Thoracoabdominal pressure gradient and gastroesophageal reflux: insights from lung transplant candidates

Esophageal Motility Abnormalities in Lung Transplant Recipients With Esophageal Acid Reflux Are Different From Matched Controls

Background/Aims

There is an increased incidence of gastroesophageal reflux disease (GERD) after lung transplantation (LT) that can be associated with graft dysfunction. It is unclear if the underlying esophageal motility changes in GERD are different following LT. This study aimed to use esophageal high-resolution manometry (HRM) to explore GERD mechanisms in LT recipients compared to matched controls.

Methods

This was a retrospective study including patients with pathologic acid reflux who underwent HRM and pH testing at our healthcare facility July 2012 to October 2019. The study included 12 LT recipients and 36 controls. Controls were matched in a 1:3 ratio for age, gender, and acid exposure time (AET).

Results

LT recipients had less hypotensive esophagogastric junction (EGJ) (mean EGJ-contractile integral 89.2 mmHg/cm in LT vs 33.9 mmHg/cm in controls, P < 0.001). AET correlated with distal contractile integral and total EGJ-contractile integral only in LT group (r = -0.79, P = 0.002 and r = -0.57, P = 0.051, respectively).

Conclusions

Following LT, acid reflux is characterized by a less hypotensive EGJ compared to controls with similar AET. The strongest correlation with AET after LT was found to be esophageal peristaltic vigor. These results add to the understanding of reflux after LT and may help tailor an individualized treatment plan.

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.

Selective dysfunction of the crural diaphragm in patients with chronic restrictive and obstructive lung disease

BACKGROUND

Gastroesophageal reflux (GER) is known to be associated with chronic lung diseases. The driving force of GER is the transdiaphragmatic pressure (Pdi) generated mainly by costal and crural diaphragm contraction. The latter also enhances the esophagogastric junction (EGJ) pressure to guard against GER.

METHODS

The relationship between Pdi and EGJ pressure was determined using high resolution esophageal manometry in patients with interstitial lung disease (ILD, n = 26), obstructive lung disease (OLD, n- = 24), and healthy subjects (n = 20).

KEY RESULTS

The patient groups did not differ with respect to age, gender, BMI, and pulmonary rehabilitation history. Patients with ILD had significantly higher Pdi but lower EGJ pressures as compared to controls and OLD patients (p < 0.001). In control subjects, the increase in EGJ pressure at all-time points during inspiration was greater than Pdi. In contrast, the EGJ pressure during inspiration was less than Pdi in 14 patients with ILD and 7 patients with OLD. The drop in EGJ pressure was usually seen after the peak Pdi in ILD group (p < 0.0001) and before the peak Pdi in OLD group, (p = 0.08). Nine patients in the ILD group had sliding hiatus hernia, compared to none in control subjects (p = 0.003) and two patients in the OLD, (p = 0.04).

CONCLUSIONS AND INFERENCES

A higher Pdi and low EGJ pressure, and dissociation between Pdi and EGJ pressure temporal relationship suggests selective dysfunction of the crural diaphragm in patients with chronic lung diseases and may explain the higher prevalence of GERD in ILD as seen in previous studies.

Abnormal bolus reflux on impedance-pH testing independently predicts 3-year pulmonary outcome and mortality in pulmonary fibrosis

BACKGROUND AND AIM

Gastroesophageal reflux has been associated with idiopathic pulmonary fibrosis (IPF), although the directionality of the relationship has been debated. Data on the value of objective reflux measures in predicting IPF disease progression and mortality remain limited. We aimed to evaluate the association between multichannel intraluminal impedance and pH testing (MII-pH) and 3-year pulmonary outcomes in IPF patients.

METHODS

This was a retrospective cohort study of adults with IPF who underwent pre-lung transplant MII-pH off acid suppression at a tertiary center. Patients were followed for 3 years after MII-pH for poor pulmonary outcomes (hospitalization for respiratory exacerbation or death). A secondary analysis was performed using mortality as outcome of interest. Time-to-event analyses using Kaplan-Meier and Cox regression were performed to evaluate associations between MII-pH and poor outcomes.

RESULTS

One hundred twenty-four subjects (mean age = 61.7 ± 8 years, 62% male) were included. Increased bolus exposure time (BET) on MII-pH was associated with decreased time to poor pulmonary outcomes and death (log-ranked P-value = 0.017 and 0.031, respectively). On multivariable Cox regression analyses controlling for potential confounders including age, sex, smoking history, body mass index, proton pump inhibitor use, baseline pulmonary function, and anti-fibrotic therapy, increased BET was an independent predictor for poor pulmonary outcomes [hazard ratio 3.18 (95% confidence interval: 1.25-8.09), P = 0.015] and mortality [hazard ratio 11.3 (95% confidence interval: 1.37-63.9), P = 0.025] over 3 years.

CONCLUSIONS

Increased BET on MII-pH is an independent predictor of poor pulmonary outcomes and mortality over 3 years in IPF patients. These findings also support a role for gastroesophageal reflux in IPF disease progression and the potential impact of routine reflux testing and treatment.

Pre-Lung transplant reflux testing demonstrates high prevalence of gastroesophageal reflux in cystic fibrosis and reduces chronic rejection risk

BACKGROUND

Gastroesophageal reflux (GER) has been associated with poor outcomes after lung transplantation for chronic lung disease, including increased risk of chronic rejection. GER is common in cystic fibrosis (CF), but factors influencing the likelihood of pre-transplant pH testing, and the impact of testing on clinical management and transplant outcomes in patients with CF are unknown.

AIM

To evaluate the role of pre-transplant reflux testing in the evaluation of lung transplant candidates with CF.

METHODS

This was a retrospective study from 2007-2019 at a tertiary medical center that included all patients with CF undergoing lung transplant. Patients with pre-transplant anti-reflux surgery were excluded. Baseline characteristics (age at transplantation, gender, race, body mass index), self-reported GER symptoms prior to transplantation, and pre-transplant cardiopulmonary testing results, were recorded. Reflux testing consisted of either 24-h pH- or combined multichannel intraluminal impedance and pH monitoring. Post-transplant care included a standard immunosuppressive regimen, and regular surveillance bronchoscopy and pulmonary spirometry in accordance with institutional practice as well as in symptomatic patients. The primary outcome of chronic lung allograft dysfunction (CLAD) was defined clinically and histologically per International Society of Heart and Lung Transplantation criteria. Statistical analysis was performed with Fisher’s exact test to assess differences between cohorts, and time-to-event Cox proportional hazards modeling.

RESULTS

After applying inclusion and exclusion criteria, a total of 60 patients were included in the study. Among all CF patients, 41 (68.3%) completed reflux monitoring as part of pre-lung transplant evaluation. Objective evidence of pathologic reflux, defined as acid exposure time > 4%, was found in 24 subjects, representing 58% of the tested group. CF patients with pre-transplant reflux testing were older (35.8 vs 30.1 years, P = 0.01) and more commonly reported typical esophageal reflux symptoms (53.7% vs 26.3%, P = 0.06) compared to those without reflux testing. Other patient demographics and baseline cardiopulmonary function did not significantly differ between CF subjects with and without pre-transplant reflux testing. Patients with CF were less likely to undergo pre-transplant reflux testing compared to other pulmonary diagnoses (68% vs 85%, P = 0.003). There was a decreased risk of CLAD in patients with CF who underwent reflux testing compared to those who did not, after controlling for confounders (Cox Hazard Ratio 0.26; 95%CI: 0.08-0.92).

CONCLUSION

Pre-transplant reflux testing revealed high prevalence of pathologic reflux in CF patients and was associated with decreased risk of CLAD. Systematic reflux testing may enhance outcomes in this patient population.

Utilization of Oil Red O staining for assessing aspiration risk in lung transplant patients: A multidisciplinary prospective study with clinical practice insights

BACKGROUND

Gastroesophageal reflux disease with microaspiration has been associated with graft dysfunction in lung transplant patients. Identifying patients with aspiration is clinically important because it enables implementation of appropriate interventions like antireflux therapy. Oil Red O (ORO) staining with determination of the lipid-laden macrophage index (LLMI) has been proposed as a noninvasive surrogate marker in the detection of aspiration. The aim of this study was to prospectively evaluate clinical utilization of ORO staining in the assessment of aspiration risk.

METHODS

All transbronchial surgical pathology biopsies obtained in lung transplant patients undergoing routine surveillance from August 2020 through November 2021 were included in this study. Clinical team members prospectively ascertained the aspiration risk category (ARC) of each patient both before and after biopsy findings and recorded reasons for change in ARC.

RESULTS

A total of 132 transbronchial biopsies with concurrent LLMI were included in the study. LLMI was low in 51 cases (38.6%), including 21 of the 54 cases (38.9%) where aspiration was suggested based on the transbronchial biopsy findings. In total, 19 cases (14.4%) underwent a change in ARC post-biopsy including 10 that were upgraded and nine cases that were downgraded. Transbronchial biopsy findings were noted as the reason for change in ARC in the majority (15/19; 79%) of cases; only a minority (2/19; 10.5%) were due to the LLMI. Notably, 16 cases (12.1%) had a low LLMI with high-risk post-biopsy ARC and nine cases (6.8%) had a high LLMI with low-risk post-biopsy ARC.

CONCLUSIONS

This study observed that clinical evaluation for aspiration relied more heavily on transbronchial biopsy findings. Although LLMI may retain clinical utility in some scenarios, reevaluation of the clinical value of ORO testing would be prudent.

Routine Reflux Testing Guides Timely Antireflux Treatment to Reduce Acute and Chronic Rejection After Lung Transplantation

INTRODUCTION

Gastroesophageal reflux has been associated with poorer lung transplantation outcomes, although no standard approach to evaluation/management has been adopted. We aimed to evaluate the effect of timely antireflux treatment as guided by routine reflux testing on postlung transplant rejection outcomes.

METHODS

This was a retrospective cohort study of lung transplant recipients at a tertiary center. All patients underwent pretransplant ambulatory pH monitoring. Timely antireflux treatment was defined as proton pump inhibitor initiation or antireflux surgery within 6 months of transplantation. Patients were separated into 3 groups: normal pH monitoring (-pH), increased reflux (+pH) with timely treatment, and +pH with delayed treatment. Rejection outcomes included acute rejection, bronchiolitis obliterans syndrome, and chronic lung allograft dysfunction per International Society for Heart and Lung Transplantation criteria. Time-to-event analyses using Cox proportional hazard models were applied. Patients not meeting outcomes were censored at death or last clinic visit.

RESULTS

One hundred seventy-five patients (59% men/mean 56.3 yr/follow-up: 496 person-years) were included. On multivariable analyses, +pH/delayed treatment patients had higher risks of acute rejection (adjust hazard ratio [aHR]:3.81 [95% confidence interval [CI]: 1.90-7.64], P = 0.0002), bronchiolitis obliterans syndrome (aHR: 2.22 [95% CI: 1.07-4.58], P = 0.03), and chronic lung allograft dysfunction (aHR: 2.97 [95% CI: 1.40-6.32], P = 0.005) than +pH/timely treatment patients. Similarly, rejection risks were increased among +pH/delayed treatment patients vs -pH patients (all P < 0.05). No significant differences in rejection risks were noted between +pH/timely treatment patients and -pH patients. Failure/complications of antireflux treatment were rare and similar among groups.

DISCUSSION

Timely antireflux treatment, as directed by pretransplant reflux testing, was associated with reduced allograft rejection risks and demonstrated noninferiority to patients without reflux. A standardized peri-transplant test-and-treat algorithm may guide timely reflux management to improve lung transplant outcomes.

Sorting out the Relationship Between Esophageal and Pulmonary Disease

The aim of this review is to explore the relationship between esophageal syndromes and pulmonary diseases considering the most recent data available. Prior studies have shown a close relationship between lung diseases such as asthma, chronic obstructive pulmonary disorders (COPD), Idiopathic pulmonary fibrosis (IPF), and lung transplant rejection and esophageal dysfunction. Although the association has long been demonstrated, the exact relationship remains unclear. Clinical experience has shown a bidirectional relationship where esophageal disease may influence the outcomes of pulmonary disease and vice versa. The impact of esophageal dysfunction on pulmonary disorders may also be related to 2 different mechanisms: the reflux pathway leading to microaspiration and the reflex pathway triggering vagally mediated airway reactions. The aim of this review is to further explore these relationships and pathophysiologic mechanisms. Specifically, we discuss the proposed hypotheses for the relationship between the 2 diseases, as well as the pathophysiology and new developments in clinical management.

Foregut Dysmotility in the Lung Transplant Patient

PURPOSE OF REVIEW

To explore the role of upper gastrointestinal disease in the clinical course of lung transplant patients - including its pathophysiology, diagnostic testing, and treatment options.

RECENT FINDINGS

Gastroesophageal reflux disease (GERD) and foregut motility disorders are more prevalent among end-stage lung disease patients and are associated with poorer outcomes in lung transplant recipients. A proposed mechanism is the exposure of the lung allograft to aspirated contents, resulting in inflammation and rejection. Diagnostic tools to assess for these disorders include multichannel intraluminal impedance and pH (MII-pH) testing, high resolution esophageal manometry (HREM), and gastric emptying scintigraphy. The main treatment options are medical management with acid suppressants and/or prokinetic agents and anti-reflux surgery. In particular, data support the use of early anti-reflux surgery to improve outcomes. Newer diagnostic tools such as MII-pH testing and HREM allow for the identification of both acid and non-acid reflux and esophageal motility disorders, respectively. Recent studies have demonstrated that early anti-reflux surgery within six months post-transplant better protects against allograft injury and pulmonary function decline when compared to late surgery. However, further prospective research is needed to evaluate the short and long-term outcomes of these diagnostic approaches and interventions.

Chicago Classification update (v4.0): Technical review of high-resolution manometry metrics for EGJ barrier function

Esophagogastric junction (EGJ) barrier function is of fundamental importance in the pathophysiology of gastroesophageal reflux disease. Impaired EGJ barrier function leads to excessive distal esophageal acid exposure or, in severe cases, esophagitis. Hence, proposed high-resolution manometry (HRM) metrics assessing EGJ integrity are clinically important and were a focus of the Chicago Classification (CC) working group for inclusion in CC v4.0. However, the EGJ is a complex sphincter comprised of both crural diaphragm (CD) and lower esophageal sphincter (LES) component, each of which is subject to independent physiological control mechanisms and pathophysiology. No single metric can capture all attributes of EGJ barrier function. The working group considered several potential metrics of EGJ integrity including LES-CD separation, the EGJ contractile integral (EGJ-CI), the respiratory inversion point (RIP), and intragastric pressure. Strong recommendations were made regarding LES-CD separation as indicative of hiatus hernia, although the numerical threshold for defining hiatal hernia was not agreed upon. There was no agreement on the significance of the RIP, only that it could localize either above the LES or between the LES and CD in cases of hiatus hernia. There was agreement on how to measure the EGJ-CI and that it should be referenced to gastric pressure in units of mmHg cm, but the numerical threshold indicative of a hypotensive EGJ varied widely among reports and was not agreed upon. Intragastric pressure was endorsed as an important metric worthy of further study but there was no agreement on a numerical threshold indicative of abdominal obesity.

Identification of Lung Transplant Recipients with a Survival Benefit after Fundoplication

BACKGROUND

Gastroesophageal reflux disease (GERD) and aspiration of enteric contents is associated with worse outcomes after lung transplant. The purpose of this study is to elucidate populations that benefit the most from fundoplication after lung transplant.

METHODS

Lung transplants from 2001-2019 (n=971) were retrospectively reviewed and stratified by a fundoplication before (n=128) or after (n=24) chronic lung allograft dysfunction (CLAD) development vs those who didn't. Patients with a fundoplication prior to CLAD were propensity-matched to those without a fundoplication. The primary outcome of interest was post-transplant survival. Time-to-event rates were calculated using a multivariable Cox proportional hazards model and Kaplan-Meier functions.

RESULTS

A fundoplication prior to CLAD improved post-transplant survival before and after propensity-matching, and remained a significant predictor after adjusting for baseline characteristics (HR:0.57, 95% CI:0.4-0.8, P=0.001). Recipients with a restrictive disorder (HR: 0.46, 95% CI:0.3-0.73, P=0.001), age <65 (HR:0.48, 95% CI:0.32-0.71, P<0.001), and both single (HR:0.47, 95% CI:0.28-0.79, P=0.005) or double (HR:0.55, 95% CI:0.32-0.93, P=0.027) lung transplants had a significant decrease in mortality after fundoplication. The effect was present after excluding early deaths and/or CLAD diagnoses. GERD diagnosed by pH, impedance or EGD was not associated with worse outcomes. Among patients with CLAD, a fundoplication was an independent predictor of post-CLAD survival (HR:0.27, 95% CI:0.12-0.61, P=0.002).

CONCLUSIONS

A fundoplication before or after CLAD development is an independent predictor of survival. Younger patients with restrictive disease, independent of the type of transplant, have a survival benefit. GERD diagnosed by conventional methods was not associated with worse survival.

The Perils and Pitfalls of Esophageal Dysmotility in Idiopathic Pulmonary Fibrosis

INTRODUCTION

Gastroesophageal reflux plays a significant role in idiopathic pulmonary fibrosis (IPF). Given the morbidity and mortality associated with IPF, understanding the mechanisms responsible for reflux is essential if patients are to receive optimal treatment and management, especially given the lack of clear benefit of antireflux therapies. Our aim was to understand the inter-relationships between esophageal motility, lung mechanics and reflux (particularly proximal reflux-a prerequisite of aspiration), and pulmonary function in patients with IPF.

METHODS

We prospectively recruited 35 patients with IPF (aged 53-75 years; 27 men) who underwent high-resolution impedance manometry and 24-hour pH-impedance, together with pulmonary function assessment.

RESULTS

Twenty-two patients (63%) exhibited dysmotility, 16 (73%) exhibited ineffective esophageal motility (IEM), and 6 (27%) exhibited esophagogastric junction outflow obstruction. Patients with IEM had more severe pulmonary disease (% forced vital capacity: P = 0.032) and more proximal reflux (P = 0.074) than patients with normal motility. In patients with IEM, intrathoracic pressure inversely correlated with the number of proximal events (r = -0.429; P = 0.098). Surprisingly, inspiratory lower esophageal sphincter pressure (LESP) positively correlated with the percentage of reflux events reaching the proximal esophagus (r = 0.583; P = 0.018), whereas in patients with normal motility, it inversely correlated with the bolus exposure time (r = -0.478; P = 0.098) and number of proximal events (r = -0.542; P = 0.056). % forced vital capacity in patients with IEM inversely correlated with the percentage of reflux events reaching the proximal esophagus (r = -0.520; P = 0.039) and inspiratory LESP (r = -0.477; P = 0.062) and positively correlated with intrathoracic pressure (r = 0.633; P = 0.008).

DISCUSSION

We have shown that pulmonary function is worse in patients with IEM which is associated with more proximal reflux events, the latter correlating with lower intrathoracic pressures and higher LESPs.

Esophageal disease in lung transplant patients

There is a very well-established and complex interplay between gastroesophageal reflux and lung disease. This is particularly true in end-stage lung disease and post-lung transplant patients. Numerous studies have shown that in patients who are undergoing pre-lung transplant evaluations for diseases such as idiopathic pulmonary fibrosis (IPF), emphysema, connective tissue disease, there is a high prevalence of gastroesophageal reflux and esophageal dysmotility. Post-lung transplant, many of the reflux issues persist or worsen, and there is some evidence to suggest that this leads to worsened long-term allograft function and bronchiolitis obliterans. Anti-reflux operations in patients with lung disease have been shown to be safe in both the pre and post-lung transplant setting and lead to improved reflux symptoms, as well as protecting against reflux induced allograft dysfunction in the post-lung transplant patients. Barrett’s esophagus and esophageal malignancy are also not unheard of in these patients, and select patients may benefit from operative intervention. This review discusses the links between gastroesophageal reflux and lung transplant patients in both the pre and post-transplant setting. We also review the approach to the workup of esophageal disease in the pre-lung transplant setting as well as the surgical management of this unique group of patients.

Reflux-Aspiration in Chronic Lung Disease

Microaspiration, or silent aspiration, is commonly suspected in patients with refractory respiratory symptoms, including unexplained chronic cough, asthma, chronic obstructive pulmonary disease, bronchiolitis, bronchiectasis, and idiopathic pulmonary fibrosis. This suspicion is driven by the high prevalence of gastroesophageal reflux in these otherwise disparate disorders. Frequently, patients receive aggressive treatment for gastroesophageal reflux disease as a means of treating their underlying respiratory conditions, even in the absence of overt symptoms of reflux. However, clinical trials have not demonstrated a clear impact on outcomes with this strategy, and in some instances there may be potential for harm. Mechanistic studies have increasingly used gastric biomarkers obtained directly from the airways to confirm the association between reflux and respiratory disease, but results are limited by methodologic flaws and correlation. The best evidence of aspiration directly causing respiratory disorders is the histopathologic detection of foreign bodies. For most of the other chronic respiratory disorders, microaspiration may be uncommon or a secondary aggravating factor, as in patients with acute exacerbations of chronic obstructive pulmonary disease or idiopathic pulmonary fibrosis. In some cases, microaspiration is probably not a significant factor at all, such as in unexplained chronic cough. It is important to distinguish between conditions in which aspiration is primarily or directly causal and conditions in which aspiration may be indirectly aggravating, to help identify whether interventions targeting reflux and aspiration precautions should be recommended to patients. Our clinical review examines some of the evidence supporting reflux-aspiration as a mechanism for several chronic respiratory disorders and offers some management considerations when reflux-aspiration is suspected.

Pathological Implications of Swallow-Associated Transient Lower Esophageal Sphincter Elevation

BACKGROUND

The lower esophageal sphincter (LES) overlaps the crural diaphragm (CD) in patients without hiatal hernia (HH). Swallowing induces esophageal peristalsis with longitudinal esophageal shortening, causing transient elevation of the LES above the CD. This phenomenon, visible on high-resolution manometry (HRM), is called swallow-induced transient HH (tHH).

METHODS

We assessed pathological implications of swallow-induced LES elevation. We included patients who underwent 24-h pH monitoring and HRM between January 1, 2017 and June 30, 2018. Patients with manometric HH were excluded. Patients were divided into 3 groups: persistent tHH, which indicated significant LES-CD separation (i.e., ≥ 1cm in ≥ 30% swallows, or ≥ 2cm in ≥ 10% swallows) at the second inspiration after the conclusion of swallow-induced esophageal peristalsis; incidental tHH, which indicated significant LES-CD separation at the first inspiration after peristalsis without meeting persistent tHH criterion; and non-tHH.

RESULTS

In total, 107 patients were included. There were 18 patients in the persistent tHH group, 54 in the incidental tHH group, and 35 in the non-tHH group. No differences were observed in esophageal body motility or LES antireflux barrier parameters among groups. However, patients with persistent tHH had significantly higher DeMeester scores, longer acid exposure time, and poorer acid clearance. Prevalence of pathological reflux was 83.3% in the persistent tHH cohort. Esophagogastroduodenoscopy showed that 76.9% of patients with persistent tHH had no HH. Endoscopic findings of the esophagogastric junction were similar among groups.

CONCLUSIONS

Persistent tHH seems to be a pathological finding associated with pathological reflux.

Esophageal Evaluation for Patients Undergoing Lung Transplant Evaluation: What Should We Do for Evaluation and Management

Lung transplantation is a high-risk, but lifesaving, procedure for patients with end-stage lung disease. Although 1-year survival is high, long-term survival is not nearly as high, due mainly to acute and chronic rejection. Bronchiolitis obliterans syndrome is the most common type of chronic rejection and often leads to poor outcomes. For this reason, esophageal testing in the lung transplant population has become a major issue, and this article discusses the evidence behind esophageal testing, the importance of esophageal dysmotility gastroesophageal reflux disease, both acidic and nonacidic reflux, and aspiration and the treatment of these findings.

Pathophysiology, diagnosis, and pharmacological treatment of gastro-esophageal reflux disease

INTRODUCTION

Gastro-esophageal reflux disease (GERD) is a highly prevalent, chronic, relapsing disorder, whose knowledge has increased in last years thanks to the advent of new sophisticated techniques, such as 24-h impedance-pH monitoring and high-resolution manometry, for the study of esophageal functions.

AREAS COVERED

This review provides an overview of our advancements in understanding the complex pathophysiology, improving the diagnosis and defining the modern pharmacological therapeutic approach to GERD.

EXPERT OPINION

The growing clinical application of impedance-pH testing has allowed us to know the diversity of patients with non-erosive reflux disease (NERD), who nowadays represent about 70% of the whole population with reflux symptoms. We have realized that NERD has to be considered as an umbrella term covering various subgroups with different pathophysiologies. The development of new impedance metrics, in particular mean nocturnal baseline impedance, seems to be promising in the improvement of the diagnostic process of this disease. There are no particularly innovative features in the pharmacological therapy of GERD, unless the interest toward drugs is able to increase the defense properties of esophageal mucosa and/or its protection. These compounds can be of help in combination with proton pump inhibitors in NERD patients with partial response to antisecretory drugs alone.

Simple Manometric Index for Comprehensive Esophagogastric Junction Barrier Competency Against Gastroesophageal Reflux

BACKGROUND

The esophagogastric junction (EGJ) is an anatomic and physiologic barrier against gastroesophageal reflux. Comprehensive evaluation of EGJ barrier parameters using high-resolution manometry in patients with GERD has not been well established. We propose a simple index for comprehensive EGJ antireflux competency.

STUDY DESIGN

Patients who underwent high-resolution manometry and 24-hour pH monitoring between January 2017 and September 2018 were included. Of these, patients with normal esophageal motility were selected. EGJ antireflux competency was assessed based on the following 3 categories: anatomic configuration of the EGJ complex (ie EGJ morphology), backflow-preventive pressure on the lower esophageal sphincter (LES) (ie LES pressure integral), and backflow-promotive pressure across the LES (ie thoracoabdominal pressure gradient). Each category was scored on a scale of 0 to 2, applying clinically meaningful divisions, and a cumulative score was calculated (EGJ index: 0 to 6 points). DeMeester score > 14.72 indicated GERD.

RESULTS

In total, 259 patients met study criteria. Of these, GERD was noted in 109 patients (42.1%). The pH parameters were gradually exacerbated, depending on the EGJ index. Good correlations were seen between EGJ index and previously proposed parameters for EGJ disruption, including LES length, LES pressure, and LES pressure integral (area under the curve > 0.9 [excellent validation]). No patient had GERD if the EGJ index score was 0. However, GERD was seen in as high as 85.7% of patients with the highest score of 6.

CONCLUSIONS

EGJ disruption severity was clearly graded based on a simple scoring method, which can improve evaluation and development of clinical strategies for GERD.

Prevalence and Natural History of Barrett's Esophagus in Lung Transplant: A Single-Center Experience

BACKGROUND

Barrett's esophagus (BE)-intestinal metaplasia in the esophagus-may progress to low-grade dysplasia (LGD), high-grade dysplasia (HGD), and ultimately, invasive esophageal adenocarcinoma (EAC). The course of BE in immunosuppressed lung transplant recipients is unknown.

METHODS

This study retrospectively reviewed the records of patients who underwent lung transplant at a single center, Norton Thoracic Institute in Phoenix, Arizona, between January 1, 2010 and October 31, 2016. Pretransplant esophagram, esophagogastroduodenoscopy, 24-hour pH monitoring, high-resolution manometry, and gastric emptying studies were analyzed.

RESULTS

Of the 466 patients who underwent lung transplant during the study period, 54 (11.59%) had BE on pretransplant esophagogastroduodenoscopy. Of these, 1 patient had HGD before lung transplant. The median age of patients was 64 years (interquartile range, 58.25 to 68.75 years); 66.7% were men. Median follow-up duration was 29.48 months (interquartile range, 19.69 to 37.98 months). Sixteen of 54 patients (29.62%) underwent antireflux surgery after lung transplant. LGD or EAC developed in 3 patients during posttransplant surveillance. One patient had a diagnosis of HGD 24 months after retransplant. She underwent complete endoscopic ablation and was dysplasia-free for 5 months, but ultimately the condition recurred, and she underwent esophagectomy for invasive cancer. Two patients had a diagnosis of LGD 7 and 13 months after lung transplant and were successfully treated with radiofrequency ablation. The rate of progression to dysplasia or EAC was 2.3% per patient-year.

CONCLUSIONS

BE seems to be more prevalent in lung transplant recipients than in the general population. The study findings suggest that patients with BE have a higher risk of BE-to-EAC progression after lung transplant and that HGD may progress rapidly in immunosuppressed patients. More intensive surveillance endoscopy may be required in patients with BE after lung transplant.