Numerical comparison and calibration of geometrical multiscale models for the simulation of arterial flows

Arterial tree hemodynamics can be simulated by means of several models of different level of complexity, depending on the outputs of interest and the desired degree of accuracy. In this work, several numerical comparisons of geometrical multiscale models are presented with the aim of evaluating the benefits of such complex dimensionally-heterogeneous models compared to other simplified simulations. More precisely, we present flow rate and pressure wave form comparisons between three-dimensional patient-specific geometries implicitly coupled with one-dimensional arterial tree networks and (i) a full one-dimensional arterial tree model and (ii) stand-alone three-dimensional fluid-structure interaction models with boundary data taken from precomputed full one-dimensional network simulations. On a slightly different context, we also focus on the set up and calibration of cardiovascular simulations. In particular, we perform sensitivity analyses of the main quantities of interest (flow rate, pressure, and solid wall displacement) in respect to the parameters accounting for the elastic and viscoelastic responses of the tissues surrounding the external wall of the arteries. Finally, we also compare the results of geometrical multiscale models in which the boundary solid rings of the three-dimensional geometries are fixed, in respect to those where the boundary interfaces are scaled to enforce the continuity of the vessels size with the surrounding one-dimensional arteries.