# Impact of the Elephant Trunk on Distal Remodelling After Surgery for Acute Type I Aortic Dissection

## TL;DR

This study examines how using an elephant trunk during aortic dissection surgery affects long-term aortic remodelling and finds that it promotes better outcomes.

## Contribution

The study compares different surgical strategies for aortic dissection and quantifies the impact of the frozen elephant trunk on aortic remodelling.

## Key findings

- TAR combined with an elephant trunk significantly promotes favorable aortic remodelling.
- FET showed faster false lumen thrombosis and regression compared to CET, though ultimate remodelling rates were not significantly different.
- Early postoperative outcomes and survival were similar across the groups.

## Abstract

For surgical repair of acute type I aortic dissection, total arch replacement (TAR) with a frozen elephant trunk (FET) has been known to result in better long-term remodelling of a residual false lumen. This study was designed to investigate the impact of the elephant trunk by comparing long-term remodelling features among different extents and strategies of aortic replacement.

We conducted a single-centre retrospective analysis of patients who underwent surgical repair for acute type I aortic dissection from January 2004 to June 2022. Patients were categorized based on the surgical strategy employed: non-TAR, conventional TAR, TAR with a classic elephant trunk (CET) and TAR-FET. The primary outcomes were positive remodelling of the residual false lumen and composite aortic events, with secondary outcomes focusing on early postoperative results.

A total of 327 patients were included. TAR, when combined with the insertion of an ET, whether it was stented or not, significantly promoted favourable aortic remodelling (P < .001). Compared with TAR-CET, the FET group tended towards faster false lumen thrombosis and regression, albeit without a significant difference in ultimate remodelling rates; 1-year and 5-year rates of proximal descending false lumen thrombosis were 85.4% (95% confidence interval [CI], 69.2-100) and 90.3% (95% CI, 75.9-100), respectively, after TAR-FET; additionally, these aforementioned rates were 65.7% (95% CI, 54.7-76.6) and 81.9% (95% CI, 71.8-91.9), respectively, after TAR-CET. No significant differences were observed in early postoperative outcomes or overall survival.

The favourable remodelling of the residual false lumen after TAR-FET shown in this study is in line with results from previous studies. CET might be a reasonable alternative to FET according to the individual patient risk profiles and institutional logistics situation.

Acute type A aortic dissection is still perceived as a high-risk operation with considerable mortality1; however, experienced centres have reported remarkable outcomes, with significantly improved early survival rates and single-digit mortality.