Gastroesophageal reflux disease and bronchiolitis obliterans syndrome: where are we today?

Incidence and Risk Factors of Abdominal Complications After Lung Transplantation

BACKGROUND

Due to the underlying diseases and the need for immunosuppression, patients after lung transplantation are particularly at risk for gastrointestinal (GI) complications that may negatively influence long-term outcome. The present study assessed the incidences and impact of GI complications after lung transplantation and aimed to identify risk factors.

METHODS

Retrospective analysis of all 227 consecutively performed single- and double-lung transplantations at the University hospitals of Lausanne and Geneva was performed between January 1993 and December 2010. Logistic regressions were used to test the effect of potentially influencing variables on the binary outcomes overall, severe, and surgery-requiring complications, followed by a multiple logistic regression model.

RESULTS

Final analysis included 205 patients for the purpose of the present study, and 22 patients were excluded due to re-transplantation, multiorgan transplantation, or incomplete datasets. GI complications were observed in 127 patients (62%). Gastro-esophageal reflux disease was the most commonly observed complication (22.9%), followed by inflammatory or infectious colitis (20.5%) and gastroparesis (10.7%). Major GI complications (Dindo/Clavien III-V) were observed in 83 (40.5%) patients and were fatal in 4 patients (2.0%). Multivariate analysis identified double-lung transplantation (p = 0.012) and early (1993-1998) transplantation period (p = 0.008) as independent risk factors for developing major GI complications. Forty-three (21%) patients required surgery such as colectomy, cholecystectomy, and fundoplication in 6.8, 6.3, and 3.9% of the patients, respectively. Multivariate analysis identified Charlson comorbidity index of ≥3 as an independent risk factor for developing GI complications requiring surgery (p = 0.015).

CONCLUSION

GI complications after lung transplantation are common. Outcome was rather encouraging in the setting of our transplant center.

The lung microbiome after lung transplantation

Lung transplantation survival remains significantly impacted by infections and the development of chronic rejection manifesting as bronchiolitis obliterans syndrome (BOS). Traditional microbiologic data has provided insight into the role of infections in BOS. Now, new non-culture-based techniques have been developed to characterize the entire population of microbes resident on the surfaces of the body, also known as the human microbiome. Early studies have identified that lung transplant patients have a different lung microbiome and have demonstrated the important finding that the transplant lung microbiome changes over time. Furthermore, both unique bacterial populations and longitudinal changes in the lung microbiome have now been suggested to play a role in the development of BOS. In the future, this technology will need to be combined with functional assays and assessment of the immune responses in the lung to help further explain the microbiome's role in the failing lung allograft.