Transplantation and Reanimation of Hearts Removed From Donors 30 Minutes After Warm, Asystolic 'Death'

Abstract

To test whether hearts from "dead," pulseless, asystolic donors could be transplanted and reanimated successfully using reperfusion manipulations. Ten infant lambs (mean [+/- SD] weight, 4 +/- 1 kg) were anesthetized and pretreated with 50% dextrose, methylprednisolone, prostaglandin E1, and sublingual nifedipine. Five of these lambs were paralyzed; hypoxic asystolic arrest occurred 10 +/- 2 minutes later. Thirty minutes following asystole (mean, 40 +/- 2 minutes after paralysis) sternotomy was performed and the hearts were excised. Aortic blood gases were as follows: pH, 6.6 +/- 0.1; PCO2, 180 +/- 20 mm Hg; and PO2, 8 +/- 2 mm Hg. Donor hearts were given 30 mL/kg of Cardiosol (Water's Instrument Co, Danburg, Conn), a new cardioplegic agent, at 4 degrees C, and explanted into iced saline. The remaining five lambs then underwent cardiopulmonary bypass, were cooled to 20 degrees C, and hypothermic arrest was instituted. After excision of the recipient's heart, the donor heart was implanted in an orthotopic position. Total cold ischemic time was 1 hour 40 minutes +/- 10 minutes. The donor heart was retroperfused for 10 minutes with low-hematocrit, low-calcium blood via a coronary sinus catheter, then normal aortic inflow reperfusion was continued for 50 minutes. Removal of the cardiopulmonary bypass and measurement of hemodynamic parameters. One half hour after the bypass, mean systolic aortic pressure was 71 +/- 6 mm Hg; mean right atrial pressure was 6 +/- 2 mm Hg; mean left atrial pressure was 7 +/- 2 mm Hg; and mean pulmonary arterial pressure was 20 +/- 8 mm Hg. No inotropic drugs were given for postbypass blood pressure support. It is possible to transplant and reanimate hearts that have been dead for 30 minutes. When further developed, the use of donors who were not brain dead but allowed to die naturally could greatly increase the donor pool.