Lung Preservation: Pulmonary Flush Route Affects Bronchial Mucosal Temperature and Expression of IFN-γ and Gro in Regional Lymph Nodes

Optimal lung preservation via flush of the pulmonary vasculature minimizes early graft failure post-lung transplantation. We hypothesized that the route of pulmonary flush has differential effects on thermal gradients in the lung and expression of inflammatory mediators. Swine underwent antegrade flush (AG) via pulmonary artery; AG/RG: antegrade + retrograde flush via pulmonary veins or AG/BA: antegrade + bronchial artery flush via bronchial artery. Temperatures were recorded in bronchial mucosa and peribronchial lymph nodes. RT-PCR was utilized to detect cytokine gene expression in the nodes. AG/BA flush resulted in greatest cooling of bronchial mucosa and lymph nodes (p < 0.001). The route of flush did not affect expression of RANTES, MCP-1, IL-8, IL-1beta, TNF-alpha or IL-6. However, expression of Gro was reduced 4-h post-preservation in all groups. Only AG/BA resulted in decreased IFN-gamma transcripts. These data show that, compared to AG or AG/RG, AG/BA flush results in the greatest cooling of lung compartments and down regulates lymph node expression of a cytokine and chemokine that have key roles in inflammation and immunity. These data suggest that pulmonary flush via AG/BA during donor harvest may be optimal to decrease the risk of early graft failure.