THE EFFECTS OF THE HYPOTHERMIC MANAGEMENT OF BRAIN-DEAD DOGS ON PRESERVING GRAFT VIABILITY IN HEART-TRANSPLANTATION

The effect of hypothermic management for brain dead dogs on preserving graft viability was evaluated through preservation and transplantatio n. After the occurrence of brain death, 43 dogs were divided into two groups; the normothermic group (37.2+/-0.3 degrees C) and the hypother mic group (31.8+/-0.3 degrees C) according to the esophageal temperatu re. After the 6-hour management of brain dead donors, the heart beat w as arrested using a cardioplegic solution followed by coronary vascula r bed washout. The donor heart was then harvested and preserved for 12 hours with simple immersion into the University of Wisconsin solution . Following preservation, orthotopic transplantation was performed in six grafts randomly selected from each group. During the 6-hour manage ment of brain dead dogs; 1)heart rates, rate-pressure products, and th e total amount of catecholamine were significantly (p<0.05) lower in t he hypothermic group than in the normothermic group, and 2) lactate co ntents collected from the coronary sinus blood and O-2-extraction rate s of the heart tended to be lower in the hypothermic group than in the normothermic group. During 12 hours of preservation, intracellular pH and creatine phosphate contents were higher in the hypothermic group than in the normothermic group. Following orthotopic transplantation, the animals in the hypothermic group showed a significantly (p<0.05) h igher recovery rate of left ventricular (LV) pressure and the maximum rate of the rise of LV pressure compared with normothermic group anima ls. We conclude that the hypothermic management of brain dead dogs may be effective in preserving graft viability and may provide a clinical application for heart transplantation with acceptable outcomes.