Risk factors for distal stent graft-induced new entry after frozen elephant trunk procedure in chronic aortic dissection.

Abstract

Background: The frozen elephant trunk (FET) procedure has emerged as an effective single-stage treatment for complex aortic pathologies. However, it carries a risk of distal stent graft-induced new entry (dSINE) in patients with chronic aortic dissection (CAD). This study investigated risk factors associated with dSINE development.

Methods: Between 2009 and 2021, 160 FET procedures were performed, including 48 cases of CAD (mean time from onset: 5.6 ± 3.8 years). After excluding five patients due to incomplete 6-month postoperative computed tomography (CT) data, 43 patients were included. A multivariable stepwise Cox proportional hazards regression analysis was conducted to identify predictors of dSINE.

Results: During a mean follow-up period of 5.9 ± 3.9 years, dSINE occurred in 22 of 43 patients (51.1%). Univariate analysis identified three significant risk factors for dSINE: total aortic diameter (TAD) > 45 mm at the distal stent-graft level (HR 5.88, 95% CI 1.35-25.52, p = 0.018), True lumen (TL) perimeter-based diameter (HR 1.22, 95% CI 1.03-1.46; p = 0.021), and TL ovality (HR 1.31, 95% CI 1.04-1.65, p = 0.022). Multivariate analysis revealed TAD > 45 mm as an independent risk factor for dSINE (HR 4.60, 95% CI 1.01-20.85, p = 0.048). The 5-year freedom from dSINE was significantly higher in patients with TAD ≤ 45 mm compared to those with TAD > 45 mm (87.5% vs. 20.8%, p < 0.01).

Conclusions: Although FET remains an important therapeutic option for CAD, dSINE represents a significant postoperative complication. TAD > 45 mm was identified as an independent risk factor. These findings may guide surgical planning for FET procedures.