Liu Minliang, Du Yuhang, Cebull Hannah L, Wu Yuxuan, Mazlout Adam, Kalyanasundaram Asanish, Agarwal Rishika, Dong Hai, Piccinelli Marina, Oshinski John N, Elefteriades John A, Gleason Rudolph L, Leshnower Bradley G
Texas Tech University.
Emory University.
Res Sq. 2025 May 16:rs.3.rs-6569327. doi: 10.21203/rs.3.rs-6569327/v1.
False lumen expansion is a major factor that determines long-term survival of uncomplicated type B aortic dissection (TBAD). The objective of this study was to investigate whether structural wall stress distributions computed from patient-specific acute TBAD geometries can be used to predict aortic growth rates.
Three-dimensional (3D) computed tomography angiography (CTA) of 9 patients with acute uncomplicated TBAD were obtained at initial hospital admission and at their most recent follow-up visits. Patient-specific structural wall stress distributions were computed from the initial baseline CTA using a forward penalty method. Spatially varying blood pressure distributions, derived from computational fluid dynamics (CFD) simulations informed by patient-specific transthoracic echocardiography (TTE) and blood pressure (BP) measurements, were incorporated into the forward penalty stress analysis. Aortic growth rates were quantified and visualized within the 3D TBAD geometries using the initial baseline and follow-up scans. Linear mixed-effects regression analyses were performed to evaluate the spatial correlations between biomechanical markers (structural wall stress, wall shear stress, and pressure) and aortic growth rates.
Utilizing initial baseline CTA, TTE, and BP data, the forward penalty analyses revealed hemodynamic and structural mechanics insights of acute uncomplicated TBADs. The linear mixed-effects model indicated that the fixed-effect association between structural wall stress and aortic growth rate distributions was statistically significant (p=0.039), which demonstrated that aortic segments experiencing high wall stress exhibited rapid growth. Fixed-effect associations were not significant when predicting growth rate using wall shear stress (p=0.86) or pressure (p=0.61) distributions. Significant Pearson correlation coefficients (p<0.05) were observed between structural wall stress and aortic growth rate in all patients.
High structural wall stress was associated with regions of high aortic growth rates, while false lumen thrombosis was associated with low wall stress. Structural wall stress derived from the forward penalty approach may be a novel predictor of aortic growth rate and failure of optimal medical therapy in acute TBAD.
假腔扩张是决定单纯B型主动脉夹层（TBAD）长期生存的主要因素。本研究的目的是调查根据患者特异性急性TBAD几何结构计算出的结构壁应力分布是否可用于预测主动脉生长速率。
在首次入院时及最近一次随访时获取9例急性单纯TBAD患者的三维（3D）计算机断层扫描血管造影（CTA）图像。使用正向罚函数法根据初始基线CTA计算患者特异性结构壁应力分布。将通过患者特异性经胸超声心动图（TTE）和血压（BP）测量结果进行计算流体动力学（CFD）模拟得出的空间变化血压分布纳入正向罚函数应力分析。利用初始基线扫描和随访扫描对3D TBAD几何结构内的主动脉生长速率进行量化和可视化。进行线性混合效应回归分析以评估生物力学标志物（结构壁应力、壁面切应力和压力）与主动脉生长速率之间的空间相关性。
利用初始基线CTA、TTE和BP数据，正向罚函数分析揭示了急性单纯TBAD的血流动力学和结构力学特征。线性混合效应模型表明，结构壁应力与主动脉生长速率分布之间的固定效应关联具有统计学意义（p = 0.039），这表明承受高壁应力的主动脉段生长迅速。使用壁面切应力（p = 0.86）或压力（p = 0.61）分布预测生长速率时，固定效应关联不显著。所有患者的结构壁应力与主动脉生长速率之间均观察到显著的Pearson相关系数（p < 0.05）。
高结构壁应力与主动脉高生长速率区域相关，而假腔血栓形成与低壁应力相关。通过正向罚函数法得出的结构壁应力可能是急性TBAD中主动脉生长速率和最佳药物治疗失败的一种新的预测指标。
