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

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.