Safety Time and Optimal Temperature of Unilateral Antegrade Cerebral Perfusion in Acute Type A Aortic Dissection: A Single-Center 15-Year Experience

Background: The optimal level of hypothermia and safe time of unilateral antegrade cerebral perfusion (uACP) in acute type A aortic dissection (ATAAD) repair remain controversial. Objectives: To analyze the association of uACP time and circulatory arrest temperature with surgical outcomes of ATAAD. Methods: We retrospectively analyzed 263 patients who had undergone ATAAD repair between 2006 and 2020 using uACP. The patients were stratified by three chronologically equivalent periods (period 1, 2006 to 2010; period 2, 2011 to 2015; period 3, 2016 to 2020) to demonstrate the decade-long evolution of surgical strategy and outcomes. Results: The mean age of the patients was 59.4 ± 12.5 years, and 68.8% were male. The hospital mortality rates were 15.1%, 12.9%, and 11.0% from period 1 to 3 (p = 0.740). The median circulatory arrest temperatures were 20, 23, and 25 °C (p < 0.001), respectively, and the median uACP times were 72, 59, and 41 minutes (p < 0.001). The incidence rates of postoperative permanent neurologic deficits were 13.2%, 10.9%, and 18.3% (p = 0.312), and those of transient neurologic deficits were 9.4%, 10.9%, and 11.9% (p = 0.936), respectively. Multivariate logistic regression analysis showed that uACP time ≥ 60 minutes was an independent predictor of hospital mortality rather than postoperative stroke. ROC curve analysis estimated an optimal cutoff value of 52 minutes of uACP time when the circulatory arrest temperature was ≥ 25 °C to predict hospital mortality (area under the curve: 0.72). Conclusions: Unilateral antegrade cerebral perfusion time was associated with hospital mortality after ATAAD surgery. A safe threshold of 50 to 60 minutes of uACP should be considered.