# Frozen Elephant Trunk in Acute Aortic Syndrome: Retrospective Results from a Low-Volume Center

## TL;DR

This study shows that the frozen elephant trunk technique for treating acute aortic dissections can be successfully used in low-volume hospitals with outcomes similar to high-volume centers.

## Contribution

The study provides evidence that the frozen elephant trunk technique is feasible in low-volume centers, with insights into surgical practice evolution and outcomes.

## Key findings

- FET procedures had longer cardiopulmonary bypass and hypothermic circulatory arrest times compared to less invasive repairs.
- FET patients had higher rates of completion TEVAR but similar mortality and stroke rates as non-FET patients.
- FET proximalization and liberal use of LSA grafts helped reduce the learning curve in low-volume centers.

## Abstract

Objective: The role of the frozen elephant trunk technique in the treatment of acute aortic dissections is currently based on results from high-volume centers only. We investigated the patient selection process, intraoperative data, the evolution of surgical practice and outcomes from a low-volume center. Methods: A retrospective analysis was conducted on 202 acute aortic dissection (AAD) patients treated between October 2014 and December 2023. Patients were categorized into those receiving less invasive open aortic repair (group 1, n = 136) and those undergoing frozen elephant trunk procedures (FETs) (group 2, n = 66). Data on demographics, surgical procedures, and outcomes were analyzed. Results: Overall 30-day mortality was 16% (13% vs. 23%; p = 0.068). Rates of postoperative disabling stroke were similar (9% vs. 8%, p = 0.190). FET procedures required longer cardiopulmonary bypass (195 min vs. 234 min, p = 0.011), hypothermic circulatory arrest (26 min vs. 43 min, p < 0.001), and selective cerebral perfusion times (26 min vs. 47 min, p < 0.001). Follow-up indicated that 17% of FET patients received completion thoracic endovascular aortic repair (TEVAR) versus 4% in non-FET patients (p = 0.002), whereas no difference was seen in open surgical reintervention. Median follow-up at 33 months showed an overall mortality of 27%, with no significant difference between groups (23% in group 1 vs. 35% in group 2, p = 0.123). Conclusions: The FET technique is feasible in low-volume centers, yielding outcomes comparable to high-volume centers. FET proximalization and a liberal use of extra-anatomical left subclavian artery (LSA) grafts ease the learning curve. Completion treatments can be effectively conducted following FET implantation to further induce positive aortic remodelling.