Distant heart procurement for human transplantation. Ultrastructural studies

The paucity of donor hearts for human transplantation can be remedied by distant heart procurement. In the present study, 12 donor hearts obtained at distant locations were preserved by infusion with 500 ml of cardioplegic solution at 4°C at 150 mm Hg and immersion in 4°C saline for rapid transmural cooling. They were transported in ice-cold saline. Maximal ischemic times were 110-182 minutes. Septal biopsies before coronary reperfusion showed normal mitochondria (11 of 12), normal nuclei (seven of 12), myofibrillar I-bands (six of 12), and capillary endothelial swelling (12 of 12). Septal biopsies 30 minutes after reperfusion showed mitochondrial swelling (six of 10), nuclear damage (10 of 10), myofibrillar contraction (10 of 10), and endothelial swelling (eight of 10). All grafts functioned satisfactorily. Eight of the 12 patients were alive 6-15 months later; four patients died (one of pulmonary hypertension and three of infection). We concluded that human hearts show significant ultrastructural changes after 3 hours of ischemia, but these worsen after reperfusion, and distant heart procurement is feasible for human transplantation.