Adjunct retrograde cerebral perfusion provides superior outcomes compared with hypothermic circulatory arrest alone : a meta-analysis

Objective: Retrograde cerebral perfusion is becoming less frequently used as a method of neuroprotection during aortic surgery. The present meta-analysis aims to compare outcomes after arch surgery with hypothermic circulatory arrest versus hypothermic circulatory arrest + retrograde cerebral perfusion. Methods: Electronic searches were performed using 7 databases from their inception to September 2016. Relevant comparative studies that included patient groups who underwent aortic arch surgery using hypothermic circulatory arrest with continuous retrograde cerebral perfusion or hypothermic circulatory arrest alone were identified, and data were extracted by 2 independent researchers. Data were aggregated using a random-effects model per predefined clinical end points. Results: Twenty-eight comparative studies were identified, with 2705 hypothermic circulatory arrest cases and 2817 hypothermic circulatory arrest + retrograde cerebral perfusion cases. No significant differences were seen between both groups in terms of age, gender, proportion of dissections and aneurysms, and hemiarch/total arch repair. The hypothermic circulatory arrest + retrograde cerebral perfusion group had slightly longer cardiopulmonary bypass time and lower body arrest time. Mortality was significantly increased for the hypothermic circulatory arrest cohort compared with the hypothermic circulatory arrest + retrograde cerebral perfusion cohort (odds ratio, 1.75; 95% confidence interval, 1.16-2.63; P =.007; I2 = 54%), but not on pooling of adjusted estimates. Stroke was also increased for the hypothermic circulatory arrest cohort (odds ratio, 1.50; 95% confidence interval, 1.07-2.10; P =.02; I2 = 29%). No difference in temporary neurologic deficit was identified (P =.66). Meta-regression found the treatment effect for mortality and stroke to be less pronounced in more contemporary series. Conclusions: These results suggest that the addition of retrograde cerebral perfusion during aortic arch surgery may provide better outcomes than using hypothermic circulatory arrest alone, although significant confounders exist. Further robust studies are required to confirm the utility of retrograde cerebral perfusion in arch surgery.