## 4 Discussion  
The paper presents a computational approach to standardize the CFD technique for the virtual process of aortic dissection repair with the use of spatial configuration of human vessels. These results demonstrated that CFD simulation can accurately quantify changes in blood distribution, velocity and wall shear stress resulting from aortic remodelling after TEVAR for acute type B dissection.  
The results from CFD calculations indicated that the TEVAR procedure improved general blood flow through the aorta and increased blood flow through the thoracic aorta and renal arteries, with a concomitant decrease of blood flow through the brachiocephalic trunk, carotid arteries, subclavian artery and iliac artery. Moreover, calculated values were in accordance with USG-Doppler data, i.e., 99.3 to 90%. Only for renal arteries were USG-Doppler investigations less accurate, but it is well known that exposure of renal arteries (especially in overweight patients) is sometimes difficult with this examination [28]. A similar approach was applied by [PERSON] et al. who successfully verified computational model with PC MRI [29]. Changes in velocity profiles were based on the changes in spatial configuration of the geometry of aorta and aortic branches. We noticed a higher-velocity profile and better velocity contour distribution in the aortic arch after endograft implantation as well as in the renal and iliac arteries after stenting. It was previously indicated that during dissection, around 80% of stroke volume enters the false lumen, which may further increase the dilation of the aorta [30]. Hence, implantation of an endograft in the thoracic aorta closed the primary entry to the false lumen and improved the flow profile. This is in line with [PERSON] et al. (2016), who noticed that there was no blood flow in the false lumen across the entry after its closure [31]. Moreover, high-flow conditions within the true lumen may stabilize the aortic integrity and limit aneurysm growth, as demonstrated previously [32].  
Analysis of 3D geometries confirmed that the appearance of wall dissection had an impact on blood hemodynamics. Higher WSS values and blood flow were observed in the area of dissociation. This is in line with [PERSON] et al. who noticed that the existence of tears and their size had an impact on blood flow and velocity [33]. Also, [PERSON] et al. indicated that a small tear decreased false lumen flow and velocity [34].  
We further showed that the TEVAR procedure decreased the WSS values and changed the WSS contour distribution in the thoracic trunk and renal arteries. Lower WSS within the aorta was a consequence of closure of the primary entry to the false lumen, which began in the aortic arch, and higher cross-sectional diameter of iliac and renal arteries. Previously, [PERSON] et al. [35] stated that a tear at the aneurysm entry resulted in high wall shear stress and low total pressure. Also, [PERSON] et al. [10] reported high values of WSS around the entry tear inside the true lumen, which could increase the likelihood of tear expansion. Moreover, post-operative remodelling of the aorta leads to changes in the lumen cross-sectional diameter, which strongly correlates with peak wall stress [36]. Furthermore, peak wall stress values are influenced by vessel centreline asymmetry and maximum diameter [37]. Therefore, changes in WSS values in the aorta and aortic branches observed in patients treated for TBAD are strongly associated with an improvement of aortic geometry post-TEVAR.