ALTHOUGH the efficacy of cardiopulmonary bypass for open heart surgery is well established, its application in other surgical areas has not been stressed. In the past two years we have used this modality for circulatory support or tissue oxygenation during operations on the lungs, brain, and aorta. The rotating disc oxygenator has been totally primed with buffer Ringer's lactate solution and bypass performed at normothermic, moderately hypothermic, and deep hypothermic body temperatures. Total circulatory arrest was instituted at a brain temperature of 10 to 15 C during removal of complicated intracerebral pathology while pulmonary embolectomy and resections of the trachea, carina, and major bronchi have been performed under normothermic conditions. Partial perfusion by peripheral cannulation of the femoral vessels has permitted aortic resections without fear of postoperative damage to the spinal cord and kidney. This report outlines our present indications, technique, and results during these surgical endeavors. Methods and Materials