Structural Stress as a Predictor of the Rate and Spatial Location of Aortic Growth in Uncomplicated Type B Aortic Dissection

OBJECTIVE: This study investigated the associations between biomechanical predictors derived from a reduced-order fluid-structure interaction (FSI) analysis and aortic growth in patients with uncomplicated type B aortic dissection (TBAD). METHODS: Baseline and follow-up CTA images from 30 patients with uncomplicated TBAD were analyzed. A reduced-order FSI analysis using the forward penalty stress computation method was performed on baseline geometries to estimate structural stress, wall shear stress (WSS), and pressure distributions. Aortic growth was quantified through nonrigid registration of baseline and follow-up surfaces. Mixed-effects linear and logistic regression analyses were performed to assess relationships between biomechanical metrics and growth outcomes while accounting for inter-patient variability. Group comparison analyses were performed to evaluate spatial differences in biomechanical variables among patient groups categorized by optimal medical therapy (OMT) and growth outcomes. RESULTS: Mixed-effects linear regression demonstrated a significantly positive association between structural stress and aortic growth rate (p = 0.0001) Logistic regression yielded area under the receiver operating characteristic curve values of 0.7164, 0.6113, 0.5711, and 0.6232 for structural stress, WSS, pressure, and aortic diameter, respectively. Group comparisons showed that only structural stress exhibited significant regional differences between growth and OMT-defined groups. CONCLUSION: Structural stress may serve as a promising predictor of both the rate and spatial location of aortic growth in uncomplicated TBAD. SIGNIFICANCE: Structural stress-based growth prediction may support risk stratification to identify patients at higher risk of TBAD progression who could benefit from timely thoracic endovascular repair.