Computational Fluid Dynamic Technique for Assessment of How Changing Character of Blood Flow and Different Value of Hct Influence Blood Hemodynamic in Dissected Aorta

Using computer tomography angiography (CTA) and computational structural analysis, we present a non-invasive method of mass flow rate/velocity and wall stress analysis in type B aortic dissection. Three-dimensional (3D) computer models of the aorta were calculated using pre-operative (baseline) and post-operative CT data from 12 male patients (aged from 51 to 64 years) who were treated for acute type B dissection. A computational fluid dynamics (CFD) technique was used to quantify the displacement forces acting on the aortic wall in the areas of endografts placement. The mass flow rate and wall stress were measured and quantified using the CFD technique. The CFD model indicated the places with a lower value of blood velocity and shear rate, which corelated with higher blood viscosity and a probability of thrombus appearance. Moreover, with the increase in Hct, blood viscosity also increased, while the intensity of blood flow provoked changing viscosity values in these areas. Furthermore, the velocity gradient near the tear surface caused high wall WSS; this could lead to a decreased resistance in the aorta's wall with further implications to a patient.

Automated summary

This study proposed a non-invasive method for analyzing mass flow rate/velocity and wall stress in type B aortic dissection using CTA and computational structural analysis. 3D computer models of the aorta were constructed from pre- and post-operative CT data, and CFD technique was used to quantify displacement forces and measure mass flow rate and wall stress. The CFD model identified areas with lower blood velocity and shear rate, indicating higher blood viscosity and likelihood of thrombus formation, as well as the impact of hematocrit levels on blood viscosity and flow dynamics.