreement. These results confirm that HRM is the gold standard for detecting tLESRs (NTC00931593).

High-resolution esophageal pressure topography is superior to conventional sleeve manometry for the detection of transient lower esophageal sphincter relaxations associated with a reflux event

BACKGROUND

Transient lower esophageal sphincter relaxations (TLESRs) are the main mechanism underlying gastro-esophageal reflux and are detected during manometric studies using well defined criteria. Recently, high-resolution esophageal pressure topography (HREPT) has been introduced and is now considered as the new standard to study esophageal and lower esophageal sphincter (LES) function. In this study we performed a head-to-head comparison between HREPT and conventional sleeve manometry for the detection of TLESRs.

METHODS

A setup with two synchronized MMS-solar systems was used. A solid state HREPT catheter, a water-perfused sleeve catheter, and a multi intraluminal impedance pH (MII-pH) catheter were introduced in 10 healthy volunteers (M6F4, age 19-56). Subjects were studied 0.5 h before and 3 h after ingestion of a standardized meal. Tracings were blinded and analyzed by the three authors according to the TLESR criteria.

KEY RESULTS

In the HREPT mode 156 TLESRs were scored, vs 143 during sleeve manometry (P = 0.10). Hundred and twenty-three TLESRs were scored by both techniques. Of all TLESRs (177), 138 were associated with reflux (78%). High-resolution esophageal pressure topography detected significantly more TLESRs associated with a reflux event (132 vs 119, P = 0.015) resulting in a sensitivity for detection of TLESRs with reflux of 96% compared to 86% respectively. Analysis of the discordant TLESRs associated with reflux showed that TLESRs were missed by sleeve manometry due to low basal LES pressure (N = 5), unstable pharyngeal signal (N = 4), and residual sleeve pressure >2 mmHg (N = 10).

CONCLUSIONS & INFERENCES

The HREPT is superior to sleeve manometry for the detection of TLESRs associated with reflux. However, rigid HREPT criteria are awaited.

Relationship between gastro-oesophageal reflux and airway diseases: the airway reflux paradigm

Our understanding of the relationship between gastro-oesophageal reflux and respiratory disease has recently undergone important changes. The previous paradigm of airway reflux as synonymous with the classic gastro-oesophageal reflux disease (GORD) causing heartburn has been overturned. Numerous epidemiological studies have shown a highly significant association of the acid, liquid, and gaseous reflux of GORD with conditions such as laryngeal diseases, chronic rhinosinusitis, treatment resistant asthma, COPD and even idiopathic pulmonary fibrosis. However, it has become clear from studies on cough hypersensitivity syndrome that much reflux of importance in the airways has been missed, since it is either non- or weakly acid and gaseous in composition. The evidence for such a relationship relies on the clinical history pointing to symptom associations with known precipitants of reflux. The tools for the diagnosis of extra-oesophageal reflux, in contrast to the oesophageal reflux of GORD, lack sensitivity and reproducibility. Unfortunately, methodology for detecting such reflux is only just becoming available and much additional work is required to properly delineate its role.

Cardiovascular compression of the esophagus and spread of gastro-esophageal reflux

BACKGROUND

Factors that determine the spread of gastro-esophageal reflux (GER) along the length of the esophagus are not known. We investigated if cardiovascular (CV) compressions on the esophagus may determine the spread of refluxate into the proximal esophagus.

METHODS

High-resolution manometry (HRM) and multi-channel intra-luminal impedance recording (MIIR) were performed simultaneously in 10 normal subjects in the recumbent and upright positions. Pulsatile pressure increases on the esophagus (marker of CV compression) were identified on the HRM. Spread of refluxate into the esophagus was determined by the MIIR.

KEY RESULTS

Cardiovascular compression zones were observed in the esophagus in 9 out of 10 subjects in recumbent position. Forty percent of GER episodes were limited to the distal esophagus in the recumbent position and CV compression pressure was greater than distal esophageal pressure at the time of GER in all such cases. On the other hand, distal esophageal pressure was greater than CV compression pressure when the refluxate extended into the proximal esophagus. In the upright position, CV compression was less frequent than recumbent position and only 12% of GER episodes were limited to the distal esophagus.

CONCLUSIONS & INFERENCES

Cardiovascular compression of the esophagus is frequently observed in normal healthy subject and restricts the spread of refluxate into the proximal esophagus.

Upper esophageal sphincter during transient lower esophageal sphincter relaxation: effects of reflux content and posture

Although some studies show that the upper esophageal sphincter (UES) contracts during transient lower esophageal sphincter relaxation (TLESR), others show that it relaxes. We hypothesized that the posture of the subject and constituents of gastroesophageal reflux (GER) may determine the type of UES response during the TLESR. High-resolution manometry and esophageal pH/impedance recording were performed in 10 healthy volunteers in the right recumbent (1 h) and upright (1 h) positions following the ingestion of a 1,000-Kcal meal. The UES pressure response during TLESR and constituents of GER (liquid, air, and pH) were determined. 109 TLESRs (58 upright and 51 recumbent) were analyzed. The majority of TLESRs were associated with GER (91% upright and 88% recumbent) events. UES relaxation was the predominant response during upright position (81% of TLESRs), and it was characteristically associated with presence of air in the reflux (92%). On the other hand, UES contraction was the predominant response during recumbent position (82% of TLESRs), and it was mainly associated with liquid reflux (71%). The rate of esophageal pressure increase (dP/dt) during the GER, but not the pH, had major influence on the type of UES response during TLESR. The dP/dt during air reflux (127 +/- 39 mmHg/s) was significantly higher than liquid reflux (31 +/- 6 mmHg/s, P < 0.0001). We concluded that the nature of UES response during TLESR, relaxation or contraction, is related to the posture and the constituents of GER. We propose that the rapid rate of esophageal pressure increase associated with air reflux determines the UES relaxation response to GER.

Transient lower oesophageal sphincter relaxation in achalasia: everything but LOS relaxation

In conducting clinical high-resolution oesophageal pressure topography (HROPT) studies we observed that after subjects sat upright between series of supine and upright test swallows, they frequently had a transient lower oesophageal sphincter relaxation (TLOSR). When achalasia patients were studied in the same protocol, they exhibited a similar HROPT event leading to the hypothesis that achalasics had incomplete TLOSRs. We reviewed clinical HROPT studies of 94 consecutive non-achalasics and 25 achalasics. Studies were analyzed for a TLOSR-like event during the study and, when observed, that TLOSR-like event was characterized for the degree and duration of distal oesophageal shortening, the degree of LOS relaxation, associated crural diaphragm (CD) inhibition, oesophageal pressurization and upper oesophageal sphincter (UOS) relaxation. About 64/94 (68%) non-achalasics and 15/24 (63%) of achalasics had a pressure topography event after the posture change characterized by a prolonged period of distal oesophageal shortening and/or LOS relaxation. Events among the non-achalasics and achalasics were similar in terms of magnitude and duration of shortening and all were associated with CD inhibition. Similar proportions had associated non-deglutitive UOS relaxations. The only consistent differences were the absence of associated LOS relaxation and the absence of HROPT evidence of reflux among the achalasics leading us to conclude that their events were incomplete TLOSRs. Achalasic patients exhibit a selective defect in the TLOSR response suggesting preservation of all sensory, central and efferent aspects of the requisite neural substrate with the notable exception of LOS relaxation, a function of inhibitory (nitrergic) myenteric plexus neurons.

Supragastric belching in patients with reflux symptoms

OBJECTIVES

Supragastric belching is a distinct belch pattern found in patients with excessive belching (aerophagia). Patients with gastroesophageal reflux disease (GERD) may also complain of belching. It has been shown that GERD patients swallow air more frequently and have more air-containing reflux episodes than do healthy controls. It is not known whether supragastric belches occur in patients with reflux symptoms.

METHODS

Fifty consecutive patients with typical reflux symptoms and 10 healthy volunteers underwent ambulatory 24-h pH-impedance monitoring off proton pump inhibitor therapy. Patients filled out a questionnaire regarding their symptoms. The number and type of reflux episodes and supragastric belches during the measurement were assessed.

RESULTS

In 24 of the 50 patients with reflux symptoms, supragastric belches were identified with a median incidence of 13 per 24 h (interquartile range: 6-52). In 5 of the 10 healthy volunteers 2, (1-6) supragastric belches were identified. In patients with reflux symptoms, 48% of the supragastric belches occurred in close temporal association with reflux episodes. Two different association patterns were observed. In 19 patients supragastric belches occurred immediately prior (<1 s) to the onset of the reflux episode. This pattern was observed in 30% of all supragastric belches. In 15 patients the supragastric belch occurred during the reflux episode, with the onset being 4-10 s after the start of the reflux episode. This pattern was observed in 18% of all identified supragastric belches.

CONCLUSIONS

Supragastric belches occur more frequently in patients with typical reflux symptoms than in healthy subjects. These belches often occur in close association with acid and weakly acidic reflux episodes. Our findings suggest that supragastric belching elicits reflux in some cases and is the patient's response to an unpleasant esophageal sensation in others.

High-resolution manometry and impedance-pH/manometry: valuable tools in clinical and investigational esophagology

Both high-resolution manometry (HRM) and impedance-pH/manometry monitoring have established themselves as research tools and both are now emerging in the clinical arena. Solid-state HRM capable of simultaneously monitoring the entire pressure profile from the pharynx to the stomach along with pressure topography plotting represents an evolution in esophageal manometry. Two strengths of HRM with pressure topography plots compared with conventional manometric recordings are (1) accurately delineating and tracking the movement of functionally defined contractile elements of the esophagus and its sphincters, and (2) easily distinguishing between luminal pressurization attributable to spastic contractions and that resultant from a trapped bolus in a dysfunctional esophagus. Making these distinctions objectifies the identification of achalasia, distal esophageal spasm, functional obstruction, and subtypes thereof. Ambulatory intraluminal impedance pH monitoring has opened our eyes to the trafficking of much more than acid reflux through the esophageal lumen. It is clear that acid reflux as identified by a conventional pH electrode represents only a subset of reflux events with many more reflux episodes being composed of less acidic and gaseous mixtures. This has prompted many investigations into the genesis of refractory reflux symptoms. However, with both technologies, the challenge has been to make sense of the vastly expanded datasets. At the very least, HRM is a major technological tweak on conventional manometry, and impedance pH monitoring yields information above and beyond that gained from conventional pH monitoring studies. Ultimately, however, both technologies will be strengthened as outcome studies evaluating their utilization become available.