  In our recent work, we introduced the reduced unified continuum formulation
for vascular fluid-structure interaction (FSI) and demonstrated enhanced solver
accuracy, scalability, and performance compared to conventional approaches. We
further verified the formulation against Womersley's deformable wall theory. In
this study, we assessed its performance in a compliant patient-specific aortic
model by leveraging 3D printing, 2D magnetic resonance imaging (MRI), and
4D-flow MRI to extract high-resolution anatomical and hemodynamic information
from an in vitro flow circuit. To accurately reflect experimental conditions,
we additionally enabled in-plane vascular motion at each inlet and outlet, and
implemented viscoelastic external tissue support and vascular tissue
prestressing. Validation of our formulation is achieved through close
quantitative agreement in pressures, lumen area changes, pulse wave velocity,
and early systolic velocities, as well as qualitative agreement in late
systolic flow structures. Our validated suite of FSI techniques can be used to
investigate vascular disease initiation, progression, and treatment at a
computational cost on the same order as that of rigid-walled simulations. This
study is the first to validate a cardiovascular FSI formulation against an in
vitro flow circuit involving a compliant vascular phantom of complex
patient-specific anatomy.
