The majority of cardiac surgical procedures are accomplished using cardioplegia-induced cardiac arrest with cardiopulmonary bypass (CPB) to maintain perfusion to other organs. Preservation of organ function during the period of total circulatory arrest can be aided by reducing the core temperature of the body. The technique of core cooling combined with cessation of blood flow is termed deep hypothermic circulatory arrest (DHCA). The long duration of surgery with DHCA mandates careful attention to prevent pressure sores and inadvertent damage to the eyes, nerve plexuses, peripheral nerves and pressure points. The use of DHCA during surgery of the distal aorta via left thoractomy presents several problems. Reversing the direction of blood flow in the superior vena cava (SVC) has been advocated as a means of improving brain protection during DHCA and extending the period of safe DHCA.