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

High-resolution impedance manometry for comparing bolus transit between patients with non-obstructive dysphagia and asymptomatic controls

BACKGROUND

Currently, there are no high-resolution impedance manometry (HRIM)-based diagnostic criteria for non-obstructive dysphagia (NOD). New impedance parameters, such as the esophageal impedance integral (EII) and volume of inverted impedance (VII) ratios, have shown strong correlations with bolus transit. This study compared the EII and VII ratios as diagnostic tools for NOD.

METHODS

We analyzed 36 participants (12 patients with achalasia, 12 patients with NOD [7 with normal motility and 5 with ineffective esophageal motility], and 12 asymptomatic controls) who underwent HRIM with a maximum of 5 swallows per participant. The EII and VII ratios were calculated as Z2 (post-swallow)/Z1 (pre-swallow). Bolus transit was retrospectively evaluated using transluminal impedance analysis.

KEY RESULTS

Both EII and VII ratios could effectively distinguish the achalasia group from the non-achalasia groups (area under the receiver operating characteristic curve [AUROC]: 0.83 for VII vs. 0.80 for EII; p = 0.73). However, the VII ratio was significantly better in discriminating asymptomatic controls from patients with dysphagia (NOD + achalasia) (AUROC: 0.81 vs. 0.68; p = 0.01). Moreover, the VII ratio was better in discriminating asymptomatic controls from patients with NOD (AUROC: 0.68 vs. 0.51; p = 0.06). In repeated swallows, the VII ratio was consistently the lowest in controls and the highest in patients with achalasia, whereas the EII ratio did not show a consistent pattern.

CONCLUSIONS & INFERENCES

The VII ratio was more reliable than the EII ratio for describing bolus transit and distinguishing patients with NOD from asymptomatic controls, even during repeated measures of subsequent swallows.

Elevated average maximum intrabolus pressure on high-resolution manometry is associated with esophageal dysmotility and delayed esophageal emptying on timed barium esophagram

BACKGROUND

Intrabolus pressure (IBP) recorded by high-resolution manometry (HRM) portrays the compartmentalized force on a bolus during esophageal peristalsis. HRM may be a reliable screening tool for esophageal dysmotility in patients with elevated average maximum IBP (AM-IBP). Timed barium esophagram (TBE) is a validated measure of esophageal emptying disorders, such as esophagogastric junction outflow obstruction and achalasia. This study aimed to determine if an elevated AM-IBP correlates with esophageal dysmotility on HRM and/or delayed esophageal emptying on TBE.

METHODS

A retrospective analysis of all HRM (unweighted sample n = 155) performed at a tertiary referral center from 09/2015-03/2017 yielded a case group (n = 114) with abnormal AM-IBP and a control group (n = 41) with a normal AM-IBP (pressure < 17 mmHg) as consistent with Chicago Classification 3. All patients received a standardized TBE, with abnormalities classified as greater than 1 cm of retained residual liquid barium in the esophagus at 1 and 5 min or as tablet retention after 5 min.

RESULTS

AM-IBP was significantly related to liquid barium retention (p = 0.003) and tablet arrest on timed barium esophagram (p = 0.011). A logistic regression model correctly predicted tablet arrest in 63% of cases. Tablet arrest on AM-IBP correlated with an optimal prediction point at 20.1 mmHg on HRM. Patients with elevated AM-IBP were more likely to have underlying esophageal dysmotility (95.6% vs. 70.7% respectively; p < 0.001), particularly esophagogastric junction outflow obstruction disorders. Elevated AM-IBP was associated with incomplete liquid bolus transit on impedance analysis (p = 0.002).

CONCLUSIONS

Our findings demonstrate that an elevated AM-IBP is associated with abnormal TBE findings of esophageal tablet retention and/or bolus stasis. An abnormal AM-IBP (greater than 20.1 mm Hg) was associated with a higher probability of retaining liquid bolus or barium tablet arrest on TBE and esophageal dysmotility on HRM. This finding supports the recent incorporation of IBP in Chicago Classification v4.0.

Chicago Classification of esophageal motility disorders: Past, present, and future

The Chicago Classification (CC) is a dynamic, evolving classification scheme created by a diverse group of international esophageal experts. Its application has transformed the way esophageal motor data are used to define motility disorders, each iteration seeking to advance, simplify, and standardize the way clinicians worldwide diagnose esophageal dysmotility. The most recent update, CC version 4.0 (CCv4.0), emphasizes the importance of clinical context and distinguishes clinically relevant, conclusive manometric diagnoses from irrelevant manometric observations. Future iterations of CC may refine the classification of spastic esophageal disorders and incorporate machine learning and physics-based modeling to improve metrics.

[Diagnosis of Dysphagia: High Resolution Manometry & EndoFLIP]

Esophageal motility disorders were re-defined when high-resolution manometry was employed to better understand their pathogenesis. Newly developed parameters including integrated relaxation pressure (IRP), distal contractile integral, and distal latency showed better diagnostic yield compared with previously used conventional parameters. Therefore, Chicago classification was formulated, and its diagnostic cascade begins by assessing the IRP value. However, IRP showed limitation due to its inconsistency, and other studies have tried to overcome this. Recent studies showed that provocative tests, supplementing the conventional esophageal manometry protocol, have improved the diagnostic yield of the esophageal motility disorders. Therefore, position change from supine to upright, solid or semi-solid swallowing, multiple rapid swallows, and the rapid drink challenge were newly added to the manometry protocol in the revised Chicago classification version 4.0. Impedance planimetry enables measurement of bag cross-sectional area at various locations. The functional lumen imaging probe (FLIP) has been applied to assess luminal distensibility. This probe can also measure pressure, serial cross-sectional areas, and tension-strain relationship. The esophagogastric junction's distensibility is decreased in achalasia. Therefore, EndoFLIP can be used to assess contractility and distensibility of the esophagus in the patients with achalasia, including repetitive antegrade or retrograde contractions. EndoFLIP can detect achalasia patients with relatively low IRP, which was difficult to diagnose using the current high-resolution manometry. EndoFLIP also provides information on the contractile activity and distensibility of the esophageal body in patients with achalasia. The use of provocative tests, newly added in Chicago classification 4.0 version, and EndoFLIP can expand understanding of esophageal motility disorders.

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

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

Could the peristaltic transition zone be caused by non-uniform esophageal muscle fiber architecture? A simulation study

BACKGROUND

Based on a fully coupled computational model of esophageal transport, we analyzed how varied esophageal muscle fiber architecture and/or dual contraction waves (CWs) affect bolus transport. Specifically, we studied the luminal pressure profile in those cases to better understand possible origins of the peristaltic transition zone.

METHODS

Two groups of studies were conducted using a computational model. The first studied esophageal transport with circumferential-longitudinal fiber architecture, helical fiber architecture and various combinations of the two. In the second group, cases with dual CWs and varied muscle fiber architecture were simulated. Overall transport characteristics were examined and the space-time profiles of luminal pressure were plotted and compared.

KEY RESULTS

Helical muscle fiber architecture featured reduced circumferential wall stress, greater esophageal distensibility, and greater axial shortening. Non-uniform fiber architecture featured a peristaltic pressure trough between two high-pressure segments. The distal pressure segment showed greater amplitude than the proximal segment, consistent with experimental data. Dual CWs also featured a pressure trough between two high-pressure segments. However, the minimum pressure in the region of overlap was much lower, and the amplitudes of the two high-pressure segments were similar.

CONCLUSIONS & INFERENCES

The efficacy of esophageal transport is greatly affected by muscle fiber architecture. The peristaltic transition zone may be attributable to non-uniform architecture of muscle fibers along the length of the esophagus and/or dual CWs. The difference in amplitude between the proximal and distal pressure segments may be attributable to non-uniform muscle fiber architecture.

Mechanisms underlying reflux symptoms and dysphagia in patients with joint hypermobility syndrome, with and without postural tachycardia syndrome

BACKGROUND

The joint hypermobility syndrome (JHS) is a common non-inflammatory connective tissue disorder which frequently co-exists with postural tachycardia syndrome (PoTS), a form of orthostatic intolerance. Gastrointestinal symptoms and dysmotility have been reported in PoTS. Dysphagia and reflux are common symptoms in JHS, yet no studies have examined the physiological mechanism for these, subdivided by PoTS status.

METHODS

Thirty patients (28 female, ages: 18-62) with JHS and symptoms of reflux (n=28) ± dysphagia (n=25), underwent high-resolution manometry and 24 hour pH-impedance monitoring after questionnaire-based symptom assessment. Esophageal physiology parameters were examined in JHS, subdivided by PoTS status.

RESULTS

Fifty-three percent of JHS patients with reflux symptoms had pathological acid reflux, 21% had reflux hypersensitivity, and 25% had functional heartburn. Acid exposure was more likely to be increased in the recumbent than upright position (64% vs 43%). The prevalence of hypotensive lower esophageal sphincter (33%) and hiatus hernia (33%) was low. Forty percent of patients with dysphagia had minor disorders of motility, 60% had functional dysphagia. Eighteen (60%) patients had coexistent PoTS-they had significantly higher dysphagia (21 vs 11.5, P=.04) and reflux scores (24.5 vs 16.5, P=.05), and double the prevalence of pathological acid reflux (64% vs 36%, P=.1) and esophageal dysmotility (50% vs 25%, P=.2) though this was not significant.

CONCLUSIONS AND INFERENCES

A large proportion of JHS patients with esophageal symptoms have true reflux-related symptoms or mild esophageal hypomotility, and this is more likely if they have PoTS.

Ineffective esophageal motility: clinical, manometric, and outcome characteristics in patients with and without abnormal esophageal acid exposure

The etiology and clinical impact of ineffective esophageal motility (IEM) remain poorly understood. Unless gastroesophageal acid reflux (GERD) is identified, symptomatic patients with IEM are challenging to treat. We sought to determine whether any clinical or functional characteristics could distinguish those patients with IEM and either normal or abnormal esophageal acid exposure.In this retrospective cohort study, we identified 46 consecutive patients presenting with heartburn, and other GER symptoms who underwent clinical, endoscopic, and functional evaluation that included high-resolution manometry (HRM) and ambulatory pH monitoring. IEM was defined using the Chicago Classification criteria (v.3) as ≥50% ineffective swallows (DCI ≤ 450 mmHg.s.cm). Esophageal acid exposure by ambulatory pH monitoring was considered abnormal when total time with esophageal pH < 4 exceeded 4.2%.Of the 46 IEM patients identified, 19 (mean age: 42 years, 37% female), had normal esophageal acid exposure and 27 patients, mean age 54 years, 33% female, evidence of pathologic acid reflux. There was a 12 years age difference between the groups, with those with normal acid exposure being significantly younger (P < 0.01); the mean body mass index (BMI) was 22.6 ± 0.6 in the normal group and 25.4 ± 0.7 in the abnormal group (P < 0.001); otherwise the groups were endoscopically and histologically similar. Symptoms were not discriminatory and heartburn and regurgitation were the most prevalent in both groups. HRM did not discriminate symptomatic patients with IEM and either normal or abnormal esophageal acid exposure. Proton pump inhibition (PPI) therapy was significantly more effective (74% vs. 10%) in patients with pathologic acid reflux (P < 0.001). As pH exposure becomes abnormal in the context of IEM, there is dominance for supine reflux.IEM appears to be an early, primary event, eventually associated with pathologic acid exposure, particularly supine. Higher BMI is also associated with abnormal esophageal acid exposure in such patients. GER symptoms are not discriminatory in patients with IEM with and without underlying pathologic acid reflux. Clinical response to PPI in such patients depends on the presence of esophageal pathologic acid exposure. Those with IEM and normal acid exposure remain symptomatic and mostly resistant to therapy.

The Esophagiome: concept, status, and future perspectives

The term "Esophagiome" is meant to imply a holistic, multiscale treatment of esophageal function from cellular and muscle physiology to the mechanical responses that transport and mix fluid contents. The development and application of multiscale mathematical models of esophageal function are central to the Esophagiome concept. These model elements underlie the development of a "virtual esophagus" modeling framework to characterize and analyze function and disease by quantitatively contrasting normal and pathophysiological function. Functional models incorporate anatomical details with sensory-motor properties and functional responses, especially related to biomechanical functions, such as bolus transport and gastrointestinal fluid mixing. This brief review provides insight into Esophagiome research. Future advanced models can provide predictive evaluations of the therapeutic consequences of surgical and endoscopic treatments and will aim to facilitate clinical diagnostics and treatment.

Novel insights into esophageal diagnostic procedures

The 21st century offers new advances in diagnostic procedures and protocols in the management of esophageal diseases. This review highlights the most recent advances in esophageal diagnostic technologies, including clinical applications of novel endoscopic devices, such as ultrathin endoscopy and confocal laser endomicroscopy for diagnosis and management of Barrett's esophagus; novel parameters and protocols in high-resolution esophageal manometry for the identification and better classification of motility abnormalities; innovative connections between esophageal motility disorder diagnosis and detection of gastroesophageal reflux disease (GERD); impedance-pH testing for detecting the various GERD phenotypes; performance of distensibility testing for better pathophysiological knowledge of the esophagus and other gastrointestinal abnormalities; and a modern view of positron emission tomography scanning in metastatic disease detection in the era of accountability as a model for examining other new technologies. We now have better tools than ever for the detection of esophageal diseases and disorders, and emerging data are helping to define how well these tools change management and provide value to clinicians. This review features novel insights from multidisciplinary perspectives, including both surgical and medical perspectives, into these new tools, and it offers guidance on the use of novel technologies in clinical practice and future directions for research.

Motility characteristics in the transition zone in Gastroesophageal Reflux Disease (GORD) patients

Background

Defects in distal oesophageal peristalsis was thought to be an indication of incomplete bolus transit (BT). However, the role of transition zone (TZ) defects in the BT in gastroesophageal reflux disease (GORD) patients needs clarification. The aim of this study was to assess the TZ defects in GORD patients and to explore the relationship between TZ defects and BT.

Methods

One hundred and two patients with reflux symptoms and 20 healthy adults were included in the study. All subjects underwent upper gastrointestinal endoscopy, high resolution impedance manometry (HRiM) and 24-h ambulatory multichannel impedance-pH (MII-pH) monitoring. Patients were subgrouped into reflux oesophagitis (RE), non-erosive reflux disease (NERD), hypersensitive oesophagus (HO) and functional heartburn (FH) classified following MII-pH monitoring. Oesophageal pressure topography was analysed to define TZ defects by spatial or temporal TZ measurements exceeding 2 cm or 1 s, weak and fragmented swallows were excluded, and the association between TZ and BT was investigated.

Results

Following liquid swallows, there were no significant differences in TZ delay time and TZ length between groups (RE: 1.75 s (1.32–2.17) and 2.50 cm (2.40–3.20); NERD: 1.60 s (1.10–2.00) and 2.20 cm (2.10–2.65); HO: 1.60 s (1.30–1.80) and 2.70 cm (2.30–3.00); FH: 1.55 s (1.20–2.17) and 3.10 cm (2.25–5.00); Healthy volunteers: 1.50 s (1.20–1.90) and 2.30 cm (2.10–3.00). However, individuals with TZ defects had lower complete BT rates compared with those without TZ defects (p < 0.001). There were also significantly more incomplete BT in patients with RE, HO and FH than in healthy controls (p < 0.05).

Conclusions

In GORD patients, TZ defects correlated with proximal bolus retention in the corresponding area independent of distal weak peristalsis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0525-1) contains supplementary material, which is available to authorized users.

Fundamentals of Neurogastroenterology: Physiology/Motility - Sensation

The fundamental gastrointestinal functions include motility, sensation, absorption, secretion, digestion and intestinal barrier function. Digestion of food and absorption of nutrients normally occurs without conscious perception. Symptoms of functional gastrointestinal disorders are often triggered by meal intake suggesting abnormalities in the physiological processes are involved in the generation of symptoms. In this manuscript, normal physiology and pathophysiology of gastrointestinal function, and the processes underlying symptom generation are critically reviewed. The functions of each anatomical region of the digestive tract are summarized. The pathophysiology of perception, motility, mucosal barrier, and secretion in functional gastrointestinal disorders as well as effects of food, meal intake and microbiota on gastrointestinal motility and sensation are discussed. Genetic mechanisms associated with visceral pain and motor functions in health and functional gastrointestinal disorders are reviewed. Understanding the basis for digestive tract functions is essential to understand dysfunctions in the functional gastrointestinal disorders.

Effects of acotiamide on esophageal motor function and gastroesophageal reflux in healthy volunteers

Background

The prevalence of gastroesophageal reflux disease (GERD) has been increasing worldwide, with proton pump inhibitor (PPI) administration the current mainstay therapy for affected individuals. However, PPI efficacy is insufficient especially for non-erosive reflux disease. Although it has been reported that prokinetic drugs improve GERD, their effects on esophageal function remain to be clearly investigated. In the present study, we evaluated the direct effects of acotiamide, a novel prokinetic agent for the treatment of functional dyspepsia, on esophageal motor function and gastroesophageal reflux.

Methods

Ten adult healthy volunteers (average age 24 years, range 20–36 years; 7 males, 3 females) were enrolled. Esophageal body peristaltic contractions and lower esophageal sphincter (LES) pressure with and without acotiamide administration were recorded using high resolution manometry using a cross-over protocol. Total and acidic reflux levels for 24 h and during the postprandial period were also recorded using a multichannel intraluminal impedance and pH monitoring system. Data were analyzed blind by one observer.

Results

Acotiamide at a standard dose of 300 mg/day did not significantly stimulate esophageal motor function. Although the frequency of swallows with weak contraction tended to decrease with acotiamide administration, the difference as compared to no administration was not statistically significant. In addition, the drug neither decreased total or postprandial gastroesophageal acid/non-acid reflux events nor accelerated esophageal clearance time.

Conclusions

Acotiamide, a novel gastrointestinal motility modulator, at a standard dose did not significantly affect esophageal motor functions or gastroesophageal reflux in healthy adults. Additional investigations with GERD patients are necessary to elucidate its clinical significance.

Trial registration

This study was registered on 1st August 2013 with the University Hospital Medical Information Network (UMIN) clinical trials registry, as number: UMIN000011260.

The four phases of esophageal bolus transit defined by high-resolution impedance manometry and fluoroscopy

We aimed to model esophageal bolus transit based on esophageal pressure topography (EPT) landmarks, concurrent intrabolus pressure (IBP), and esophageal diameter as defined with fluoroscopy. Ten healthy subjects were studied with high-resolution impedance manometry and videofluoroscopy. Data from four 5-ml barium swallows (2 upright, 2 supine) in each subject were analyzed. EPT landmarks were utilized to divide bolus transit into four phases: phase I, upper esophageal sphincter (UES) opening; phase II, UES closure to the transition zone (TZ); phase III, TZ to contractile deceleration point (CDP); and phase IV, CDP to completion of bolus emptying. IBP and esophageal diameter were analyzed to define functional differences among phases. IBP exhibited distinct changes during the four phases of bolus transit. Phase I was associated with filling via passive dilatation of the esophagus and IBP reflective of intrathoracic pressure. Phase II was associated with auxotonic relaxation and compartmentalization of the bolus distal to the TZ. During phase III, IBP exhibited a slow increase with loss of volume related to peristalsis (auxotonic contraction) and passive dilatation in the distal esophagus. Phase IV was associated with the highest IBP and exhibited isometric contraction during periods of nonemptying and auxotonic contraction during emptying. IBP may be used as a marker of esophageal wall state during the four phases of esophageal bolus transit. Thus abnormalities in IBP may identify subtypes of esophageal disease attributable to abnormal distensibility or neuromuscular dysfunction.

Effects of viscosity and volume on the patterns of esophageal motility in healthy adults using high-resolution manometry

The purpose of this study was to determine the effects of age, sex, body mass index (BMI), viscosity, and volume on esophageal motility using high-resolution manometry (HRM). Manometric studies were performed on 60 asymptomatic volunteers (27 men and 33 women, age: 19-56 years) while in a supine position. Manometric protocol included 10 water swallows (5 cc), 10 jelly swallows (5 cc), and 1 water swallow (20 cc). Evaluation of HRM parameters including length of proximal pressure trough (PPT length), distal latency (DL), contractile front velocity (CFV), distal contractile integral (DCI), and 4-second integrated relaxation pressure (IRP) was performed using MATLAB. Significant differences were noted in median IRP between water 5 cc (median 7.2 mmHg [range 5.5-9.6]), jelly 5 cc (median 6.0 mmHg [range 3.8-8.0]), and water 20 cc {(Median 4.8 mmHg [range 3.3-7.4]), P < 0.01}. DL were significantly different between water 5 cc, jelly 5 cc, and water 20 cc (P < 0.01), and in terms of PPT, proportions of small (2 cm ≤ < 5 cm) and large (5 cm≤) break for jelly 5 cc were significantly higher than those for the water 5 cc swallow (P < 0.05). Furthermore, DCI increased with age for water 5 cc, and a significant negative correlation was noticed between proportions of small break and BMI for water 5 cc. Manometric measurements vary depending on age, BMI, viscosity, and volume. These findings need to be taken into account in the interpretation of manometry results.

Utilizing intrabolus pressure and esophagogastric junction pressure to predict transit in patients with Dysphagia

Background/Aims

High-resolution manometry (HRM), with a greatly increased number of recording sites and decreased spacing between sites, allows evaluation of the dynamic simultaneous relationship between intrabolus pressure (IBP) and esophagogastric junction (EGJ) relaxation pressure. We hypothesized that bolus transit may occur when IBP overcomes integrated relaxation pressure (IRP) and analyzed the relationships between peristalsis pattern and the discrepancy between IBP and IRP in patients with dysphagia.

Methods

Twenty-two dysphagia patients with normal EGJ relaxation were examined with a 36-channel HRM assembly. Each of the 10 examinations was performed with 20 and 30 mmHg pressure topography isobaric contours, and findings were categorized based on the Chicago classification. We analyzed the relationships between peristalsis pattern and the discrepancy between IBP and IRP.

Results

Twenty-two patients were classified by the Chicago classification: 1 patient with normal EGJ relaxation and normal peristalsis, 8 patients with intermittent hypotensive peristalsis and 13 patients with frequent hypotensive peristalsis. A total of 220 individual swallows were analyzed. There were no statistically significant relationships between peristalsis pattern and the discrepancy between IBP and IRP on the 20 or 30 mmHg isobaric contours.

Conclusions

Peristalsis pattern was not associated with bolus transit in patients with dysphagia. However, further controlled studies are needed to evaluate the relationship between bolus transit and peristalsis pattern using HRM with impedance.

High-resolution Manometry and Globus: Comparison of Globus, Gastroesophageal Reflux Disease and Normal Controls Using High-resolution Manometry

Background/Aims

Globus is a foreign body sense in the throat without dysphagia, odynophagia, esophageal motility disorders, or gastroesophageal reflux. The etiology is unclear. Previous studies suggested that increased upper esophageal sphincter pressure, gastroesophageal reflux and hypertonicity of esophageal body were possible etiologies. This study was to quantify the upper esophageal sphincter (UES) pressure, contractile front velocity (CFV), proximal contractile integral (PCI), distal contractile integral (DCI) and transition zone (TZ) in patient with globus gastroesophageal reflux disease (GERD) without globus, and normal controls to suggest the correlation of specific high-resolution manometry (HRM) findings and globus.

Methods

Fifty-seven globus patients, 24 GERD patients and 7 normal controls were studied with HRM since 2009. We reviewed the reports, and selected 5 swallowing plots suitable for analysis in each report, analyzed each individual plot with ManoView. The 5 parameters from each plot in 57 globus patients were compared with that of 24 GERD patients and 7 normal controls.

Results

There was no significant difference in the UES pressure, CFV, PCI and DCI. TZ (using 30 mmHg isobaric contour) in globus showed significant difference compared with normal controls and GERD patients. The median values of TZ were 4.26 cm (interquartile range [IQR], 2.30-5.85) in globus patients, 5.91 cm (IQR, 3.97-7.62) in GERD patients and 2.26 cm (IQR, 1.22-2.92) in normal controls (P = 0.001).

Conclusions

HRM analysis suggested that UES pressure, CFV, PCI and DCI were not associated with globus. Instead increased length of TZ may be correlated with globus. Further study comparing HRM results in globus patients within larger population needs to confirm their correlation.

High-resolution Manometry and Globus: Comparison of Globus, Gastroesophageal Reflux Disease and Normal Controls Using High-resolution Manometry

BACKGROUND/AIMS

Globus is a foreign body sense in the throat without dysphagia, odynophagia, esophageal motility disorders, or gastroesophageal reflux. The etiology is unclear. Previous studies suggested that increased upper esophageal sphincter pressure, gastroesophageal reflux and hypertonicity of esophageal body were possible etiologies. This study was to quantify the upper esophageal sphincter (UES) pressure, contractile front velocity (CFV), proximal contractile integral (PCI), distal contractile integral (DCI) and transition zone (TZ) in patient with globus gastroesophageal reflux disease (GERD) without globus, and normal controls to suggest the correlation of specific high-resolution manometry (HRM) findings and globus.

METHODS

Fifty-seven globus patients, 24 GERD patients and 7 normal controls were studied with HRM since 2009. We reviewed the reports, and selected 5 swallowing plots suitable for analysis in each report, analyzed each individual plot with ManoView. The 5 parameters from each plot in 57 globus patients were compared with that of 24 GERD patients and 7 normal controls.

RESULTS

There was no significant difference in the UES pressure, CFV, PCI and DCI. TZ (using 30 mmHg isobaric contour) in globus showed significant difference compared with normal controls and GERD patients. The median values of TZ were 4.26 cm (interquartile range [IQR], 2.30-5.85) in globus patients, 5.91 cm (IQR, 3.97-7.62) in GERD patients and 2.26 cm (IQR, 1.22-2.92) in normal controls (P = 0.001).

CONCLUSIONS

HRM analysis suggested that UES pressure, CFV, PCI and DCI were not associated with globus. Instead increased length of TZ may be correlated with globus. Further study comparing HRM results in globus patients within larger population needs to confirm their correlation.

Evaluation of Esophageal Motor Function With High-resolution Manometry

For several decades esophageal manometry has been the test of choice to evaluate disorders of esophageal motor function. The recent introduction of high-resolution manometry for the study of esophageal motor function simplified performance of esophageal manometry, and revealed previously unidentified patterns of normal and abnormal esophageal motor function. Presentation of pressure data as color contour plots or esophageal pressure topography led to the development of new tools for analyzing and classifying esophageal motor patterns. The current standard and still developing approach to do this is the Chicago classification. While this methodical approach is improving our diagnosis of esophageal motor disorders, it currently does not address all motor abnormalities. We will explore the Chicago classification and disorders that it does not address.

Characterization of esophageal pressure-flow abnormalities in patients with non-obstructive dysphagia and normal manometry findings

BACKGROUND AND AIM

Patients with non-obstructive dysphagia (NOD) report symptoms of impaired esophageal bolus transit without evidence of bolus stasis. In such patients, manometric investigation may diagnose esophageal motility disorders; however, many have normal motor patterns. We hypothesized that patients with NOD would demonstrate evidence of high flow-resistance during bolus passage which in turn would relate to the reporting of bolus hold up perception.

METHODS

Esophageal pressure-impedance recordings of 5 mL liquid and viscous swallows from 18 NOD patients (11 male; 19-71 years) and 17 control subjects (9 male; 25-60 years) were analyzed. The relationship between intrabolus pressure and bolus flow timing in the esophagus was assessed using the pressure flow index (PFI). Bolus perception was assessed swallow by swallow using standardized descriptors.

RESULTS

NOD patients were characterized by a higher PFI than controls. The PFI defined a pressure-flow abnormality in all patients who appeared normal based on the assessment esophageal motor patterns and bolus clearance. The PFI was higher for individual swallows during which subjects reported perception of bolus passage.

CONCLUSION

Bolus flow-resistance is higher in NOD patients compared with controls as well as higher in relation to perception of bolus transit, suggesting the presence of an esophageal motility disorder despite normal findings on conventional analysis.

Upper esophageal sphincter and esophageal motility in patients with chronic cough and reflux: assessment by high-resolution manometry

The pathophysiology of chronic cough and its association with dsymotility and laryngopharyngeal reflux remains unclear. This study applied high-resolution manometry (HRM) to obtain a detailed evaluation of pharyngeal and esophageal motility in chronic cough patients with and without a positive reflux-cough symptom association probability (SAP). Retrospective analysis of 66 consecutive patients referred for investigation of chronic cough was performed. Thirty-four (52%) were eligible for inclusion (age 55 [19-77], 62% female). HRM (ManoScan 360, Given/Sierra Scientific Instruments, Mountain View, CA) with 10 water swallows was performed followed by a 24-hour ambulatory pH monitoring. Of this group, 21 (62%) patients had negative reflux-cough SAP (group A) and 13 (38%) had positive SAP (group B). Results from 23 healthy controls were available for comparison (group C). Detailed analysis revealed considerable heterogeneity. A small number of patients had pathological upper esophageal sphincter (UES) function (n=9) or esophageal dysmotility (n=1). The overall baseline UES pressure was similar, but average UES residual pressure was higher in groups A and B than in control group C (-0.2 and -0.8mmHg vs. -5.4mmHg; P<0.018 and P<0.005). The percentage of primary peristaltic contractions was lower in group B than in groups A and C (56% vs. 79% and 87%; P=0.03 and P<0.002). Additionally, intrabolus pressure at the lower esophageal sphincter was higher in group B than in group C (15.5 vs. 8.9; P=0.024). HRM revealed changes to UES and esophageal motility in patients with chronic cough that are associated with impaired bolus clearance. These changes were most marked in group B patients with a positive reflux-cough symptom association.

Evaluation of esophageal motor function in clinical practice

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

High-resolution manometry correlates of ineffective esophageal motility

OBJECTIVES

There are currently no criteria for ineffective esophageal motility (IEM) and ineffective swallow (IES) in esophageal pressure topography (EPT). Our aims were to use high-resolution manometry metrics to define IEM within the Chicago Classification and to determine the distal contractile integral (DCI) threshold for IES.

METHODS

The EPT of 150 patients with either dysphagia or reflux symptoms were reviewed. Peristaltic function in EPT was defined by the Chicago Classification; the corresponding conventional line tracing (CLT) were reviewed separately. Generalized linear mixed models were used to find thresholds for DCI corresponding to traditionally determined IES and failed swallows. An external validation sample was used to confirm these thresholds.

RESULTS

In terms of swallow subtypes, IES in CLT were a mixture of normal, weak, and failed peristalsis in EPT. A DCI of 450 mm Hg-s-cm was determined to be optimal in predicting IES. In the validation sample, the threshold of 450 mm Hg-s-cm showed strong agreement with CLT determination of IES (positive percent agreement 83%, negative percent agreement 90%). The patient diagnostic level agreement between CLT and EPT was good (78.6% positive percent agreement and 63.9% negative percent agreement), with negative agreement increasing to 92.0% if proximal breaks were excluded.

CONCLUSIONS

The manometric correlate of IEM in EPT is a mixture of failed swallows and weak swallows with breaks in the middle/distal troughs. A DCI value <450 mm Hg-s-cm can be used to predict IES previously defined in CLT. IEM can be defined by >5 swallows with weak/failed peristalsis or with a DCI <450 mm Hg-s-cm.

New insights into pharyngo-esophageal bolus transport revealed by pressure-impedance measurement

BACKGROUND

Pharyngeal propulsion, strength of peristalsis and esophago-gastric junction (EJG) resistance are determinants of esophageal bolus transport. This study used pressure-impedance methods to correlate pharyngo-esophageal function with the esophageal bolus trajectory pathway and pressures generated during bolus transport.

METHODS

Pharyngo-esophageal pressure-impedance measurements were performed in 20 healthy adult controls. Pharyngeal automated impedance manometry (AIM) analysis was performed to derive pharyngeal swallow function variables. The esophageal time of nadir impedance (TZn) was used to track bolus trajectory pathway. The inflection, or flow stasis point (FSP), of the trajectory curve was determined as were the pressures within the bolus (PZn) above and below the FSP. The size of 20 mmHg isocontour defect (20 mmHg IC defect) measured the integrity of the peristaltic wave.

KEY RESULTS

For viscous boluses, weaker pharyngeal bolus propulsion correlated with the FSP being located higher in the esophagus. Pressure within the bolus was observed to increase at the FSP and below the FSP in a manner that correlated with the magnitude of esophageal peak pressures. Larger 20 mmHg IC defects were associated with lower pressures within the bolus at the FSP and below.

CONCLUSIONS & INFERENCES

The FSP of the bolus trajectory pathway appears to represent a switch from bolus propulsion due to pharyngeal mechanisms to bolus propulsion due to esophageal mechanisms. 20 mmHg IC defects significantly reduce bolus driving pressure at or below the FSP.

Anatomy and physiology of the esophageal body

The primary role of the esophagus is to propel swallowed food or fluid into the stomach and to prevent or clear gastroesophageal reflux. This function is achieved by an organized pattern that involves a sensory pathway, neural reflexes, and a motor response that includes esophageal tone, peristalsis, and shortening. The motor function of the esophagus is controlled by highly complex voluntary and involuntary mechanisms. There are three different functional areas in the esophagus: the upper esophageal sphincter, the esophageal body, and the LES. This article focused on anatomy and physiology of the esophageal body.

Analysis of intersegmental trough and proximal latency of smooth muscle contraction using high-resolution esophageal manometry

BACKGROUND AND AIMS

Intersegmental troughs (ISTs) between striated and smooth muscle contraction segments on high-resolution manometry (HRM) have been linked to hypomotility disorders. We investigated the relationship between ISTs, latency of initiation of smooth muscle contraction, and motor patterns in symptomatic patients and normal controls.

METHODS

HRM Clouse plots were analyzed in 199 participants (47.2±1.2 y, 112F/87M), categorized into 110 participants with gastroesophageal reflux disease (GERD), 74 symptomatic participants without GERD, and 15 healthy controls. IST length was measured in centimeters and percentage esophageal length, designated extended when ≥20% esophageal length on >30% swallows. Proximal latency was measured as the time interval between onset of skeletal and smooth muscle contraction segments, and designated prolonged when ≥4s in ≥50% of swallows.

RESULTS

ISTs of any length were noted in 74.6% swallows and in 92.5% of participants, with a similar frequency across the 3 groups. ISTs and proximal latency were both longer in the GERD group, especially when Barrett esophagus was present, compared with non-GERD patients or controls (P≤0.03 across groups); extended IST and prolonged proximal latency followed similar trends. On multivariate logistic regression, extended IST predicted GERD [odds ratio (OR), 2.30; 95% confidence intervals (CI) 1.18-4.47], as did lower esophageal sphincter pressure <5 mm Hg (OR, 3.79-3.96; 95% CI 1.77-8.49), after controlling for age and sex; prolonged proximal latency predicted both GERD (OR, 2.03; 95% CI 1.01-4.12) and Barrett esophagus (OR 1.91, 95% CI 1.24-2.94).

CONCLUSIONS

Measurement of IST and proximal latency add value to HRM analysis, and may be markers of esophageal hypomotility.

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

BACKGROUND

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

PURPOSE

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

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

BACKGROUND

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

METHODS

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

KEY RESULTS

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

CONCLUSIONS & INFERENCES

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

Weak peristalsis in esophageal pressure topography: classification and association with Dysphagia

OBJECTIVES

Esophageal manometry is frequently used to assess for weak peristalsis. Although commonly used clinically, there are currently no validated metrics of weak peristalsis in high-resolution esophageal pressure topography (EPT). This study aimed to develop a classification of weak peristalsis in EPT based on a comparative analysis of control subjects and patients with unexplained non-obstructive dysphagia.

METHODS

High-resolution esophageal pressure topography (high-resolution impedance manometry) studies were carried out in 16 control subjects to verify EPT features associated with incomplete bolus transit (IBT). The technique of superimposing EPT plots in a computer simulation was used to derive normal limits of peristaltic integrity in EPT in another 75 control subjects. The occurrence of critical EPT defects was then compared between control subjects and 113 patients with non-obstructive dysphagia identified from a large clinical series.

RESULTS

IBT occurred with failed peristalsis or with breaks in the 20 mm Hg isobaric contour occurring at the proximal or distal pressure troughs in EPT plots. The normal range for isobaric contour breaks was 0-20% for large (>5 cm) and 0-30% for small (2-5 cm) breaks, with both occurring significantly more frequently in dysphagic patients. Failed peristalsis was not more frequent in dysphagic patients.

CONCLUSIONS

A classification of weak peristalsis adapted to EPT is proposed based on the occurrence of breaks in the 20 mm Hg isobaric contour wherein weak peristalsis with large breaks is defined by those occurring with >20% of swallows and weak peristalsis with small breaks defined by those occurring with >30% of swallows.

High resolution esophageal manometry evaluation in symptomatic patients after gastric banding for morbid obesity

BACKGROUND

Dysphagia and vomiting are frequent after laparoscopic gastric banding (LAGB). These symptoms could be secondary to esophageal motility disorders. Our aim was to assess esophageal motility and clearance in symptomatic LAGB patients using high resolution manometry (HRM).

METHODS

Twenty-two LAGB patients with esophageal symptoms (dysphagia, vomiting, and regurgitations) were included. Esophageal motility was studied using HRM (ManoScan®, Sierra Systems) and classified according to the Chicago classification.

RESULTS

The median delay between surgery and manometry evaluation was 6.3 years (range 1-10). Manometric data were considered as normal in only 2 patients. Achalasia was diagnosed in 3 cases, functional EGJ obstruction in 15, hypotensive peristalsis in 2. During swallowing pan-esophageal pressurization was observed in 6 patients, hiatal hernia pressurization in 7 and gastric pouch pressurization in 2. The intra-bolus pressure was elevated in 18 patients. LAGB was deflated in 6 patients and removed in 12. In 2 patients with unchanged symptoms after LAGB removal motility disorders persisted (1 achalasia, 1 functional EGJ obstruction).

CONCLUSION

In symptomatic LAGB patients, esophageal dysmotility is frequent. High resolution manometry allows the assessment of esophageal clearance and provides guidance for the choice of treatment.

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

BACKGROUND

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

RATIONALE

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

CONCLUSION

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

Gender differences in proximal esophageal contractions

CONTEXT: There are reports showing that gender has an influence on swallowing and on the contractions of the distal esophageal body. OBJECTIVE: In this investigation we studied the effect of gender on proximal esophageal contraction. METHODS: We studied 20 men (22-68 years old, median 39 years) and 44 women (18-61 years old, median 41 years) without symptoms and without gastrointestinal or respiratory diseases. We measured the time interval between the onset of pharyngeal contraction 1 cm proximal to the upper esophageal sphincter and the onset of the proximal esophageal contraction 5 cm from the pharyngeal recording. We also measured the amplitude, duration and area under the curve of the proximal esophageal contractions. The recording was performed by the manometric method with continuous perfusion. The contractions were recorded in duplicate after swallows of a 5 mL bolus of water. RESULTS: There were no differences between men and women in the interval between the onset of pharyngeal and of esophageal contractions or in the amplitude of esophageal contractions. The duration of contractions was longer in women (2.35 ± 0.60 s) than in men (2.07 ± 0.62 s) but the difference did not reach statistical significance (P = 0.087). The area under the curve of the esophageal contraction was higher in women (130.2 ± 55.2 mm Hg x s) than in men (97.4 ± 49.4 mm Hg x s, P = 0.026). CONCLUSION: We conclude that there is a difference between men and women in the proximal esophageal contractions in response to wet swallows, although this difference is of no clinical relevance.

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

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