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

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.