How to diagnose GERC more effectively: reflections on post-reflux swallow-induced peristaltic wave index and mean nocturnal baseline impedance.

INTRODUCTION: Post-reflux swallow-induced peristaltic wave index (PSPWI) and mean nocturnal baseline impedance (MNBI) are novel parameters reflect esophageal clearance capacity and mucosal integrity. They hold potential in aiding the recognition of gastroesophageal reflux-induced chronic cough (GERC). Our study aims to investigate their diagnostic value in GERC. METHODS: This study included patients suspected GERC. General information and relevant laboratory examinations were collected, and final diagnosis were determined following guidelines for chronic cough. The parameters of multichannel intraluminal impedance-pH monitoring (MII-pH) in patients were analyzed and compared to explore their diagnostic value in GERC. RESULTS: A total of 186 patients were enrolled in this study. The diagnostic value of PSPWI for GERC was significant, with the area under the working curve (AUC) of 0.757 and a cutoff value of 39.4%, which was not statistically different from that of acid exposure time (AET) (p > 0.05). The combined diagnostic value of AET > 4.4% and PSPWI < 39.4% was superior to using AET > 4.4% alone (p < 0.05). Additionally, MNBI and distal MNBI also contributed to the diagnosis of GERC, with AUC values of 0.639 and 0.624, respectively. AET > 4.4% or PSPWI < 39.4% is associated with a 44% reduction in missed diagnoses of non-acid GERC compared to AET > 6.0% or symptom association probability (SAP) ≥ 95%, and may be more favorable for identifying GERC. CONCLUSION: The diagnostic value of PSPWI for GERC is comparable to that of AET. Combining PSPWI < 39.4% or AET > 4.4% can improve the diagnostic efficiency by reducing the risk of missed diagnoses in cases where non-acid reflux is predominant. Distal MNBI and MNBI can serve as secondary reference indices in the diagnosis of GERC.

The effects of simulated gastroesophageal reflux on infant pig oropharyngeal feeding physiology.

The neural connectivity among the oral cavity, pharynx, and esophagus is a critical component of infant feeding physiology. Central integration of oral and pharyngeal afferents alters motor outputs to structures that power swallowing, but the potential effects of esophageal afferents on preesophageal feeding physiology are unclear. These effects may explain the prevalence of oropharyngeal dysphagia in infants suffering from gastroesophageal reflux (GER), though the mechanism underlying this relationship remains unknown. Here we use the validated infant pig model to assess the impacts of simulated GER on preesophageal feeding parameters. We used high-speed videofluoroscopy and electromyography to record bottle-feeding before and following the infusion of a capsaicin-containing solution into the lower esophagus. Sucking parameters were minimally affected by capsaicin exposure, such that genioglossus activity was unchanged and tongue kinematics were largely unaffected. Aspects of the pharyngeal swallow were altered with simulated GER, including increased thyrohyoid muscle activity, increased excursions of the hyoid and thyroid per swallow, decreased swallow frequency, and increased bolus sizes. These results suggest that esophageal afferents can elicit changes in pharyngeal swallowing. In addition, decreased swallowing frequency may be the mechanism by which esophageal pathologies induce oropharyngeal dysphagia. Although recent work indicates that oral or pharyngeal capsaicin may improve dysphagia symptoms, the decreased performance following esophageal capsaicin exposure highlights the importance of designing sensory interventions based upon neurophysiology and the mechanisms underlying disordered feeding. This mechanistic approach requires comprehensive data collection across the entirety of the feeding process, which can be achieved using models such as the infant pig.NEW & NOTEWORTHY Simulated gastroesophageal reflux (GER) in an infant pig model resulted in significant changes in pharyngeal swallowing, which suggests that esophageal afferents are centrally integrated to alter motor outputs to the pharynx. In addition, decreased swallow frequency and increased bolus sizes may be underlying mechanisms by which esophageal pathologies induce oropharyngeal dysphagia. The infant pig model used here allows for a mechanistic approach, which can facilitate the design of intervention strategies based on neurophysiology.

Manometric esophagogastric junction barrier metrics as predictors of gastroesophageal reflux.

BACKGROUND: High-resolution manometry (HRM) tools, like esophagogastric junction contractile integral (EGJ-CI), assess EGJ barrier function. GOALS: This study aimed to evaluate the relationships between manometric EGJ metrics with esophageal acid exposure. STUDY: We conducted a retrospective review of 284 patients who underwent HRM and ambulatory reflux testing between 11/2017-1/2020. EGJ-CI and total-EGJ-CI were manually calculated. Pathologic acid exposure was defined as pH < 4 with esophageal acid exposure time (EAET) exceeding 6.0%. Pearson's correlation, univariable and multivariable regression models were utilized to assess the relationships between pathologic acid exposure and EGJ parameters. Sensitivity and specificity thresholds for EGJ-CI and total EGJ-CI were optimized with ROC analyses. RESULTS: On univariable analysis, patients with pathologic acid exposure had increased odds of having lower mean basal LES pressures, EGJ-CI, and total EGJ-CI than patients without pathologic acid exposure. On multivariable analysis, age, EGJ-CI and mean DCI were significant predictors of pathologic acid exposure. There were significant, though weak, correlations between EAET and EGJ-CI and total EGJ-CI (r = - 0.18, - 0.19, p < 0.01, respectively). An EGJ-CI cutoff of 44.16 as a predictor for pathologic acid exposure had a sensitivity of 46% and specificity of 42% (AUC 0.60). Total EGJ-CI cutoff of 11,461.3 for pathologic acid exposure had a sensitivity of 44% and a specificity of 43% (AUC 0.62). CONCLUSION: EGJ-CI can independently predict pathologic acid exposure. However, the poor correlation between EGJ-CI and acid exposure, as well as the low sensitivity and specificity of calculated thresholds, indicate that mechanisms other than EGJ barrier function may impact acid exposure.

Laryngopharyngeal reflux disease: Updated examination of mechanisms, pathophysiology, treatment, and association with gastroesophageal reflux disease.

Laryngopharyngeal reflux disease (LPRD) is an inflammatory condition in the laryngopharynx and upper aerodigestive tract mucosa caused by reflux of stomach contents beyond the esophagus. LPRD commonly presents with sym-ptoms such as hoarseness, cough, sore throat, a feeling of throat obstruction, excessive throat mucus. This complex condition is thought to involve both reflux and reflex mechanisms, but a clear understanding of its molecular mechanisms is still lacking. Currently, there is no standardized diagnosis or treatment protocol. Therapeutic strategies for LPRD mainly include lifestyle modifications, proton pump inhibitors and endoscopic surgery. This paper seeks to provide a comprehensive overview of the existing literature regarding the mechanisms, patho-physiology and treatment of LPRD. We also provide an in-depth exploration of the association between LPRD and gastroesophageal reflux disease.

The cardiovascular effects of large hiatal hernias: a narrative review of cases and studies.

Hiatal hernia (HH) is a common disease in the general population. It is often asymptomatic, but if it does present clinical manifestations, these are usually gastrointestinal. Gastroesophageal reflux is the main symptom that accompanies it. Depending on the severity of the hernia, it is classified into several subtypes from I-IV. Especially, IV type (giant HH) can lead to various cardiopulmonary symptoms with several degrees of severity. It is necessary to keep this possibility in mind among the various differential diagnoses that may occur in this clinical setting. The current paper aims to review the literature on classic and novel information on the HH - cardiovascular system relationship. Epidemiological data, physiological aspects of the heart compressed by HH, cardiovascular symptoms, electrocardiographic changes, echocardiographic alterations and clinical implications are discussed.

Normally, the stomach and the heart are not in direct contact because they are in different cavities, the thorax and the abdomen, respectively. When part of the stomach moves toward the chest through the diaphragm, we say there is a hiatal hernia (HH). Most of the time the HH symptoms are mild and clearly digestive. In severe cases, surgical repair of the HH is required. Even in these circumstances, digestive symptoms continue to be the most frequent. However, some patients present cardiovascular symptoms and few or no digestive symptoms. This easily creates diagnostic confusion, which leads to incorrect treatments and unnecessary expenses. In extreme cases, as seen in giant HH, the degree of cardiovascular involvement is very serious. There are documented cases that have suffered cardiac arrest, arrhythmias of different types and symptoms like classic acute myocardial infarction. It is required that clinical doctors and surgeons are aware that this complication exists. Only with this in mind can a timely diagnosis be achieved. Some emergency measures have been saving, gastric decompression with a tube being the most important. The main mechanism that explains the serious cardiovascular consequences of giant HH is cardiac compression. The dissemination of this knowledge can help save lives.

A new predictive scoring model for globus pharyngeus in patients with gastroesophageal reflux disease.

BACKGROUND: Globus pharyngeus is a clinical condition, wherein, a patient senses a lump or a foreign body in the throat with a tightening or choking feeling. A strong association between globus pharyngeus and gastroesophageal reflux disease (GERD) was reported. Therefore, we sought to investigate the predictive factors of globus pharyngeus in patients with established GERD and fit a predictive scoring model for globus pharyngeus. METHODS: In this case-control study, 143 patients having globus pharyngeus along with GERD ( case ) and 109 patients having globus pharyngeus without GERD ( control ) were enrolled. Data comprising demographics, comorbidities, and psychosocial stress levels were recorded. The predictive factors of globus pharyngeus in patients with GERD were unraveled, and a predictive scoring model was fit for globus pharyngeus. RESULTS: Proton pump inhibitor usage in the case group was significantly higher compared to controls (63.63% vs 24.78%, P < 0.001), and differences in Hiatus Hernia and Stress levels were highly significant between the two groups ( P < 0.001). Multivariate logistic regression revealed that variates, Hiatus Hernia, psychosocial stress, and age were highly significant ( P < 0.001) independent predictors of globus pharyngeus. Using the regression coefficients of all the independent predictor variables, a predictive scoring model was fitted, which yielded an area under receiver operating characteristic (AUROC) curve of 78.9. CONCLUSION: Hiatus hernia, psychosocial stress, and age are significant independent predictors of globus pharyngeus in GERD, and our predictive scoring model may help in identifying patients at higher odds of experiencing globus pharyngeus and modulate treatment accordingly.

Relationship between endoscopic gastroesophageal valve grading and mean nocturnal baseline impedance and postreflux swallow-induced peristaltic wave index in patients with gastroesophageal reflux disease.

This study aimed to investigate the relationship between endoscopic gastroesophageal valve grading and mean nocturnal baseline impedance (MNBI) and postreflux swallow-induced peristaltic wave index (PSPWI) in patients with gastroesophageal reflux disease (GERD). A total of 120 patients diagnosed with GERD disease were included in the study. According to the classification of endoscopic gastroesophageal valves, the patients were divided into 5 groups, group 1 as baseline group, and Group 2-4 as Hill grade I-IV. Basic information about the patients was collected, including age and gender. The mean nocturnal baseline impedance and creep wave index induced by swallowing after rumination were measured by high resolution creep measurement technique. Through statistical analysis, the relationship between valve classification and observation index was discussed. In terms of MNBI, impedance values gradually decreased with increasing valve classification. The average impedance of the Grade 1 group was 23.5 mm Hg/cm2, while the average impedance of the Grade 5 group was 15.2 mm Hg/cm2. This reduction showed a significant decreasing trend (P < .001). In addition, in terms of the peristaltic wave index caused by swallowing after regurgitation, the peristaltic wave index gradually increased with the increase of valve classification. The mean index in the Grade 1 group was 1.8 beats/min, while the mean index in the Grade 5 group was 3.6 beats/min. This increase showed a significant positive relationship (P < .001). Endoscopic gastroesophageal valve grading was significantly correlated with MNBI and PSPWI in patients with GERD. These observations can serve as useful tools for assessing the severity of GERD and monitoring disease progression.

Differences Between Patients with Heartburn Refractory to Vonoprazan and Those Refractory to Proton Pump Inhibitors.

BACKGROUND: Vonoprazan, a potassium-competitive acid blocker, demonstrates more potent acid inhibition than proton pump inhibitors (PPIs). This study aimed to evaluate the effect of vonoprazan in patients with unproven gastroesophageal reflux disease (GERD) by comparing patients with vonoprazan-refractory heartburn with those with PPI-refractory heartburn. METHODS: This study included 104 consecutive patients with vonoprazan- or PPI-refractory heartburn (52 patients each), no erosive esophagitis on endoscopy and who underwent combined multichannel intraluminal impedance-pH (MII-pH) testing with vonoprazan/PPI discontinuation. Patients' backgrounds, symptom scores from four questionnaires, MII-pH results and high-resolution manometry results were compared between the two groups. RESULTS: The vonoprazan group demonstrated significantly higher GERD symptoms and scores of abdominal pain and diarrhea on the Gastrointestinal Symptom Rating Scale questionnaire. MII-pH results revealed that the vonoprazan group demonstrated 40.4%, 17.3%, and 42.3% and the PPIs group exhibited 26.9%, 17.3%, and 55.8% of abnormal acid reflux [true non-erosive reflux disease (NERD)], reflux hypersensitivity and functional heartburn, respectively. The vonoprazan group demonstrated higher true NERD rates but with no significant difference (p = 0.307). Among the vonoprazan group, eight patients with true NERD underwent another MII-pH test on vonoprazan, and all cases demonstrated normal acid exposure times (0.0% [0.0-0.3]). CONCLUSION: Patients with unproven GERD with vonoprazan-refractory heartburn demonstrated more symptoms, including not only GERD symptoms but also functional dyspepsia and irritable bowel syndrome symptoms, than those with PPI-refractory heartburn.

Update on extraesophageal manifestations of gastroesophageal reflux.

PURPOSE OF REVIEW: Symptoms/complications related to extraesophageal reflux (EER) are increasingly prevalent presentations and pose significant challenges for clinicians. We summarize and discuss clinical advances and developments in pathophysiology, testing and treatment algorithms of upper/lower airway manifestations of EER. RECENT FINDINGS: Growing evidence supports likely multifactorial causes of laryngeal symptoms, including EER, oropharyngeal pathologies, allergic conditions, and cognitive-affective processes (brain-larynx interaction). Diagnostic paradigm for laryngopharyngeal reflux (LPR) is shifting towards a personalized approach with noninvasive strategies/prediction tools to risk-stratify patients for upfront reflux testing over empiric acid suppression trials. Management should be multipronged to include antireflux therapies and treatments targeting other causes. Lower airway complications of EER may result in lung dysfunction and poor transplant outcomes. Esophageal symptoms are often absent and routine esophageal/reflux testing to guide timely antireflux therapies may lead to improved outcomes. Modalities that leverage impedance technology may be important, given the potential role of nonacidic reflux. Novel impedance-based metrics such as mean nocturnal baseline impedance and postreflux swallow-induced peristaltic wave index may provide adjunctive diagnostic values. SUMMARY: Standardized approach to diagnosis/management of EER should include multidisciplinary care teams and consider different phenotypes, nonreflux contributors, and the complex gut-airway relationships. Prompt antireflux therapies after careful candidate selection may improve outcomes of these airway complications.

Enhanced Runge-Kutta-driven feature selection model for early detection of gastroesophageal reflux disease.

Gastroesophageal reflux disease (GERD) profoundly compromises the quality of life, with prolonged untreated cases posing a heightened risk of severe complications such as esophageal injury and esophageal carcinoma. The imperative for early diagnosis is paramount in averting progressive pathological developments. This study introduces a wrapper-based feature selection model based on the enhanced Runge Kutta algorithm (SCCRUN) and fuzzy k-nearest neighbors (FKNN) for GERD prediction, named bSCCRUN-FKNN-FS. Runge Kutta algorithm (RUN) is a metaheuristic algorithm designed based on the Runge-Kutta method. However, RUN's effectiveness in local search capabilities is insufficient, and it exhibits insufficient convergence accuracy. To enhance the convergence accuracy of RUN, spiraling communication and collaboration (SCC) is introduced. By facilitating information exchange among population individuals, SCC expands the solution search space, thereby improving convergence accuracy. The optimization capabilities of SCCRUN are experimentally validated through comparisons with classical and state-of-the-art algorithms on the IEEE CEC 2017 benchmark. Subsequently, based on SCCRUN, the bSCCRUN-FKNN-FS model is proposed. During the period from 2019 to 2023, a dataset comprising 179 cases of GERD, including 110 GERD patients and 69 healthy individuals, was collected from Zhejiang Provincial People's Hospital. This dataset was utilized to compare our proposed model against similar algorithms in order to evaluate its performance. Concurrently, it was determined that features such as the internal diameter of the esophageal hiatus during distention, esophagogastric junction diameter during distention, and external diameter of the esophageal hiatus during non-distention play crucial roles in influencing GERD prediction. Experimental findings demonstrate the outstanding performance of the proposed model, with a predictive accuracy reaching as high as 93.824 %. These results underscore the significant advantage of the proposed model in both identifying and predicting GERD patients.

Analysis of the Correlation Between Dynamic Characteristics and Symptoms of Gastroesophageal Reflux Disease.

OBJECTIVE: To investigate the esophageal motility characteristics of gastroesophageal reflux disease (GERD) and their relationship with symptoms. PATIENTS AND METHODS: We examined 101 patients diagnosed with GERD by endoscopy and divided them into 3 groups as follows: nonerosive reflux disease (NERD), reflux esophagitis, and Barrett esophagus. Esophageal high-resolution manometry and the GERD Questionnaire were used to investigate the characteristics of esophageal dynamics and symptoms. In addition, the reflux symptom index was completed and the patients were divided into 7 groups according to symptoms. We then determined the correlation between dynamic esophageal characteristics and clinical symptoms. RESULTS: Upper (UES) and lower (LES) esophageal sphincter pressures and the 4-second integrated relaxation pressure in the RE group were lower than those in the NERD group. The 4-second integrated relaxation pressure in the Barrett esophagus group was also lower than that in the NERD group. In the analysis of extraesophageal symptoms, high-resolution manometry showed significant differences in UES pressures among all groups. Further subgroup analysis showed that compared with the group without extraesophageal symptoms, the UES pressure of the groups with pharyngeal foreign body sensation, throat clearing, and multiple extraesophageal symptoms was lower. CONCLUSIONS: As GERD severity increases, motor dysfunction of the LES and esophageal body gradually worsens, and the LES plays an important role in GERD development. Decreased UES pressure plays an important role in the occurrence of extraesophageal symptoms, which is more noticeable in patients with pharyngeal foreign body sensation and throat clearing.

Saliva Production and Esophageal Motility Influence Esophageal Acid Clearance Related to Post-reflux Swallow-Induced Peristaltic Wave.

BACKGROUND: The post-reflux swallow-induced peristaltic wave (PSPW) brings salivary bicarbonate to neutralize residual distal esophageal mucosal acidification. AIMS: To determine if reduced saliva production and esophageal body hypomotility would compromise PSPW-induced pH recovery in the distal esophagus. METHODS: In this multicenter retrospective cross-sectional study, patients with confirmed Sjogren's syndrome and scleroderma/mixed connective tissue disease (MCTD) who underwent high resolution manometry (HRM) and ambulatory pH-impedance monitoring off antisecretory therapy were retrospectively identified. Patients without these disorders undergoing HRM and pH-impedance monitoring for GERD symptoms were identified from the same time-period. Acid exposure time, numbers of reflux episodes and PSPW, pH recovery with PSPW, and HRM metrics were extracted. Univariate comparisons and multivariable analysis were performed to determine predictors of pH recovery with PSPW. RESULTS: Among Sjogren's syndrome (n = 34), scleroderma/MCTD (n = 14), and comparison patients with reflux symptoms (n = 96), the scleroderma/MCTD group had significantly higher AET, higher prevalence of hypomotility, lower detected reflux episodes, and very low numbers of PSPW (p ≤ 0.004 compared to other groups). There was no difference in pH-impedance metrics between Sjogren's syndrome, and comparison patients (p ≥ 0.481). Proportions with complete pH recovery with PSPW was lower in Sjogren's patients compared to comparison reflux patients (p = 0.009), predominantly in subsets with hypomotility (p < 0.001). On multivariable analysis, diagnosis of Sjogren's syndrome, scleroderma/MCTD or neither (p = 0.014) and esophageal hypomotility (p = 0.024) independently predicted lack of complete pH recovery with PSPW, while higher total reflux episodes trended (p = 0.051). CONCLUSIONS: Saliva production and motor function are both important in PSPW related pH recovery.

The Milan score: A novel manometric tool for a more efficient diagnosis of gastro-esophageal reflux disease.

OBJECTIVE: A definitive diagnosis of gastroesophageal reflux disease (GERD) depends on endoscopic and/or pH-study criteria. However, high resolution manometry (HRM) can identify factors predicting GERD, such as ineffective esophageal motility (IEM), esophago-gastric junction contractile integral (EGJ-CI), evaluating esophagogastric junction (EGJ) type and straight leg raise (SLR) maneuver response. We aimed to build and externally validate a manometric score (Milan Score) to stratify the risk and severity of the disease in patients undergoing HRM for suspected GERD. METHODS: A population of 295 consecutive patients undergoing HRM and pH-study for persistent typical or atypical GERD symptoms was prospectively enrolled to build a model and a nomogram that provides a risk score for AET > 6%. Collected HRM data included IEM, EGJ-CI, EGJ type and SLR. A supplemental cohort of patients undergoing HRM and pH-study was also prospectively enrolled in 13 high-volume esophageal function laboratories across the world in order to validate the model. Discrimination and calibration were used to assess model's accuracy. Gastroesophageal reflux disease was defined as acid exposure time >6%. RESULTS: Out of the analyzed variables, SLR response and EGJ subtype 3 had the highest impact on the score (odd ratio 18.20 and 3.87, respectively). The external validation cohort consisted of 233 patients. In the validation model, the corrected Harrel c-index was 0.90. The model-fitting optimism adjusted calibration slope was 0.93 and the integrated calibration index was 0.07, indicating good calibration. CONCLUSIONS: A novel HRM score for GERD diagnosis has been created and validated. The MS might be a useful screening tool to stratify the risk and the severity of GERD, allowing a more comprehensive pathophysiologic assessment of the anti-reflux barrier. TRIAL REGISTRATION: ClinicalTrials.gov (Identifier: NCT05851482).

Proximal esophageal impedance baseline increases the yield of impedance-pH and is associated with response to PPIs in chronic cough patients.

BACKGROUND: Chronic cough significantly impairs the quality of life. Although various studies focused on MNBI as assessed in the distal esophagus, scarce data are available on the clinical value of proximal measurements. AIM: To investigate the role of proximal MNBI in the workup of patients with chronic cough and its ability to predict PPI response. METHODS: Demographic, clinical, endoscopy findings, impedance-pH and HRM tracings from consecutive cough patients were evaluated. MNBI was calculated at proximal and distal esophagus. RESULTS: One hundred and sixty four patients were included. In addition to traditional variables, when considering also the PSPW index or MNBI at 3 cm or 15 cm, the proportion of patients with pathological impedance-pH monitoring significantly increased. 70/164 patients were responders, while 94 (57.3%) were non-responder to double PPI dose (p < 0.05). Patients with pathologic MNBI at 3 cm and/or 15 cm as well as those with pathologic PSPW index were characterized by a significantly higher proportion of responders than that observed among patients with normal impedance-pH variables (p < 0.001). The proportion of responders with pathological MNBI at 15 cm was significantly higher than the proportion of responders with pathological MNBI at 3 cm (82.8% vs. 64.3%, p < 0.05). At multivariable model, pathological MNBI at both 3 cm and 15 cm as well as PSPW index were associated with PPI responsiveness. The strongest association with PPI response was observed for MNBI at 15 cm. CONCLUSIONS: The assessment of MNBI at proximal esophagus increases the diagnostic yield of impedance-pH monitoring and may represent a useful predictor of PPI responsiveness in the cumbersome clinical setting of suspected reflux-related cough.

The impact of lung transplantation on esophageal motility and inter-relationships with reflux and lung mechanics in patients with restrictive and obstructive respiratory disease.

BACKGROUND: For many patients with lung disease the only proven intervention to improve survival and quality of life is lung transplantation (LTx). Esophageal dysmotility and gastroesophageal reflux (GER) are common in patients with respiratory disease, and often associate with worse prognosis following LTx. Which, if any patients, should be excluded from LTx based on esophageal concerns remains unclear. Our aim was to understand the effect of LTx on esophageal motility diagnosis and examine how this and the other physiological and mechanical factors relate to GER and clearance of boluses swallowed. METHODS: We prospectively recruited 62 patients with restrictive (RLD) and obstructive (OLD) lung disease (aged 33-75 years; 42 men) who underwent high resolution impedance manometry and 24-h pH-impedance before and after LTx. KEY RESULTS: RLD patients with normal motility were more likely to remain normal (p = 0.02), or if having abnormal motility to change to normal (p = 0.07) post-LTx than OLD patients. Esophageal length (EL) was greater in OLD than RLD patients' pre-LTx (p < 0.001), reducing only in OLD patients' post-LTx (p = 0.02). Reduced EL post-LTx associated with greater contractile reserve (r = 0.735; p = 0.01) and increased likelihood of motility normalization (p = 0.10). Clearance of reflux improved (p = 0.01) and associated with increased mean nocturnal baseline impedance (p < 0.001) in RLD but not OLD. Peristaltic breaks and thoraco-abdominal pressure gradient impact both esophageal clearance of reflux and boluses swallowed (p < 0.05). CONCLUSIONS AND INFERENCES: RLD patients are more likely to show improvement in esophageal motility than OLD patients post-LTx. However, the effect on GER is more difficult to predict and requires other GI, anatomical and pulmonary factors to be taken into consideration.

Recent advances in the knowledge of the mechanism of reflux hypersensitivity.

Reflux hypersensitivity (RH) is a subtype of gastroesophageal reflux disease. The Rome IV criteria separated RH from the original nonerosive reflux disease subgroup and classified it as a new functional oesophageal disease. Recently, the pathogenesis of RH has become the focus of research. According to the latest research reports, upregulation of acid-sensitive receptors, distribution of calcitonin gene-related peptide-positive nerve fibres, and psychiatric comorbidity have key roles in the pathogenesis of RH. This work reviews the latest findings regarding RH mechanisms.

The Evaluation of Gastric Emptying Using the 13 C-Acetate Breath Test in Neurologically Impaired Patients - A Focus on the Stomach Function and Morphology.

PURPOSE: We explored factors affecting gastric emptying in neurologically impaired (NI) patients using the 13C-acetate breath test. METHODS: Twenty-four NI patients were classified by the presence of gastroesophageal reflux disease (GERD), which was treated by fundoplication plus gastrostomy, or the absence of GERD, which was treated by gastrostomy alone, along with gastric malposition involving cascade stomach and organoaxial gastric volvulus (OGV). Gastric emptying parameters (GEPs), which were the emptying half time (T 1/2 , minute), the lag phase time (T lag , minute), and the gastric emptying coefficient (GEC), were measured before and after surgery. We evaluated the relationship between GEPs and GERD, gastric malposition, and surgical intervention. All data were expressed as the median (interquartile range). RESULTS: The T1/2 and GEC of patients with OGV were significantly worse than in those without OGV before surgery (T1/2 with OGV: 241.3 [154.9, 314.3] vs. T1/2 without OGV: 113.7 [105.2, 151.4], p = 0.01, GEC with OGV: 3.19 [2.46, 3.28] vs. GEC without OGV: 3.65 [3.24, 3.90], p = 0.02). GERD and cascade stomach were not associ ated with GEPs. The GEPs of all NI patients showed no significant difference between before and after surgery. The surgical change in T1/2 (ΔT 1/2 ) in the patients with OGV was significantly lower than in those without OGV (ΔT1/2 with OGV: -47.1 [-142.7, -22.1] vs. ΔT1/2 without OGV: -3.78 [-26.6, 12.0], p = 0.03). CONCLUSION: Stomach malposition, such as OGV, seems to affect gastric emptying and may be improved by surgi cal intervention.

The role of high-resolution impedance manometry to identify rumination syndrome in children with unexplained foregut symptoms.

OBJECTIVES: Diagnosis of rumination syndrome (RS) relies on Rome IV criteria. Oesophageal high-resolution impedance manometry (HRIM) can objectively demonstrate the episodes of rumination, but its role in the diagnostic pathway is not yet established. We aimed to demonstrate the clinical contribution of this tool for the timely diagnosis of RS and diagnostic work-up of children with unexplained foregut symptoms deemed to be due to other conditions. METHODS: HRIMs performed between 2012 and 2021 were searched to retrieve all diagnoses of RS. Medical records were reviewed for clinical data. RESULTS: Out of 461 HRIMs performed, 76 children had manometric diagnosis of RS (35 male, median age: 13 years). Of them, 47% were not clinically suspected as the symptoms did not fulfil clinical criteria for RS. The indications for HRIM in these cases were investigation of unexplained foregut symptoms (37%), suspected refractory gastroesophageal reflux disease (8%) and dysphagia (2%). Among all HRIMs performed for investigations of unexplained foregut symptoms (n = 80), 35% demonstrated rumination episodes. CONCLUSION: Identification of characteristic patterns of rumination on HRIM in children with unexplained foregut symptoms enables the immediate diagnosis of RS. Thus, in situations of diagnostic uncertainty, the use of HRIM at early stages of the diagnostic pathway would reduce unnecessary investigations and treatments.

Reflux Monitoring in Lung Disease: Is There a Better Metric than Esophageal Acid Exposure Time?

ABSTRACT: Ambulatory reflux monitoring can be performed with either a telemetry capsule to monitor for esophageal acid exposure alone for a period of 48-96 hours, and a 24 hour catheter based impedance/pH study which is most valuable for evaluating patients with objective evidence of GERD who are incompletely relieved with proton pump inhibitors. Some would consider catheter-based impedance/pH as the "best" test to evaluate patients with extraesophageal symptoms including suspected pulmonary complications of GERD. This editorial provides comment on the use of novel advanced metrics, mean nocturnal baseline impedance and post-reflux induced-swallow peristaltic wave index in analysis of these studies.