Temperature Selection in Antegrade Cerebral Perfusion for Aortic Arch Surgery: A Meta-Analysis

The increasing use of antegrade cerebral perfusion (ACP) during aortic arch surgery has corresponded with a trend toward warmer target temperatures for hypothermic circulatory arrest. This meta-analysis examined the clinical outcomes using colder or warmer circulatory arrest targets with ACP.

Electronic searches were performed using four databases from their inception to February 2017. Comparative studies of adult patients who underwent aortic arch operations using ACP at different circulatory arrest temperatures were included. Data were extracted by 2 independent researchers and analyzed according to predefined end points using a random-effects model.

The literature search identified 18 comparative studies, with 1,215 patients in the "cold" cohort and 1,417 in the "warm" cohort. Mean hypothermic circulatory arrest temperatures were 20.3°C and 26.5°C in the cold and warm groups, respectively. A trend existed for increased permanent neurologic deficit overall when colder targets were used (odds ratio, 1.45; 95% confidence interval, 0.98 to 2.13; p = 0.06); this became significant when adjusted estimates were aggregated (odds ratio, 1.65; 95% confidence interval, 1.06 to 2.55; p = 0.03). No difference in the mortality rate was seen when adjusted effects were aggregated. Temporary neurologic deficit, postoperative dialysis, ventilator time, and intensive care unit stay were significantly reduced in the warm cohort overall. No significant differences in reexploration for bleeding were found.

ACP with warmer circulatory arrest temperatures may reduce the incidence of permanent neurologic deficit as well as potentially other clinical outcomes. Further studies are required to determine the safe circulatory arrest durations for visceral organs at warmer temperatures.