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.
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The Chicago Classification (CC) of esophageal motility disorders, utilizing an algorithmic scheme to analyze clinical high‐resolution manometry (HRM) studies, has gained acceptance worldwide. 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.
Background Recent literature has shown increasing incidence and prevalence rates of eosinophilic esophagitis (EoE). However, data are mainly based on small studies and come from centers dedicated to ...EoE. Aim of this study was to estimate the incidence rates of EoE by using a large database.
Methods We performed a cross‐sectional study of the pathology reports describing esophageal eosinophilia from 1996 through 2010, using the nationwide network and registry of histo‐ and cytopathology in The Netherlands (PALGA). All histopathology reports nationwide enter this database. We classified cases according to the diagnosis made by the pathologist. Annual incidence rates of EoE were estimated.
Key Results Our search criteria yielded 8838 positive pathology reports. Eosinophilic esophagitis was diagnosed in 674 patients, of which 74% were men. In another 174 patients, no distinction was made between eosinophilia caused by gastro‐esophageal reflux disease or EoE. The incidence of EoE increased considerably over the years, being 0.01 in 1996, 0.01 in 2000, 0.14 in 2005, and 1.31 per 100 000 persons in 2010. Eosinophilic esophagitis was diagnosed in all age groups, but in 2010 the highest incidence was seen in 20–29 years old males, in whom it was estimated to be 3.23 per 100 000 persons. The incidence in children was 0.73 per 100 000 in 2010. No seasonal variation in diagnosis of EoE was observed.
Conclusions & Inferences In this large study, we found robust data on increasing incidence rates of pediatric and adult EoE in the past 15 years. This rapidly increasing incidence has not reached a plateau yet.
Background and aim: It is not known why some reflux episodes evoke symptoms and others do not. We investigated the determinants of perception of gastro-oesophageal reflux. Methods: In 32 patients ...with symptoms suggestive of gastro-oesophageal reflux, 24 hour ambulatory pH and impedance monitoring was performed after cessation of acid suppressive therapy. In the 20 patients who had at least one symptomatic reflux episode, characteristics of symptomatic and asymptomatic reflux episodes were compared. Results: A total of 1807 reflux episodes were detected, 203 of which were symptomatic. Compared with asymptomatic episodes, symptomatic episodes were associated with a larger pH drop (p<0.001), lower nadir pH (p<0.05), and higher proximal extent (p<0.005). Symptomatic reflux episodes had a longer volume and acid clearance time (p<0.05 and p<0.002). Symptomatic episodes were preceded by a higher oesophageal cumulative acid exposure time (p<0.05). The proximal extent of episodes preceding regurgitation was larger than those preceding heartburn; 14.8% of the symptomatic reflux episodes were weakly acidic. In total, 426 pure gas reflux episodes occurred, of which 12 were symptomatic. Symptomatic pure gas reflux was more frequently accompanied by a pH drop than asymptomatic gas reflux (p<0.05). Conclusions: Heartburn and regurgitation are more likely to be evoked when the pH drop is large, proximal extent of the refluxate is high, and volume and acid clearance is delayed. Sensitisation of the oesophagus occurs by preceding acid exposure. Weakly acidic reflux is responsible for only a minority of symptoms in patients off therapy. Pure gas reflux associated with a pH drop (“acid vapour”) can be perceived as heartburn and regurgitation.
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.
Summary
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.
Laparoscopic Nissen fundoplication (LNF) is the most frequently performed operation for gastro-oesophageal reflux disease (GORD). However, 12% of the patients have persistent reflux symptoms and 19% ...develop gas-related symptoms after LNF. Weakly acidic reflux and inability to belch have been alleged to cause these symptoms, respectively. The effect of LNF on weakly acidic reflux and (supra) gastric belching was evaluated.
In 31 patients upper gastrointestinal endoscopy, stationary oesophageal manometry and 24-h impedance-pH monitoring off acid secretion inhibiting drugs was performed before and 6 months after primary LNF for GORD that was refractory to proton pump inhibitors. Patients filled out validated questionnaires on GERD-HRQoL before and 3, 6 and 12 months after surgery.
LNF reduced reflux symptoms (18.6→1.6; p = 0.015). The procedure drastically reduced the incidence (number per 24 h) of acid (76.0→1.6; p < 0.001) and weakly acidic (13.6→5.7; p = 0.001) as well as liquid (53.4→5.4; p<0.001) and mixed reflux episodes (36.3→1.9; p < 0.001). In contrast, gas reflux was reduced to lesser extent (35.6→25.7; p = 0.022). Proximal, mid-oesophageal and distal reflux were reduced to a similar extent. Persistent GORD symptoms were neither preceded by acid nor by weakly acidic reflux. The number of air swallows did not change, but the number of gastric belches (GBs) was greatly reduced (68.5→23.9; p < 0.001). Twenty-three patients had supragastric belches (SGBs), both before and after surgery, whereas eight patients had no SGBs at all. The majority of SGBs were not reflux associated and the frequency was greatly increased after LNF (20.8→46.0; p = 0.036). Reflux-associated SGBs were abolished after surgery (14.0→0.4; p < 0.001).
LNF similarly controls acid and weakly acidic reflux, but gas reflux is reduced to lesser extent. Persistent reflux symptoms are neither caused by acid nor by weakly acidic reflux. LNF alters the belching pattern by reducing GBs (air venting from stomach) and increasing SGBs (no air venting from stomach). This explains the increase in belching experienced by some patients after LNF, despite the reduction in gastric belching. It can be hypothesised that the reduction in GBs after LNF incites patients to increase SGBs in a futile attempt to vent air from the stomach.
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.
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.
Background
The prevalence of gastroesophageal reflux disease (GERD) has increased in the last decades and it is now one of the most common chronic diseases. Throughout time our insight in the ...pathophysiology of GERD has been characterized by remarkable back and forth swings, often prompted by new investigational techniques. Even today, the pathophysiology of GERD is not fully understood but it is now recognized to be a multifactorial disease. Among the factors that have been shown to be involved in the provocation or increase of reflux, are sliding hiatus hernia, low lower esophageal sphincter pressure, transient lower esophageal sphincter relaxation, the acid pocket, obesity, increased distensibility of the esophagogastric junction, prolonged esophageal clearance, and delayed gastric emptying. Moreover, multiple mechanisms influence the perception of GERD symptoms, such as the acidity of the refluxate, its proximal extent, the presence of gas in the refluxate, duodenogastroesophageal reflux, longitudinal muscle contraction, mucosal integrity, and peripheral and central sensitization. Understanding the pathophysiology of GERD is important for future targets for therapy as proton pump inhibitor‐refractory GERD symptoms remain a common problem.
Purpose
In this review we provide an overview of the mechanisms leading to reflux and the factors influencing perception, in the light of historical developments. It is clear that further research remains necessary despite the recent advances in the understanding of the pathophysiology of GERD.
This review provides an overview of the current understanding of the pathophysiological mechanisms causing GERD and the factors which influence perception.
Background
An international group of experts evaluated and revised recommendations for ambulatory reflux monitoring for the diagnosis of gastro‐esophageal reflux disease (GERD).
Methods
Literature ...search was focused on indications and technical recommendations for GERD testing and phenotypes definitions. Statements were proposed and discussed during several structured meetings.
Key Results
Reflux testing should be performed after cessation of acid suppressive medication in patients with a low likelihood of GERD. In this setting, testing can be either catheter‐based or wireless pH‐monitoring or pH‐impedance monitoring. In patients with a high probability of GERD (esophagitis grade C and D, histology proven Barrett's mucosa >1 cm, peptic stricture, previous positive pH monitoring) and persistent symptoms, pH‐impedance monitoring should be performed on treatment. Recommendations are provided for data acquisition and analysis. Esophageal acid exposure is considered as pathological if acid exposure time (AET) is greater than 6% on pH testing. Number of reflux episodes and baseline impedance are exploratory metrics that may complement AET. Positive symptom reflux association is defined as symptom index (SI) >50% or symptom association probability (SAP) >95%. A positive symptom‐reflux association in the absence of pathological AET defines hypersensitivity to reflux.
Conclusions and Inferences
The consensus group determined that grade C or D esophagitis, peptic stricture, histology proven Barrett's mucosa >1 cm, and esophageal acid exposure greater >6% are sufficient to define pathological GERD. Further testing should be considered when none of these criteria are fulfilled.
The consensus group proposes to define pathological GERD as at least one of the following criteria: Grade C or D esophagitis, peptic stricture, Barrett's mucosa >1 cm and esophageal acid exposure >6%. Number of reflux episodes and baseline impedance should be considered as exploratory tools for further research.
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.
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.
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