Physiological augmentation of esophageal distension pressure and peristalsis during conditions of increased esophageal emptying resistance

BACKGROUND

Abdominal compression has been implemented as a provocative maneuver in high-resolution impedance manometry (HRIM) to "challenge" normal esophageal physiology with the aim of revealing abnormal motor patterns which may explain symptoms. In this study, we measured the effects of abdominal compression on esophageal functioning utilizing novel pressure-impedance parameters and attempted to identify differences between healthy controls and globus patients.

METHODS

Twenty-two healthy volunteers (aged 23-32 years, 41% female) and 22 globus patients (aged 23-72 years, 68% female) were evaluated with HRIM using a 3.2-mm water perfused manometric and impedance catheter. All participants received 10 × 5 mL liquid swallows; healthy controls also received 10 × 5 mL liquid swallows with abdominal compression created using an inflatable cuff. All swallows were analyzed to assess esophageal pressure topography (EPT) and pressure-flow metrics, indicative of distension pressure, flow timing and bolus clearance were derived.

KEY RESULTS

The effect of abdominal compression was shown as a greater contractile vigor of the distal esophagus by EPT and higher distension pressure based on pressure-flow metrics. Age and body mass index also increased contractile vigor and distension pressure. Globus patients were similar to controls.

CONCLUSIONS AND INTERFERENCES

Intrabolus pressure and contractile vigor are indicative of the physiological modulation of bolus transport mechanisms. Provocative testing by abdominal compression induces changes in these esophageal bolus dynamics.

Intra- and interrater reliability of the Chicago Classification of achalasia subtypes in pediatric high-resolution esophageal manometry (HRM) recordings

BACKGROUND

Subtyping achalasia by high-resolution manometry (HRM) is clinically relevant as response to therapy and prognosis have shown to vary accordingly. The aim of this study was to assess inter- and intrarater reliability of diagnosing achalasia and achalasia subtyping in children using the Chicago Classification (CC) V3.0.

METHODS

Six observers analyzed 40 pediatric HRM recordings (22 achalasia and 18 non-achalasia) twice by using dedicated analysis software (ManoView 3.0, Given Imaging, Los Angeles, CA, USA). Integrated relaxation pressure (IRP4s), distal contractile integral (DCI), intrabolus pressurization pattern (IBP), and distal latency (DL) were extracted and analyzed hierarchically. Cohen's κ (2 raters) and Fleiss' κ (>2 raters) and the intraclass correlation coefficient (ICC) were used for categorical and ordinal data, respectively.

RESULTS

Based on the results of dedicated analysis software only, intra- and interrater reliability was excellent and moderate (κ=0.89 and κ=0.52, respectively) for differentiating achalasia from non-achalasia. For subtyping achalasia, reliability decreased to substantial and fair (κ=0.72 and κ=0.28, respectively). When observers were allowed to change the software-driven diagnosis according to their own interpretation of the manometric patterns, intra- and interrater reliability increased for diagnosing achalasia (κ=0.98 and κ=0.92, respectively) and for subtyping achalasia (κ=0.79 and κ=0.58, respectively).

CONCLUSIONS

Intra- and interrater agreement for diagnosing achalasia when using HRM and the CC was very good to excellent when results of automated analysis software were interpreted by experienced observers. More variability was seen when relying solely on the software-driven diagnosis and for subtyping achalasia. Therefore, diagnosing and subtyping achalasia should be performed in pediatric motility centers with significant expertise.

Objectively diagnosing rumination syndrome in children using esophageal pH-impedance and manometry

BACKGROUND

Rumination syndrome is characterized by recurrent regurgitation of recently ingested food into the mouth. Differentiation with other diagnoses and gastroesophageal reflux disease (GERD) in particular, is difficult. Recently, objective pH-impedance (pH-MII) and manometry criteria were proposed for adults. The aim of this study was to determine diagnostic ambulatory pH-MII and manometry criteria for rumination syndrome in children.

METHODS

Clinical data and 24-hour pH-MII and manometry recordings of children with a clinical suspicion of rumination syndrome were reviewed. Recordings were analyzed for retrograde bolus flow extending into the proximal esophagus. Peak gastric and intraesophageal pressures closely related to these events were recorded and checked for a pattern compatible with rumination. Events were classified into primary, secondary, and supragastric belch-associated rumination.

KEY RESULTS

Twenty-five consecutive patients (11 males, median age 13.3 years [IQR 5.9-15.8]) were included; recordings of 18 patients were suitable for analysis. Rumination events were identified in 16/18 patients, with 50% of events occurring <30 minutes postprandially. Fifteen of 16 patients showed ≥1 gastric pressure peak >30 mmHg, while only 50% of all events was characterized by peaks >30 mmHg and an additional 20% by peaks >25 mmHg. Four patients had evidence of acid GERD, all showing secondary rumination.

CONCLUSIONS AND INFERENCES

Combined 24-hour pH-MII and manometry can be used to diagnose rumination syndrome in children and to distinguish it from GERD. Rumination patterns in children are similar compared with adults, albeit with lower gastric pressure increase. We propose a diagnostic cutoff for gastric pressure increase >25 mmHg associated with retrograde bolus flow into the proximal esophagus.

Reflux monitoring in children

Recently, multichannel intraluminal impedance (MII) monitoring was added to the repertoire of tests to evaluate the (patho)physiology of gastroesophageal reflux (GER) in children. Its advantage above the sole monitoring of the esophageal pH lies in the ability of the detection of both acid and nonacid GER and to discern between liquid and gas GER. Currently, combined 24 h pH-MII monitoring is recommended for evaluation of gastro-esophageal reflux disease (GERD) and its relation to symptoms in infants and children, despite the lack of reference values in these age groups. There is new evidence in the current issue of this Journal supporting the role of pH-MII monitoring for the evaluation of children presenting with gastrointestinal symptoms suggestive of GERD and the prediction of the presence of reflux esophagitis. However, several issues should be taken into account when performing pH-MII clinically.

Inter- and intrarater reliability of the Chicago Classification in pediatric high-resolution esophageal manometry recordings

BACKGROUND

The Chicago Classification (CC) facilitates interpretation of high-resolution manometry (HRM) recordings. Application of this adult based algorithm to the pediatric population is unknown. We therefore assessed intra and interrater reliability of software-based CC diagnosis in a pediatric cohort.

METHODS

Thirty pediatric solid state HRM recordings (13M; mean age 12.1 ± 5.1 years) assessing 10 liquid swallows per patient were analyzed twice by 11 raters (six experts, five non-experts). Software-placed anatomical landmarks required manual adjustment or removal. Integrated relaxation pressure (IRP4s), distal contractile integral (DCI), contractile front velocity (CFV), distal latency (DL) and break size (BS), and an overall CC diagnosis were software-generated. In addition, raters provided their subjective CC diagnosis. Reliability was calculated with Cohen's and Fleiss' kappa (κ) and intraclass correlation coefficient (ICC).

KEY RESULTS

Intra- and interrater reliability of software-generated CC diagnosis after manual adjustment of landmarks was substantial (mean κ = 0.69 and 0.77 respectively) and moderate-substantial for subjective CC diagnosis (mean κ = 0.70 and 0.58 respectively). Reliability of both software-generated and subjective diagnosis of normal motility was high (κ = 0.81 and κ = 0.79). Intra- and interrater reliability were excellent for IRP4s, DCI, and BS. Experts had higher interrater reliability than non-experts for DL (ICC = 0.65 vs ICC = 0.36 respectively) and the software-generated diagnosis diffuse esophageal spasm (DES, κ = 0.64 vs κ = 0.30). Among experts, the reliability for the subjective diagnosis of achalasia and esophageal gastric junction outflow obstruction was moderate-substantial (κ = 0.45-0.82).

CONCLUSIONS & INFERENCES

Inter- and intrarater reliability of software-based CC diagnosis of pediatric HRM recordings was high overall. However, experience was a factor influencing the diagnosis of some motility disorders, particularly DES and achalasia.

Applying the Chicago Classification criteria of esophageal motility to a pediatric cohort: effects of patient age and size

BACKGROUND

Applying the 2012 Chicago Classification (CC) of esophageal motility disorders to pediatric patients is problematic as it relies upon adult-derived criteria. As shorter esophageal length and smaller esophago-gastric junction (EGJ) diameter may influence CC metrics, we explored the potential for age- and size-adjustment of diagnostic criteria.

METHODS

We evaluated 76 high-resolution solid state impedance-manometry recordings in children referred for manometry (32M; mean age 9 ± 1 years) and 25 recordings from healthy adult subjects (7M; mean age 36 ± 2 years). CC metrics; integrated relaxation pressure (IRP4s, mmHg), contractile front velocity (CFV, cm/s), distal contractile integral (DCI, mmHg cm/s), distal latency (DL, s), and peristaltic break size (BS, cm) were derived for 10 liquid swallows using CC analysis software. Effects of age and size were examined using regression analysis.

KEY RESULTS

Younger patient age and shorter size correlated significantly with greater IRP4s (p < 0.05), shorter DL (p < 0.001) and smaller BS (p < 0.05). Standard diagnostic CC criteria were adjusted using the slope of the linear regression equation to define the age/size-related trend. Sixty-six percent of the pediatric cohort showed abnormal motility when applying standard CC criteria. Adjustment for age and size reduced this to 50% and 53% respectively, with the largest reduction being in the IRP4s- and DL-dependent disorders EGJ outflow obstruction and diffuse esophageal spasm (13% to 7% and 5% and 14% to 1 and 5%, respectively).

CONCLUSIONS & INFERENCES

CC metrics, particularly IRP4s and DL, are age and size dependent, and therefore, require adjustment to improve accuracy of diagnosis of esophageal motility disorders in children.