Delayed Gastric Emptying in Prelung Transplant Patients Is Associated With Posttransplant Acute Cellular Rejection Independent of Reflux

Efficacy and safety of gastric per-oral endoscopic myotomy (GPOEM) in lung transplant patients with refractory gastroparesis: a systematic review and meta-analysis

BACKGROUND

Post-lung transplant gastroparesis is a frequent debilitating complication of lung transplant recipients, as it can increase the risk for gastro-esophageal reflux disease and subsequent graft dysfunction. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of GPOEM in lung transplant patients with refractory gastroparesis.

METHODS

The present systematic review and meta-analysis wer performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. We selected studies that analyzed the gastroparesis cardinal symptom index (GCSI) before and after the procedure to verify the efficacy of GPOEM. Random-effects model was used and the analysis was performed with STATA 17.

RESULTS

Four observational studies (one conference abstract) with 104 patients were included in the meta-analysis. Prior treatments for gastroparesis included prokinetic agents and botulinum toxin in 78% (78/104) and 66.7% (66/99), respectively. Pooled estimate for clinical efficacy of GPOEM was 83% (95% CI 76%-90%). The pooled mean reduction in GCSI following the procedure was - 2.01 (- 2.35, - 1.65, p = 0.014). Three studies reported statistically significant improvement of gastro-esophageal retention or emptying in the post-GPOEM period. 30-day post-operative complications included minor or major bleeding (11.6%), severe reflux (1.2%), and pyloric stenosis (1.2%) requiring re-intervention. 90-day all-cause mortality was 2.6% with one patient dying from severe allograft rejection.

CONCLUSION

Our study showed that GPOEM is an effective and safe strategy for lung transplant patients with refractory gastroparesis and should be considered as a therapeutic strategy in this population. Larger multicenter trials are needed in the future to further evaluate the effect of GPOEM on allograft function and rates of rejection.

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.

Esophageal Dysfunction in Post-lung Transplant: An Enigma

The prevalence of lung transplants has increased over the years, albeit with a low survival rate amongst all solid organ transplants, including liver and heart transplantation. Microaspiration is one of the primary mechanisms that has been implicated in the pathogenesis of lung injury following lung transplants. Of late, esophageal dysfunction such as gastroesophageal reflux and esophageal hypercontractility is often noted post-lung transplant. However, reflux is associated with chronic allograft lung injury such as bronchiolitis obliterans syndrome, which is one of the predictors for long-term survival in this specialized population. Its role in acute lung injury post-lung transplant is still being explored. This review critically examines the salient points which provide the current understanding of the characteristics, pathophysiology, and implications of esophageal dysfunction following lung transplant.