Post-mortem Administration of Urokinase in Canine Lung Transplantation From Non-heart-beating Donors

Background: We previously reported that post-mortem heparinization by closed-chest cardiac massage within 30 minutes after cardiac arrest is beneficial in lung transplantation (LTx) from non-heart-beating donors (NHBDs) by preventing formation of microthrombi. In this study, we evaluated the effects of post-mortem administration of urokinase 60 minutes after cardiac arrest. Methods: Left LTx was performed in 12 pairs of mongrel dogs. Donors were sacrificed and left at room temperature for 2 hours. In Group 1 (n = 6), heparin sodium (1,000 U/kg) was administered intravenously 60 minutes after cardiac arrest, then closed-chest cardiac massage was performed for 1 minute to distribute the heparin. In Group 2 (n = 6), the donors were treated as in Group 1, except, in addition to heparin sodium, urokinase (120,000 U) was administered intravenously before and at the end of cardiac massage. After 2 hours of cardiac arrest, donor lungs were flushed with low-potassium dextran glucose solution. After left LTx, the right pulmonary artery was ligated, and recipients were followed up for 3 hours. Uni- and multivariate repeat analyses were performed to obtain statistical data. Results: Group 2 had significantly better arterial oxygen tension, lower pulmonary vascular resistance and lower wet/dry weight ratio of the transplanted lung than Group 1. d-dimer level during the warm ischemia was significantly lower in Group 2 than in Group 1. Conclusions: Post-mortem administration of urokinase along with heparin is beneficial in LTx from NHBDs by fibrinolytic action on already formed pulmonary microthrombi in the cadaver donor lungs.