A one-dimensional model for aspiration in blood vessels

Abstract

This work introduces a reduced one-dimensional model for aspiration in blood vessels that accounts for the elasticity of both the vessel wall and the catheter. The inclusion of vessel wall viscoelasticity transforms the governing equation for the flow rate into a parabolic form, enabling accurate resolution of the sharp pressure gradients near the catheter tip that a purely hyperbolic formulation cannot capture. A simplified catheter equilibrium approximation is proposed that reproduces the fully elastic catheter model with high accuracy while reducing computation time significantly. The numerical treatment is based on a relaxation of the hyperbolic subsystem that yields a Lax-Friedrichs-type finite volume scheme and facilitates nodal solvers, enabling efficient coupling between catheterized and uncatheterized vessel segments, including bifurcations and the catheter tip. An implicit-explicit splitting strategy ensures that the viscoelastic terms incur only negligible additional computational cost relative to the purely hyperbolic model. The model is validated against three-dimensional CFD simulations and reference data from the literature, including a suction-force-suction-distance analysis. Numerical experiments investigating the role of catheter elasticity and suction force on the hemodynamics are presented, and an uncertainty quantification study demonstrates the suitability of the framework for efficient parameter studies.