## 4 Discussion
### Effect of the Aneurysm Size Modification  
As the WSS time evolution showed, there was a clear distinction in the magnitude when the aneurysm evolved in size, except for UG-3, which showed an increase followed by a decrease. These results were similar to those obtained by [PERSON], who found that the WSS curves were clearly separated from each other, with the scaled geometry being the one with a higher WSS. The curves obtained by that research group were closer to each other than those found for the present case. This is because, in the present case, the aneurysm \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Case**} & \multicolumn{2}{c}{**Aneurysm Wall**} & \multicolumn{2}{c}{**Average Displacement Difference [\%]**} \\ \cline{2-4}  & **Thickness [mm]** & **Diastole** & **Systole** \\ \hline \multirow{2}{*}{RG-1} & 0.2 & \(57.1\) & \(50.0\) \\  & 0.1 & \(142.9\) & \(120.0\) \\ \cline{2-4}  & 0.2 & \(-4.2\) & \(-5.4\) \\ \multirow{2}{*}{UG-1} & 0.1 & \(-11.3\) & \(-11.8\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Percentage differences for the displacement at the aneurysm with respect to a wall thickness of 0.35 mm. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Case**} & \multicolumn{2}{c}{**Aneurysm Wall**} & \multicolumn{2}{c}{**Average von Mises Stress Difference [\%]**} \\ \cline{2-4}  & **Thickness [mm]** & **Diastole** & **Systole** \\ \hline \multirow{2}{*}{RG-1} & 0.2 & \(75.9\) & \(79.5\) \\  & 0.1 & \(244.8\) & \(263.6\) \\ \cline{2-4}  & 0.2 & \(82.5\) & \(87.5\) \\ \multirow{2}{*}{UG-1} & 0.1 & \(200.0\) & \(212.5\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Percentage differences in the von Mises stress at the aneurysm for a wall thickness of 0.35 mm. size was modified but the wall thickness remained constant for each case. Other differences were that the geometries were different, and a non-Newtonian blood model was used. Table 5 shows that ruptured geometries demonstrated an increment in the average WSS of between 205 and 276% for the size I case. UG-2 showed a reduction in its WSS of around 36%, considering both systole and diastole, for its largest variation. UG-3 showed an increase of up to 31% at diastole for variation II, but there was a decrease of less than 5% for its largest size, a difference that can be considered negligible. The distinctive behavior of UG-3 can be explained by the changes in the blood flow path as the aneurysm evolved, as seen in Figure 21. In the original geometry, for the smallest size, the blood travelled through a recirculation zone prior to entry into the aneurysm and then the main bifurcation. For the size II aneurysm, the blood flow entered the aneurysm more directly and with more velocity, which explains the WSS increment. The blood flow pattern was similar in the largest variation, but just like for the rest of the cases, there was a decrease in the WSS, because the blood flow reached the dome with a lower velocity. In terms of displacement, a larger aneurysm might be expected to have greater displacements because the distance from the anchor point to the artery is longer. This was observed for most cases, and the maximum value was achieved at the top of the aneurysms, where the blood flow changed in magnitude and direction, transferring its momentum to the aneurysm wall. The distinctive behavior of UG-3 can be explained by the complexity of its geometry, which included three bifurcations, and the tendency of its maximum values to be located near the neck.