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Background and Purpose: Establishing normative values of high-resolution esophageal manometry is necessary for accurate interpretation and comparison of measurements. In this systematic review, we aimed to summarize normal values for different esophageal high-resolution manometry systems. Moreover, we assessed the effect of body position, bolus consistency, and provocative maneuvers on these normative thresholds. We searched Medline, Embase, and the Cochrane Library from January 1st, 2006, to January 20th, 2020, for studies that reported normative data of high-resolution manometry in healthy volunteers. We assessed methodological quality of the included studies and planned a descriptive analysis. We analyzed data from 54 articles describing normative thresholds in high-resolution manometry using solid-state or water-perfused systems. Forty-six studies performed the manometry study in the supine position with liquid swallows, whereas sixteen studies described normative values in the upright position. Twelve studies assessed normative values for different bolus consistencies, and nine studies evaluated different provocative maneuvers. There is a considerable variety of normative values for esophageal high-resolution manometry depending on the equipment used and the protocols performed to obtain measurements. This should be taken into account when evaluating measurements in clinical practice and when comparing results of published research studies., (© 2020 John Wiley & Sons Ltd.)

Chicago Classification v4.0 (CCv4.0) is the updated classification scheme for esophageal motility disorders using metrics from high-resolution manometry (HRM). Fifty-two diverse international experts separated into seven working subgroups utilized formal validated methodologies over two-years to develop CCv4.0. Key updates in CCv.4.0 consist of a more rigorous and expansive HRM protocol that incorporates supine and upright test positions as well as provocative testing, a refined definition of esophagogastric junction (EGJ) outflow obstruction (EGJOO), more stringent diagnostic criteria for ineffective esophageal motility and description of baseline EGJ metrics. Further, the CCv4.0 sought to define motility disorder diagnoses as conclusive and inconclusive based on associated symptoms, and findings on provocative testing as well as supportive testing with barium esophagram with tablet and/or functional lumen imaging probe. These changes attempt to minimize ambiguity in prior iterations of Chicago Classification and provide more standardized and rigorous criteria for patterns of disorders of peristalsis and obstruction at the EGJ., (© 2020 John Wiley & Sons Ltd.)

High-resolution manometry revolutionized the assessment of esophageal motility disorders and upgraded the classification through the Chicago Classification. A known disadvantage of standard HRM, however, is the inability to record esophageal motility function for an extended time interval; therefore, it represents only a more snapshot view of esophageal motor function. In contrast, ambulatory esophageal manometry measures esophageal motility over a prolonged period and detects motor activity during the entire circadian cycle. Furthermore, ambulatory manometry has the ability to measure temporal correlations between symptoms and motor events. This article aimed to review the clinical implications of ambulatory esophageal manometry for various symptoms, covering literature on the manometry catheter, interpretation of findings, and relevance in clinical practice specific to the evaluation of non-cardiac chest pain, chronic cough, and rumination syndrome., (© 2020 The Authors. Neurogastroenterology & Motility published by John Wiley & Sons Ltd.)

Background: Esophageal stasis is a hallmark of achalasia. Timed barium esophagogram (TBE) is used to measure stasis but exposes patients to ionizing radiation. It is suggested that esophageal stasis can be objectified on high-resolution manometry (HRM) as well using a rapid drinking challenge test (RDC). We aimed to assess esophageal stasis in achalasia by a RDC during HRM and compare this to TBE., Methods: Thirty healthy subjects (15 male, age 40 [IQR 34-49]) and 90 achalasia patients (53 male, age 47 [36-59], 30 untreated/30 treated symptomatic/30 treated asymptomatic) were prospectively included to undergo HRM with RDC and TBE. RDC was performed by drinking 200 mL of water. Response to RDC was measured by basal and relaxation pressure in the esophagogastric junction (EGJ) and esophageal pressurization during the last 5 seconds., Key Results: EGJ basal and relaxation pressure during RDC were higher in achalasia compared to healthy subjects (overall P < .01). Esophageal body pressurization was significantly higher in untreated (43 [33-35 mm Hg]) and symptomatic treated patients (25 [16-32] mm Hg) compared to healthy subjects (6 [3-7] mm Hg) and asymptomatic treated patients (11 [8-15] mm Hg, overall P < .01). A strong correlation was observed between esophageal pressurization during RDC and barium column height at 5 minutes on TBE (r = .75, P < .01), comparable to the standard predictor of esophageal stasis, IRP (r = .66, P < .01)., Conclusions & Inferences: The RDC can reliably predict esophageal stasis in achalasia and adequately measure treatment response to a degree comparable to TBE. We propose to add this simple test to each HRM study in achalasia patients., (© 2018 The Authors. Neurogastroenterology & Motility Published by John Wiley & Sons Ltd.)

Background: Gastro-esophageal reflux can be the cause of chronic cough. In the assessment of the temporal association between reflux and cough, previous studies have used a two-minute time window, based on studies in patients with heartburn. However, it remains unclear whether the optimal time window duration for the evaluation of reflux-induced cough is two minutes as well. Therefore, we aimed to determine whether a two-minute time window is optimal to diagnose reflux-induced cough., Methods: In this multicenter study, 137 patients with chronic cough were evaluated using 24-h pH-impedance-pressure monitoring. Repetitive symptom association analysis was employed using an array of time windows of various duration. For each time window, the symptom association probability (SAP) and symptom index (SI) were calculated., Key Results: A total of 4377 cough burst episodes and 5074 reflux episodes were detected. The number of patients with a positive SAP increased with increasing window duration until a plateau was reached around a time window duration of 1.5 min. Similarly, the SI increased steeply until a window duration of about 2 min, after which a linear increase was seen., Conclusions and Inferences: A two-minute time window seems appropriate for evaluation of the relationship between reflux and chronic cough using 24-h pH-impedance-pressure monitoring. A time window duration of 30 s or 1 min is too short to diagnose patients with reflux-induced cough accurately., (© 2017 John Wiley & Sons Ltd.)

High-resolution manometry (HRM) and new analysis algorithms, summarized in the Chicago Classification, have led to a restructured classification of oesophageal motility disorders. This advance has led to increased detection of clinically relevant disorders, in particular achalasia. It has become apparent that the cardinal feature of achalasia - impaired lower oesophageal sphincter (LES) relaxation - can occur in several disease phenotypes: without peristalsis (type I), with pan-oesophageal pressurization (type II), with premature (spastic) distal oesophageal contractions (type III), or with preserved peristalsis (outlet obstruction). Furthermore, no manometric pattern is perfectly sensitive or specific for achalasia caused by a myenteric plexopathy, and there is no biomarker for this pathology. Consequently, physiological testing reveals other syndromes not meeting achalasia criteria that also benefit from therapies formerly reserved for achalasia. These findings have become particularly relevant with the development of a minimally invasive technique for performing a long oesophageal myotomy, the per-oral endoscopic myotomy (POEM). Optimal management is to render treatment in a phenotype-specific manner; that is, POEM calibrated to patient-specific physiology for spastic achalasia and the spastic disorders, and more conservative strategies such as pneumatic dilation for the disorders limited to the LES. This Consensus Statement examines the effect of HRM on our understanding of oesophageal motility disorders, with a focus on the diagnosis, epidemiology and management of achalasia and achalasia-like syndromes.

Purpose of Review: High-resolution manometry (HRM) is increasingly performed worldwide, to study esophageal motility. The Chicago classification is subsequently applied to interpret the manometric findings and facilitate a diagnosis of esophageal motility disorders. This review will discuss new insights regarding the diagnosis and management using the Chicago classification., Recent Findings: Recent studies have demonstrated that high-resolution manometry is superior to conventional manometry, and has a higher sensitivity to diagnose achalasia. Furthermore, the subclassification of achalasia as used in the Chicago classification has prognostic value and can be used to direct treatment. Diagnosis of esophageal spasm has been improved by using the distal latency as diagnostic criterion. Recently, criteria for minor disorders of peristalsis have been sharpened, leading to a lower rate of patients with abnormal results, thereby increasing the relevance of a diagnosis. High-resolution manometry is now considered the gold standard for diagnosis of esophageal motility disorders. The Chicago classification provides a standardized approach for analysis and categorization of abnormalities that has led to a significant increase in our knowledge regarding the diagnosis and management of motility disorders. Further refinement of the classification will be required.

Background: Pseudoachalasia is a condition in which clinical and manometric signs of achalasia are mimicked by another abnormality, most often a malignancy., Aim: To identify risk factors that suggest presence of malignancy-associated pseudoachalasia., Methods: In this retrospective cohort study, achalasia patients newly diagnosed by manometry were included. Patients with a normal initial endoscopy, clinical and manometric signs of achalasia who were afterwards found to have an underlying malignant cause were classified as pseudoachalasia. Clinical and diagnostic findings were compared between malignant pseudoachalasia and achalasia., Results: We included 333 achalasia patients [180 male, median age 50 (38-62)]. Malignant pseudoachalasia was diagnosed in 18 patients (5.4%). Patients with malignancy-associated pseudoachalasia were older at time of diagnosis [67 (54-71) vs. 49 (37-60) years], had a shorter duration of symptoms [6 (5-10) vs. 25 (11-60) months] and lost more weight [12 (9-17) vs. 5 (0-12) kg). In 61% of the pseudoachalasia patients, the oesophagogastric junction (OGJ) was difficult or impossible to pass during endoscopy, compared to 23% in achalasia. Age ≥55 years (OR 5.93), duration of symptoms ≤12 months (OR 14.5), weight loss ≥10 kg (OR 6.73) and difficulty passing the OGJ during endoscopy (OR 6.06) were associated with a higher risk of malignant pseudoachalasia., Conclusions: Advanced age, short duration of symptoms, considerable weight loss and difficulty in passing the OGJ during endoscopy, are risk factors that suggest potential malignancy-associated pseudoachalasia. To exclude pseudoachalasia, additional investigations are warranted when two or more risk factors are present., (© 2017 John Wiley & Sons Ltd.)

Background: Rumination syndrome is characterized by recurrent regurgitation of recently ingested food into the mouth. Differentiation with other diagnoses and gastroesophageal reflux disease (GERD) in particular, is difficult. Recently, objective pH-impedance (pH-MII) and manometry criteria were proposed for adults. The aim of this study was to determine diagnostic ambulatory pH-MII and manometry criteria for rumination syndrome in children., Methods: Clinical data and 24-hour pH-MII and manometry recordings of children with a clinical suspicion of rumination syndrome were reviewed. Recordings were analyzed for retrograde bolus flow extending into the proximal esophagus. Peak gastric and intraesophageal pressures closely related to these events were recorded and checked for a pattern compatible with rumination. Events were classified into primary, secondary, and supragastric belch-associated rumination., Key Results: Twenty-five consecutive patients (11 males, median age 13.3 years [IQR 5.9-15.8]) were included; recordings of 18 patients were suitable for analysis. Rumination events were identified in 16/18 patients, with 50% of events occurring <30 minutes postprandially. Fifteen of 16 patients showed ≥1 gastric pressure peak >30 mmHg, while only 50% of all events was characterized by peaks >30 mmHg and an additional 20% by peaks >25 mmHg. Four patients had evidence of acid GERD, all showing secondary rumination., Conclusions and Inferences: Combined 24-hour pH-MII and manometry can be used to diagnose rumination syndrome in children and to distinguish it from GERD. Rumination patterns in children are similar compared with adults, albeit with lower gastric pressure increase. We propose a diagnostic cutoff for gastric pressure increase >25 mmHg associated with retrograde bolus flow into the proximal esophagus., (© 2017 John Wiley & Sons Ltd.)

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., (© 2016 John Wiley & Sons Ltd.)

Background: Manometric criteria to diagnose achalasia are absent peristalsis and incomplete relaxation of the esophagogastric junction (EGJ), determined by an integrated relaxation pressure (IRP) >15 mm Hg. However, EGJ relaxation seems normal in a subgroup of patients with typical symptoms of achalasia, no endoscopic abnormalities, stasis on timed barium esophagogram (TBE), and absent peristalsis on high-resolution manometry (HRM). The aim of our study was to further characterize these patients by measuring EGJ distensibility and assessing the effect of achalasia treatment., Methods: Impedance planimetry (EndoFLIP) was used to measure EGJ distensibility and compared to previous established data of 15 healthy subjects. In case the EGJ distensibility was impaired, achalasia treatment followed. Eckardt score, HRM, TBE, and EGJ distensibility measurements were repeated >3 months after treatment., Key Results: We included 13 patients (5 male; age 19-59 years) with typical symptoms of achalasia, Eckardt score of 7 (5-7). High-resolution manometry showed absent peristalsis with low basal EGJ pressure of 10 (5.8-12.9) mm Hg and IRP of 9.3 (6.1-12) mm Hg. Esophageal stasis was 4.6 (2.7-6.9) cm after 5 minutes. Esophagogastric junction distensibility was significantly reduced in patients compared to healthy subjects (0.8 [0.7-1.2] mm 2 /mm Hg vs 6.3 [3.8-8.7] mm 2 /mm Hg). Treatment significantly improved the Eckardt score (7 [5-7] to 2 [1-3.5]) and EGJ distensibility (0.8 [0.7-1.2] mm 2 /mm Hg to 3.5 [1.5-6.1] mm 2 /mm Hg)., Conclusions & Inferences: A subgroup of patients with clinical and radiological features of achalasia but manometrically normal EGJ relaxation has an impaired EGJ distensibility and responds favorably to achalasia treatment. Our data suggest that this condition can be considered as achalasia and treated as such., (© 2016 John Wiley & Sons Ltd.)

High-resolution esophageal manometry (HRM) is a recent development used in the evaluation of esophageal function. Our aim was to assess the inter-observer agreement for diagnosis of esophageal motility disorders using this technology. Practitioners registered on the HRM Working Group website were invited to review and classify (i) 147 individual water swallows and (ii) 40 diagnostic studies comprising 10 swallows using a drop-down menu that followed the Chicago Classification system. Data were presented using a standardized format with pressure contours without a summary of HRM metrics. The sequence of swallows was fixed for each user but randomized between users to avoid sequence bias. Participants were blinded to other entries. (i) Individual swallows were assessed by 18 practitioners (13 institutions). Consensus agreement (≤ 2/18 dissenters) was present for most cases of normal peristalsis and achalasia but not for cases of peristaltic dysmotility. (ii) Diagnostic studies were assessed by 36 practitioners (28 institutions). Overall inter-observer agreement was 'moderate' (kappa 0.51) being 'substantial' (kappa > 0.7) for achalasia type I/II and no lower than 'fair-moderate' (kappa >0.34) for any diagnosis. Overall agreement was somewhat higher among those that had performed >400 studies (n = 9; kappa 0.55) and 'substantial' among experts involved in development of the Chicago Classification system (n = 4; kappa 0.66). This prospective, randomized, and blinded study reports an acceptable level of inter-observer agreement for HRM diagnoses across the full spectrum of esophageal motility disorders for a large group of clinicians working in a range of medical institutions. Suboptimal agreement for diagnosis of peristaltic motility disorders highlights contribution of objective HRM metrics., (© 2014 International Society for Diseases of the Esophagus.)

Objectives: Enhanced characterization of esophageal peristaltic and sphincter function provided by esophageal pressure topography (EPT) offers a potential diagnostic advantage over conventional line tracings (CLT). However, high-resolution manometry (HRM) and EPT require increased equipment costs over conventional systems and evidence demonstrating a significant diagnostic advantage of EPT over CLT is limited. Our aim was to investigate whether the inter-rater agreement and/or accuracy of esophageal motility diagnosis differed between EPT and CLT., Methods: Forty previously completed patient HRM studies were selected for analysis using a customized software program developed to perform blinded independent interpretation in either EPT or CLT (six pressure sensors) format. Six experienced gastroenterologists with a clinical focus in esophageal disease (attendings) and six gastroenterology trainees with minimal manometry experience (fellows) from three academic centers interpreted each of the 40 studies using both EPT and CLT formats. Rater diagnoses were assessed for inter-rater agreement and diagnostic accuracy, both for exact diagnosis and for correct identification of a major esophageal motility disorder., Results: The total group agreement was moderate (κ=0.57; 95% CI: 0.56-0.59) for EPT and fair (κ=0.32; 0.30-0.33) for CLT. Inter-rater agreement between attendings was good (κ=0.68; 0.65-0.71) for EPT and moderate (κ=0.46; 0.43-0.50) for CLT. Inter-rater agreement between fellows was moderate (κ=0.48; 0.45-0.50) for EPT and poor to fair (κ=0.20; 0.17-0.24) for CLT. Among all raters, the odds of an incorrect exact esophageal motility diagnosis were 3.3 times higher with CLT assessment than with EPT (OR: 3.3; 95% CI: 2.4-4.5; P<0.0001), and the odds of incorrect identification of a major motility disorder were 3.4 times higher with CLT than with EPT (OR: 3.4; 2.4-5.0; P<0.0001)., Conclusions: Superior inter-rater agreement and diagnostic accuracy of esophageal motility diagnoses were demonstrated with analysis using EPT over CLT among our selected raters. On the basis of these findings, EPT may be the preferred assessment modality of esophageal motility.

Background: Using conventional manometry, gastro-esophageal reflux disease (GERD) was associated with a reduced lower esophageal sphincter (LES) pressure and impaired peristalsis. However, with a large overlap between GERD patients and controls, these findings are of limited clinical relevance. It is uncertain whether the more detailed information of high-resolution manometry (HRM) can discriminate GERD patients. Therefore, we aimed to determine to which extent HRM findings can predict GERD., Methods: HRM measurements in 69 patients with GERD and 40 healthy subjects were compared and the predictive value of HRM for the diagnosis of GERD was explored., Key Results: GERD patients had a significantly lower contraction amplitude (55 vs 64 mmHg; p = 0.045) and basal LES pressure (10 vs 13.2 mmHg; p = 0.034) than healthy controls. GERD patients more often had a hiatal hernia than healthy subjects (30% vs 7%; p = 0.005). Patients with reflux esophagitis had a lower DCI than patients without reflux esophagitis (558 vs 782 mmHg cm s; p = 0.045). No significant difference was seen in contractile front velocity, distal latency, number of peristaltic breaks, residual LES pressure and LES length. On multivariate logistic regression analysis, both esophagogastric junction type I (OR 4.971; 95% CI 1.33-18.59; p = 0.017) and mean wave amplitude (OR 0.95; 95% CI 0.90-0.98; p = 0.013) were found to be independent predictors of GERD. However, the sensitivity and specificity of these findings were low., Conclusions & Inferences: Hiatal hernia, low contraction amplitude and LES pressure are associated with GERD, but do not predict the disease with sufficient accuracy. Routine esophageal HRM can therefore not be used to distinguish GERD patients from healthy subjects., (© 2015 John Wiley & Sons Ltd.)

Background: Esophageal high-resolution manometry (HRM) has rapidly gained much popularity worldwide. The Chicago Classification for esophageal motility disorders is based on a set of normative values for key metrics that was obtained using one of the commercially available HRM systems. Thus, it is of great importance to evaluate whether these normative values can be used for other HRM systems as well., Purpose: In this review, we describe the presently available HRM systems, the currently known normative thresholds and the factors that influence them, and assess the use of these thresholds. Numerous factors including the type of HRM system, demographic factors, catheter diameter, body position during testing, consistency of bolus swallows, and esophageal length have an influence on the normative data. It would thus be ideal to have different sets of normal values for each of these factors, yet at the moment the amount of normative data is limited. We suggest broadening the normal range for parameters, as this would allow abnormal values to be of more significance. In addition, we suggest conducting studies to assess the physiological relevance of abnormal values and stress that for each system different normative thresholds may apply., (© 2014 John Wiley & Sons Ltd.)

Background: The Chicago Classification (CC) of esophageal motility disorders, utilizing an algorithmic scheme to analyze clinical high-resolution manometry (HRM) studies, has gained acceptance worldwide., Methods: This 2014 update, CC v3.0, developed by the International HRM Working Group, incorporated the extensive clinical experience and interval publications since the prior (2011) version., Key Results: Chicago Classification v3.0 utilizes a hierarchical approach, sequentially prioritizing: (i) disorders of esophagogastric junction (EGJ) outflow (achalasia subtypes I-III and EGJ outflow obstruction), (ii) major disorders of peristalsis (absent contractility, distal esophageal spasm, hypercontractile esophagus), and (iii) minor disorders of peristalsis characterized by impaired bolus transit. EGJ morphology, characterized by the degree of overlap between the lower esophageal sphincter and the crural diaphragm and baseline EGJ contractility are also part of CC v3.0. Compared to the previous CC version, the key metrics of interpretation, the integrated relaxation pressure (IRP), the distal contractile integral (DCI), and the distal latency (DL) remain unchanged, albeit with much more emphasis on DCI for defining both hypo- and hypercontractility. New in CC v3.0 are: (i) the evaluation of the EGJ at rest defined in terms of morphology and contractility, (ii) 'fragmented' contractions (large breaks in the 20-mmHg isobaric contour), (iii) ineffective esophageal motility (IEM), and (iv) several minor adjustments in nomenclature and defining criteria. Absent in CC v3.0 are contractile front velocity and small breaks in the 20-mmHg isobaric contour as defining characteristics., Conclusions & Inferences: Chicago Classification v3.0 is an updated analysis scheme for clinical esophageal HRM recordings developed by the International HRM Working Group., (© 2014 John Wiley & Sons Ltd.)

Background: The diagnosis of a sliding hiatal hernia is classically made with endoscopy or barium esophagogram. Spatial separation of the lower esophageal sphincter (LES) and diaphragm, the hallmark of hiatal hernia, can also be observed on high-resolution manometry (HRM), but the diagnostic accuracy of this finding has not yet been investigated. To determine the diagnostic value of HRM in the detection of hiatal hernia., Methods: HRM recordings, endoscopy reports, and barium esophagograms of 90 patients were analyzed for the presence and size of a hiatal hernia. The diagnostic value of a hernia specific HRM pressure pattern was calculated, and the agreement of HRM with endoscopy and barium esophagogram for the assessment of hernia size., Key Results: HRM was found to be highly sensitive and specific for hiatal hernia detection, with a sensitivity of 92% and specificity of 95%, exceeding the sensitivity of endoscopy or radiography alone (both 73%). Patients with a hiatal hernia on HRM were manometrically characterized by an esophagogastric junction (EGJ) with partial or complete separation of the LES and crural diaphragm (CD), the latter being associated with significantly lower EGJ pressure. A cutoff value of spatial LES-CD separation on HRM of 1.85 cm yielded the optimal performance in identifying hiatal hernia. Agreement between HRM, endoscopy, and radiography for size of hiatal hernias was good (ICC [95% CI] 0.74 [0.65-0.82])., Conclusions & Inferences: With HRM, the presence or absence and size of a hiatal hernia can be assessed with greater sensitivity than with endoscopy or radiography alone., (© 2015 John Wiley & Sons Ltd.)

Background: The Chicago classification for esophageal motility disorders was designed for a 36-channel manometry system with sensors spaced at 1 cm. However, many motility laboratories outside the USA use catheters with a lower resolution in the segments outside the esophagogastric junction. Our aim was to investigate the effect of spatial resolution on the Chicago metrics and diagnosis., Methods: In 20 healthy volunteers and 47 patients with upper gastrointestinal symptoms, high-resolution manometric studies of the esophagus were retrospectively reanalyzed using the original 1-cm spacing in the segments outside the 7-cm esophagogastric junction segment, and again after manually increasing the spacing between sensors to 2, 3, and 4 cm (above the lower esophageal sphincter region). Measurements were analyzed in random order and the investigator was blinded to the outcome of the analyses performed in another resolution of the same patient. Intra-class correlation coefficients (ICC) and Kappa values were determined., Key Results: There was a very strong correlation between the 1-cm and 2-cm analysis for all Chicago metrics studied in healthy volunteers (ICCs: distal contractile integral 0.998; contractile front velocity (CFV) 0.964; distal latency 0.919; peristaltic break size 0.941). The 2-cm spacing analysis also correlated very well with the 1-cm analysis for the different Chicago diagnoses obtained in the patients (Kappa values ranging from 0.665 to 1.000). When the sensor spacing was increased to 3 and 4 cm, the correlation was reduced to moderate for the Chicago metrics, especially for break size and CFV of peristalsis., Conclusions & Inferences: The Chicago classification for esophageal motility disorders is still valid and the same normal values can be used when catheters with a slightly lower resolution are used (i.e., 2-cm vs 1-cm spacing). For larger sensor intervals, the classification and the normal values will need to be adjusted., (© 2014 John Wiley & Sons Ltd.)

Background: Esophageal high-resolution manometry (HRM) allows accurate evaluation of esophageal motility. Normal values for HRM were established in the United States and several new parameters were introduced since. We aimed to provide a complete set of normal values for HRM obtained in a European population, including all current metrics used to describe the function of the upper esophageal sphincter (UES), the esophageal body, and the esophagogastric junction (EGJ)., Methods: Fifty healthy volunteers underwent esophageal HRM. Subjects swallowed 10 liquid boluses in supine position, after which UES, EGJ, and contraction wave parameters were evaluated. Mean and median values with 5-95th percentile ranges were calculated., Key Results: The normative thresholds (5-95th percentile) for the various parameters were; UES resting pressure 34.6-137.7 mmHg, UES residual pressure 0.0-8.5 mmHg, UES 0.2-s integrated relaxation pressure (IRP) 0.0-14.5 mmHg, EGJ length 3.1-6.3 cm, EGJ resting pressure 3.0-31.2 mmHg, EGJ 4-s IRP 2.0-15.5 mmHg, intrabolus pressure (IBP) 6.6-19.5 mmHg, distal contractile integral 178-2828 mmHg*s*cm, contractile front velocity (CFV) 2.9-5.9 cm s(-1) , distal latency 5.4-8.5 s, and transition zone length 0.0-8.2 cm., Conclusions & Inferences: Most HRM parameters assessed in this study resemble the previously described values on which the current criteria are based, supporting the widespread use of these criteria for clinical purposes. However, vigor of the esophageal contraction was lower and transition zone length larger than in previous reports. Peristaltic breaks occur frequently in healthy subjects., (© 2014 John Wiley & Sons Ltd.)

Water-perfused high-resolution manometry (HRM) catheters with 36 unidirectional pressure channels have recently been developed, but normal values are not yet available. Furthermore, the technique has not been validated and compared with solid-state HRM. We therefore aimed to develop normal values for water-perfused HRM and to assess the level of agreement between water-perfused HRM and solid-state HRM. We included 50 healthy volunteers (mean age 35 yr, range 21-64 yr; 15 women, 35 men). Water-perfused HRM and solid-state HRM were performed in a randomized order. Normal values were calculated as 5th and 95th percentile ranges, and agreement between the two systems was assessed with intraclass correlation coefficient (ICC) statistics. The 5th-95th percentile range was 3.0-6.6 cm/s for contractile front velocity (CFV), 141.6-3,674 mmHg·s·cm for distal contractile integral (DCI), 6.2-8.7 s for distal contraction latency (DL), and 1.0-18.8 mmHg for integrated relaxation pressure (IRP 4s). Mean (SD) and ICC for water-perfused HRM and solid-state HRM were 4.4 (1.1) vs. 3.9 (0.9) cm/s, ICC: 0.49 for CFV; 1,189 (1,023) vs. 1,092 (1,019) mmHg·s·cm, ICC: 0.90 for DCI; 7.4 (0.8) vs. 6.9 (0.9) s, ICC: 0.50 for DL; and 8.1 (4.8) vs. 7.9 (5.1), ICC: 0.39 for IRP 4s. The normal values for this water-perfused HRM system are only slightly different from previously published values with solid-state HRM, and moderate to good agreement was observed between the two systems, with only small differences in outcome measures.

Background: Esophageal high-resolution manometry (HRM) is a novel method to assess esophageal motility. Several software and hardware systems are currently available. A set of normal values for HRM parameters was established in the US, using proprietary tactile-sensing catheter technology (Given Imaging). We wished to determine normal values for HRM performed with another type of catheter (Unisensor)., Methods: Fifty-two healthy volunteers underwent supine HRM. Each subject swallowed 10 liquid water boluses. Esophageal contraction parameters were evaluated and normal values were calculated (defined as 5th and 95th percentile of values)., Key Results: The normal range for the following parameters was calculated; distal contractile integral (mean 1319.44, with a 5-95th percentile range [185.65-3407.60]), contractile front velocity (mean 3.98, 5-95th percentile range [2.40-6.50]), Intrabolus pressure (mean 9.68, range [1.00-19.00]), contraction amplitude measured 5 cm above the esophagogastric junction (EGJ; mean 78.76, range [23.00-146.00]), contraction amplitude 15 cm above the EGJ (mean 43.66, range [3.60-96.00]), transition zone (TZ) length (mean 1.34, range [0.00-5.63]), upper esophageal sphincter (UES) pressure (mean 81.63, range [19.50-165.10]), EGJ length (mean 2.97, range [2.17-4.00]), EGJ resting pressure (mean 29.35, range [8.95-51.40]), EGJ relaxation pressure (mean 16.79, range [1.00-39.35]), IRPs4 (mean 13.42, range [2.59-28.28]), and gastric pressure (mean 5.06, range [0.00-9.46])., Conclusions & Inferences: Overall, the normal values of esophageal HRM parameters obtained with the Unisensor catheter resemble those of the previously published series. Marked differences in upper limits of normal were found for parameters related to the esophageal sphincters and TZ length. Users of HRM should be aware of these differences and define pathology based on comparison to appropriate normal values., (© 2013 John Wiley & Sons Ltd.)

Disorders of gastrointestinal motility are frequently seen in clinical practice. Apart from motility disorders, factors leading to lowered visceroperception thresholds are recognized as commonly involved in the pathogenesis of functional gastrointestinal disorders. The wide array of gastrointestinal motility and viscerosensitivity tests available is in contrast with the relatively limited number of tests used universally in clinical practice. The main reason for this discrepancy is that the outcome of a test only becomes truly important when it carries clinical consequences. The main goal of this Review is to assess the place of the presently available gastrointestinal motility and sensitivity tests in the clinical armamentarium of the gastroenterologist.

Background: Non-obstructive dysphagia patients prove to be a difficult category for clinical management. Esophageal high-resolution manometry (HRM) is a novel method, used to analyze dysphagia. However, it is not yet clear how findings on HRM relate to bolus transport through the esophagus., Methods: Twenty healthy volunteers and 20 patients with dysphagia underwent HRM and videofluoroscopy in a supine position. Each subject swallowed five liquid and five solid barium boluses. Esophageal contraction parameters and bolus transport were evaluated with HRM and concurrent videofluoroscopy., Key Results: Stasis of liquid and solid barium boluses occurred in patients and in healthy volunteers in 64% and 41% and in 84% and 82% of the swallows, respectively. Overall, 70% of the liquid and 72% of the solid bolus swallows were followed by a peristaltic contraction, the difference not being statistically significant. Statistically significant associations were found for transition zone length of liquid and solid boluses, and for DCI and distal contraction amplitudes for liquid stasis. No correlation was found between the degree of stasis and other manometric parameters., Conclusions & Inferences: Stasis of both liquid and solid boluses occurs frequently in patients and in controls and can be regarded as physiological. Motility patterns can predict the effectiveness of bolus transit and level of stasis to some degree but the relationship between esophageal motility and transit is complex and far from perfect. Esophageal manometry is therefore currently deemed unfit to be used for the prediction of bolus transit, and should rather be used for the identification of treatable esophageal motility disorders., (© 2012 Blackwell Publishing Ltd.)

Esophageal impedance monitoring and high-resolution manometry (HRM) are useful tools in the diagnostic work-up of patients with upper gastrointestinal complaints. Impedance monitoring increases the diagnostic yield for gastroesophageal reflux disease in adults and children and has become the gold standard in the diagnostic work-up of reflux symptoms. Its role in the work-up for belching disorders and rumination seems promising. HRM is superior to other diagnostic tools for the evaluation of achalasia and contributes to a more specific classification of esophageal disorders in patients with non-obstructive dysphagia. The role of HRM in patients with dysphagia after laparoscopic placement of an adjustable gastric band seems promising. Future studies will further determine the clinical implications of the new insights which have been acquired with these techniques. This review aims to describe the clinical applications of impedance monitoring and HRM.

Background: A number of commercial and research systems are available for making high-resolution manometry recordings. purpose: In this document, we review the standard equipment, patient preparation and routine protocol for high-resolution manometry. The major differences between HRM systems lie in the method of signal transduction, with solid-state catheter systems recording form intraluminal transducers and water perfusion systems recording pressures from external transducers via a perfused silicone catheter. The variations in recording systems result in different mechanical and electrical characteristics which dictate different techniques for setting up and using equipment. These issues are relevant in terms of costs and day to day management, but have little clinical significance. After the equipment is prepared for a manometric study, the esophagus is intubated transnasally with the manometric catheter and the catheter is positioned so that the UES and LES/diaphragm are visualized on the recording screen. The subject then undergoes 10 5 ml water swallows in the supine position. Manometric data may be integrated with other data streams such as multichannel impedance or images from fluoroscopy to increase the power of the technique in difficult cases., (© 2012 Blackwell Publishing Ltd.)

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., (© 2012 Blackwell Publishing Ltd.)

Background:   Esophageal high-resolution manometry (HRM) is a novel method for esophageal function testing that has prompted the development of new parameters for quantitative analysis of esophageal function. Until now, the reproducibility of these parameters has not been investigated., Methods: Twenty healthy volunteers underwent HRM on two separate days. Standard HRM parameters were measured. In addition, in conventional (virtual) line tracings, lower esophageal sphincter (LES) resting pressure, relaxation pressure, and relative relaxation pressure were measured. Firstly, for each variable, the mean percentage of covariation (100×SD/mean: %COV) was derived as a measure of inter- and intra-individual variation. Secondly, Kendall's coefficients of concordance (W values) were calculated. Thirdly, Bland-Altman plots were used to express concordance graphically., Key Results: Statistically significant concordance values were found for upper esophageal sphincter (UES) pressure (W=0.90, P=0.02), transition zone length (W=0.92, P=0.01), LES length (W=0.81, P=0.04), LES pressure (W=0.75, P=0.05), LES relaxation pressure (W=0.75, P=0.03), relative LES relaxation pressure (W=0.78, P=0.05), gastric pressure (W=0.81, P=0.04), and contraction amplitude 5cm above the LES (W=0.86, P=0.03). In conventional setting, only LES resting pressure (W=0.835, P=0.03) proved significant. In HRM tracings, concordance values for contraction wave parameters, and in conventional line tracings, LES relaxation pressure and relative relaxation pressure did not reach levels of statistical significance., Conclusions & Inferences: Esophageal HRM yields reproducible results. Parameters that represent anatomic structures show better reproducibility than contraction wave parameters. The reproducibility of LES resting and relaxation pressure assessed with HRM is better than with conventional manometry and further supports the clinical use of HRM., (© 2011 Blackwell Publishing Ltd.)

High-resolution manometry capable of pressure monitoring from the pharynx to the stomach together with pressure topography plotting represents an unquestionable evolution in oesophageal manometry. However, with this advanced technology come challenges and one of those is devising the optimal scheme to apply high-resolution oesophageal pressure topography (HROPT) to the clinical evaluation of patients. The first iteration of the Chicago classification was based on a systematic analysis of motility patterns in 75 control subjects and 400 consecutive patients. This review summarizes the analysis process as it has evolved. Individual swallows are analysed in a stepwise fashion for the morphology of the oesophagogastric junction (OGJ), the extent of OGJ relaxation, the propagation velocity of peristalsis, the vigour of the peristaltic contraction, and abnormalities of intrabolus pressure utilizing metrics that have now been customized to HROPT. These results are then synthesized into a comprehensive diagnosis that, although based on conventional manometry criteria, is also customized to HROPT measures. The resultant classification objectifies the identification of three unique subtypes of achalasia. Additionally, it provides enhanced detail in the description of distal oesophageal spasm, nutcracker oesophagus subtypes, and OGJ obstruction. It is our expectation that modification of this classification scheme will continue to occur and this should further clarify the utility of pressure topography plotting in assessing oesophageal motility disorders.

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

Manometry measures pressure within the oesophageal lumen and sphincters, and provides an assessment of the neuromuscular activity that dictates function in health and disease. It is performed to investigate the cause of functional dysphagia, unexplained "non-cardiac" chest pain, and in the pre-operative work-up of patients referred for anti-reflux surgery. Manometric techniques have improved in a step-wise fashion from a single pressure channel to the development of high-resolution manometry (HRM) with up to 36 pressure sensors. At the same time, advances in computer processing allow pressure data to be presented in real time as a compact, visually intuitive "spatiotemporal plot" of oesophageal pressure activity. HRM recordings reveal the complex functional anatomy of the oesophagus and its sphincters. Spatiotemporal plots provide objective measurements of the forces that move food and fluid from the pharynx to the stomach and determine the risk of reflux events. The introduction of commercially available HRM has been followed by rapid uptake of the technique. This review examines the current evidence that supports the move of HRM from the research setting into clinical practice. It is assessed whether a detailed description of pressure activity identifies clinically relevant oesophageal dysfunction that is missed by conventional investigation, increasing diagnostic yield and accuracy. The need for a new classification system for oesophageal motor activity based on HRM recordings is discussed. Looking ahead the potential of this technology to guide more effective medical and surgical treatment of oesophageal disease is considered because, ultimately, it is this that will define the success of HRM in clinical practice.

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

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

The manometric common cavity phenomenon has been used as indicator of gastro-oesophageal reflux of liquid or gaseous substances. Using combined pH and impedance recording as reference standard the value of a common cavity as indicator of gastro-oesophageal reflux was tested. Ten healthy male subjects underwent combined stationary pressure, pH and impedance recording for 4.5 h. After 1.15 h of recording, a reflux-eliciting meal was consumed. The chi-squared and Kolmogorov-Smirnov tests were used for the statistical analysis. A common cavity was found in 95 (43%) of the 223 reflux events detected by impedance, while seven common cavities were unrelated to a reflux episode. In 54% of the reflux events detected by impedance without a common cavity, a possible common cavity was obscured by either contractile activity or artefacts of various origin. The types of reflux associated with a common cavity (liquid 60%, mixed 31%, gas 9%) and without a common cavity (liquid 59%, mixed 29%, gas 12%) did not differ, or did the acidity of the reflux episodes (with common cavity: acid 67%; without common cavity: acid 58%). The common cavity is a specific but not a sensitive marker of gastro-oesophageal reflux. Furthermore, common cavities are not specific for a particular type of reflux.

The lower esophageal high-pressure zone (HPZ) consists of the intrinsic lower esophageal sphincter (LES) and the diaphragmatic sphincter. In patients with a hiatal hernia these constituents are separated. We performed high-resolution manometry of the esophagogastric HPZ in six controls, six patients with a small hernia, and six patients with a large hernia. Prevalence of a double-peak pressure profile of the HPZ was noted. Pressures and distances between the peaks were assessed. Prevalence of the double-peak profile was similar between patients with a small hernia and controls, but patients with a large hernia showed a higher prevalence with inspiration (P < 0.05) than the others. The distance between the two peaks was larger in patients with a large hernia (P < 0.05). In conclusion, high-resolution manometry makes it possible to distinguish the diaphragmatic pressure component from the LES. Two pressure peaks can be found both in hernia patients and in healthy volunteers.