“…Major thoracic aortic surgery utilizing hypothermic circulatory arrest carries the potential risks of mortality and major morbidity, although outcomes have improved over the past few decades. For example, series of proximal aortic replacement report overall 30-day/inhospital mortality ranging from 3.7% to 12.1% [1,2,6,10,[19][20][21][22]. Not surprisingly, mortality rates are lower in elective than nonelective cases: reported elective mortality rates range from 1.7% to 7.6% [2,[6][7][8]23], whereas nonelective cases have been associated with mortality rates of 15.4% to 26%, with the highest rates being seen after acute type A aortic dissection repair, which was one of the reasons for excluding these patients in the current study [2,6,9].…”