Three-dimensional characterization of ascending aortic strain, motion and growth in patients undergoing thoracic endovascular aortic repair

Abstract

Objective: We utilized vascular deformation mapping (VDM) to assess ascending aortic motion, regional stiffness and growth in patients who underwent zone 2/3 thoracic endovascular aortic repair (TEVAR) to quantify changes in ascending aorta biomechanics after endograft implantation. Methods: Multi-planar, multi-directional aortic motion, aortic strain, and three-dimensional aortic growth was extracted by VDM from electrocardiography-gated computed tomography angiograms. Aortic displacement and strain were compared between patients who underwent TEVAR (both pre- and post-procedure) and in patients with dilated ascending aorta (>4.0 cm) and a non-dilated control group. Results: One hundred twenty subjects were included for analysis. Between pre-TEVAR and post-TEVAR, total displacement decreased (4.87 ± 1.52 mm vs 4.13 ± 1.43 mm; P = .03). Ascending aortic cross-sectional area strain at the sinuses (SVS), mid-ascending (MA), and proximal arch (PA) were lower in the pre-TEVAR group (SVS, 8.3% ± 4.7%; MA, 6.2% ± 3.2%; PA, 6.3% ± 3.0%; all P < .001) compared with non-dilated controls (SVS, 14.0% ± 6.6%; MA, 14.9% ± 6.6%; PA, 14.9% ± 6.9%). TEVAR increased aortic strain at the MA (pre-TEVAR, 6.2% ± 3.2%; post-TEVAR, 8.5% ± 4.6%; P < .001) and PA (pre-TEVAR, 6.3% ± 3.0%; post-TEVAR, 9.0% ± 4.6%; P < .001). A moderate, negative correlation (R = −0.57; P = .007) between MA aortic growth rate and aortic strain was observed post-TEVAR. Conclusions: Zone 2/3 TEVAR introduces changes in ascending aortic biomechanics. Patients with lower post-TEVAR strain, suggesting higher aortic stiffness, may be at highest risk of progressive growth. Imaging-based assessment of aortic biomechanics may help improve risk stratification for long-term outcomes post-TEVAR.