Hage A, Stevens LM, Ouzounian M, et al. - Researchers examined how various brain perfusion techniques and nadir temperature cooling strategies impact outcomes after aortic arch repair in a contemporary, multicentre cohort. They assessed 2,520 patients who underwent aortic arch repair with hypothermic circulatory arrest (HCA) between 2002 and 2018 in 11 centers of the Canadian Thoracic Aortic Collaborative. In multivariable analysis, they identified antegrade cerebral perfusion as protective against mortality, stroke, composite of mortality or stroke and Society of Thoracic Surgeons-defined composite (STS-COMP), as compared with HCA alone. With retrograde cerebral perfusion, outcomes similar to antegrade cerebral perfusion were attained. When compared with HCA with nadir temperature < 24°C, a propensity score analysis of 647 matched pairs led to the identification of nadir temperature ≥ 24°C as a predictor of lower mortality, stroke, composite of mortality or stroke and STS-COMP. These findings suggest that for improved survival and neurological outcomes, predictive factors were antegrade cerebral perfusion and nadir temperature ≥ 24°C during HCA for aortic arch repair.