Zone proximalization in frozen elephant trunk: what is the optimal zone for open intervention? A systematic review and meta-analysis.

Introduction: The treatment of complex aortic lesions involving the ascending, arch, and proximal descending aorta, remains challenging for surgeons despite the evolution of surgical techniques and aortic prostheses over decades. The frozen elephant trunk (FET) approach offers a one-stage repair of this entity of aortic pathologies. The main scope of this systematic review and meta-analysis is to evaluate the clinical outcomes and effectiveness of FET.

Evidence Acquisition: In a systematic review, multiple electronic databases including EMBASE, Scopus, and PubMed/MEDLINE were searched from inception to June 2021 to identify relevant studies reporting on outcomes of total arch replacement (TAR) with FET.

Evidence Synthesis: Eighty-five studies met inclusion criteria, encompassing 10960 patients. Meta-analysis was conducted using the R-studio (RStudio, Boston, MA, USA) and STATA software (StataCorp LLC, College Station, TX, USA). The pooled in-hospital mortality rate was 7% (95% CI 0.05-0.09; I=76%) and 12% for renal failure (95% CI 0.09-0.15; I=88%), while the rates for paraplegia and cerebrovascular accidents were 3% (95% CI 0.02-0.04; I=0%) and 6% (95% CI 0.05-0.08; I=73%), respectively. Lower heterogeneity was attained after the stratification by the aortic pathologies, except for the renal failure. The distal anastomosis of the stent in zone 2 was significantly correlated with a lower renal failure development compared to zone 3 (odds ratio 0.52; 95% CI 0.33-0.82; P=0.069; I=0%).

Conclusions: Our results indicate that the morbidities and mortality following TAR with FET were acceptable. We also associated the distal anastomosis in zone 2 with fewer renal failure development compared to that in zone 3.