Abstract
BACKGROUND: The pathophysiology behind gastroesophageal reflux disease and its association with poor outcomes after lung transplantation is incompletely understood. The physiologic impact of lung transplantation on pulmonary function, intrathoracic pressures, and vagal innervation may affect esophageal motility, bolus clearance and reflux risk. However, the effect of changes in esophageal function after lung transplantation on the risk of poor post-transplant outcomes remains unclear. AIM: To evaluate the association between change in esophageal motility pre-/post-lung transplantation and rejection outcome. METHODS: This was a retrospective cohort study of lung transplant recipients who underwent both pre-and post-transplant esophageal testing including high resolution manometry (HRM) at a tertiary center. Acute cellular rejection (ACR) was defined histologically per International Society for Heart and Lung Transplantation criteria. Univariate analyses were performed using student's t-test, χ (2) test, and Spearman's correlation where appropriate. Multivariable time-to-event analysis using Cox proportional hazards model was applied. Subjects not meeting ACR outcome were censored at death or date of last clinic visit. RESULTS: 55 subjects (65% men, mean age: 61, median follow-up: 840 days) were included, with 17 (31%) experiencing ACR. Increase in failed swallows correlated with lower baseline total lung capacity (TLC) (R = -0.32, P = 0.05) and decreased post-transplant esophageal bolus clearance (R = -0.45, P = 0.004). On multivariable analysis, post-transplant hypomotility independently predicted increased ACR (HR: 3.62, 95%CI: 1.11-11.8; P = 0.03). Kaplan-Meier analysis demonstrated increased ACR for subjects with increased vs unchanged failed swallows post-transplant (P = 0.048). On Cox regression, a 20% elevated risk of ACR was found for every 10% increase in failed swallows, after controlling for confounders including reflux severity. CONCLUSION: Esophageal hypomotility, specifically an increase in failed swallows on HRM, from pre- to post-lung transplantation was independently associated with ACR. Additionally, lower baseline TLC correlated with increase in failed swallows, suggesting restrictive lung disease may be associated with post-transplant esophageal hypomotility. Lung transplantation may affect esophageal function and contribute to rejection outcomes. Routine esophageal function testing may help identify patients at higher risk for poor lung transplantation outcomes.