Hypothermia and cerebral protection strategies in aortic arch surgery: a comparative effectiveness analysis from the STS Adult Cardiac Surgery Database

TLDR

Hypothermic circulatory arrest is essential for aortic arch surgery, yet the optimal cerebral protection strategy remains uncertain. The study evaluated the use and comparative effectiveness of hypothermia and cerebral perfusion strategies in aortic arch surgery using the STS database from 2011‑2014. Strategies were compared by a composite endpoint of operative mortality or neurologic complication across 12,521 repairs, with the most common combinations being straight deep/profound hypothermia without CP, deep/profound plus retrograde CP, and deep/profound plus antegrade CP. Overall, the composite endpoint occurred in 23% of cases (mortality 12%, stroke 8%); strategies lacking cerebral perfusion had a significantly higher risk (OR 1.6), while no single remaining strategy was superior, underscoring the need for randomized trials.

Abstract

Hypothermic circulatory arrest is essential to aortic arch surgery, although consensus regarding optimal cerebral protection strategy remains lacking. We evaluated the current use and comparative effectiveness of hypothermia/cerebral perfusion (CP) strategies in aortic arch surgery.Using the Society of Thoracic Surgeons Database, cases of aortic arch surgery with hypothermic circulatory arrest from 2011 to 2014 were categorized by hypothermia strategy-deep/profound (D/P; ≤20°C), low-moderate (L-M; 20.1-24°C), and high-moderate (H-M; 24.1-28°C)-and CP strategy-no CP, antegrade (ACP), retrograde (RCP) or both ACP/RCP. After adjusting for potential confounders, strategies were compared by composite end-point (operative mortality or neurologic complication).Of the 12 521 aortic arch repairs with hypothermic circulatory arrest, the most common combined strategies were straight D/P without CP (25%), D/P + RCP (16%) and D/P + ACP (14%). Overall rates of the primary end-point, operative mortality and stroke were 23%, 12% and 8%, respectively. Among the 7 most common strategies, the 2 not utilizing CP (straight D/P and straight L-M) appeared inferior, associated with significantly higher risk of the composite end-point (odds ratio: 1.6; P < 0.01); there was no significant difference in composite outcome between the remaining strategies (D/P + ACP, D/P + RCP, L-M + ACP, L-M + RCP and H-M + ACP).In a comparative effectiveness study of cerebral protection strategies for aortic arch repair, strategies without adjunctive CP, including the most commonly utilized strategy of straight D/P hypothermia, appeared inferior to those utilizing CP. There was no clearly superior strategy among remaining techniques, and randomized trials are needed to define best practice.