A study of proximal esophageal baseline impedance in identifying and predicting laryngopharyngeal reflux

Anatomic and Manometric Abnormalities of the Upper and Lower Esophageal Sphincters in Patients With Reflux Disease

RESEARCH QUESTION

Laryngopharyngeal reflux (LPR) may cause inflammation of the laryngeal and pharyngeal mucosa. Gastroesophageal reflux disease (GERD) involves retrograde flow of gastric content into the esophagus below the upper esophageal sphincter (UES). The goal of this study was to investigate the esophageal anatomical and manometric variations of the esophagus in patients with LPR and/or GERD.

METHODS

Adult voice center patients who underwent diagnostic workup for reflux complaints with 24-hour multichannel intraluminal pH-impedance testing and esophageal manometry were included in this retrospective study. Subjects were classified as having LPR (>10 proximal reflux events), LPR + GERD (>10 proximal reflux events plus >73 distal reflux events) or were assigned to a control group (≤10 proximal events and ≤73 distal reflux events) based on pH study results. Anatomic and manometric parameters were evaluated between groups.

RESULTS

There were 169 cases (65 male, 104 female) included in this study. The average age was 50.50 ± 17.29. Subjects in the LPR group had significantly higher UES relaxation pressures and greater UES length compared with the control group. Lower esophageal sphincter relaxation pressure was significantly higher in the control group compared with the LPR group or the GERD + LPR group. Subjects in the GERD + LPR group had a significantly shorter intra-abdominal portion of the lower esophageal sphincter compared with the LPR only group and the control group. Intrabolus pressure was significantly lower in both the LPR group and the LPR + GERD group compared with the control group. Distal wave amplitude was significantly lower in the LPR + GERD group compared to both the LPR group and the control group. The percentage of swallows with incomplete clearance was significantly greater in the LPR + GERD group than both the control group and the LPR group. The LPR group had significantly fewer swallows with incomplete clearance than the control group.

CONCLUSIONS

Anatomic and manometric abnormalities are present in subjects with LPR with or without GERD and may contribute to the pathogenesis of reflux disease. Further research is needed to confirm or refute these findings.

Diagnosis of Laryngopharyngeal Reflux: Past, Present, and Future-A Mini-Review

Laryngopharyngeal reflux (LPR) is a variant of gastroesophageal reflux disease (GERD) in which gastric refluxate irritates the lining of the aerodigestive tract and causes troublesome airway symptoms or complications. LPR is a prevalent disease that creates a significant socioeconomic burden due to its negative impact on quality of life, tremendous medical expense, and possible cancer risk. Although treatment modalities are similar between LPR and GERD, the diagnosis of LPR is more challenging than GERD due to its non-specific symptoms/signs. Due to the lack of pathognomonic features of endoscopy, mounting evidence focused on physiological diagnostic testing. Two decades ago, a dual pH probe was considered the gold standard for detecting pharyngeal acidic reflux episodes. Despite an association with LPR, the dual pH was unable to predict the treatment response in clinical practice, presumably due to frequently encountered artifacts. Currently, hypopharygneal multichannel intraluminal impedance-pH catheters incorporating two trans-upper esophageal sphincter impedance sensors enable to differentiate pharyngeal refluxes from swallows. The validation of pharyngeal acid reflux episodes that are relevant to anti-reflux treatment is, therefore, crucial. Given no diagnostic gold standard of LPR, this review article aimed to discuss the evolution of objective diagnostic testing and its predictive role of treatment response.

Accuracy of High-Resolution Pharyngeal Manometry Metrics for Predicting Aspiration and Residue in Oropharyngeal Dysphagia Patients with Poor Pharyngeal Contractility

Several physiological metrics can be derived from pharyngeal high-resolution impedance manometry (HRPM), but their clinical relevance has not been well established. We investigated the diagnostic performance of these metrics in relation to videofluoroscopic (VFS) assessment of aspiration and residue in patients with oropharyngeal dysphagia. We analyzed 263 swallows from 72 adult patients (22-91 years) with diverse medical conditions. Metrics of contractility, upper esophageal sphincter (UES) opening and relaxation, flow timing, intrabolus distension pressure, and a global Swallow Risk Index (SRI) were derived from pressure-impedance recordings using pressure-flow analysis. VFS data were independently scored for airway invasion and pharyngeal residue using the Penetration-Aspiration Scale and the Normalized Residue Ratio Scale, respectively. We performed multivariate logistic regression analyses to determine the relationship of HRPM metrics with radiological outcomes and receiver-operating characteristic (ROC) analysis to evaluate their diagnostic accuracy. We identified aspiration in 25% and pharyngeal residue in 84% of the swallows. Aspiration was independently associated with hypopharyngeal peak pressure < 65 mmHg (HypoPeakP) [adjusted odds ratio (OR) 5.27; 95% Confidence Interval (CI) (0.99-28.1); p = 0.051], SRI > 15 [OR 4.37; 95% CI (1.87-10.2); p < 0.001] and proximal esophageal contractile integral (PCI) < 55 mmHg·cm·s [OR 2.30; 95% CI (1.07-4.96); p = 0.034]. Pyriform sinus residue was independently predicted by HypoPeakP < 65 mmHg [OR 7.32; 95% CI (1.93-27.7); p = 0.003], UES integrated relaxation pressure (UES-IRP) > 3 mmHg [OR 2.96; 95% CI (1.49-5.88); p = 0.002], and SRI > 15 [OR 2.17; 95% CI (1.04-4.51); p = 0.039]. Area under ROC curve (AUC) values for individual HRPM metrics ranged from 0.59 to 0.74. Optimal cut-off values were identified. This study demonstrates the diagnostic value of certain proposed and adjunct HRPM metrics for identifying signs of unsafe and inefficient bolus transport in patients with oropharyngeal dysphagia.

The role of pH-impedance monitoring in swallowing disorders

PURPOSE OF REVIEW

To review the current evidence about the usefulness and the place of pH study in the management of patients with swallowing disorders.

RECENT FINDINGS

Gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) are found in approximately 30% of patients with esophageal or oropharyngeal dysphagia. Patients with suspected GERD may benefit from gastrointestinal endoscopy and proton pump inhibitors according to guidelines. The diagnosis of LPR in patients with oropharyngeal dysphagia is more controversial because there are no gold standard and diagnostic guidelines. The clinical diagnosis based on empirical therapeutic trial is a reasonable first-line strategy, but many dysphagic patients should not respond to treatment. These patients require hypopharyngeal-esophageal multichannel intraluminal impedance-pH monitoring (HEMII-pH), which is the most effective examination providing important information on GERD and LPR features. At the HEMII-pH, GERD patients often report upright (daytime) and supine (nighttime) liquid acid esophageal events with significant esophageal distal acid exposure time. LPR patients have more frequently upright (daytime) gaseous weakly acid or nonacid pharyngeal reflux events without distal esophageal acid exposure abnormalities in many times. The features of reflux at the HEMII-pH may indicate a personalized treatment for dysphagic patients combining proton pump inhibitors, alginate/magaldrate or gastroprokinetic in cases of esophageal dysmotility.

SUMMARY

GERD and LPR are prevalent causes of dysphagia. The large number of reflux patients who do not respond to empirical treatment makes important the awareness of otolaryngologists about pH-impedance monitoring indication, features, and interpretation.

Correlation of Esophageal Mean Nocturnal Baseline Impedance With Markers of Laryngopharyngeal Reflux

OBJECTIVES

Mean nocturnal baseline impedance (MNBI) is a measure of the esophageal epithelial barrier function calculated via high-resolution impedance manometry and can be used as a diagnostic tool and treatment response predictor for gastroesophageal reflux disease (GERD). However, its utility for laryngopharyngeal reflux (LPR) has been minimally studied. We aimed to investigate the relationship of MNBI between patients with suspected LPR, healthy controls, and their 24-h multichannel intraluminal impedance-pH (MII-pH) study results.

METHODS

Retrospective patient series analysis was performed of patients with suspected LPR and healthy controls who underwent 24-h MII-pH monitoring. MNBI values were calculated from impedance channels at the level of the hypopharynx, proximal esophagus, and distal esophagus. We compared these MNBI values between the subject groups with secondary analysis on MII-pH results, reflux symptom index, reflux findings score, DeMeester score, and salivary pepsin levels.

RESULTS

Twenty-three patients with suspected LPR and 14 healthy controls were enrolled. Decreased distal esophageal MNBI was found to be significantly decreased in patients with suspected LPR compared with healthy controls (p < 0.01) and in subjects with positive MII-pH studies compared to negative MII-pH studies (p < 0.01). There were no significant correlations of MNBI at the hypopharynx or proximal esophagus.

CONCLUSION

Distal esophageal MNBI has significant correlations with many phenotypic and biological markers of LPR. These findings indicate that MNBI has the potential to be applied to LPR, similar to its emerging use as a diagnostic tool and treatment response predictor for GERD.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Mean nocturnal baseline impedance, a novel metric of multichannel intraluminal impedance-pH monitoring in diagnosing gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common disease with increasing prevalence worldwide. However, the diagnosis of GERD is challenging because there are no definite gold standard criteria. Recently, a novel impedance parameter, namely mean nocturnal baseline impedance (MNBI), has been proposed, which reflects the burden of longitudinal reflux and the integrity of esophageal mucosa. MNBI has shown an immense promise for increasing the diagnostic rate of multichannel intraluminal impedance-pH (MII-pH) monitoring and predicting the response to proton pump inhibitor (PPI) or anti-reflux intervention in patients with reflux symptoms. The present paper reviews the association between baseline impedance and esophageal mucosal integrity, the acquisition of MNBI in 24-h MII-pH monitoring, the clinical utilization of MNBI in improving the diagnosis rate of GERD in patients with typical reflux symptoms, predicting the response to PPI or anti-reflux treatment in these patients, the utilization of MNBI in diagnosing patients with atypical symptoms or extra-esophageal symptoms, and the correlation between reflux burden and MNBI. MNBI should be routinely assessed using MII-pH monitoring.

The Number of Interstitial Cells of Cajal Differs Among Different Subtypes of Achalasia and is Related to Patients' Prognosis

INTRODUCTION

Achalasia is a primary esophageal motility disorder with heterogeneous manometric subtypes and prognosis, characterized by degeneration of the esophageal myenteric plexus, and reduction in interstitial cells of Cajal (ICCs). This study aimed to explore the histopathologic characteristics of lower esophageal sphincter (LES) muscle from patients with achalasia with different subtypes and different prognosis.

METHODS

We examined specimens of LES muscle from 122 patients with achalasia who underwent peroral endoscopic myotomy and from 10 control patients who underwent esophagectomy for esophageal cancer. Hematoxylin-eosin staining was performed to assess inflammation infiltration, fibrosis, and atrophy. Specific immunohistochemical staining was performed to identify ICCs and neuronal nitric oxide synthase (nNOS).

RESULTS

The number of ICCs in patients with type I achalasia was significantly lower than that in patients with type II achalasia, followed by that in control patients (type I vs type II vs control group= 0.4 vs 1.2 vs 9.5; P < 0.001). The number of nNOS-positive cells was significantly lower in patients with achalasia than that in control patients (type I vs type II vs control group = 0.0 vs 0.0 vs 8.0; P < 0.001). Nonrecurrent group had significantly more ICCs than recurrent group (type I: nonrecurrent vs recurrent = 1.0 vs 0.1; P = 0.010; type II: nonrecurrent vs recurrent = 2.0 vs 0.4; P = 0.004).

DISCUSSION

ICCs and nNOS-positive cells reduced significantly in LES muscle of patients with achalasia. The number of ICCs differed among different achalasia subtypes and was related to patients' clinical prognosis.

Normative Ambulatory Reflux Monitoring Metrics for Laryngopharyngeal Reflux: A Systematic Review of 720 Healthy Individuals

OBJECTIVES

To review the normative data for acid, weakly acid, and nonacid proximal esophageal (PRE) and hypopharyngeal reflux (HRE) events in diagnosing laryngopharyngeal reflux (LPR) using ambulatory reflux monitoring.

DATA SOURCES

PubMed, Cochrane Library, and Scopus.

REVIEW METHODS

A literature search was conducted about the normative data for PRE and HRE on multichannel intraluminal impedance-pH monitoring (MII-pH), hypopharyngeal-esophageal MII-pH (HEMII-pH), or oropharyngeal pH monitoring using PICOTS (population, intervention, comparison, outcome, timing, and setting) and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statements. Outcomes reviewed included device characteristics, impedance/pH sensor placements, study duration, number/average and percentiles of PRE or HRE occurrence, and the event characteristics (pH, composition, and position).

RESULTS

Of 154 identified studies, 18 met criteria for analysis, including 720 healthy individuals. HEMII-pH, MII-pH, and oropharyngeal pH monitoring were used in 7, 6, and 5 studies, respectively. The definition and inclusion/exclusion criteria of healthy individuals varied substantially across studies, with 6 studies considering only digestive symptoms to exclude potential LPR patients. Substantial heterogeneity across studies was noted, including impedance/pH sensor placements/configurations and definitions of composition (liquid, gas, mixed) and type (acid, weakly acid, nonacid) of PRE/HRE. The 95th percentile thresholds were 10 to 73 events for PRE, 0 to 10 events for HRE on HEMII-pH, and 40 to 128 for events with pH <6.0 on oropharyngeal pH monitoring. Most HREs were nonacid and occurred upright. The mean HRE among healthy individuals was 1.

CONCLUSION

The low number of studies and the heterogeneity in inclusion criteria, definitions, and characterization of PRE and HRE limit the establishment of consensual normative criteria for LPR on ambulatory reflux monitoring. Future large multicenter studies are needed.