Safety of prolonged bilateral antegrade cerebral perfusion in aortic arch surgery with moderate hypothermia

Objectives: This study investigates the impact of bilateral antegrade cerebral perfusion (ACP) time on outcomes in aortic arch surgery.

Methods: In total, 961 patients underwent either hemiarch (n = 385) or total arch replacement (n = 576) with bilateral ACP and moderate hypothermia management between 2006 and 2020 across 2 aortic centres. ACP time was categorized into 4 groups (≤30 min: n = 169, 30-60 min: n = 298, 60-90 min: n = 261, >90 min: n = 233). Inverse probability of treatment weighting yielded a well-balanced cohort among the 4 groups except for the cannulation site. Adjusted cubic spline and multivariable logistic analysis were performed, controlling for surgical procedure, cannulation site and cardiopulmonary bypass (CPB) time, to identify the relationship between ACP time and major in-hospital complications including mortality, stroke, acute renal failure and prolonged ventilation.

Results: There remained a significant difference in surgical procedures and CPB time in the matched cohort. The incidences of mortality and stroke did not show significant trend (P = 0.052 and 0.717, respectively). Cubic spline curves showed that odds ratios did not increase linearly for any complications with increasing ACP time. Furthermore, ACP time, even exceeding 90 min, was not associated with complication rates [mortality: odds ratio = 1.459 (0.368-6.049), P = 0.595; stroke: 0.310 (0.058-1.635), P = 0.166; renal failure: 1.744 (0.521-6.094), P = 0.374; prolonged ventilation: 1.502 (0.535-4.286), P = 0.442], whereas CPB time was associated with mortality and prolonged ventilation.

Conclusions: Even when ACP time exceeded 90 min, it was not associated with major in-hospital complications, questioning its validity as a marker for surgical insult.