Cerebral protection in acute type A aortic dissection surgery: a systematic review and meta-analysis

Background: Acute type A aortic dissection (ATAAD) still challenges physicians and warrants emergent surgical management. Two main methods to reduce cerebrovascular events in ATAAD surgeries are antegrade cerebral perfusion (ACP) and retrograde cerebral perfusion (RCP). We conducted a systematic review and meta-analysis to compare the outcomes of ACP and RCP methods during the ATAAD surgery. Methods: In this study, we searched the databases until March 29th, 2023. Studies that reported the data for comparison of different types of brain perfusion protection during aortic surgery in patients with ATAAD were included. Results: Twenty-six studies met the eligibility criteria. All studies had a low risk of bias as they were evaluated by the Joanna Briggs Institute (JBI) critical appraisal tool. Eventually, we included 26 studies in the current meta-analysis, and a total of 13,039 patients were evaluated. The calculated risk ratio (RR) for permanent neurologic dysfunction (PND) in ACP and RCP comparison was RR =1.23, 95% confidence interval (CI): (0.84, 1.80) (P value =0.2662), and in unilateral ACP (uACP) and bilateral ACP (bACP) was RR =1.2786, 95% CI: (0.7931, 2.0615) (P value =0.3132). When comparing the ACP-RCP and uACP-bACP groups, significant differences were found between ACP-RCP the groups in terms of circulatory arrest time (P value =0.0017 and P value =0.1995, respectively), cardiopulmonary bypass time (P value =0.5312 and P value =0.7460, respectively), intensive care unit (ICU)-stay time (P value =0.2654 and P value =0.0099), crossclamp time (P value =0.6228 and P value =0.2625), and operative mortality (P value =0.9368 and P value =0.2398, respectively), and when comparing the u-ACP and b-ACP groups for transient neurologic deficit (TND), an RR of 1.32, 95% CI: (1.05, 1.67) (P value =0.0199). The results showed high heterogeneity and no publication bias. Conclusions: This study demonstrated that the ACP and RCP are both safe and acceptable techniques to use in emergent settings. The uACP technique is equivalent to bACP in terms of PND and mortality, however, uACP is preferred over bACP in terms of TND.