Early vs. Late Endovascular Extension Following Frozen Elephant Trunk Procedure: Effects on Clinical Outcomes and Aortic Remodeling.

BACKGROUND/OBJECTIVES: The frozen elephant trunk (FET) technique was introduced as a possible single-stage procedure for treating aortic arch pathologies. However, up to a third of patients are reported to need subsequent completion (extension). This retrospective analysis aimed to evaluate the impact of early (within 30 days; EC group) versus late (>30 days; LC group) endovascular completion with thoracic endovascular aortic repair (TEVAR) in patients treated with FET.

METHODS

A single-center, retrospective analysis of all consecutive patients for the period between June 2017 and December 2023 who underwent FET and received endovascular extension was conducted. Indications for endovascular extension were aneurysms of the descending aorta, aneurysmal progress, endoleak, malperfusion, distal stent-induced new entry (dSINE), and aortic rupture.

RESULTS

A total of 37 of 232 FET patients received endovascular extension (15.9%). Average age at the time of TEVAR was 63.3 ± 10.3 years. There was an increase in the maximum total aortic diameter post-FET from 40.8 ± 9 mm to 45.1 ± 14 mm prior to TEVAR. Only 14 patients (37.8%) had the desired complete occlusion of the false lumen or aneurysm prior to extension; 23 (62.2%) still had relevant perfusion of the false lumen or aneurysm. The EC and LC groups were defined by time between FET and TEVAR: a mean of 4.8 ± 5.2 days in the EC group and 18.4 ± 18 months in the LC group. The EC group had markedly more complex procedures, reflected in intensive care (10.7 ± 6.9 vs. 0.1 ± 0.3 days, < 0.001) and hospitalization (22.4 ± 14.0 vs. 8.1 ± 5.6 days, = 0.003) durations. There was one early death due to multiorgan failure in the EC group and there were none in the LC group. There were no major cardiac events in either group. In the EC group, seven patients (50%) suffered from postoperative respiratory failure and four (28.6%) developed acute kidney failure requiring dialysis. Only one patient in the LC group (4.3%) experienced complications. During follow-up, another three patients (21.4%) of the EC group died, but none of the LC group did. Post-extension aortic remodeling was similar in both groups, with complete occlusion achieved in 27 cases (72%) during early follow-up and increased to 90.6% after a mean of 22.0 ± 23.4 months.

CONCLUSIONS

Following aortic arch repair using FET, there is still a need for second-stage repair in 16% of patients. Endovascular completion post-FET is safe and feasible with a technical success rate of 100%, but early completion is associated with greater morbidity and mortality. TEVAR extension surgery may be better delayed, if possible, until after recovery from the hybrid arch repair.