METHODS

Thirty-two dogs were used, weighing 9 to 20 kg. The animals were killed with an overdose of pentobarbital after arterial and venous catheters had been placed in the inferior vena cava and aorta via the femoral vessels. Respiratory failure invariably preceded disappearance of pulses by 5 to 15 min. During this time, 3 mg./kg. heparin was given intravenously. Four to 12 min. after cessation of the animals’ circulation, extracorporeal perfusion was instituted. The apparatus employed gravity drainage with a disposable bubble oxygenator, a DeBakey pump, and a heat exchanger. The extracorporeal circuit was usually primed with lactated Ringer’s solution, pre-cooled by recirculation to 15 C. In 2 of the experiments on liver transplantation, 5% glucose in water was used for the priming fluid. In all experiments, 1 gm. procaine chloride per liter was added to the perfusate.