Aortic Arch Reconstructive Surgery With Conventional Techniques vs Frozen Elephant Trunk: A Systematic Review and Meta-Analysis

Background: Frozen elephant trunk (FET) surgery offers a new alternative in the management of complex thoracic aortic aneurysms and dissections. We performed a systematic review and meta-analysis of comparator observational studies evaluating the efficacy of FET compared with conventional aortic arch surgery, primarily focusing on mortality and stroke as well as the secondary outcomes of spinal cord ischemia, major bleeding, and operative time. Methods: We searched MEDLINE, EMBASE, PubMed, and the Cochrane Library for trials and studies comparing the FET technique with conventional surgery in patients with aortic aneurysms or dissections, or both. The overall quality of evidence was low, as assessed by Grading of Recommendations, Assessment, Development, and Evaluation, based primarily on the risk of bias secondary to study design, plausible confounding, and imprecision. Results: Meta-analysis revealed a significant reduction in mortality (12 studies, 1803 patients: odds ratio [OR], 0.55; 95% CI, 0.39-0.78) and a nonsignificant reduction in stroke (12 studies, 1803 patients: OR, 0.78; 95% CI, 0.52-1.15) favouring FET; however, FET was associated with a significant increase in spinal cord ischemia (9 studies, 1476 patients: OR, 2.20; 95% CI, 1.10-4.37). No significant differences between groups were observed regarding major bleeding, cardiopulmonary bypass time, or cross-clamp time. Conclusions: Current evidence suggests that FET surgery is associated with lower mortality in patients with thoracic aneurysmal disease and dissections, without a significant increase in stroke, bleeding, or operative times. However, the risk of spinal cord ischemia is increased in patients who undergo FET. A well-powered randomized trial is needed to evaluate this evolving field.