Frozen Elephant Trunk for Aortic Arch Reconstruction is Associated with Reduced Mortality as Compared to Conventional Techniques

Branched and fenestrated endovascular aortic arch repair in patients with native proximal aortic landing zone

OBJECTIVE

Fenestrated and branched thoracic endovascular repair (f/bTEVAR) have been successfully applied in patients with diverse aortic arch pathologies. The aim of this study is to present the early and mid-term outcomes of patients with native proximal aortic landing (NPAL) managed with f/bTEVAR.

METHODS

A single-center retrospective analysis of patients with NPAL, managed with f/bTEVAR, between September 1, 2011, and June 30, 2022, was conducted. All patients were treated with custom-made devices (Cook Medical) with landing within Ishimaru zones 0 to 2. Primary outcomes were technical success, mortality, stroke, and retrograde type A dissection at 30 days. Follow-up outcomes were considered secondary.

RESULTS

A total of 126 patients were included (69.8% males; mean age, 70.8 ± 4.2 years; 18.3% urgent). The main indications (60.4%) for repair were aortic arch (29.4%) and thoracoabdominal aortic aneurysms (31.0%). Seventy-two patients (57.1%) were managed with fTEVAR. Proximal landing in zone 0 and 1 was chosen in 97.6%. Technical success was 94.4%, and 30-day mortality was 11.9%. Strokes were diagnosed in 13.5% of patients and major strokes were identified in 7.9% cases. Retrograde type A dissection rate was 3.9%. The multivariate analysis confirmed landing in Ishimaru zone 0 as an independently related factor for stroke (P = .005), whereas stroke (P < .001), pericardial effusion (P < .001), and acute kidney injury (P < .001) were independently related to 30-day mortality. Mean follow-up was 17.5 ± 9.3 months. The estimated survival rate and the freedom from reintervention rate were 72.6% (standard error, 4.4%) and 46.4% (standard error, 6.0%) at 24-month follow-up, respectively.

CONCLUSIONS

Stroke rate after endovascular arch repair was alarming among patients with NPAL. Proximal landing to zone 0 was related to higher risk of stroke. Reinterventions were common within the 24-month follow-up.

The evolution of arch surgery: Frozen elephant trunk or conventional elephant trunk?

Treatment of aortic arch aneurysms and dissections require highly complex surgical procedures with devastating complications and mortality rates. Currently, repair of the complete arch until the proximal descending thoracic aorta consists of a two-stage procedure, called elephant trunk (ET) technique, or a single stage a single-stage technique referred to as frozen elephant trunk (FET). There is conflicting evidence about the perioperative results of ET in comparison with FET. We carried out a meta-analysis to investigate possible differences in perioperative and early (up to 30 days) outcomes of ET vs. FET, particularly for mortality, spinal cord injury (SCI), stroke, and renal failure. We also performed a meta-regression to explore the effects of age and sex as possible cofactors. Twenty-one studies containing data from interventions conducted between 1997 and 2019 and published between 2008 and 2021 with 3153 patients (68.5% male) were included. ET was applied to 1,693 patients (53.7%) and FET to 1460 (46.3%). Overall mortality after ET was 250/1693 (14.8%) and after FET 116/1460 (7.9%). Relative risk (RR) and 95% confidence interval (CI) were 1.37 [1.04 to 1.81], p = 0.027. There was no significant effect of age and sex. SCI occurrence after the second stage of ET was 45/1693 (2.7%) and after FET 70/1,460 patients (4.8%) RR 0.53 [0.35 to 0.81], p = 0.004. Age and sex were not associated with the risk of SCI. No significant differences were observed between ET and FET in the incidence of stroke and renal failure. Our results indicate that ET is associated with higher early mortality but lower incidence of SCI compared to FET. When studies published in the last 5 years were analyzed, no significant differences in mortality or SCI were found between ET and FET. This difference is attributed to a decrease in mortality after ET, as the mortality after FET did not change significantly over time.

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; I²=76%) and 12% for renal failure (95% CI 0.09-0.15; I²=88%), while the rates for paraplegia and cerebrovascular accidents were 3% (95% CI 0.02-0.04; I²=0%) and 6% (95% CI 0.05-0.08; I²=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; I²=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.

“Why is frozen elephant trunk better than classical elephant trunk?”

The treatment of complex aortic arch disease, in chronic or acute setting, has always represented a fascinating challenge for the heart surgeon also because, often, the involvement of the aortic arch is associated with a simultaneous involvement of the ascending aorta and of the proximal portion of the descending thoracic aorta. In recent years, there have been many surgical and/or endovascular techniques and approaches in a single step or multiple steps proposed with the aim of treating and simplifying these complex conditions. The first procedure available for this purpose was the conventional elephant trunk technique, proposed by the German surgeon Hans Borst, back in 1983. In the following years, the technique has undergone modifications, up to what is nowadays considered its most modern evolution, represented by the frozen elephant trunk which allows managing the proximal descending thoracic aorta using the antegrade release of a self-expandable stent graft. In this review article, we try to analyze the advantages and drawbacks of both techniques from clinical and practical points of view.