Optimal Temperature Management in Aortic Arch Surgery: A Systematic
Review and Network Meta-Analysis
Abstract
Objectives: New temperature management concepts of moderate and
mild hypothermic circulatory arrest during aortic arch surgery have
gained weight over profound cooling. Comparisons of all temperature
levels have rarely been performed. We performed direct and indirect
comparisons of deep hypothermic circulatory arrest (DHCA) (≤20°C),
moderate hypothermic circulatory arrest (MHCA) (20.1°C to 25°C), and
mild hypothermic circulatory arrest (mild HCA) (≥25.1°C) in a network
meta-analysis. Methods: The literature was systematically
searched for all papers published through February 2022 reporting on
clinical outcomes after aortic arch surgery utilizing DHCA, MHCA and
mild HCA. The primary outcome was operative morality. The secondary
outcomes were postoperative stroke and acute kidney failure (AKI).
Results: A total of 34 studies were included, with a total of
12 370 patients. DHCA was associated with significantly higher
postoperative incidence of stroke when compared with MHCA (odds ratio
(OR), 1.46, 95% (confidence interval) CI, 1.19-1.78) and mild HCA: (OR,
1.50, 95% CI, 1.14-1.98). Furthermore, DHCA and MHCA were associated
with higher operative mortality when compared with mild HCA (OR 1.71,
95% CI, 1.23-2.39 and OR 1.50, 95% CI, 1.12-2.00, respectively).
Separate analysis of randomized and propensity score matched studies
showed sustained increased risk of stroke with DHCA in contrast to MHCA
and mild HCA (OR, 1.61, 95% CI, 1.18-2.20, P-value = 0.0029 and OR,
1.74, 95% CI, 1.09-2.77, P-value = 0.019). Conclusions: In the
included studies, the moderate to mild hypothermia strategies were
associated with decreased operative mortality and the risk of
postoperative stroke. Large-scale prospective studies are warranted to
further explore appropriate temperature management for the treatment of
aortic arch pathologies.