Inter-observer agreement for diagnostic classification of esophageal motility disorders defined in high-resolution manometry

Interrater Reliability of Functional Lumen Imaging Probe Panometry and High-Resolution Manometry for the Assessment of Esophageal Motility Disorders

INTRODUCTION

High-resolution manometry (HRM) and functional lumen imaging probe (FLIP) are primary and/or complementary diagnostic tools for the evaluation of esophageal motility. We aimed to assess the interrater agreement and accuracy of HRM and FLIP interpretations.

METHODS

Esophageal motility specialists from multiple institutions completed the interpretation of 40 consecutive HRM and 40 FLIP studies. Interrater agreement was assessed using intraclass correlation coefficient (ICC) for continuous variables and Fleiss' κ statistics for nominal variables. Accuracies of rater interpretation were assessed using the consensus of 3 experienced raters as the reference standard.

RESULTS

Fifteen raters completed the HRM and FLIP studies. An excellent interrater agreement was seen in supine median integral relaxation pressure (ICC 0.96, 95% confidence interval 0.95-0.98), and a good agreement was seen with the assessment of esophagogastric junction (EGJ) outflow, peristalsis, and assignment of a Chicago Classification version 4.0 diagnosis using HRM (κ = 0.71, 0.75, and 0.70, respectively). An excellent interrater agreement for EGJ distensibility index and maximum diameter (0.91 [0.90-0.94], 0.92 [0.89-0.95]) was seen, and a moderate-to-good agreement was seen in the assignment of EGJ opening classification, contractile response pattern, and motility classification (κ = 0.68, 0.56, and 0.59, respectively) on FLIP. Rater accuracy for Chicago Classification version 4.0 diagnosis on HRM was 82% (95% confidence interval 78%-84%) and for motility diagnosis on FLIP Panometry was 78% (95% confidence interval 72%-81%).

DISCUSSION

Our study demonstrates high levels of interrater agreement and accuracy in the interpretation of HRM and FLIP metrics and moderate-to-high levels for motility classification in FLIP, supporting the use of these approaches for primary or complementary evaluation of esophageal motility disorders.

A Short History of High-Resolution Esophageal Manometry

High-resolution esophageal manometry (HRM) utilizes sufficient pressure sensors such that intraluminal pressure is monitored as a continuum along luminal length, similar to time viewed as a continuum on polygraph tracings in 'conventional' manometry. When HRM is coupled with pressure topography plotting, and pressure amplitude is transformed into spectral colors with isobaric areas indicated by same-colored regions, "Clouse plots" are generated. HRM has several advantages compared to the technology that it replaced: (1) the contractility of the entire esophagus can be viewed simultaneously in a uniform standardized format, (2) standardized objective metrics of peristaltic and sphincter function can be systematically applied for interpretation, and (3) topographic patterns of contractility are more easily recognized with greater reproducibility. Leveraging these advantages led to the current standard for the interpretation of clinical esophageal HRM studies, the Chicago Classification (CC), now in its fourth iteration. Compared to conventional manometry, HRM has vastly improved the sensitivity for detecting achalasia, largely due to the objectivity and accuracy of identification of impaired esophagogastric junction (EGJ) relaxation. Additionally, it has led to the subcategorization of achalasia into three clinically relevant subtypes, differentiated by the contractile function of the esophageal body, and identified an additional disorder of EGJ outflow obstruction wherein esophageal peristalsis is preserved. Headway has also been made in understanding hypocontractile and hypercontractile conditions. In summary, HRM and the CC process have revolutionized our understanding of esophageal motility and motility disorders. Moving forward, there will always be remaining challenges, but we now have the tools to meet them.

Achalasia: investigation and management

Achalasia, characterised by the absence of peristalsis and failure of relaxation of the lower oesophageal sphincter, is an uncommon degenerative condition that results in dysphagia. If left untreated it can lead to aspiration, oesophageal perforation, oesophagitis and malnutrition. It has a range of immune, allergic, viral and genetic aetiological causes. Successful diagnosis relies on the use of oesophagogastroduodenoscopy, barium swallow and oesophageal manometry to characterise the severity of the disease and to rule out underlying malignancy. Although no treatment can reverse the degenerative process, therapeutic strategies including lifestyle modification, medication, endoscopic and operative intervention can help to reduce symptoms. This article reviews the latest methods used to investigate and manage achalasia.

Automated Chicago Classification for Esophageal Motility Disorder Diagnosis Using Machine Learning

The goal of this paper is to provide a Machine Learning-based solution that can be utilized to automate the Chicago Classification algorithm, the state-of-the-art scheme for esophageal motility disease identification. First, the photos were preprocessed by locating the area of interest—the precise instant of swallowing. After resizing and rescaling the photos, they were utilized as input for the Deep Learning models. The InceptionV3 Deep Learning model was used to identify the precise class of the IRP. We used the DenseNet201 CNN architecture to classify the images into 5 different classes of swallowing disorders. Finally, we combined the results of the two trained ML models to automate the Chicago Classification algorithm. With this solution we obtained a top-1 accuracy and f1-score of 86% with no human intervention, automating the whole flow, from image preprocessing until Chicago classification and diagnosis.

Esophageal motility abnormalities in Egyptian patients using high resolution esophageal manometry: a descriptive study

Background and aim

For many years, esophageal manometry has been used for assessment of upper gastro-intestinal (GI) symptoms. Chicago classification is the key for diagnosis and managing motility disorders as it is considered as a standardized approach for categorization of esophageal abnormalities. The aim of this study is to analyze types of esophageal motility findings in Egyptian cases who were suffering from upper GI complaints. Methods: This descriptive study included 378 subjects who were suffering from upper GI complaints as dysphagia, vomiting, chest pain and regurgitation in the period between 10/2015–7/2020. Esophageal HRM study was performed for all patients (MMS Laborie device). The catheter was positioned and confirmed passing across the EGJ (esophago-gastric junction) using landmarks. Swallows and resting status were recorded. Anatomical landmarks were placed.

Results

Most of the patients were complaining of upper GI symptoms. Males were 49.2% of cases. Mean age was 41.3. Dysphagia was the prominent symptom while chest pain was the least symptom. Many manometry findings were observed including ineffective motility, achalasia, absent contractility, EGJ outflow obstruction, jackhammer esophagus and normal findings. Type II achalasia was the dominant type in achalasia patients while Type III was the least. LES was normotensive in most of the cases. Hiatus hernia (HH) was detected in 40.2% of the cases.

Conclusion

This is considered the first Egyptian descriptive study to determine the prevalence of esophageal motility abnormalities in Egyptian patients complaining of upper GI symptoms. HRM is very important for patients complaining of upper GI symptoms.

Evaluation of Esophageal Motility and Lessons from Chicago Classification version 4.0

PURPOSE OF REVIEW

Chicago Classification has standardized clinical approach to primary esophageal motility disorders. With new clinical data and advancing treatments, Chicago Classification has undergone multiple revisions to reflect updated findings and enhance diagnostic accuracy. This review will describe the recently published Chicago Classification version 4.0 (CCv4.0), which aimed to enhance diagnostic characterization and limit overdiagnosis of inconclusive esophageal motility diagnoses.

RECENT FINDINGS

Key revisions outlined in CCv4.0 include (1) a modified standardized HRM study protocol performed in supine and upright positions, (2) recommended ancillary testing and manometric provocation for inconclusive manometric diagnoses (3) the required presence of obstructive symptoms for conclusive diagnoses of esophagogastric junction outflow obstruction, distal esophageal spasm and hypercontractile esophagus, and (4) requirement of confirmatory testing for esophagogastric junction outflow obstruction. These key modifications aim to improve diagnostic accuracy and consistency of clinically relevant esophageal motility disorders, and subsequently clinical outcomes.

Integrated Relaxation Pressure Classification and Probe Positioning Failure Detection in High-Resolution Esophageal Manometry Using Machine Learning

High-resolution esophageal manometry is used for the study of esophageal motility disorders, with the help of catheters with up to 36 sensors. Color pressure topography plots are generated and analyzed and using the Chicago algorithm a final diagnosis is established. One of the main parameters in this algorithm is integrated relaxation pressure (IRP). The procedure is time consuming. Our aim was to firstly develop a machine learning based solution to detect probe positioning failure and to create a classifier to automatically determine whether the IRP is in the normal range or higher than the cut-off, based solely on the raw images. The first step was the preprocessing of the images, by finding the region of interest—the exact moment of swallowing. Afterwards, the images were resized and rescaled, so they could be used as input for deep learning models. We used the InceptionV3 deep learning model to classify the images as correct or failure in catheter positioning and to determine the exact class of the IRP. The accuracy of the trained convolutional neural networks was above 90% for both problems. This work is just the first step in fully automating the Chicago Classification, reducing human intervention.

Clinical usefulness of esophageal high resolution manometry and adjunctive tests: An update

High resolution manometry (HRM), developed from conventional manometry, is the gold standard for assessment of esophageal motor function worldwide. The Chicago Classification, now in its fourth iteration, is the modern standard for HRM categorization of esophageal motility disorders. The HRM protocol has expanded from the original 10 supine swallow standard, to include upright swallows, and provocative maneuvers such as multiple rapid swallows, rapid drink challenge and standardized test meal. Impedance has been incorporated into HRM for visualization of bolus clearance. Futhermore, barium radiography and functional lumen imaging probe complement HRM when evidence of esophagogastric junction obstruction is inconclusive. The biggest impact of HRM is in the improved diagnosis and subtyping of achalasia spectrum disorders, with implications on management. Spastic disorders and absent contractility are better characterized. Within the reflux spectrum, HRM provides definition of morphology and tone of the esophagogastric junction, and assesses integrity of esophageal body peristalsis, which have pathophysiologic implications for reflux and its clearance. HRM provides characterization of behavioral disorders such as supragastric belching and rumination syndrome, which can mimic reflux disease. Thus, HRM has revolutionized the evaluation of esophageal motor function, and has expanded the utility of esophageal manometry in clinical practice.

A deep-learning-based unsupervised model on esophageal manometry using variational autoencoder

High-resolution manometry (HRM) is the primary method for diagnosing esophageal motility disorders and its interpretation and classification are based on variables (features) from data of each swallow. Modeling and learning the semantics directly from raw swallow data could not only help automate the feature extraction, but also alleviate the bias from pre-defined features. With more than 32-thousand raw swallow data, a generative model using the approach of variational auto-encoder (VAE) was developed, which, to our knowledge, is the first deep-learning-based unsupervised model on raw esophageal manometry data. The VAE model was reformulated to include different types of loss motivated by domain knowledge and tuned with different hyper-parameters. Training of the VAE model was found sensitive on the learning rate and hence the evidence lower bound objective (ELBO) was further scaled by the data dimension. Case studies showed that the dimensionality of latent space have a big impact on the learned semantics. In particular, cases with 4-dimensional latent variables were found to encode various physiologically meaningful contraction patterns, including strength, propagation pattern as well as sphincter relaxation. Cases with so-called hybrid L2 loss seemed to better capture the coherence of contraction/relaxation transition. Discriminating capability was further evaluated using simple linear discriminative analysis (LDA) on predicting swallow type and swallow pressurization, which yields clustering patterns consistent with clinical impression. The current work on modeling and understanding swallow-level data will guide the development of study-level models for automatic diagnosis as the next stage.

ACG Clinical Guidelines: Diagnosis and Management of Achalasia

Achalasia is an esophageal motility disorder characterized by aberrant peristalsis and insufficient relaxation of the lower esophageal sphincter. Patients most commonly present with dysphagia to solids and liquids, regurgitation, and occasional chest pain with or without weight loss. High-resolution manometry has identified 3 subtypes of achalasia distinguished by pressurization and contraction patterns. Endoscopic findings of retained saliva with puckering of the gastroesophageal junction or esophagram findings of a dilated esophagus with bird beaking are important diagnostic clues. In this American College of Gastroenterology guideline, we used the Grading of Recommendations Assessment, Development and Evaluation process to provide clinical guidance on how best to diagnose and treat patients with achalasia.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Prospective serial diagnostic study: the effects of position and provocative tests on the diagnosis of oesophageal motility disorders by high-resolution manometry

BACKGROUND

Standard high-resolution manometry (HRM) protocols are based on 10 single water swallows acquired in the supine position.

AIMS

To assess the impact of position, rapid drink challenge and solid test meal on the diagnosis of oesophageal motility disorders.

METHODS

Seventy-two healthy volunteers (20-76 years) and 366 consecutive patients (18-90 years) completed HRM with 10 single water swallows in the supine and upright positions. Rapid drink challenge was performed twice, before and after the solid test meal. Diagnosis based on single water swallows in the supine position (Chicago Classification v3.0) was compared with results in the upright position and with provocative tests.

RESULTS

Overall, diagnostic agreement in the supine and upright positions was present in 296/438 (67.6%) subjects. This increased to 90.0% when ineffective oesophageal motility was considered with normal motility. Integrated relaxation pressure was 4 mm Hg higher in the supine position. There was a higher prevalence of inconsistent, likely false positive, diagnoses of outlet obstruction in the supine compared to the upright position (16/20 vs 1/4 patients, P = 0.0007). Similarly, the difference in concordance for the diagnosis of oesophago-gastric junction obstruction or achalasia between single water swallows in the supine and upright positions with solid test meal was significant (12/29 (41.4%) vs 12/14 (85.7%), P = 0.0087).

CONCLUSION

Diagnostic agreement for oesophageal motility disorders based on single water swallows in the upright and supine positions was moderate, with frequent discordant findings for ineffective motility and outlet obstruction. HRM studies can be performed in either position, using appropriate reference values. Rapid drink challenge or solid test meal can resolve diagnostic discrepancies.

British Society of Gastroenterology guidelines for oesophageal manometry and oesophageal reflux monitoring

These guidelines on oesophageal manometry and gastro-oesophageal reflux monitoring supersede those produced in 2006. Since 2006 there have been significant technological advances, in particular, the development of high resolution manometry (HRM) and oesophageal impedance monitoring. The guidelines were developed by a guideline development group of patients and representatives of all the relevant professional groups using the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool. A systematic literature search was performed and the GRADE (Grading of Recommendations Assessment, Development and Evaluation) tool was used to evaluate the quality of evidence and decide on the strength of the recommendations made. Key strong recommendations are made regarding the benefit of: (i) HRM over standard manometry in the investigation of dysphagia and, in particular, in characterising achalasia, (ii) adjunctive testing with larger volumes of water or solids during HRM, (iii) oesophageal manometry prior to antireflux surgery, (iv) pH/impedance monitoring in patients with reflux symptoms not responding to high dose proton pump inhibitors and (v) pH monitoring in all patients with reflux symptoms responsive to proton pump inhibitors in whom surgery is planned, but combined pH/impedance monitoring in those not responsive to proton pump inhibitors in whom surgery is planned. This work has been endorsed by the Clinical Services and Standards Committee of the British Society of Gastroenterology (BSG) under the auspices of the oesophageal section of the BSG.

Clinical measurement of gastrointestinal motility and function: who, when and which test?

Symptoms related to abnormal gastrointestinal motility and function are common. Oropharyngeal and oesophageal dysphagia, heartburn, bloating, abdominal pain and alterations in bowel habits are among the most frequent reasons for seeking medical attention from internists or general practitioners and are also common reasons for referral to gastroenterologists and colorectal surgeons. However, the nonspecific nature of gastrointestinal symptoms, the absence of a definitive diagnosis on routine investigations (such as endoscopy, radiology or blood tests) and the lack of specific treatments make disease management challenging. Advances in technology have driven progress in the understanding of many of these conditions. This Review serves as an introduction to a series of Consensus Statements on the clinical measurements of gastrointestinal motility, function and sensitivity. A structured, evidence-based approach to the initial assessment and empirical treatment of patients presenting with gastrointestinal symptoms is discussed, followed by an outline of the contribution of modern physiological measurement on the management of patients in whom the cause of symptoms has not been identified with other tests. Discussions include the indications for and utility of high-resolution manometry, ambulatory pH-impedance monitoring, gastric emptying studies, breath tests and investigations of anorectal structure and function in day-to-day practice and clinical management.

Impaired motility in Barrett's esophagus: A study using high-resolution manometry with physiologic challenge

BACKGROUND

Esophageal dysmotility may predispose to Barrett's esophagus (BE). We hypothesized that high-resolution manometry (HRM) performed with additional physiologic challenge would better delineate dysmotility in BE.

METHODS

Included patients had typical reflux symptoms and underwent endoscopy, HRM with single water swallows and adjunctive testing with solids and rapid drink challenge (RDC) before ambulatory pH-impedance monitoring. BE and endoscopy-negative reflux disease (ENRD) subjects were compared against functional heartburn patient-controls (FHC). Primary outcome was incidence of HRM contractile abnormalities with standard and adjunctive swallows. Secondary outcomes included clearance measures and symptom association on pH-impedance.

KEY RESULTS

Seventy-eight patients (BE 25, ENRD 27, FHC 26) were included. Water swallow contractility was reduced in both BE (median DCI 87 mm Hg/cm/s) and ENRD (442 mm Hg/cm/s) compared to FHC (602 mm Hg/cm/s; P < .001 and .04, respectively). With the challenge of solid swallows and RDC, these parameters improved in ENRD (solids = 1732 mm Hg/cm/s), becoming similar to FHC (1242 mm Hg/cm/s; P = .93), whereas abnormalities persisted in BE (818 mm Hg/cm/s; P < .01 c.f. FHC). In BE and ENRD, reflux events (67 vs 57 events/24 hour) and symptom frequency were similar; yet symptom correlation was significantly better in ENRD compared to BE, which was comparable to FHC (symptom index 30% vs 4% vs 0%, respectively). Furthermore, bolus clearance and exposure times were more pronounced in BE (P < .01).

CONCLUSIONS & INFERENCES

Reduced contractile effectiveness persisted in BE with the more representative esophageal challenge of swallowing solids and free drinking; while in ENRD and FHC peristalsis usually improved, demonstrating peristaltic reserve. Furthermore, symptom association and refluxate clearance were reduced in BE. These factors may underlie BE pathogenesis.

Variation in esophageal physiology testing in clinical practice: Results from an international survey

BACKGROUND

Advances in clinical measurement of esophageal motility and function have improved the assessment of swallowing disorders and reflux symptoms. Variation in data acquisition, analysis, and reporting exists and impacts on diagnosis and management.

AIMS AND METHODS

This study examined variation in esophageal manometry methodology between institutions to establish the status in current practice. A structured survey was distributed through international NGM societies using an Internet-based platform. Questions explored infrastructure, technology, analysis, and reporting.

KEY RESULTS

Responses were received from 91 centers from 29 countries. Eighteen (20%) centers used "conventional" manometry, 75 (82%) high-resolution manometry, and 53 (58%) HR impedance manometry. All centers documented motility for single water swallows. The Chicago Classification was applied by 65 (71.4%) centers. In contrast, analysis of EGJ morphology varied widely. Adjunctive testing was often applied: multiple rapid swallows (77%), rapid drink challenge (77%), single solid swallows (63%), and a standard test meal (18%). Of 86 (94.5%) units that offered pH impedance (pH-Z) studies, approximately half (53.5%) performed tests on acid-suppressant medication in patients with a high pretest probability (eg, erosive esophagitis). Most (75.6%) centers manually reviewed every reflux event. Others examined pH-Z data only prior to symptoms. To assess symptom association with reflux events, 73.6% centers analyzed each symptom separately, whereas 29.7% centers pooled symptoms.

CONCLUSIONS AND INFERENCES

There is marked variation in the data acquisition, analysis, and reporting of esophageal manometry studies. Further efforts to improve quality and uniformity in testing and reporting are required. This survey provides information upon which best-practice guidelines can be developed.

Factors Determining the Inter-observer Variability and Diagnostic Accuracy of High-resolution Manometry for Esophageal Motility Disorders

Background/Aims

Although high-resolution manometry (HRM) has the advantage of visual intuitiveness, its diagnostic validity remains under debate. The aim of this study was to evaluate the diagnostic accuracy of HRM for esophageal motility disorders.

Methods

Six staff members and 8 trainees were recruited for the study. In total, 40 patients enrolled in manometry studies at 3 institutes were selected. Captured images of 10 representative swallows and a single swallow in analyzing mode in both high-resolution pressure topography (HRPT) and conventional line tracing formats were provided with calculated metrics.

Results

Assessments of esophageal motility disorders showed fair agreement for HRPT and moderate agreement for conventional line tracing (κ = 0.40 and 0.58, respectively). With the HRPT format, the κ value was higher in category A (esophagogastric junction [EGJ] relaxation abnormality) than in categories B (major body peristalsis abnormalities with intact EGJ relaxation) and C (minor body peristalsis abnormalities or normal body peristalsis with intact EGJ relaxation). The overall exact diagnostic accuracy for the HRPT format was 58.8% and rater’s position was an independent factor for exact diagnostic accuracy. The diagnostic accuracy for major disorders was 63.4% with the HRPT format. The frequency of major discrepancies was higher for category B disorders than for category A disorders (38.4% vs 15.4%; P < 0.001).

Conclusions

The interpreter’s experience significantly affected the exact diagnostic accuracy of HRM for esophageal motility disorders. The diagnostic accuracy for major disorders was higher for achalasia than distal esophageal spasm and jackhammer esophagus.

Chicago Classification of Esophageal Motility Disorders: Lessons Learned

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.

Trends in diagnoses after implementation of the Chicago classification for esophageal motility disorders (V3.0) for high-resolution manometry studies

To determine trends in the diagnostic distribution of esophageal motility disorders after implementation of the Chicago Classification Version 3.0 (CC V3.0) for interpretation of high-resolution manometry (HRM) studies compared to non-Chicago Classification criteria. Retrospective trends analysis of patients with an HRM study conducted at a single center from January 1, 2013 to September 30, 2015. The implementation of the CC V3.0 for manometry interpretation occurred in September 2014. Patient charts were manually reviewed for data collection including demographics and HRM diagnoses. The prevalence and relative risks (RR) of CC V3.0 diagnostic categories (i.e. normal, indeterminate, achalasia, and EGJ outflow obstruction [EJGOO], and major and minor motility disorders) were calculated before and after CC V3.0 implementation. Four hundred sixty-five HRM studies were included in the study including 268 before and 179 after CC V3.0 implementation. The mean ± SD age was 54 ± 15.4 years and 59.8% were female (n = 278). The percentage with indeterminate diagnosis decreased from 35.3% before CC V3.0 implementation to 16.8% after implementation (adjusted RR 0.5, 95%CI 0.30-0.70, p < 0.001). The percentage with a major motility disorders decreased from 13.9% to 7.3% (adjusted RR 0.5, 95%CI 0.2-1.0, p < 0.001). The percentage with EJGOO and minor diagnoses increased from 1.4% to 14.5% and 11.9% to 22.9%, respectively. The percentage with achalasia and normal diagnosis did not change over the study period. Implementation of CCV3.0 was associated with changes in the distribution of esophageal motility diagnoses in clinical practice. The percentage of indeterminate and major diagnosis decreased and EGJOO and minor diagnoses increased. The decrease in the number of indeterminate studies suggests that the CC V3.0 may clarify the criteria for the interpreting physician. The increase in studies with a diagnosis of EGJ outflow obstruction may reflect the heterogeneity of disorders with clinically relevant outflow obstruction.

A System to Assess the Competency for Interpretation of Esophageal Manometry Identifies Variation in Learning Curves

BACKGROUND & AIMS

Quality esophageal high-resolution manometry (HRM) studies require competent interpretation of data. However, there is little understanding of learning curves, training requirements, or measures of competency for HRM. We aimed to develop and use a competency assessment system to examine learning curves for interpretation of HRM data.

METHODS

We conducted a prospective multicenter study of 20 gastroenterology trainees with no experience in HRM, from 8 centers, over an 8-month period (May through December 2015). We designed a web-based HRM training and competency assessment system. After reviewing the training module, participants interpreted 50 HRM studies and received answer keys at the fifth and then at every second interpretation. A cumulative sum procedure produced individual learning curves with preset acceptable failure rates of 10%; we classified competency status as competency not achieved, competency achieved, or competency likely achieved.

RESULTS

Five (25%) participants achieved competence, 4 (20%) likely achieved competence, and 11 (55%) failed to achieve competence. A minimum case volume to achieve competency was not identified. There was no significant agreement between diagnostic accuracy and accuracy for individual HRM skills.

CONCLUSIONS

We developed a competency assessment system for HRM interpretation; using this system, we found significant variation in learning curves for HRM diagnosis and individual skills. Our system effectively distinguished trainee competency levels for HRM interpretation and contrary to current recommendations, found that competency for HRM is not case-volume specific.

A Procedure for the Automatic Analysis of High-Resolution Manometry Data to Support the Clinical Diagnosis of Esophageal Motility Disorders

OBJECTIVE

Degenerative phenomena may affect esophageal motility as a relevant social-health problem. The diagnosis of such disorders is usually performed by the analysis of data from high-resolution manometry (HRM). Inter- and intraobserver variability frequently affects the diagnosis, with potential interpretative and thus therapeutic errors, with unnecessary or worse treatments. This may be avoided with automatic procedures that minimize human intervention in data processing.

METHODS

In order to support the traditional diagnostic process, an automatic procedure was defined considering a specific physiomechanical model that is able to objectively interpret data from HRM. A training set (N = 226) of healthy volunteers and pathological subjects was collected in order to define the model parameters distributions of the different groups of subjects, providing a preliminary database. A statistical algorithm was defined for an objective identification of the patient's healthy or pathological condition by comparing patient parameters with the database.

RESULTS

A collection of HRMs including subjects of the training set has been built. Statistical relationships between parameters and pathologies have been established leading to a preliminary database. An automatic diagnosis procedure has been developed to compare model parameters of a specific patient with the database. The procedure was able to match the correct diagnosis up to 86% of the analyzed subjects.

CONCLUSION

The success rate of the automatic procedure addresses the suitability of the developed algorithms to provide a valid support to the clinicians for the diagnostic activity.

SIGNIFICANCE

The objectivity of developed tools increases the reliability of data interpretation and, consequently, patient acceptance.

Methods of anorectal manometry vary widely in clinical practice: Results from an international survey

BACKGROUND

Ano-rectal manometry (ARM) is the most commonly performed investigation for assessment of anorectal dysfunction. Its use is supported by expert consensus documents and international guidelines. Variation in technology, data acquisition, and analysis affect results and clinical interpretation. This study examined variation in ARM between institutions to establish the status of current practice.

METHODS

A 50-item web-based questionnaire assessing analysis and interpretation of ARM was distributed by the International Anorectal Physiology Working Group via societies representing practitioners that perform ARM. Study methodology and performance characteristics between institutions were compared.

KEY RESULTS

One hundred and seven complete responses were included from 30 countries. Seventy-nine (74%) institutions performed at least two studies per week. Forty-nine centers (47%) applied conventional ARM (≤8 pressure sensors) and 57 (53%) high-resolution ARM (HR-ARM). Specialist centers were most likely to use HR-ARM compared to regional hospitals and office-based practice (63% vs 37%). Most conventional ARM systems used water-perfused technology (34/49); solid-state hardware was more frequently used in centers performing HR-ARM (44/57). All centers evaluated rest and squeeze. There was marked variation in the methods used to report results of maneuvers. No two centers had identical protocols for patient preparation, setup, study, and data interpretation, and no center fully complied with published guidelines.

CONCLUSIONS & INFERENCES

There is significant discrepancy in methods for data acquisition, analysis, and interpretation of ARM. This is likely to impact clinical interpretation, transfer of data between institutions, and research collaboration. There is a need for expert international co-operation to standardize ARM.

Diagnostic yield of high-resolution manometry with a solid test meal for clinically relevant, symptomatic oesophageal motility disorders: serial diagnostic study

BACKGROUND

The use of high-resolution manometry (HRM) to diagnose oesophageal motility disorders is based on ten single water swallows (SWS); however, this approach might not be representative of oesophageal function during the ingestion of normal food. We tested whether inclusion of a standardised solid test meal (STM) to HRM studies increases test sensitivity for major motility disorders. Additionally, we assessed the frequency and cause of patient symptoms during STM.

METHODS

Consecutive patients who were referred for investigation of oesophageal symptoms were recruited at Nottingham University Hospitals (Nottingham, UK) in the development study and at University Hospital Zürich (Zürich, Switzerland) in the validation study. HRM was done in the upright, seated position with a solid-state assembly. During HRM, patients ingested ten SWS, followed by a standardised 200 g STM. Diagnosis of oesophageal motility disorders was based on the Chicago Classification validated for SWS (CCv3) and with STM (CC-S), respectively. These studies are registered with ClinicalTrials.gov, numbers NCT02407938 and NCT02397616.

FINDINGS

The development cohort included 750 patients of whom 360 (48%) had dysphagia and 390 (52%) had reflux or other symptoms. The validation cohort consisted of 221 patients, including 98 (44%) with dysphagia and 123 (56%) with reflux symptoms. More patients were diagnosed with a major motility disorder by use of an STM than with SWS in the development set (321 [43%] patients diagnosed via STM vs 163 [22%] via SWS; p<0·0001) and validation set (73 [33%] vs 49 [22%]; p=0·014). The increase was most evident in patients with dysphagia (241 [67%] of 360 patients on STM vs 125 [35%] patients on SWS in the development set, p<0·0001), but was also present in those referred with reflux symptoms (64 [19%] of 329 patients vs 32 [10%] patients in the development set, p=0·00060). Reproduction of symptoms was reported by nine (1%) of 750 patients during SWS and 461 (61%) during STM (p<0·0001). 265 (83%) of 321 patients with major motility disorders and 107 (70%) of 152 patients with minor motility disorders reported symptoms during the STM (p=0·0038), compared with 89 (32%) of 277 patients with normal motility as defined with CC-S (p<0·0001).

INTERPRETATION

The diagnostic sensitivity of HRM for major motility disorders is increased with use of the STM compared with SWS, especially in patients with dysphagia. Observations made during STM can establish motility disorders as the cause of oesophageal symptoms.

FUNDING

None.

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

BACKGROUND

The factors that determine how people eat when they are healthy or have disease have not been defined. We used high resolution manometry (HRM) to assess pharyngeal swallowing and oesophageal motility during ingestion of a solid test meal (STM) in healthy volunteers and patients with motility disorders.

METHODS

This study was based at University Hospital Zurich (Zürich, Switzerland). Healthy volunteers who responded to an advertisement completed HRM with ten single water swallows (SWS) in recumbent and upright positions followed by a 200 g rice STM in the upright position. Healthy volunteers were stratified for age and sex to ensure a representative population. For comparison, consecutive patients with major motility disorders on SWS and patients with dysphagia but no major motility disorders on SWS (disease controls) were selected from a database that was assembled prospectively; the rice meal data were analysed retrospectively. During STM, pharyngeal swallows were timed and oesophageal contractions were classified as representing normal motility or different types of abnormal motility in accordance with established metrics. Factors that could potentially be associated with eating speed were investigated, including age, sex, body-mass index, and presence of motility disorder. We compared diagnoses based on SWS findings, assessed with the Chicago Classification v3.0, with those based on STM findings, assessed with the Chicago Classification adapted for solids. These studies are registered with ClinicalTrials.gov, numbers NCT02407938 and NCT02397616.

FINDINGS

Between April 2, 2014, and May 13, 2015, 72 healthy volunteers were recruited and underwent HRM. Additionally, we analysed data from 54 consecutive patients with major motility disorders and 53 with dysphagia but no major motility disorders recruited between April 2, 2013, and Dec 18, 2014. We found important variations in oesophageal motility and eating speed during meal ingestion in healthy volunteers and patients. Increased time between swallows was accompanied by more effective oesophageal contractions (in healthy volunteers, 20/389 [5%] effective swallows at <4 s between swallows vs 586/900 [65%] effective swallows at >11 s between swallows, p<0·0001). Obstructive, spastic, or hypercontractile swallows were rare in healthy volunteers (total <1%). Patients with motility disorders ate slower than healthy volunteers (14·95 g [IQR 11-25] per min vs 32·9 g [25-40] per min, p<0·0001) and pathological oesophageal motility were reproduced when patients consumed the STM. In healthy volunteers, eating speed was associated only with frequency of swallows (slope 2·5 g per min per pharyngeal swallow per min [95% CI 1·1-4·0], p=0·0009), whereas in patients with dysphagia, it was correlated with frequency of effective oesophageal contractions (6·4 g per min per effective contraction per min [4·3-8·5], p<0·0001). Diagnostic agreement was good between the HRM with SWS and rice STM (intra-class correlation coefficient r=0·81, 95% CI 0·74-0·87, p<0·0001).

INTERPRETATION

Our results show normative values for pharyngeal swallowing and oesophageal motility in healthy volunteers. Detailed analysis of HRM data acquired during an STM shows that the rate-limiting factor for intake of solids in health is the frequency of pharyngeal swallowing and not oesophageal contractility. The reverse is true in patients with oesophageal motility disorders, in whom the frequency of effective oesophageal contractions determines eating speed.

FUNDING

University Hospital Zurich.

The learning curve for interpretation of oesophageal high-resolution manometry: a prospective interventional cohort study

BACKGROUND

High-resolution manometry has become the preferred choice of oesophagologists for oesophageal motor assessment, but the learning curve among trainees remains unclear.

AIM

To determine the learning curve of high-resolution manometry interpretation.

METHODS

A prospective interventional cohort study was performed on 18 gastroenterology trainees, naïve to high-resolution manometry (median age 32 ± 4.0 years, 44.4% female). An intake questionnaire and a 1-h standardised didactic session were performed at baseline. Multiple 1-h interpretation sessions were then conducted periodically over 15 months where 10 studies were discussed; 5 additional test studies were provided for interpretation, and results were compared to gold standard interpretation by the senior author. Hypothetical management decisions based on trainee interpretation were separately queried. Accuracy was compared across test interpretations and sessions to determine the learning curve, with a goal of 90% accuracy.

RESULTS

Baseline accuracy was low for abnormal body motor patterns (53.3%), but higher for achalasia/outflow obstruction (65.9%). Recognition of achalasia reached 90% accuracy after six sessions (P = 0.01), while overall accurate management decisions reached this threshold by the 4th session (P < 0.001). Based on our data, the threshold of 90% accuracy for recognition of any abnormal from normal pattern was reached after 30 studies (3rd session) but fluctuated. Diagnosis of oesophageal body motor patterns remained suboptimal; accuracy of advisability of fundoplication improved, but did not reach 90%.

CONCLUSIONS

High-resolution manometry has a steep learning curve among trainees. Achalasia recognition is achieved early, but diagnosis of other abnormal motor patterns and management decisions require further supervised training.

Practice guidelines on the use of esophageal manometry - A GISMAD-SIGE-AIGO medical position statement

Patients with esophageal symptoms potentially associated to esophageal motor disorders such as dysphagia, chest pain, heartburn and regurgitation, represent one of the most frequent reasons for referral to gastroenterological evaluation. The utility of esophageal manometry in clinical practice is: (1) to accurately define esophageal motor function, (2) to identify abnormal motor function, and (3) to establish a treatment plan based on motor abnormalities. With this in mind, in the last decade, investigations and technical advances, with the introduction of high-resolution esophageal manometry, have enhanced our understanding and management of esophageal motility disorders. The following recommendations were developed to assist physicians in the appropriate use of esophageal manometry in modern patient care. They were discussed and approved after a comprehensive review of the medical literature pertaining to manometric techniques and their recent application. This position statement created under the auspices of the Gruppo Italiano di Studio per la Motilità dell'Apparato Digerente (GISMAD), Società Italiana di Gastroenterologia ed Endoscopia Digestiva (SIGE) and Associazione Italiana Gastroenterologi ed Endoscopisti Digestivi Ospedalieri (AIGO) is intended to help clinicians in applying manometric studies in the most fruitful manner within the context of their patients with esophageal symptoms.

Identification of Quality Measures for Performance of and Interpretation of Data From Esophageal Manometry

BACKGROUND & AIMS

Esophageal manometry is the standard for the diagnosis of esophageal motility disorders. Variations in the performance and interpretation of esophageal manometry result in discrepant diagnoses and unnecessary repeated procedures, and could have negative effects on patient outcomes. We need a method to benchmark the procedural quality of esophageal manometry; as such, our objective was to formally develop quality measures for the performance and interpretation of data from esophageal manometry.

METHODS

We used the RAND University of California Los Angeles Appropriateness Method (RAM) to develop validated quality measures for performing and interpreting esophageal manometry. The research team identified potential quality measures through a literature search and interviews with experts. Fourteen experts in esophageal manometry ranked the proposed quality measures for appropriateness via a 2-round process on the basis of RAM.

RESULTS

The experts considered a total of 29 measures; 17 were ranked as appropriate and were as follows: related to competency (2), assessment before the esophageal manometry procedure (2), the esophageal manometry procedure itself (3), and interpretation of data (10). The data interpretation measures were integrated into a single composite measure. Eight measures therefore were found to be appropriate quality measures for esophageal manometry . Five other factors also were endorsed by the experts, although these were not ranked as appropriate quality measures.

CONCLUSIONS

We identified 8 formally validated quality measures for the performance and interpretation of data from esophageal manometry on the basis of RAM. These measures represent key aspects of a high-quality esophageal manometry study and should be adopted uniformly. These measures should be evaluated in clinical practice to determine how they affect patient outcomes.

Clinical Application of Esophageal High-resolution Manometry in the Diagnosis of Esophageal Motility Disorders

Esophageal high-resolution manometry (HRM) is replacing conventional manometry in the clinical evaluation of patients with esophageal symptoms, especially dysphagia. The introduction of HRM gave rise to new objective metrics and recognizable patterns of esophageal motor function, requiring a new classification scheme: the Chicago classification. HRM measurements are more detailed and more easily performed compared to conventional manometry. The visual presentation of acquired data improved the analysis and interpretation of esophageal motor function. This led to a more sensitive, accurate, and objective analysis of esophageal motility. In this review we discuss how HRM changed the way we define and categorize esophageal motility disorders. Moreover, we discuss the clinical applications of HRM for each esophageal motility disorder separately.