Successful six-hour cardiopulmonary preservation with simple hypothermic crystalloid flush

Combined heart and lung transplantation was performed in 12 cynomolgus or rhesus monkeys. The donor heart was preserved with 10 ml/kg of cold crystalloid potassium cardioplegia. The lungs were preserved by perfusing the pulmonary artery over 4 minutes with 60 ml/kg donor weight of cold Euro-Collins solution modified with 8 mEq/L of MgSO4. For six animals in group A, the heart and lungs were immediately transplanted with a mean ischemic time of 1 hour 54 minutes. For six animals in group B, the heart and lungs were stored in a cold extracellular electrolyte solution at 2 degrees to 3 degrees C and transplantation was delayed, with a mean ischemic time of 6 hours and 15 minutes. Anesthesia and mechanical volume ventilation were continued for 8 hours postoperatively with the Fio2 regulated to 40% and with 2 cm positive end-expiratory pressure. Arterial Po2 was sampled at 1, 2, 3, 4, 6, and 8 hours after removal of the aortic cross clamp. Animal survival and cause of death were recorded. All animals were successfully extubated by 10 hours after transplantation. The mean arterial Po2 for group B was initially depressed (89 mm Hg 1 hour after removal of the aortic cross clamp) but rapidly recovered. The mean Po2 for both groups A and B was 184 mm Hg 8 hours after reperfusion. There was no significant difference in the mean hourly Po2 between groups A and B except for the first hour after reperfusion. One animal in each group died of pulmonary insufficiency in the early postoperative period.(ABSTRACT TRUNCATED AT 250 WORDS)