Effect of methylprednisolone and prostacyclin on bronchial perfusion in lung transplantation

In an experimental investigation using modified unilateral lung transplantation in pigs, the effects of systemic administration of methylprednisolone and prostacyclin on bronchial mucosal blood flow were assessed. Laser Doppler velocimetry (LDV) and radioisotope studies using radiolabeled erythrocytes (RI) were employed to measure blood flow at the donor main carina and upper lobe carina after 3 hours of reperfusion. The recipient carina was used as a reference point. Five groups of 6 animals each were studied. Group I served as control. In group II, methylprednisolone (20 mg/kg) was administered to the recipient. In group III, prostacyclin (4 ng.kg-1.min-1) was given to the recipient, and in group IV, prostacyclin (100 micrograms intravenously) was administered to the donor. In group V, prostacyclin was given to the recipient and the donor animals as in groups III and IV, respectively. In group I, bronchial blood flow at the donor main carina was 37.6% +/- 2.2% (LDV) and 44.1% +/- 14.8% (RI) of reference blood flow. No significant differences were found between the controls and groups II, III, and IV. In group V, bronchial blood flow was markedly increased both at the donor main carina (LDV, 39.8% +/- 6.2%, p = 0.12; RI, 55.7% +/- 11.4%, p < 0.2) and the donor upper lobe carina (LDV, 65.8% +/- 5.4%, p < 0.05; RI, 76.8% +/- 21.3%, p < 0.2). We conclude that systemic administration of prostacyclin to the donor and recipient results in marked improvement of bronchial blood flow and may reduce the incidence of bronchial complications after lung transplantation.