Renal artery aneurysm (RAA) is a condition that affects approximately 0.1% of the general population. The rate of incidence is minimal compared to other type of aneurysm but a high number of ruptures have been reported in pregnancy, especially at the third trimester. The concerning issue is that the maternal mortality rate stretches up to 50% and the fetal mortality rate approaching 85% with a universal loss of the affected kidney. This study aimed at investigating the effectiveness of stent in treatment of RAA using the fluid-structure interaction (FSI) approach. The flow pattern, wall shear stress (WSS), deformation and von Mises stress experienced are compared between RAA model without stent and with Abbott RX Herculink stent. A simple PIV experiment, observing the flow profile was conducted as a validation steps in ensuring the simulation results are reliable and accurate. The findings show that the simulation and PIV data are in good agreement in terms of the flow profile. The presence of stent managed to reduce the blood flow maximum velocity down to 46% and minimized the circulation of blood in the aneurysm dome. As for the WSS, the used of stent succeeded in decreasing the WSS experienced by the wall of aneurysm by 71% and below the baseline level of WSS that could induced rupture. The deformation of RAA and maximum von Mises stress reduced by 58% and 73% respectively when stent is used. In addition, the maximum von Mises stress after the stent placement is lower than the threshold value for the ultimate tensile strength of the tissue. This study concluded that the stent placement is effective in reducing the risk of aneurysm rupture in renal artery it can be one of the baseline for the further study regarding the RAA.

Renal arteries are the arteries that supply blood to the kidneys. Renal arteries are the arteries that supply blood to the kidneys. Renal artery aneurysm (RAA) is the second most common visceral aneurysm to occur, which accounts for 22% of the visceral aneurysm. In general population, RAA rate of occurrence was only 0.1%. However, due to the extensive used of angiography technique, RAA has been discovered more frequently. Some claimed that the previous rate of incidence should be higher now because of the capability of angiography. The rupture of this aneurysm could result in haemorrhage, kidney lost and mortality. The size of the renal artery which is different compared to other types of arteries such as the abdominal aorta could produce different flow condition when the artery is inflicted with RAA condition. Thus, a thorough analysis is desired as RAA studies are very limited compared to other aneurysm conditions. In this study, the efficiency of the stent porosity was investigated in treating the RAA. Fluid-structure interaction (FSI) simulations and particle image velocimetry (PIV) experiments were the approaches taken to investigate the flow patterns of the blood when the stent of different porosities was placed in the aneurysm entrance. The effect of wall shear stress (WSS), the deformation of the artery and von Mises stress were also observed in determining the possibility of aneurysm rupture. The study found that the placement of stent of different porosities succeeds in providing an obstruction to the blood from circulating inside the aneurysm sac. This in turns reduced the WSS experienced by the aneurysm sac up a significant value of 96%. This reduction is crucial in order to prevent the aneurysm from rupture. Moreover, the placement of the stent provided support to the renal artery and preventing it from experiencing buckling failure. The maximum deformation of the artery reduced by 42% with stent was placed in the renal artery. In fact, the von Mises stress decreased below the threshold limit of 0.5 MPa with the presence of the stent. In addition, the study found that the stent of porosity 80% has a similar impact to the stent of lower porosity in the case of RAA at main renal artery.