Technological insights: Combined impedance manometry for esophageal motility testing-current results and further implications

Characterizing Biomarkers of Continuous Peristalsis and Bolus Transit during Oral Feeding in Infants at pH-Impedance Evaluation: Clinical and Research Implications

OBJECTIVE

To examine the biomarkers of pharyngoesophageal swallowing during oral feeding sessions in infants undergoing pH-impedance testing and determine if swallow frequencies are distinct between oral- and partially oral-fed infants.

STUDY DESIGN

One oral feeding session was performed in 40 infants during pH-impedance studies and measurements included swallowing frequency, multiple swallow rate, air and liquid swallow rates, esophageal swallow clearance time (ESCT), and gastroesophageal reflux (GER) characteristics. Linear and mixed statistical models were applied to examine the swallowing markers and outcomes.

RESULTS

Infants (30.2 ± 4.4 weeks birth gestation) were evaluated at 41.2 ± 0.4 weeks postmenstrual age (PMA). Overall, 10,675 swallows were analyzed during the oral feeding sessions (19.3 ± 5.4 min per infant) and GER events were noted (2.5 ± 0.3 per study). Twenty-four-hour acid reflux index (ARI) was 9.5 ± 2.0%. Differences were noted in oral- and partially oral-fed infants for: volume consumption (p<0.01), consumption rate (p<0.01), and length of hospital stay in days (p<0.01). Infants with ARI >7% had greater frequency of swallows (p=0.01). The oral-fed group had greater ARI (12.7 ± 3.3%, p=0.05).

CONCLUSIONS

Oropharyngeal swallowing regulatory characteristics decrease over the feeding duration and were different between ARI >7% vs ≤7%. Although GER is less in infants who are partially oral-fed, the neonates with increased acid exposure achieved greater oral intakes and shorter hospitalizations, despite the presence of comorbidities. Pharyngoesophageal stimulation as during consistent feeding or GER events can activate peristaltic responses and rhythms, which may be contributory to the findings.

Characteristics of Esophageal Motility and Associated Symptom Profiles in Patients with Esophageal Diverticulum: A Study Based on High-Resolution Impedance Manometry

BACKGROUND

Esophageal diverticulum (ED) is an uncommon structural disorder with heterogenous manifestations and elusive pathophysiology. Our aim was to investigate esophageal motility and associated symptom profiles in patients with ED based on high-resolution impedance manometry (HRIM).

METHODS

Consecutive patients with ED referred to our motility laboratory between 2015 to 2022 were identified in our electronic database. All patients were evaluated based on an upper endoscopy, HRIM, and standardized symptom questionnaires. Patients with ED were further stratified into upper, middle, and lower (epiphrenic) cases. Esophageal motility was evaluated with HRIM and the updated Chicago Classification v4.0.

RESULTS

Twenty-four patients with ED (9 upper, 4 middle, and 11 epiphrenic) were analyzed. Patients with ED were generally older (mean: 65 ± 13.3 years) and predominantly women (58.3%). Most ED cases were unilaterally located (95.8%) and left-side predominant (62.5%). Mean symptom duration was 20 months (range: 1-120) and the most common symptoms were dysphagia (70.8%) and regurgitation (37.5%). Erosive esophagitis was noted in 16 patients (69.6%), while barium stasis was noted in 5 patients (20.8%). Fourteen patients (58.3%) were diagnosed with esophageal motility disorders using HRIM, with achalasia being the most common diagnosis (n = 5, 20.8%). Patients with epiphrenic diverticulum had significantly higher symptom scores and achalasia prevalence.

CONCLUSION

Patients with ED tended to be older and was associated with a high prevalence of EMD. A multi-disciplinary evaluation, including complete anatomical and motility surveys, may help clarify the underlying pathophysiology and tailor further treatment strategies.

Interpretation of Impedance Data on High-resolution Impedance Manometry Studies-A Worldwide Survey

Background/Aims

Esophageal manometry is the gold standard for esophageal motility evaluation. High-resolution esophageal manometry with impedance (HRIM) allows concurrent assessment of bolus transit and manometry. Inconsistencies between concomitant impedance and manometry data pose a clinical dilemma and has not yet been addressed. We aim to assess interpretation trends of HRIM data among gastroenterologists worldwide.

Methods

A cross-sectional study using an anonymous survey was conducted among gastroenterologists worldwide. Statistical analysis was performed to compare responses between providers.

Results

We received responses from 107 gastroenterologists (26 countries). Most were adult providers (69, 64.5%), and most (77, 72.0%) had > 5 years of experience. Impedance was found to be helpful by 83 (77.6%) participants, but over 30% reported inconsistencies between impedance and manometry data. With incomplete bolus clearance and normal manometry 41 (38.7%) recommended observation, 41 (38.7%) recommended 24-hours pH-impedance, and 16 (15.1%) recommended prokinetics. With abnormal manometry and complete bolus clearance, 60 (57.1%) recommended observation while 18 (17.1%) recommended 24-hours pH impedance and 15 (14.3%) recommended prokinetics. A significant difference was found between providers from different continents in treating cases with discrepancy between impedance and manometry findings (P < 0.001). No significant differences were seen in responses between adult versus pediatric providers and between providers with different years of experience.

Conclusions

There is no consensus on interpreting HRIM data. Providers' approaches to studies with inconsistencies between manometry and impedance data vary. There is an unmet need for guidelines on interpreting impedance data in HRIM studies.

Twenty-four-hour pH metry alone is inferior to additional impedance monitoring in the diagnosis of gastroesophageal reflux disease, particularly in presence of reduced gastric acid secretion

BACKGROUND

Current gold standard for the diagnosis of gastroesophageal reflux disease (GERD) is 24-hour pH metry though it fails to detect non-acidic reflux. The sensitivity of 24-hour pH metry alone (both catheter-based and Bravo capsule) is questionable, especially if gastric acid secretion is low due to reduced parietal cell mass, Helicobacter pylori-induced gastric atrophy and antisecretory therapy. Accordingly, we analyzed the diagnostic ability of 24-hour pH metry as compared to impedance monitoring in relation to the gastric pH without antisecretory therapy.

METHODS

A retrospective analysis of prospectively collected data from 150 patients with suspected GERD undergoing a 24-hour pH impedance study was done.

RESULTS

Among 150 patients with symptoms suggestive of GERD, 106 (70.6%) had confirmed GERD diagnosed either by 24-hour pH metry alone (10 [9.4%]), impedance monitoring alone (49 [46.2%]) or both (47 [44.3%]). Abnormal reflux of acidic and non-acidic gastric contents was detected by 24-hour pH metry and 24-hour impedance monitoring in 57/106 (53.7%) and 96/106 (90.5%) of patients, respectively (p < .00001). Patients with GERD diagnosed by 24-hour impedance monitoring had a higher mean gastric pH (2.9 [median 1.3, IQR 5.3]) than those diagnosed by 24-hour pH metry (2.1 [median 1.4, IQR 2.6]) or both (1.6 [median 1.2, IQR 2.1]) (p = 0.001).

CONCLUSION

Twenty-four-hour impedance monitoring detects GERD more often than 24-hour pH metry. Patients with higher mean gastric pH leading to non-acidic reflux were more often diagnosed by 24-hour impedance monitoring than 24-hour pH metry. Thus, 24-hour pH metry alone is inferior to additional impedance monitoring in the diagnosis of GERD, particularly in presence of reduced gastric acid secretion.

Distension-evoked motility analysis in human esophagus

BACKGROUND

The major function of the esophagus is to transport food from the mouth to the stomach by peristaltic muscle action. However, only few techniques exist for detailed evaluation of motor activity of the esophagus in vivo. The aim of this study is to use distension combined with manometry and impedance planimetry [pressure-cross-sectional area (P-CSA) recordings] to assess esophageal peristaltic motor function in terms of the mechanical energy output, and to examine the change in the motor activity of the esophagus in response to butylscopolamine, an anticholinergic drug known to impair the smooth muscle contraction in the gastrointestinal tract.

METHODS

The probe with CSA measurements was positioned 7 cm above the lower esophageal sphincter in 16 healthy volunteers before and during butylscopolamine administration. Distension-evoked esophageal peristalsis was analyzed using P-CSA data during distension up to pressures of 5 kPa. The P-CSA, work output (area of the tension-CSA curves), and propulsive tension were analyzed.

KEY RESULTS

The wave-like peristalsis resulted in P-CSA loops consisting of relaxation and contraction phases. The work increased with the distension pressure (from 1311 ± 198 to 16 330 ± 1845 μJ before butylscopolamine vs from 2615 ± 756 to 11 404 ± 1335 μJ during butylscopolamine administration), and propulsive tension increased from 18.7 ± 1.9 to 88.5 ± 5.5 N m(-1) before the drug and from 23.1 ± 3.9 to 79.5 ± 3.3 N m(-1) during butylscopolamine administration). Significantly, lower values were found during butylscopolamine administration compared with the distension before using the drug (P < 0.01).

CONCLUSIONS & INFERENCES

Esophageal muscle properties during peristalsis can be assessed in vivo in terms of mechanical energy output parameters. Butylscopolamine impaired muscle contraction which could be detected as altered contraction parameters. The analysis can be further used as an adjunct tool of the combined manometry and impedance planimetry recordings to derive advanced esophageal motor function parameters for studying the physiological and pathophysiological mechanical consequences of esophageal contractions.

Critical analysis of esophageal multichannel intraluminal impedance monitoring 20 years later

Multichannel intraluminal impedance (MII) for the evaluation of esophageal diseases was created in 1991 trying to solve previous limitations of esophageal function test. MII-pH is able to determine the physical characteristics of the refluxate (liquid, gas, or mixed) and nonacidic GER. MII-manometry can determine the presence of bolus and its relation with peristalsis. This paper makes a critical analysis of the clinical applications of MII 20 years after its creation. Literature review shows that MII made great contributions for the understanding of esophageal physiology; however, direct clinical applications are few. MII-pH was expected to identify patients with normal acid reflux and abnormal nonacidic reflux. These patients are rarely found off therapy, that is, nonacidic reflux parallels acid reflux. Furthermore, the significance of isolated nonacidic reflux is unclear. Contradictory MII-manometry and conventional manometry findings lack better understanding and clinical implication as well as the real significance of bolus transit.

A new era in esophageal diagnostics: the image-based paradigm of high-resolution manometry

BACKGROUND

The development of high-resolution (HRM) catheters and software displays of manometric recordings in color-coded pressure plots has changed the diagnostic assessment of esophageal disease. HRM may offer advantages over conventional methods, including improved identification of motility disorders, hiatal hernia, and outflow obstruction, and ease interpretation.

STUDY DESIGN

HRM studies were obtained in 50 healthy volunteers and 106 patients. HRM was performed using a 36-channel catheter, with sensors spaced at 1-cm intervals. Manometric findings were classified into abnormalities of the gastroesophageal barrier and those of the esophageal body and validated by comparison with endoscopic and radiographic diagnostic methods.

RESULTS

The mean time for HRM was significantly lower than that for a conventional method (8.1versus 24.4 minutes; p < 0.0001). A structurally defective lower esophageal sphincter (LES) was present in 53 (57.3%) patients, a hypertensive LES in 6 (7.8%), and impaired LES relaxation in 17 patients (16.7%). Validating the LES findings, 86.3% (44 of 51) of patients with a defective sphincter by HRM had radiographic or endoscopic evidence of a hiatal hernia, and 80% (41 of 51) had a positive pH study, endoscopic erosive esophagitis, or Barrett's esophagus. Evidence of a hiatal hernia by HRM was seen in 33 (56%) patients; a hiatal hernia was seen in 91% (30 of 33) of these on endoscopy and 81% (17 of 21) on barium swallow. Fifty-eight patients (54.7%) had an abnormal body motility.

CONCLUSIONS

HRM studies are shorter than those using conventional methods. Interpretation is image based, and correlation with objective endoscopic and physiologic findings confirms the accuracy of interpretation. The introduction of HRM is a significant advance in the outpatient evaluation of esophageal function.

Decreased levels of adiponectin in obese patients with gastroesophageal reflux evaluated by videoesophagography: possible relationship between gastroesophageal reflux and metabolic syndrome

BACKGROUND

Body mass index (BMI) and obesity are reportedly associated with symptoms of gastroesophageal reflux disease (GERD). The present study was designed to investigate the effect of metabolic disorders including obesity on the levels of functional gastroesophageal reflux by videoesophagography.

METHODS

Twenty-one patients with GERD-associated symptoms were examined by videoesophagography. On their initial visit, all patients completed the Japanese version of the Carlsson-Dent self-administered questionnaire (QUEST). The findings of videoesophagography were evaluated by the X-ray severity scores for gastroesophageal reflux (XRSS), which were defined for the total diagnosis of functional gastroesophageal reflux. Correlation between XRSS scores and physical or metabolic markers was evaluated.

RESULTS

The mean XRSS in the QUEST-positive group (4.7+/-0.6) was significantly higher than that in the QUEST-negative group (3.3+/-0.5, P<0.05). XRSS correlated positively with BMI (P<0.05) and waist circumference (P<0.05), but negatively with high-density lipoprotein-cholesterol (P<0.05), serum adiponectin (P<0.05) and active ghrelin (P<0.05). In the multivariate analysis, serum adiponectin level, BMI and triglyceride independently affected the XRSS.

CONCLUSION

Videoesophagography is a useful diagnostic modality for the evaluation of patients with GERD symptoms. Functional gastroesophageal reflux is seen in obese patients, especially with decreased levels of adiponectin.