Gastroesophageal reflux symptoms are not sufficient to guide esophageal function testing in lung transplant candidates

Esophageal Function Testing Patterns in the Evaluation and Management of Lung Transplantation: Results of a National Survey

GOALS

We surveyed esophageal motility laboratories affiliated with adult pulmonary transplant centers to determine esophageal function testing (EFT) practices.

BACKGROUND

Gastroesophageal reflux and esophageal dysmotility are associated with worse lung transplant outcomes, yet no consensus guidelines for EFT exist in this population.

STUDY

A deidentified online survey was sent to gastrointestinal motility laboratory directors of 49 academic and community-affiliated medical centers that perform lung transplants. Practice characteristics, including annual lung transplant volume and institutional EFT practices pre-lung transplantation and post-lung transplantation were queried. Respondents were categorized by transplant volume into small and large programs based on median annual volume.

RESULTS

Among 35 respondents (71% response rate), the median annual transplant volume was 37, and there were 18 large programs. Institutional EFT protocols were used pretransplant by 24 programs (68.6%) and post-transplant by 12 programs (34.2%). Among small and large programs, 52.9% and 72.2% always obtained high-resolution manometry before transplant, respectively. Endoscopy before transplant was performed more often in small programs (n=17, 100%) compared with large programs (n=15,83.3%). Pretransplant endoscopy ( P =0.04), barium esophagram ( P <0.01), and high-resolution manometry ( P =0.04) were more common than post-transplant. In contrast, post-transplant reflux monitoring off-therapy was more common than pretransplant ( P =0.01). In general, pulmonologists direct referrals for EFT and gastroenterology consultation (n=28, 80.0%), with symptoms primarily prompting testing.

CONCLUSIONS

In the absence of established guidelines, substantial variability exists in pretransplant and post-transplant EFT, directed by pulmonologists. Standardized EFT protocols and gastroenterologist-directed management of esophageal dysfunction has potential to improve lung transplant outcomes.

A practical approach to ineffective esophageal motility

BACKGROUND AND PURPOSE

Ineffective esophageal motility (IEM) is the most frequently diagnosed esophageal motility abnormality and characterized by diminished esophageal peristaltic vigor and frequent weak, absent, and/or fragmented peristalsis on high-resolution esophageal manometry. Despite its commonplace occurrence, this condition can often provoke uncertainty for both patients and clinicians. Although the diagnostic criteria used to define this condition has generally become more stringent over time, it is unclear whether the updated criteria result in a more precise clinical diagnosis. While IEM is often implicated with symptoms of dysphagia and gastroesophageal reflux disease, the strength of these associations remains unclear. In this review, we share a practical approach to IEM highlighting its definition and evolution over time, commonly associated clinical symptoms, and important management and treatment considerations. We also share the significance of this condition in patients undergoing evaluation for anti-reflux surgery and consideration for lung transplantation.

Concurrent abnormal non-acid reflux is associated with additional chronic rejection risk in lung transplant patients with increased acid exposure

Acid reflux has been associated with allograft injury and rejection in lung transplant patients; however, the pathogenic role of non-acid reflux remains debated. We aimed to evaluate the impact of concurrent abnormal non-acid reflux with acid reflux on chronic rejection in lung transplant patients with acid reflux. This was a retrospective cohort study of lung transplant recipients who underwent pre-transplant combined impedance-pH study off acid suppression. Only subjects with acid exposure >4% were included. Non-acid reflux (pH > 4) episodes >27 was considered abnormal per prior normative studies. Chronic rejection was defined as chronic lung allograft dysfunction (CLAD) per International Society for Heart and Lung Transplantation criteria. Time-to-event analyses were performed using Cox proportional hazards and Kaplan-Maier methods, with censoring at death, anti-reflux surgery, or last follow-up. In total, 68 subjects (28 abnormal/40 normal non-acid reflux) met inclusion criteria for the study. Baseline demographic/clinical characteristics were similar between groups. Among this cohort of patients with increased acid exposure, subjects with concurrent abnormal non-acid reflux had significantly higher risk of CLAD than those without on Kaplan-Meier analysis (log-ranked P = 0.0269). On Cox multivariable regression analysis controlling for body mass index, age at transplantation, and proton pump inhibitor use, concurrent abnormal non-acid reflux remained independently predictive of increased CLAD risk (hazard ratio 2.31, confidence interval: 1.03-5.19, P = 0.04). Presence of concurrent abnormal non-acid reflux in lung transplant subjects with increased acid exposure is associated with additional risk of chronic rejection. Non-acid reflux may also contribute to pathogenicity in lung allograft injury/rejection, supporting a potential role for impedance-based testing in this population.

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.

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.

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.

Acid exposure time is sensitive for detecting gastroesophageal reflux disease and is associated with long-term survival after lung transplant

Gastroesophageal reflux disease (GERD) is common in patients who have undergone lung transplantation and is associated with poorer outcomes, but guidelines are lacking to direct management strategies in this population. We assessed the diagnostic yield of impedance metrics compared to pH-metry alone for detecting GERD among lung transplant recipients and evaluated their association with clinical outcomes. We performed a retrospective cohort study of consecutive patients who underwent lung transplantation. Demographic data, acid exposure time (AET), number of reflux episodes, mean nocturnal baseline impedance (MNBI), post-reflux swallowing-induced peristaltic wave index (PSPWI), and clinical outcomes including mortality were collected. The relationship between GERD metrics and clinical outcomes was assessed using Wilcoxon signed-rank test and Fisher's exact test as appropriate. Of the 76 patients studied, 29 (38%) had GERD based on abnormal AET after lung transplantation. One (1.3%) patient had GERD based on elevated number of reflux episodes and abnormal distal MNBI detected GERD in 19 (26%) patients, resulting in 62% sensitivity and 94% specificity. Two (2.6%) patients had normal PSPWI. Patients with low distal MNBI had significantly decreased forced expiratory volume in 1 second (FEV1) at 3-year posttransplant compared to those without low distal MNBI (P = 0.03). Three-year survival was significantly worse among patients with elevated AET (66.7% vs. 89.1%, P = 0.03) but not with low distal MNBI (68.4% vs. 84.3%, P = 0.18). Abnormal AET is more sensitive for detecting GERD than other reflux metrics studied and is associated with survival, suggesting pH-metry alone may be sufficient to guide GERD management after lung transplant.

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.

Relationship Between Esophageal Disease and Pulmonary Fibrosis

Esophageal disorders are prevalent among patients with chronic lung diseases, including idiopathic pulmonary fibrosis (IPF). Gastroesophageal reflux disease (GERD) has been associated with IPF prevalence, severity, and respiratory decline. The pathophysiologic relationship between GERD and IPF is likely bidirectional, with aspiration of refluxate leading to lung inflammation and fibrosis, while the restrictive pulmonary physiology may contribute to altered transdiaphragmatic pressure gradient and increased reflux. Esophageal symptoms are frequently absent and do not predict esophageal dysfunction or pathologic reflux in patients with IPF, and objective diagnostic tools including upper endoscopy, ambulatory reflux monitoring, and high-resolution manometry are often needed. Impedance-based testing that identifies both weakly/non-acidic and acid reflux may provide important additional diagnostic value beyond pH-based acid testing alone. Novel metrics and maneuvers, including advanced impedance measures on impedance-pH study and provocative testing on HRM, may hold promise to future diagnostic advancements. The main treatment options include medical therapy with acid suppressants and anti-reflux surgery, although their potential benefits in pulmonary outcomes of IPF require further validations. Future directions of research include identifying phenotypes of IPF patients who may benefit from esophageal testing and treatment, determining the optimal testing strategy and protocol, and prospectively assessing the value of different esophageal therapies to improve outcomes while minimizing risks. This review will discuss the pathophysiology, evaluation, and management of esophageal diseases, particularly GERD, in patients with IPF, as informed by the most recent publications in the field, in hopes of identifying targets for future study and research.

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.

Recipient Comorbidities for Prediction of Primary Graft Dysfunction, Chronic Allograft Dysfunction and Survival After Lung Transplantation

Since candidates with comorbidities are increasingly referred for lung transplantation, knowledge about comorbidities and their cumulative effect on outcomes is scarce. We retrospectively collected pretransplant comorbidities of all 513 adult recipients transplanted at our center between 1992–2019. Multiple logistic- and Cox regression models, adjusted for donor-, pre- and peri-operative variables, were used to detect independent risk factors for primary graft dysfunction grade-3 at 72 h (PGD3-T72), onset of chronic allograft dysfunction grade-3 (CLAD-3) and survival. An increasing comorbidity burden measured by Charleston-Deyo-Index was a multivariable risk for survival and PGD3-T72, but not for CLAD-3. Among comorbidities, congestive right heart failure or a mean pulmonary artery pressure >25 mmHg were independent risk factors for PGD3-T72 and survival, and a borderline risk for CLAD-3. Left heart failure, chronic atrial fibrillation, arterial hypertension, moderate liver disease, peptic ulcer disease, gastroesophageal reflux, diabetes with end organ damage, moderate to severe renal disease, osteoporosis, and diverticulosis were also independent risk factors for survival. For PGD3-T72, a BMI>30 kg/m2 was an additional independent risk. Epilepsy and a smoking history of the recipient of >20packyears are additional independent risk factors for CLAD-3. The comorbidity profile should therefore be closely considered for further clinical decision making in candidate selection.

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.

Swallowing and laryngeal complications in lung and heart transplantation: Etiologies and diagnosis

Despite continued surgical advancements in the field of cardiothoracic transplantation, post-operative complications remain a burden for the patient and the multidisciplinary team. Lesser-known complications including swallowing disorders (dysphagia), and voice disorders (dysphonia), are now being reported. Such disorders are known to be associated with increased morbidity and mortality in other medical populations, however their etiology amongst the heart and lung transplant populations has received little attention in the literature. This paper explores the potential mechanisms of oropharyngeal dysphagia and dysphonia following transplantation and discusses optimal modalities of diagnostic evaluation and management. A greater understanding of the implications of swallowing and laryngeal dysfunction in the heart and lung transplant populations is important to expedite early diagnosis and management in order to optimize patient outcomes, minimize allograft injury and improve quality of life.

Predictors of Abnormal Functional Luminal Impedance Planimetry Findings in Non-mechanical Esophagogastric Junction Outflow Obstruction

BACKGROUND

Esophagogastric junction outflow obstruction (EGJOO) is a common but nonspecific motility pattern identified by esophageal high-resolution manometry (HRM). Functional luminal impedance planimetry (FLIP) provides information regarding lower esophageal sphincter (LES) mechanics, which can identify achalasia spectrum disorders and is useful in evaluating EGJOO. However, the relationship between HRM and FLIP parameters in EGJOO is not clearly defined.

AIMS

To identify predictors of abnormal FLIP findings in patients with non-mechanical EGJOO.

METHODS

This is a retrospective cohort study of patients with non-mechanical EGJOO who underwent FLIP between 10/1/16 and 7/1/19. Demographic data including age and gender, examination indication, concomitant medications, HRM parameters, symptom burden, and FLIP metrics of diameter and distensibility index (DI) were collected. DI was categorized as not low (DI > 2.8), borderline low (DI 1.1-2.8), and definitely low (DI ≤ 1). Kruskal-Wallis and Fisher's exact tests were used to assess the relationship between HRM and FLIP parameters and to identify predictors of abnormal FLIP.

RESULTS

Among the 44 patients studied, most were female (n = 33, 75%) and the median age was 63. The median IRP was 18.2, and 10 (23%) patients used chronic narcotics. Lower total heartburn and regurgitation scores, and LES diameter by FLIP are associated with definitely low DI.

CONCLUSIONS

In patients with non-mechanical EGJOO, reflux burden scores and FLIP diameters can aid in predicting DI. These results may provide useful adjunctive data to help in differentiating which patients have meaningful outflow obstruction.

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.

Esophageal Motility Disorders Associated With Death or Allograft Dysfunction After Lung Transplantation? Results of a Retrospective Monocentric Study

OBJECTIVES

Pathological gastroesophageal reflux (GER) is a known risk factor for bronchiolitis obliterans syndrome (BOS) after lung transplantation. This study aimed at determining whether functional esophageal evaluation might predict BOS occurrence and survival in this setting.

METHODS

Ninety-three patients who underwent esophageal high-resolution manometry and 24-hour pH-impedance monitoring within the first year after lung transplantation were retrospectively included. A univariable analysis was performed to evaluate the parameters associated with GER disease and BOS occurrence. The Cox regression model was used to identify the prognostic factors of death or retransplantation.

RESULTS

Thirteen percent of patients exhibited major esophageal motility disorders and 20% pathological GER. GER occurrence was associated with younger age, cystic fibrosis, and hypotensive esophagogastric junction. Within a median follow-up of 62 months, 10 patients (11%) developed BOS, and no predictive factors were identified. At the end of the follow-up, 10 patients died and 1 underwent retransplantation. The 5-year cumulative survival rate without retransplantation was lower in patients with major esophageal motility disorders compared with that in those without (75% vs 90%, P = 0.01) and in patients who developed BOS compared with that in those without (66% vs 91%; P = 0.005). However, in multivariable analysis, major esophageal motility disorders and BOS were no longer significant predictors of survival without retransplantation.

DISCUSSION

Major esophageal motility disorders and BOS were associated with allograft survival in lung transplantation in the univariable analysis. Although the causes of this association remain to be determined, this observation confirms that esophageal motor dysfunction should be evaluated in the context of lung transplantation.

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.

Extraesophageal syndrome of gastroesophageal reflux: relationships with lung disease and transplantation outcome

Gastroesophageal reflux disease (GERD) is prevalent and may be associated with both esophageal and extraesophageal syndromes, which include various pulmonary conditions. GERD may lead to pulmonary complications through the "reflux" (aspiration) or "reflex" (refluxate-triggered, vagally mediated airway spasm) mechanisms. While GERD may cause or worsen pulmonary disorders, changes in respiratory mechanics due to lung disease may also increase reflux. Typical esophageal symptoms are frequently absent and objective assessment with reflux monitoring is often needed for diagnosis. Impedance monitoring should be considered in addition to traditional pH study due to the involvement of both acidic and weakly acidic/nonacidic reflux. Antireflux therapy may improve outcomes of some pulmonary complications of GERD, although careful selection of a candidate is paramount to successful outcomes. Further research is needed to identify the optimal testing strategy and patient phenotypes that would benefit from antireflux therapy to improve pulmonary outcomes.

Esophageal Function Tests are Not Associated with Barium Swallow Findings in Advanced Lung Disease

Gastroesophageal reflux disease and esophageal dysmotility are common in patients with advanced lung disease (ALD) and are associated with worse outcomes. Assessing esophageal function in these patients is relevant for determining pulmonary transplant eligibility and prognosticating post-transplant outcomes. Barium Swallow (BaS) is a non-invasive testing modality often performed as a complement to formal esophageal function tests (EFTs), but its role and clinical utility in this context is unknown. Therefore, we aimed to determine the relationship between BaS and EFTs with high-resolution manometry (HRM) and 24-h ambulatory pH-metry in patients with ALD. We performed a retrospective study of 226 consecutive patients undergoing evaluation for lung transplantation at a single center. All patients underwent EFTs and BaS independent of clinical history or symptoms per institutional protocol. Appropriate statistical tests were performed to evaluate the relationship between EFTs and BaS. Mucosal, reflux and motility findings were categorized. Abnormal motility was reported in 133 (59%) patients by BaS and 99 (44%) by HRM, with a significant difference in the proportions of patients with abnormal studies (p < 0.01). There were 7 (26%) patients with abnormal barium tablet passage who had normal HRM. The sensitivity (35%) and specificity (77%) for detecting pathologic reflux with BaS was poor. Inducibility of reflux and barium column height were not associated with pH-metry results. No clinically significant luminal irregularities were identified. In conclusion, while BaS can non-invasively assess esophageal mucosa, its findings are not associated with EFTs in patients with ALD.

Gastroesophageal Reflux and Microaspiration in Lung Transplant Recipients: The Utility of a Single Esophageal Manometry and pH Probe Monitoring Study

BACKGROUND

Gastroesophageal reflux (GER) in recipients of lung transplant (LTX) is associated with chronic allograft rejection, presumably via microaspiration that damages airway epithelium. Most LTX programs perform a single post-LTX esophageal study to evaluate for GER; the efficacy of this test is unclear.

METHODS

Patients with 1 year of post-LTX follow-up, including routine bronchoscopies with bronchoalveolar lavage fluid (BALF) samples as well as high-resolution esophageal manometry and pH probe monitoring (HREMpH), were evaluated. BALF samples were analyzed with competitive enzyme-linked immunosorbent assay to detect bile salts, which are indicative of aspiration. These results were compared to results of HREMpH studies post LTX.

RESULTS

Ninety BALF samples were analyzed for bile salts and acted as disease positive for this evaluation. Of the 13 HREMpH cases, 8 were positive for GER, but only 3 were positive for bile salts via assay. Of the 5 HREMpH-negative cases, 2 experienced aspiration. A solitary HREMpH study had 60.0% sensitivity and 37.5% specificity with positive and negative likelihood ratios: 0.96 and 1.07, respectively.

CONCLUSION

Microaspiration appears to be an intermittent phenomenon, and HREMpH screening poorly correlates with BALF evidence of aspiration; which may not be adequate. As aspiration detection is crucial in this population, further analysis is warranted.

Esophageal contractility increases and gastroesophageal reflux does not worsen after lung transplantation

Gastroesophageal reflux and esophageal dysmotility are common in patients with advanced lung disease and are associated with allograft dysfunction after lung transplantation. The effect of transplantation on reflux and esophageal motility is unclear. The aim of this study was to describe the changes in esophageal function occurring after lung transplantation. A retrospective cohort study was performed on lung transplant candidates evaluated at a tertiary care center between 2015 and 2016. A total of 76 patients who underwent lung transplantation had high-resolution manometry and ambulatory pH-metry before and after transplant. Demographic data, esophageal function testing results, and clinical outcomes such as pulmonary function testing were collected and analyzed using appropriate statistical tests and multivariable regression. Of the 76 patients, 59 (78%) received a bilateral transplant. There was a significant increase in esophageal contractility posttransplant, with an increase in median distal contractile integral from 1470 to 2549 mmHg cm s (P < 0.01). There were 19 patients with Jackhammer esophagus posttransplant, including 15 patients with normal motility pretransplant. Nine patients with ineffective or fragmented peristalsis pretransplant had normal manometry posttransplant. Abnormal pH-metry was observed in 35 (46%) patients pretransplant and 29 (38%) patients posttransplant (P = 0.33). Patients with gastroesophageal reflux disease posttransplant had less improvement in pulmonary function at one year, as measured by forced expiratory volume (P = 0.04). These results demonstrate that esophageal contractility increases significantly after lung transplantation, with an associated change in motility classification. In comparison, gastroesophageal reflux does not worsen, but is associated with worse pulmonary function, posttransplant.