Optimal time for post-mortem heparinization in canine lung transplantation with non-heart-beating donors

Background: We previously reported that post-mortem heparinization by closed-chest cardiac massage is beneficial in lung transplantation from non-heart-beating donors by preventing formation of microthrombi. In this study, we evaluated the optimal time for post-mortem heparinization in canine lung transplantation from non-heart-beating donors. Methods: Left lung transplantation was performed in 25 weight-matched pairs of mongrel dogs. Donors were killed with an intravenous injection of potassium chloride and left at room temperature for 2 hours. The cadaver donors were assigned randomly to one of five study groups. In Group H0, heparin sodium (1,000 U/kg) was given intravenously before cardiac arrest. In Groups H10, H30, H45 and H60, heparin sodium (1,000 U/kg) was given intravenously 10, 30, 45 and 60 minutes after cardiac arrest, respectively, followed by closed-chest cardiac massage for 2 minutes. After 2 hours of cardiac arrest, donor lungs were flushed with low-potassium dextran glucose solution and preserved for 60 minutes. After left lung allotransplantation, the right pulmonary artery was ligated, and recipient animals were followed up for 3 hours. Uni- and multivariate repeat analyses were utilized for statistical assessment. Results: After transplantation, gas exchange was significantly worse in Groups H45 and H60 than in Groups H0, H10 and H30. Thrombin/anti-thrombin III complex concentration during warm ischemia was significantly higher in Groups H30, H45 and H60 than in Groups H0 and H10. Conclusions: The optimal time for post-mortem heparinization in lung transplantation from non-heart-beating donors is approximately 30 minutes after cardiac arrest.