We have recently found that retrograde cerebral perfusion can be performed by simply elevating central venous pressure to 15 mmHg in the Trendelenburg position when the aortic arch is open during aortic arch surgery. During deep hypothermic (15 degrees C) perfusion of the lower half of the body with the descending aorta occluded, and with single cannulation of the right atrium for drainage, oxygen-saturated venous blood perfuses the brain retrogradely, supplying it with oxygen. This method renders clamping of the aortic arch and the arch vessels unnecessary. Eleven cases of aortic arch aneurysm (9 males, 2 females; 5 true aneurysms, 5 dissecting aneurysms, one combined aneurysm; mean age, 63 years) were operated using this technique, whose clinical significance was then evaluated. Median sternotomy was performed in 4 cases, left thoracotomy in 7. Patch replacement was performed in 2 cases and graft replacement in 9 cases (the proximal arch in 2, the whole arch in 2, the distal arch in 5). In two cases coronary artery bypass surgery using the internal thoracic artery was performed simultaneously via lateral thoracotomy. Operation time was 517 +/- 139 min, pump time was 211 +/- 34 min, cardiac arrest time was 84 +/- 34 min and the lowest rectal temperature was 15.7 +/- 1.1 degrees C. In the venous return, PO2 was 188 +/- 136 mmHg, and SO2 97.5 +/- 2.9%, the respective values in the retrogradely perfused blood in the aortic arch being 46 +/- 12 mmHg and 68.8 +/- 18.8%.(ABSTRACT TRUNCATED AT 250 WORDS)