## 3 Results  
### Flow Analysis  
The CFD results indicated that in all analysed cases, the TEVAR procedure changed blood hemodynamics in aortic lumen and adjacent branches. As expected after TEVAR, more blood was  
Figure 1: Representative 3D reconstructions of the aorta and aortic branches before (**Panel 1**) and after (**Panel 2**) the thoracic endovascular aortic repair (TEVAR) procedure. CTA scans were used to reconstruct the aortic arch (**A**), the left renal artery (**B**), the right common iliac artery (**C**). Blue colour represents aorta, red colour represents aortic stent graft. Post—TEVAR refers to 7 months after operation. 3D reconstructions were performed with ANSYS FLUENT software. directed into the true lumen due to complete closure of the false lumen (Table 2). CFD results indicated a 7-fold increase in blood flow through the true lumen after TEVAR compared to pre-TEVAR (62.28 \(\pm\) 1.23 mL/s and 9.02 \(\pm\) 0.26 mL/s, respectively, \(p\) < 0.0001; Table 2). Calculated results were verified with USG-Doppler data, where an 8-fold increase in blood flow through the true lumen was noticed after TEVAR compared to pre-TEVAR (64.81 \(\pm\) 0.89 mL/s and 8.07 \(\pm\) 1.54 mL/s, respectively, \(p\) < 0.0001; Table 2). Therefore, we accomplished 96% and 90% accuracy for CFD results compared to USG-Doppler in the post-TEVAR and pre-TEVAR procedures (Table 2). As post-interventional aortic remodelling contributes to blood flow distribution into aortic branches, we analysed changes in blood flow pre- and post-TEVAR with CFD and compared those results with USG-Doppler data. We recorded flow changes in three branches of the aortic arch--the brachiocephalic trunk, carotid artery and subclavian artery. CFD results indicated no significant change in blood flow through those arteries (Table 2), which was verified with USG-Doppler data (Table 2). The accuracy of CFD calculations in post-TEVAR was 97.8%, 97.7% and 98.5% for the brachiocephalic trunk, carotid artery and subclavian artery, respectively (Table 2) and 99.8%, 99.7%, 99.9% for the brachiocephalic trunk, carotid artery and subclavian artery, respectively, pre-TEVAR (Table 2). There was also a strong positive correlation between CFD and USG-Doppler data for all outflows (\(r\) = 0.942, \(r\) = 0.906, \(r\) = 0.948 for the brachiocephalic trunk, carotid artery and subclavian artery, respectively). Also, CFD results indicated that catheter stent intervention in renal arteries contributed to a significant increase of blood flow post-TEVAR compared to pre-TEVAR (10.37 \(\pm\) 0.63 mL/s and 9.33 \(\pm\) 0.29 mL/s, respectively, \(p\) = 0.43; Table 2). This was in line with USG-Doppler data where increased blood flow post-TEVAR compared to pre-TEVAR was observed (9.84 \(\pm\) 0.46 mL/s and 9.16 \(\pm\) 0.38 mL/s, respectively, \(p\) = 0.043; Table 2). Also, a strong positive relationship between CFD and USG-Doppler data was shown (\(r\) = 0.784). Therefore, the accuracy of CFD calculations in post-TEVAR was 95% (Table 2) and 98.2% pre-TEVAR (Table 2). Finally, no significant change in blood flow in the iliac was detected post-TEVAR compared to pre-TEVAR (2.01 \(\pm\) 0.07 mL/s and 2.14 \(\pm\) 0.12 mL/s, respectively, \(p\) = 0.079; Table 2). This was in line with USG-Doppler data where blood flow slightly decreased after TEVAR (2.02 \(\pm\) 0.15 mL/s and 2.24 \(\pm\) 0.17 mL/s, respectively, \(p\) = 0.079; Table 2). The accuracy of CFD calculations post-TEVAR was 99.3% (Table 2) and 95.5% pre-TEVAR (Table 2). Moreover, a strong positive relationship between CFD and USG-Doppler data was shown (\(r\) = 0.805). After detailed analysis of changes in blood flow distribution post- and pre-TEVAR, we decided to analyse changes in blood velocity in two areas of the aorta: the aortic arch, where dissections began in all analysed cases and the renal arteries, where changes in blood flow were highest after TEVAR.