New Approaches to Management of PPI-Refractory Gastroesophageal Reflux Disease

Evidence-based clinical practice guidelines for gastroesophageal reflux disease 2021

In Japan, with the increasing prevalence of gastroesophageal reflux disease (GERD) and growing public interest, the Japanese Society of Gastroenterology issued Evidence-based Clinical Practice Guidelines for GERD (1st edition) in 2009 and a revised 2nd edition in 2015. A number of studies on GERD were subsequently conducted in Japan and abroad, and vonoprazan, a potassium-competitive acid blocker (P-CAB), became available for the first time in Japan in February 2015. The revised 3rd edition (Japanese edition), which incorporates new findings and information, was published in April 2021. These guidelines are summarized herein, particularly sections related to the treatment of GERD. The important clinical issues addressed in the present revision are (i) the introduction of treatment algorithms that classify GERD into reflux esophagitis and non-erosive reflux disease, (ii) the clarification of treatment algorithms based on to the severity of reflux esophagitis, and (iii) the positioning of vonoprazan in the treatment for GERD. The present guidelines propose vonoprazan as the initial/maintenance treatment for severe reflux esophagitis. They also recommend vonoprazan or PPI as an initial treatment for mild reflux esophagitis and recommended PPI and proposed vonoprazan as maintenance treatment. These updated guidelines offer the best clinical strategies for GERD patients in Japan and hope that they will be of global use for the diagnosis and treatment for GERD.

A novel ex vivo porcine model of acid-induced esophageal damage for preliminary functional evaluations of anti-gastroesophageal reflux disease medical devices

Aim

The aim of the study was to set up a porcine ex vivo model of acid-induced damage and to evaluate its performance by means of multichannel intraluminal impedance and pH (MII-pH) live recording, histology, and Evans blue (EB) permeability assay.

Materials and Methods

Thirteen esophagi, collected at a slaughterhouse, were ablated of their sphincters, pinned upright on a support, and placed in a thermostatic hood at 37°C with two infusion tubes and an MII-pH probe inserted in the top end. Three esophagi (histology controls) were only left in the hood for 3.5 h before sampling, while the remaining organs underwent the experimental protocol including saline infusion and recovery recording, and acid solution infusion and recovery recording.

Results

MII-pH analysis highlighted a significantly stronger decrease during acid infusion when compared to saline, but a better post-infusion recovery for saline solution. At the end of the protocol, MII was still statistically lower than baseline. The acid-damaged esophagi significantly absorbed more EB dye, and histology revealed strong mucosal exfoliation.

Conclusion

The proposed model of esophageal acid damage seems to be repeatable, reliable, and achievable using organs collected at the slaughterhouse. MII recording proved to have good sensitivity in detecting mucosal alterations also in ex vivo trials.

Individualized medicine of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common disease worldwide, and its prevalence is increasing in both developed and developing countries. GERD is divided into three subtypes, namely, erosive esophagitis, nonerosive reflux disease (NERD), and Barrett's esophagus. The etiology, pathogenesis, clinical manifestations, and response to treatment of GERD invariably show high heterogeneity or significant individual difference, especially NERD and refractory GERD. On the other hand, advanced technology has currently provided a wide range of methods for the diagnosis and treatment of GERD patients; however, the long-term efficacy and quality of life of some patients are unsatisfactory. Therefore, each GERD patient needs a specialized management strategy aiming at his/her own condition, which is known as individualized medicine or personalized medicine. The goal of GERD treatment is to relieve the symptoms, while symptomatic remission is directly related to the quality of life. In other words, health-related quality of life and patient satisfaction may be reasonable criteria for GERD. In this paper, we will discuss the individualized medicine of GERD.

An analysis of 342 patients with refractory gastroesophageal reflux disease symptoms using questionnaires, high-resolution manometry, and impedance-pH monitoring

Symptoms of refractory gastroesophageal reflux disease (GERD) are commonly encountered in clinical practice. The aim of this study was to analyze the data obtained from questionnaires, high-resolution manometry (HRM), and ambulatory impedance-pH monitoring in patients with persisting GERD symptoms and to explore the possible underlying causes for this clinical presentation. After completing the questionnaires, the selected patients underwent endoscopy, HRM, and ambulatory impedance-pH monitoring. Based on the results of these investigations, we divided the patients into 4 groups: reflux esophagitis (RE), hypersensitive esophagus (HE), functional heartburn (FH), and nonerosive gastroesophageal reflux disease (NERD). The data from 342 patients were analyzed. One hundred twenty-nine (37.72%) patients experienced refractory GERD symptoms related to acid reflux. The scores on some scales in the Gastrointestinal Symptom Rating Scale (GSRS) questionnaire differed significantly among groups (all P < 0.05). Liquid reflux occurred more frequently in patients with GERD (RE and NERD), while gas reflux was more common in non-GERD patients (FH and HE; all P < 0.05). The RE and NERD groups showed more percent bolus exposure time (BET) when upright (all P < 0.05). Acid exposure time (AET) in the RE and NERD groups was longer than that in the HE and FH groups (all P < 0.05). Fewer than half of the patient symptoms were related to acid reflux. The GSRS questionnaire may be an optimal indicator for patients with refractory GERD symptoms. BET and AET are useful indices to distinguish GERD from other diseases. Gas reflux is probably related to persisting symptoms in FH and HE patients.

Estimation of gastric pH in cynomolgus monkeys, rats, and dogs using [(13)C]-calcium carbonate breath test

BACKGROUND

The determination of gastric pH is important for the confirmation of efficacy of anti-secretory drugs. However, current methods for measurement of gastric pH provide significant stress to animals and humans.

AIM

The objective of this study is to establish an easy and reliable gastric pH measurement method by determining (13)CO2 concentration in expired air of monkeys, dogs, and rats after oral administration of Ca(13)CO3.

METHODS

A correlation of (13)CO2 concentration determined by a Ca(13)CO3 breath test with gastric pH just before Ca(13)CO3 administration was analyzed in the 3 animal species. The equations and contribution ratios of regression line were calculated from logarithmic (13)CO2 concentrations at 15min after administration of Ca(13)CO3 using the linear regression analysis.

RESULTS

The (13)CO2 concentration in the Ca(13)CO3 breath test was well correlated with the gastric pH just before Ca(13)CO3 administration in the 3 animal species (r=-0.977 to -0.952). The equations of regression line between the (13)CO2 concentration and the gastric pH in each animal species showed good contribution ratios (R(2)≥0.89).

CONCLUSIONS

The Ca(13)CO3 breath test is an informative tool to estimate gastric pH in animals and will be applicable as a new noninvasive tool for patients with GERD/PPI-resistant symptoms.

Parameters on esophageal pH-impedance monitoring that predict outcomes of patients with gastroesophageal reflux disease

BACKGROUND & AIMS

pH-impedance monitoring detects acid and nonacid reflux events, but little is known about which parameters predict outcomes of different management strategies. We evaluated a cohort of medically and surgically managed patients after pH-impedance monitoring to identify factors that predict symptom improvement after therapy.

METHODS

In a prospective study, we followed up 187 subjects undergoing pH-impedance testing from January 2005 through August 2010 at Washington University in St. Louis, Missouri (mean age, 53.8 ± 0.9 y; 70.6% female). Symptom questionnaires assessed dominant symptom intensity (DSI) and global symptom severity (GSS) at baseline and at follow-up evaluation. Data collected from pH impedance studies included acid exposure time (AET), reflux exposure time (RET) (duration of impedance decrease 5 cm above lower esophageal sphincter, reported as the percentage of time similar to AET), symptom reflux correlation (symptom index and symptom association probability [SAP]), and the total number of reflux events. Univariate and multivariate analyses were performed to determine factors associated with changes in DSI and GSS after therapy.

RESULTS

Of the study subjects, 49.7% were tested on proton pump inhibitor (PPI) therapy and 68.4% were managed medically. After 39.9 ± 1.3 months of follow-up, DSI and GSS scores decreased significantly (P < .05). On univariate analysis, an abnormal AET predicted decreased DSI and GSS scores (P ≤ .049 for each comparison); RET and SAP from impedance-detected reflux events (P ≤ .03) also were predictive. On multivariate analysis, abnormal AET consistently predicted symptomatic outcome; other predictors included impedance-detected SAP, older age, and testing performed off PPI therapy. Abnormal RET, acid symptom index, or SAP, and numbers of reflux events did not independently predict a decrease in DSI or GSS scores.

CONCLUSIONS

Performing pH-impedance monitoring off PPI therapy best predicts response to antireflux therapy. Key parameters with predictive value include increased AET, and correlation between symptoms and reflux events detected by impedance.

Development of quality measures for the care of patients with gastroesophageal reflux disease

BACKGROUND & AIMS

Gastroesophageal reflux disease (GERD) is a common and costly disorder. Symptoms attributed to GERD have a wide spectrum of presentations and complications that have led to complex diagnostic and management algorithms. As such, there is considerable variation in clinical approaches to GERD. In contrast to multiple published guidelines for the management of GERD, there are few validated GERD quality measures. The objective of this study was to use a well-described, formal methodology to develop valid, physician-led quality measures for all aspects of care for patients with GERD.

METHODS

Quality measures were identified from the literature, consensus guidelines, and GERD experts. Eight clinical experts ranked potential measures for validity on the basis of the RAND/University of California, Los Angeles Appropriateness Methodology.

RESULTS

Of the 52 proposed quality measures, 24 were rated as valid, and 1 new measure was developed. These valid measures were related to initial diagnosis and management (9), monitoring (3), further diagnostic testing (4), proton pump inhibitor refractory symptoms (2), symptoms of chest pain (1), erosive esophagitis (3), esophageal stricture or ring (1), and surgical therapy (2). Fifteen of these measures were ranked with the highest validity. Twenty-seven measures were determined to be equivocal; 89% of these were extracted from guidelines that were based on low or moderate level evidence.

CONCLUSIONS

We used RAND/University of California, Los Angeles Appropriateness Methodology to develop quality measures for GERD care. By examining performance on these valid, formally developed quality measures, clinical practices and individual providers can assess their adherence with them and direct quality improvement efforts accordingly.

Refractory gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a condition that develops when the reflux of stomach contents into the esophagus causes troublesome symptoms, esophageal injury, and/or complications. Use of proton pump inhibitors (PPI) remains the standard therapy for GERD and is effective in most patients. Those whose symptoms are refractory to PPIs should be evaluated further and other treatment options should be considered, according to individual patient characteristics. Response to PPIs could be total (no symptoms), partial (residual breakthrough symptoms), or absent (no change in symptoms). Patients experiencing complete response do not usually need further management. Patients with partial response can be treated surgically or by using emerging endoscopic therapies. Patients who exhibit no response to PPI need further evaluation to rule out other causes.

Overlap in patients with dyspepsia/functional dyspepsia

Patients with dyspepsia/functional dyspepsia (FD) show frequent overlapping of other gastrointestinal (GI) diseases, such as irri-table bowel syndrome, and non-GI diseases, in addition to internal subgroup overlapping. These overlap patients have more frequent or more severe symptoms, poorer health-related quality of life and higher somatization scores, and they are more like-ly to experience anxiety, depression or insomnia compared to non-overlap patients. The higher prevalence of overlap in patients with dyspepsia/FD is not by chance, indicating common pathogeneses, including visceral hypersensitivity, altered GI motility, in-fection, and stressful early life events. There are few clinical trials targeting overlap in patients with dyspepsia/FD, and no ther-apeutic strategy has been established. Further studies in this research area are needed. In this review, we describe the epidemi-ology, pathogenesis and treatment of overlap in patients with dyspepsia/FD.(J Neurogastroenterol Motil 2014;20:447-457).