Cerebral protection in aortic arch surgery: systematic review and meta-analysis

Consensus regarding optimal cerebral protection strategy in aortic arch surgery is lacking. We therefore performed a systematic review and meta-analysis to assess outcome differences between unilateral antegrade cerebral perfusion (ACP), bilateral ACP, retrograde cerebral perfusion (RCP) and deep hypothermic circulatory arrest (DHCA). A systematic literature search was performed in Embase, Medline, Web of Science, Cochrane and Google Scholar for all papers published till February 2021 reporting on early clinical outcome after aortic arch surgery utilizing either unilateral, bilateral ACP, RCP or DHCA. The primary outcome was operative mortality. Other key secondary endpoints were occurrence of postoperative disabling stroke, paraplegia, renal and respiratory failure. Pooled outcome risks were estimated using random-effects models. A total of 222 studies were included with a total of 43 720 patients. Pooled postoperative mortality in unilateral ACP group was 6.6% [95% confidence interval (CI) 5.3-8.1%], 9.1% (95% CI 7.9-10.4%), 7.8% (95% CI 5.6-10.7%), 9.2% (95% CI 6.7-12.7%) in bilateral ACP, RCP and DHCA groups, respectively. The incidence of postoperative disabling stroke was 4.8% (95% CI 3.8-6.1%) in the unilateral ACP group, 7.3% (95% CI 6.2-8.5%) in bilateral ACP, 6.4% (95% CI 4.4-9.1%) in RCP and 6.3% (95% CI 4.4-9.1%) in DHCA subgroups. The present meta-analysis summarizes the clinical outcomes of different cerebral protection techniques that have been used in clinical practice over the last decades. These outcomes may be used in advanced microsimulation model. These findings need to be placed in the context of the underlying aortic disease, the extent of the aortic disease and other comorbidities.