We have devised a simple hypothermic retrograde cerebral circulation technique for protecting the brain during aortic arch surgery. The central venous pressure is simply elevated (15 to 18 mmHg) while the aortic arch is open and the descending aorta occluded, causing oxygen-saturated venous blood from the lower half of the body, which is undergoing deep hypothermic (15 degrees C to 18 degrees C) perfusion, to circulate in the brain in a retrograde fashion, supplying it with oxygen. Twenty-six cases of distal aortic arch aneurysm treated using this method, through a left thoracotomy with femoral vein cannulation, were evaluated. Retrograde cerebral circulation time was 59.6 +/- 13.1 minutes (40 to 93 min). Retrograde flow was 43.9 +/- 13.0 (25 to 62) mL/min. Significant oxygen and apparent lactate extraction were noted in the brain. Early death resulted in 3 of the first 14 cases (21.4%) from embolism, and in 1 of the other 12 cases (8.3%) from massive bleeding and multiple organ failure. Only one late death occurred. No death was attributed to the method itself. This method, with its simplified operative procedure using a lateral thoracotomy, supplied oxygen to the brain and protected it during interruption of the cerebral circulation. Careful management of the atherosclerotic aorta is needed.