Abstract / Summary
This study aimed to systematically characterize the spatiotemporal patterns of distal aortic remodeling following total arch replacement (TAR) using the frozen elephant trunk (FET) technique (Sun’s procedure) and identify segment-specific predictors of negative aortic remodeling (NAR) in patients with acute DeBakey type I aortic dissection (ADTIAD). We retrospectively analyzed patients who had undergone TAR + FET for ADTIAD between January 2015 and December 2024. Eligible patients underwent an initial postoperative computed tomography angiography (CTA) scan before discharge and at least one follow-up CTA beyond 3 months postoperatively. The residual distal aorta was divided into five anatomical segments (S1–S5). Serial CTA data were analyzed to evaluate segment-specific changes in aortic, true lumen (TL), and false lumen (FL) dimensions; cross-sectional areas; and FL status. NAR was defined according to changes in aortic and TL areas. In total, 252 patients were included (mean age: 50.68 ± 10.13 years; 83.7% male). Positive remodeling, characterized by TL expansion and rapid FL obliteration, was predominant in the stent-covered segment, whereas persistent FL patency and progressive aortic dilatation were observed in distal segments. NAR prevalence increased rapidly within 3–12 months postoperatively and subsequently plateaued. Multivariable analysis revealed segment-specific predictors of NAR, with proximal remodeling associated mainly with procedural factors and distal segment remodeling influenced by the TL area ratio, residual entry tears, and FL thrombosis status. Distal aortic remodeling after FET demonstrates significant spatiotemporal heterogeneity, underscoring the need for early surveillance and targeted intervention to improve long-term outcomes.