Unilateral vs. Bilateral Selective Cerebral Perfusion for Acute Type A Aortic Dissection with Frozen Elephant Trunk: Systematic Review and Meta-Analysis.

Background/Objectives: Previous studies failed to demonstrate the best cerebral perfusion option during total aortic arch replacement surgery. We therefore sought to investigate clinical results of patients who received unilateral (u) versus bilateral (b) selective antegrade cerebral perfusion (SACP) during total aortic arch replacement by means of the frozen elephant trunk (FET) technique for acute type A aortic dissections (ATAADs). Methods: A systematic review and meta-analysis was performed by including relevant studies reporting outcomes of patients with ATAADs undergoing total arch replacement with the FET technique using either unilateral or bilateral SACP. Pubmed, ScienceDirect, SciELO, DOAJ, and Cochrane library databases were searched until May 2023. Results: A total of 44 papers with 5983 patients were included, 3872 for unilateral SACP and 2111 for bilateral SACP. Although patients undergoing bSACP presented a higher incidence of preoperative comorbidities compared to uSACP, there was not a significant difference in terms of mortality and major postoperative complications between the two groups. Distal body circulatory arrest time was not associated with any outcome at meta-regression, while longer SACP times in the whole population were significantly associated with higher neurological complications. Significant increased mortality was found in long uSACP. Conclusions: Our analysis showed that centers already apply the appropriate perfusion strategy tailored to the complexity of the patient's condition. It is therefore crucial to tailor the approach to the complexities of individual patients rather than seeking a definitive superiority between the two perfusion techniques to optimize outcomes during FET for ATAAD. Further studies are warranted to confirm these results.