[Thoracic aneurysm repair using circulatory arrest or retrograde cerebral perfusion]

Ascending aortic and transverse arch aneurysm repair requires some brain protection. At our hospital, profound hypothermia, circulatory arrest and retrograde cerebral perfusion have been used. Thirty patients for whom we used such brain protection techniques were studied with regard to incidence of stroke. Of these 30 patients, 7 underwent circulatory arrest with median arrest time was 31 minutes (range, 25 to 42 minutes), and 23 underwent retrograde cerebral perfusion with median perfusion time was 59 minutes (range, 24 to 123 minutes). The overall 30-day mortality rate was 16.6% (5 of 30 patients); these patients were all aortic dissection cases, and had exhibited signs of vital organs ischemia before the operation. Of the twenty-five patients who survived the operation, incidence of stroke was observed in 2 patients. One was a saccular transverse arch aneurysm, who underwent 71 minutes retrograde cerebral perfusion; debris was the cause of stroke in this case. The other was a Stanford type A aortic dissection, who underwent 32 minutes perfusion; malperfusion caused stroke in this case. Stroke did not occur in any of the 3 patients who underwent retrograde cerebral perfusion for more than 100 minutes. These results suggest that a uniform and constant cooling of the entire brain is important for brain protection. To this end, transapical aortic cannulation is effective to prevent malperfusion. It is also suggested that retrograde cerebral perfusion time can be up to 100 minutes, a longer duration hitherto accepted.