Comparative evaluation of single-artery cannulation with passive venous drainage versus traditional dual-cannula ex vivo lung perfusion in a rat model.

BACKGROUND

Ex vivo lung perfusion (EVLP) has emerged as a critical technique for lung preservation and evaluation prior to transplantation. While conventional rat EVLP systems utilize closed-loop dual cannulation of pulmonary artery (PA) and vein, the effect of the simplified model using single PA cannulation with passive venous drainage is unknown.

METHODS

We developed two EVLP models in rats: a semi-closed circuit with PA-only cannulation and left atrial incision for passive venous drainage (SC-EVLP), and a closed circuit employing both arterial and venous cannulation (C-EVLP). Donor lungs were perfused for a defined duration and subsequently orthotopically transplanted. We evaluated pulmonary function parameters, histopathological injury scores, inflammatory cytokine levels, and apoptotic marker expression at the end of perfusion and posttransplantation.

RESULTS

Compared to the conventional EVLP, the SC-EVLP group exhibited significantly lower PA pressure and improved dynamic lung compliance throughout perfusion. Although the levels of tumor necrosis factor-α in the perfusate were higher in the SC-EVLP group, other cytokine levels in the perfusate and bronchoalveolar lavage fluid exhibited no significant differences. Pulmonary edema was reduced in the SC-EVLP group, as indicated by a lower lung wet-to-dry ratio. After transplantation, lungs from the SC-EVLP group exhibited lower histological injury scores, reduced apoptosis, and decreased serum cytokine levels, suggesting attenuated inflammation and tissue damage.

CONCLUSIONS

In a rat model, single PA cannulation with passive venous drainage reduced pulmonary edema during EVLP and reduced lung injury and systemic inflammation after transplantation.