Are the Chicago 3.0 manometric diagnostics consistent with Chicago 4.0?

There is little information on the degree of concordance between the results obtained using the Chicago 3.0 (CCv3.0) and Chicago 4.0 (CCv4.0) protocols to interpret high-resolution manometry (HRM) seeking to determine the value provided by the new swallowing maneuvers included in the last protocol. This is a study of diagnostic tests, evaluating concordance by consistency between the results obtained by the CCv3.0 and CCv4.0 protocols, in patients undergoing HRM. Concordance was assessed with the kappa test. Bland-Altman scatter plots, and Lin's correlation-concordance coefficient (CCC) were used to assess the agreement between IRP measured with swallows in the supine and seated position or with solid swallows. One hundred thirty-two patients were included (65% women, age 53 ± 17 years). The most frequent HRM indication was dysphagia (46.1%). Type I was the most common type of gastroesophageal junction. The most frequent CCv4.0 diagnoses were normal esophageal motility (68.9%), achalasia (15.5%), and ineffective esophageal motility (IEM; 5.3%). The agreement between the results was substantial (Kappa 0.77 ± 0.05), with a total agreement of 87.9%. Diagnostic reclassification occurred in 12.1%, from IEM in CCv3.0 to normal esophageal motility in CCv4.0. Similarly, there was a high level of agreement between the IRP measured in the supine compared to the seated position (CCC0.92) and with solid swallows (CCC0.96). In conclusion, the CCv4.0 protocol presents a high concordance compared to CCv3.0. In the majority of manometric diagnoses there is no reclassification of patients with provocation tests. However, the more restrictive criteria of CCv4.0 achieve a better reclassification of patients with IEM.

Latin American consensus on diagnosis of gastroesophageal reflux disease

BACKGROUND

Diagnosing gastroesophageal reflux disease (GERD) can be challenging given varying symptom presentations, and complex multifactorial pathophysiology. The gold standard for GERD diagnosis is esophageal acid exposure time (AET) measured by pH-metry. A variety of additional diagnostic tools are available. The goal of this consensus was to assess the individual merits of GERD diagnostic tools based on current evidence, and provide consensus recommendations following discussion and voting by experts.

METHODS

This consensus was developed by 15 experts from nine countries, based on a systematic search of the literature, using GRADE (grading of recommendations, assessment, development and evaluation) methodology to assess the quality and strength of the evidence, and provide recommendations regarding the diagnostic utility of different GERD diagnosis tools, using AET as the reference standard.

KEY RESULTS

A proton pump inhibitor (PPI) trial is appropriate for patients with heartburn and no alarm symptoms, but nor for patients with regurgitation, chest pain, or extraesophageal presentations. Severe erosive esophagitis and abnormal reflux monitoring off PPI are clearly indicative of GERD. Esophagram, esophageal biopsies, laryngoscopy, and pharyngeal pH monitoring are not recommended to diagnose GERD. Patients with PPI-refractory symptoms and normal endoscopy require reflux monitoring by pH or pH-impedance to confirm or exclude GERD, and identify treatment failure mechanisms. GERD confounders need to be considered in some patients, pH-impedance can identify supragrastric belching, impedance-manometry can diagnose rumination.

CONCLUSIONS

Erosive esophagitis on endoscopy and abnormal pH or pH-impedance monitoring are the most appropriate methods to establish a diagnosis of GERD. Other tools may add useful complementary information.

Updates to the modern diagnosis of GERD: Lyon consensus 2.0

The Lyon Consensus provides conclusive criteria for and against the diagnosis of gastro-oesophageal reflux disease (GERD), and adjunctive metrics that consolidate or refute GERD diagnosis when primary criteria are borderline or inconclusive. An international core and working group was assembled to evaluate research since publication of the original Lyon Consensus, and to vote on statements collaboratively developed to update criteria. The Lyon Consensus 2.0 provides a modern definition of actionable GERD, where evidence from oesophageal testing supports revising, escalating or personalising GERD management for the symptomatic patient. Symptoms that have a high versus low likelihood of relationship to reflux episodes are described. Unproven versus proven GERD define diagnostic strategies and testing options. Patients with no prior GERD evidence (unproven GERD) are studied using prolonged wireless pH monitoring or catheter-based pH or pH-monitoring off antisecretory medication, while patients with conclusive GERD evidence (proven GERD) and persisting symptoms are evaluated using pH-impedance monitoring while on optimised antisecretory therapy. The major changes from the original Lyon Consensus criteria include establishment of Los Angeles grade B oesophagitis as conclusive GERD evidence, description of metrics and thresholds to be used with prolonged wireless pH monitoring, and inclusion of parameters useful in diagnosis of refractory GERD when testing is performed on antisecretory therapy in proven GERD. Criteria that have not performed well in the diagnosis of actionable GERD have been retired. Personalisation of investigation and management to each patient's unique presentation will optimise GERD diagnosis and management.

The Brief Esophageal Dysphagia Questionnaire shows better discriminative capacity for clinical and manometric findings than the Eckardt score: Results from a multicenter study

INTRODUCTION

Grading dysphagia is crucial for clinical management of patients. The Eckardt score (ES) is the most commonly used for this purpose. We aimed to compare the ES with the recently developed Brief Esophageal Dysphagia Questionnaire (BEDQ) in terms of their correlation and discriminative capacity for clinical and manometric findings and evaluate the effect of gastroesophageal reflux symptoms on both.

METHODS

Symptomatic patients referred for high-resolution manometry (HRM) were prospectively recruited from seven centers in Spain and Latin America. Clinical data and several scores (ES, BEDQ, GERDQ) were collected and contrasted to HRM findings. Standard statistical analysis was performed.

KEY RESULTS

426 patients were recruited, 31.2% and 41.5% being referred exclusively for dysphagia and GERD symptoms, respectively. Both BEDQ and ES were independently associated with achalasia. Only BEDQ was independently associated with being referred for dysphagia and with relevant HRM findings. ROC curve analysis for achalasia diagnosis showed AUC of 0.809 for BEDQ and 0.765 for ES, with the main difference being higher BEDQ sensitivity (80.0% vs 70.8% for ES). GERDQ independently predicted ES but not BEDQ. In the absence of dysphagia (BEDQ = 0), GERD symptoms significantly determine ES.

CONCLUSIONS AND INFERENCES

Our study suggests both the BEDQ and ES can complementarily describe symptomatic burden in achalasia. BEDQ has several advantages over the ES in the dysphagia evaluation, basically due to its higher sensitivity for manometric diagnosis and independence of GERD symptoms. ES should be used as an achalasia-specific metric, while BEDQ is a better symptom-generic evaluating tool.

Breaks in peristaltic integrity predict abnormal esophageal bolus clearance better than contraction vigor or residual pressure at the esophagogastric junction

BACKGROUND

High-resolution impedance manometry (HRIM) evaluates esophageal peristalsis and bolus transit. We used esophageal impedance integral (EII), the ratio between bolus presence before and after an expected peristaltic wave, to evaluate predictors of bolus transit.

METHODS

From HRIM studies performed on 61 healthy volunteers (median age 27 years, 48%F), standard metrics were extracted from each of 10 supine water swallows: distal contractile integral (DCI, mmHg cm s), integrated relaxation pressure (IRP, mmHg), and breaks in peristaltic integrity (cm, using 20 mmHg isobaric contour). Pressure and impedance coordinates for each swallow were exported into a dedicated, python-based program for EII calculation (EII ratio ≥ 0.3 = abnormal bolus clearance). Univariate and multivariate analyses were performed to assess predictors of abnormal bolus clearance.

KEY RESULTS

Of 591 swallows, 80.9% were intact, 10.5% were weak, and 8.6% failed. Visual analysis overestimated abnormal bolus clearance compared to EII ratio (p ≤ 0.01). Bolus clearance was complete (median EII ratio 0.0, IQR 0-0.12) in 82.0% of intact swallows in contrast to 53.3% of weak swallows (EII ratio 0.29, IQR 0.0-0.57), and 19.6% of failed swallows (EII ratio 0.5, IQR 0.34-0.73, p < 0.001). EII correlated best with break length (ρ = 0.52, p < 0.001), compared to IRP (ρ: -0.17) or DCI (ρ: -0.42). On ROC analysis, breaks predicted abnormal bolus transit better than DCI or IRP (AUC 0.79 vs. 0.25 vs. 0.44, p ≤ 0.03 for each). On logistic regression, breaks remained independently predictive of abnormal bolus transit (p < 0.001).

CONCLUSIONS & INFERENCES

Breaks in peristaltic integrity predict abnormal bolus clearance better than DCI or IRP in healthy asymptomatic subjects.

The Spanish version of the esophageal hypervigilance and anxiety score shows strong psychometric properties: Results of a large prospective multicenter study in Spain and Latin America

BACKGROUND

Anxiety is a significant modulator of sensitivity along the GI tract. The recently described Esophageal Hypervigilance and Anxiety Score (EHAS) evaluates esophageal-specific anxiety. The aims of this study were as follows: 1. translate and validate an international Spanish version of EHAS. 2. Evaluate its psychometric properties in a large Hispano-American sample of symptomatic individuals.

METHODS

A Spanish EHAS version was developed by a Delphi process and reverse translation. Patients referred for high-resolution manometry (HRM) were recruited prospectively from seven Spanish and Latin American centers. Several scores were used: EHAS, Hospital Anxiety and Depression Scale (HADS), Eckardt score (ES), Gastroesophageal Reflux Questionnaire (GERDQ), and the Brief Esophageal Dysphagia Questionnaire (BEDQ). Standardized psychometric analyses were performed.

KEY RESULTS

A total of 443 patients were recruited. Spanish EHAS showed excellent reliability (Cronbach´s alpha = 0.94). Factor analysis confirmed the presence of two factors, corresponding to the visceral anxiety and hypervigilance subscales. Sufficient convergent validity was shown by moderate significant correlations between EHAS and other symptomatic scores. Patients with high EHAS scores had significantly more dysphagia. There was no difference in EHAS scores when compared normal vs abnormal or major manometric diagnosis.

CONCLUSIONS AND INFERENCES

A widely usable Spanish EHAS version has been validated. We confirm its excellent psychometric properties in our patients, confirming the appropriateness of its use in different populations. Our findings support the appropriateness of evaluating esophageal anxiety across the whole manometric diagnosis spectrum.

Chicago Classification update (V4.0): Technical review on diagnostic criteria for ineffective esophageal motility and absent contractility

Esophageal hypomotility disorders manifest with abnormal esophageal body contraction vigor, breaks in peristaltic integrity, or failure of peristalsis in the context of normal lower esophageal sphincter relaxation on esophageal high-resolution manometry (HRM). The Chicago Classification version 4.0 recognizes two hypomotility disorders, ineffective esophageal motility (IEM) and absent contractility, while fragmented peristalsis has been incorporated into the IEM definition. Updated criteria for ineffective swallows consist of weak esophageal body contraction vigor measured using distal contractile integral (DCI, 100-450 mmHg·cm·s), transition zone defects >5 cm measured using a 20 mmHg isobaric contour, or failure of peristalsis (DCI < 100 mmHg·cm·s). More than 70% ineffective swallows and/or ≥50% failed swallows are required for a conclusive diagnosis of IEM. When the diagnosis is inconclusive (50%-70% ineffective swallows), supplementary evidence from multiple rapid swallows (absence of contraction reserve), barium radiography (abnormal bolus clearance), or HRM with impedance (abnormal bolus clearance) could support a diagnosis of IEM. Absent contractility requires 100% failed peristalsis, consistent with previous versions of the classification. Consideration needs to be given for the possibility of achalasia in absent contractility with dysphagia despite normal IRP, and alternate complementary tests (including timed upright barium esophagram and functional lumen imaging probe) are recommended to confirm or refute the presence of achalasia. Future research to quantify esophageal bolus retention on stationary HRM with impedance and to understand contraction vigor thresholds that predict bolus clearance will provide further refinement to diagnostic criteria for esophageal hypomotility disorders in future iterations of the Chicago Classification.

Esophagogastric junction morphology and contractile integral on high-resolution manometry in asymptomatic healthy volunteers: An international multicenter study

BACKGROUND

Esophagogastric junction contractile integral (EGJ-CI) and EGJ morphology are high-resolution manometry (HRM) metrics that assess EGJ barrier function. Normative data standardized across world regions and HRM manufacturers are limited.

METHODS

Our aim was to determine normative EGJ metrics in a large international cohort of healthy volunteers undergoing HRM (Medtronic, Laborie, and Diversatek software) acquired from 16 countries in four world regions. EGJ-CI was calculated by the same two investigators using a distal contractile integral-like measurement across the EGJ for three respiratory cycles and corrected for respiration (mm Hg cm), using manufacturer-specific software tools. EGJ morphology was designated according to Chicago Classification v3.0. Median EGJ-CI values were calculated across age, genders, HRM systems, and regions.

RESULTS

Of 484 studies (28.0 years, 56.2% F, 60.7% Medtronic studies, 26.0% Laborie, and 13.2% Diversatek), EGJ morphology was type 1 in 97.1%. Median EGJ-CI was similar between Medtronic (37.0 mm Hg cm, IQR 23.6-53.7 mm Hg cm) and Diversatek (34.9 mm Hg cm, IQR 22.1-56.1 mm Hg cm, P = 0.87), but was significantly higher using Laborie equipment (56.5 mm Hg cm, IQR 35.0-75.3 mm Hg cm, P < 0.001). 5^th percentile EGJ-CI values ranged from 6.9 to 12.1 mm Hg cm. EGJ-CI values were consistent across world regions, but different between manufacturers even within the same world region (P ≤ 0.001). Within Medtronic studies, EGJ-CI and basal LESP were similar in younger and older individuals (P ≥ 0.3) but higher in women (P < 0.001).

CONCLUSIONS

EGJ morphology is predominantly type 1 in healthy adults. EGJ-CI varies widely in health, with significant gender influence, but is consistent within each HRM system. Manufacturer-specific normative values should be utilized for clinical HRM interpretation.

Validation and psychometric evaluation of the Spanish version of Brief Esophageal Dysphagia Questionnaire (BEDQ): Results of a multicentric study

BACKGROUND

The recently developed Brief Esophageal Dysphagia Questionnaire (BEDQ) evaluates esophageal obstructive symptoms. Its initial evaluation showed strong psychometric properties. The aims of this study were to (a) translate and validate an international Spanish version of BEDQ and (b) evaluate its psychometric properties in a large Hispano-American sample of symptomatic individuals.

METHODS

A Spanish BEDQ version was performed by Hispano-American experts using a Delphi process and reverse translation. Patients were prospectively recruited from seven centers in Spain and Latin America among individuals referred for high-resolution manometry (HRM). Patients completed several scores: Hospital Anxiety & Depression Scale (HADS), Eckardt score (ES), Gastroesophageal Reflux Questionnaire (GERDQ), and the BEDQ. Standardized psychometric analyses were performed.

KEY RESULTS

A total of 426 patients were recruited. Spanish BEDQ showed excellent reliability (Cronbach's alpha = 0.91). Factor analysis confirmed its unidimensional character. Moderate significant correlations between BEDQ and other symptomatic scores were found, suggesting sufficient convergent validity. Patients with abnormal or obstructive HRM findings scored significantly higher when compared to normal or non-obstructive findings, respectively. Using a cutoff of 10, BEDQ showed a sensitivity of 65.38% and a specificity of 66.21% and an area under the curve of 0.71 for obstructive or major manometric diagnosis.

CONCLUSIONS AND INFERENCES

A widely usable Spanish BEDQ version has been validated. We confirm its excellent psychometric properties in our patients, confirming the appropriateness of its use in different populations.

Esophageal motility disorders on high-resolution manometry: Chicago classification version 4.0©

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.

Ineffective esophageal motility and bolus clearance. A study with combined high-resolution manometry and impedance in asymptomatic controls and patients

BACKGROUND

The definition and relevance of ineffective esophageal motility (IEM) remains debated. Our aim was to determine motility patterns and symptoms associated with IEM defined as impaired bolus clearance.

METHODS

To define altered bolus clearance, normal range of swallows with complete bolus transit (CBT) on high-resolution impedance manometry (HRIM) was determined in 44 asymptomatic controls. The results were then applied to a cohort of 81 patients with esophageal symptoms to determine the motility patterns which best predicted altered bolus clearance. Subsequently, in a cohort of 281 consecutive patients the identified motility patterns were compared with patients' customary symptoms.

KEY RESULTS

In asymptomatic controls, the normal range of swallows with CBT was 50%-100%. In patients, altered bolus transit (<50% CBT) was only associated with 30% or more failed contractions (P < .001). Neither weak peristalsis nor absence of contraction reserve (CR) was associated with altered bolus clearance. The patterns which best predicted altered bolus clearance were failed contractions ≥30% (specificity 88.2% and sensitivity of 84.6%), and ≥70% ineffective (failed + weak) contractions (sensitivity 84.6% and specificity 80.9%). No motility pattern was correlated to symptom scores.

CONCLUSIONS AND INFERENCES

Based on bolus clearance assessed by HRIM, ≥30% failed contractions and ≥70% ineffective contractions have the best sensitivity and specificity to predict altered bolus clearance. Weak contractions and absence of CR are not relevant with respect to bolus clearance.

Fair reliability of eckardt scores in achalasia and non-achalasia patients: Psychometric properties of the eckardt spanish version in a multicentric study

BACKGROUND

Eckardt symptom score (ESS) is the most used tool for the evaluation of esophageal symptoms. Recent data suggest that it might have suboptimal reliability and validity. The aims of this study were as follows: (a) Develop and validate an international Spanish ESS version. (b) Perform psychometric ESS evaluation in patients with achalasia and non-achalasia patients.

METHODS

Eckardt symptom score translation was performed by Delphi process. ESS psychometric evaluation was done in two different samples of patients referred for manometry. First sample: 430 dysphagia non-achalasia patients. Second sample: 161 achalasia patients. Internal consistency was evaluated using Cronbach's α and Guttman coefficient (<0.5 = unacceptable. 0.5-0.7 = fair. >0.7 = acceptable).

KEY RESULTS

Our data show that in patients without and with achalasia, ESS behaves similarly. Both show a fair reliability with Cronbach's α of 0.57 and 0.65, respectively. Based on our results, we recommend interpretation of the Spanish ESS be done with caution. The psychometric quality of the ESS could not be improved by removal of any items based on the single-factor structure of the scale and no items meeting criteria for elimination.

CONCLUSIONS AND INFERENCES

Eckardt symptom score Spanish translation was developed. ESS showed a fair reliability for the evaluation of patients with any causes of dysphagia. Our results highlight the need for development and psychometric validation of new dysphagia scoring tools.

Anxiety can significantly explain bolus perception in the context of hypotensive esophageal motility: Results of a large multicenter study in asymptomatic individuals

BACKGROUND

Previous studies have not been able to correlate manometry findings with bolus perception. The aim of this study was to evaluate correlation of different variables, including traditional manometric variables (at diagnostic and extreme thresholds), esophageal shortening, bolus transit, automated impedance manometry (AIM) metrics and mood with bolus passage perception in a large cohort of asymptomatic individuals.

METHODS

High resolution manometry (HRM) was performed in healthy individuals from nine centers. Perception was evaluated using a 5-point Likert scale. Anxiety was evaluated using Hospitalized Anxiety and Depression scale (HAD). Subgroup analysis was also performed classifying studies into normal, hypotensive, vigorous, and obstructive patterns.

KEY RESULTS

One hundred fifteen studies were analyzed (69 using HRM and 46 using high resolution impedance manometry (HRIM); 3.5% swallows in 9.6% of volunteers were perceived. There was no correlation of any of the traditional HRM variables, esophageal shortening, AIM metrics nor bolus transit with perception scores. There was no HRM variable showing difference in perception when comparing normal vs extreme values (percentile 1 or 99). Anxiety but not depression was correlated with perception. Among hypotensive pattern, anxiety was a strong predictor of variance in perception (R² up to .70).

CONCLUSION AND INFERENCES

Bolus perception is less common than abnormal motility among healthy individuals. Neither esophageal motor function nor bolus dynamics evaluated with several techniques seems to explain differences in bolus perception. Different mechanisms seem to be relevant in different manometric patterns. Anxiety is a significant predictor of bolus perception in the context of hypotensive motility.

Normal values of esophageal pressure responses to a rapid drink challenge test in healthy subjects: results of a multicenter study

BACKGROUND

Multiple water swallow is increasingly used as a complementary challenge test in patients undergoing high-resolution manometry (HRM). Our aim was to establish the range of normal pressure responses during the rapid drink challenge test in a large population of healthy subjects.

METHODS

Pressure responses to a rapid drink challenge test (100 or 200 mL of water) were prospectively analyzed in 105 healthy subjects studied in nine different hospitals from different countries. Esophageal motility was assessed in all subjects by solid-state HRM. In 18 subjects, bolus transit was analyzed using concomitant intraluminal impedance monitoring.

KEY RESULTS

A virtually complete inhibition of pressure activity was observed during multiple swallow: Esophageal body pressure was above 20 mm Hg during 1 (0-8) % and above 30 mm Hg during 1 (0-5) % of the swallow period, and the pressure gradient across the esophagogastric junction was low (-1 (-7 to 4) mm Hg). At the end of multiple swallow, a postswallow contraction was evidenced in only 50% of subjects, whereas the remaining 50% had non-transmitted contractions. Bolus clearance was completed after 7 (1-30) s after the last swallow, as evidenced by multichannel intraluminal impedance.

CONCLUSIONS & INFERENCES

The range of normal pressure responses to a rapid drink challenge test in health has been established in a large multicenter study. Main responses are a virtually complete inhibition of esophageal pressures with a low-pressure gradient across esophagogastric junction. This data would allow the correct differentiation between normal and disease when using this test.

Colonic content in health and its relation to functional gut symptoms

BACKGROUND

Gut content may be determinant in the generation of digestive symptoms, particularly in patients with impaired gut function and hypersensitivity. Since the relation of intraluminal gas to symptoms is only partial, we hypothesized that non-gaseous component may play a decisive role.

METHODS

Abdominal computed tomography scans were evaluated in healthy subjects during fasting and after a meal (n = 15) and in patients with functional gut disorders during basal conditions (when they were feeling well) and during an episode of abdominal distension (n = 15). Colonic content and distribution were measured by an original analysis program.

KEY RESULTS

In healthy subjects both gaseous (87 ± 24 mL) and non-gaseous colonic content (714 ± 34 mL) were uniformly distributed along the colon. In the early postprandial period gas volume increased (by 46 ± 23 mL), but non-gaseous content did not, although a partial caudad displacement from the descending to the pelvic colon was observed. No differences in colonic content were detected between patients and healthy subjects. Symptoms were associated with discrete increments in gas volume. However, no consistent differences in non-gaseous content were detected in patients between asymptomatic periods and during episodes of abdominal distension.

CONCLUSIONS & INFERENCES

In patients with functional gut disorders, abdominal distension is not related to changes in non-gaseous colonic content. Hence, other factors, such as intestinal hypersensitivity and poor tolerance of small increases in luminal gas may be involved.

Intestinal gas content and distribution in health and in patients with functional gut symptoms

BACKGROUND

The precise relation of intestinal gas to symptoms, particularly abdominal bloating and distension remains incompletely elucidated. Our aim was to define the normal values of intestinal gas volume and distribution and to identify abnormalities in relation to functional-type symptoms.

METHODS

Abdominal computed tomography scans were evaluated in healthy subjects (n = 37) and in patients in three conditions: basal (when they were feeling well; n = 88), during an episode of abdominal distension (n = 82) and after a challenge diet (n = 24). Intestinal gas content and distribution were measured by an original analysis program. Identification of patients outside the normal range was performed by machine learning techniques (one-class classifier). Results are expressed as median (IQR) or mean ± SE, as appropriate.

KEY RESULTS

In healthy subjects the gut contained 95 (71, 141) mL gas distributed along the entire lumen. No differences were detected between patients studied under asymptomatic basal conditions and healthy subjects. However, either during a spontaneous bloating episode or once challenged with a flatulogenic diet, luminal gas was found to be increased and/or abnormally distributed in about one-fourth of the patients. These patients detected outside the normal range by the classifier exhibited a significantly greater number of abnormal features than those within the normal range (3.7 ± 0.4 vs 0.4 ± 0.1; p < 0.001).

CONCLUSIONS & INFERENCES

The analysis of a large cohort of subjects using original techniques provides unique and heretofore unavailable information on the volume and distribution of intestinal gas in normal conditions and in relation to functional gastrointestinal symptoms.

Abdominothoracic mechanisms of functional abdominal distension and correction by biofeedback

BACKGROUND & AIMS

In patients with functional gut disorders, abdominal distension has been associated with descent of the diaphragm and protrusion of the anterior abdominal wall. We investigated mechanisms of abdominal distension in these patients.

METHODS

We performed a prospective study of 45 patients (42 women, 24-71 years old) with functional intestinal disorders (27 with irritable bowel syndrome with constipation, 15 with functional bloating, and 3 with irritable bowel syndrome with alternating bowel habits) and discrete episodes of visible abdominal distension. Subjects were assessed by abdominothoracic computed tomography (n = 39) and electromyography (EMG) of the abdominothoracic wall (n = 32) during basal conditions (without abdominal distension) and during episodes of severe abdominal distension. Fifteen patients received a median of 2 sessions (range, 1-3 sessions) of EMG-guided, respiratory-targeted biofeedback treatment; 11 received 1 control session before treatment.

RESULTS

Episodes of abdominal distension were associated with diaphragm contraction (19% ± 3% increase in EMG score and 12 ± 2 mm descent; P < .001 vs basal values) and intercostal contraction (14% ± 3% increase in EMG scores and 6 ± 1 mm increase in thoracic antero-posterior diameter; P < .001 vs basal values). They were also associated with increases in lung volume (501 ± 93 mL; P < .001 vs basal value) and anterior abdominal wall protrusion (32 ± 3 mm increase in girth; P < .001 vs basal). Biofeedback treatment, but not control sessions, reduced the activity of the intercostal muscles (by 19% ± 2%) and the diaphragm (by 18% ± 4%), activated the internal oblique muscles (by 52% ± 13%), and reduced girth (by 25 ± 3 mm) (P ≤ .009 vs pretreatment for all).

CONCLUSIONS

In patients with functional gut disorders, abdominal distension is a behavioral response that involves activity of the abdominothoracic wall. This distension can be reduced with EMG-guided, respiratory-targeted biofeedback therapy.

Mechanisms of postprandial abdominal bloating and distension in functional dyspepsia

OBJECTIVE

Patients with irritable bowel syndrome and abdominal bloating exhibit abnormal responses of the abdominal wall to colonic gas loads. We hypothesised that in patients with postprandial bloating, ingestion of a meal triggers comparable abdominal wall dyssynergia. Our aim was to characterise abdominal accommodation to a meal in patients with postprandial bloating.

DESIGN

A test meal (0.8 kcal/ml nutrients plus 27 g/litre polyethylenglycol 4000) was administered at 50 ml/min as long as tolerated in 10 patients with postprandial bloating (fulfilling Rome III criteria for postprandial distress syndrome) and 12 healthy subjects, while electromyographic (EMG) responses of the anterior wall (upper and lower rectus, external and internal oblique via bipolar surface electrodes) and the diaphragm (via six ring electrodes over an oesophageal tube in the hiatus) were measured. Means +/- SD were calculated.

RESULTS

Healthy subjects tolerated a meal volume of 913±308 ml; normal abdominal wall accommodation to the meal consisted of diaphragmatic relaxation (EMG activity decreased by 15±6%) and a compensatory contraction (25±9% increase) of the upper abdominal wall muscles (upper rectus and external oblique), with no changes in the lower anterior muscles (lower rectus and internal oblique). Patients tolerated lower volume loads (604±310 ml; p=0.030 vs healthy subjects) and developed a paradoxical response, that is, diaphragmatic contraction (14±3% EMG increment; p<0.01 vs healthy subjects) and upper anterior wall relaxation (9±4% inhibition; p<0.01 vs healthy subjects).

CONCLUSIONS

In functional dyspepsia, postprandial abdominal distension is produced by an abnormal viscerosomatic response to meal ingestion that alters normal abdominal accommodation.

Abdominal accommodation induced by meal ingestion: differential responses to gastric and colonic volume loads

BACKGROUND

Using an experimental model of colonic gas infusion, we previously showed that the abdominal walls adapt to its content by an active phenomenon of abdominal accommodation. We now hypothesized that abdominal accommodation is a physiological phenomenon, and aimed to confirm that it can be induced by ingestion of a meal; a secondary aim was to determine whether the response to gut filling is region-specific.

METHODS

In healthy subjects (n = 24) a nutrient test meal was administered until tolerated at a rate of 50 mL min(-1). Electromyographic (EMG) activity of the anterior wall (upper and lower rectus, external and internal oblique) was measured via four pairs of surface electrodes, and EMG activity of the diaphragm via intraluminal electrodes on an esophageal tube. To address the secondary aim, the response to gastric filling was compared with that induced by colonic filling (1440 mL 30 min(-1) anal gas infusion; n = 8).

KEY RESULTS

Participants tolerated 927 ± 66 mL of meal (450-1500 mL). Meal ingestion induced progressive diaphragmatic relaxation (EMG reduction by 16 ± 2%; P < 0.01) and selective contraction of the upper abdominal wall (24 ± 2% increase in activity of the upper rectus and external oblique; P < 0.01 for both), with no significant changes in the lower rectus (4 ± 2%) or internal oblique (5 ± 3%). Colonic gas infusion induced a similar response, but with an overall contraction of the anterior wall.

CONCLUSIONS & INFERENCES

Meal ingestion induces a metered and region-specific response of the abdominal walls to accommodate the volume load. Abnormal abdominal accommodation could be involved in postprandial bloating.

Accommodation of the abdomen to its content: integrated abdomino-thoracic response

BACKGROUND

  We previously showed that changes in intra-abdominal content induce a volume-dependent muscular response of the anterior abdominal wall and the diaphragm. We aimed to determine the contribution of the thorax to abdominal accommodation and the influence of the intra-abdominal expansion rate.

METHODS

  Gas (1440 mL total load) was infused into the colon of nine healthy subjects, while abdomino-thoracic perimeters (by tape measure), electromyography (EMG) activity of the diaphragm (via six ring electrodes over an esophageal tube in the hiatus), intercostals and anterior abdominal wall (via five pairs of surface electrodes) and the position of the diaphragm by ultrasonography were measured. Infusion rates of 24, 48, and 96 mL min(-1) were tested on separate days.

KEY RESULTS

  Gas infusion induced anterior abdominal wall contraction (18 ± 1% EMG increment; P < 0.001) with relatively modest girth increment (4.9 ± 0.9 mm; P = 0.001), diaphragmatic relaxation (by 15 ± 1%; P < 0.001) with cephalad displacement (by 23 ± 6 mm; P = 0.005), and intercostal contraction (by 19 ± 2%; P < 0.001) with increased thoracic perimeter (by 2.0 ± 0.5 mm; P = 0.009). Responses were similar with the three infusion rates.

CONCLUSIONS & INFERENCES

  Accommodation of intra-abdominal loads involves a volume-related integrated abdomino-thoracic response regardless of the expansion rate.

Postoperative pain after haemorrhoidectomy: role of impaired evacuation

AIM

We hypothesized that obstructive defaecation is associated with more postoperative pain after haemorrhoidectomy.

METHOD

Fifty patients with grade IV haemorrhoids were included in a prospective study. Impaired evacuation was defined as the inability to evacuate a rectal balloon. Perianal sensitivity was evaluated by means of an algometer, and anxiety and depression were assessed by the hospital anxiety and depression (HAD) scale. Over the first 10 days after a Milligan-Morgan haemorrhoidectomy, the following parameters were measured on daily questionnaires: pain (associated with and unrelated to defaecation by means of visual analogue scales), number of bowel movements, faecal consistency and analgesic requirement on demand (tramadol 50 mg p.o., number of doses). Results are expressed as median and interquartile range or mean ± SE.

RESULTS

Patients with impaired evacuation (14 women, eight men; age range 28-61 years) experienced more postoperative pain than patients with nonimpaired evacuation (eight women, 20 men; age range 24-70 years): 3.2 (2.1) vs 2.1 (1.8) defaecatory pain, respectively (P = 0.045), and 2.4 (2.3) vs 1.7 (2.3) nondefecatory pain, respectively (P = 0.048). There was no difference between the groups regarding stool consistency, number of bowel movements [12.5 (7.3) vs 15.5 (7.2), respectively; NS] and analgesic requirement [1.0 (6.1) vs 1.0 (5.2) extra doses on demand, respectively; NS] during the 10 postoperative days. No differences related to age, sex, HAD scores or perianal sensitivity were found.

CONCLUSION

Impaired anal evacuation is predictive of postoperative pain after haemorrhoidectomy.