Comparative Fluid-Structure Interaction Analysis on Influence of Banding Conditions to Ascending Aorta Aneurysm Formation in Rat

Abstract Background: Ascending aortic aneurysm in an important cause of mortality in cardiovascular diseases. Stenosis of aortic is considered to be a risk factor as the ascending aortic aneurysm grows. Animal models have been demonstrated that ascending aortic aneurysm could be induced by supra valvular banding of the ascending aortic. Our objective is to compare different banding conditions on the formation of aneurysms for more precise experiment and improving the preclinical value. Therefore, three comparison banding groups of banding altitude, banding severity and banding angle are established based on rat. Then flow pattern, wall shear stress (WSS) and vessel deformation of each model are calculated and discussed using transient two-way fluid-structure interaction (FSI) analysis in order to explore the influence of different banding methods on the generation of ascending aorta aneurysm.Results: Banding methods lead to different shapes or amplitudes of flow beam, WSS and vessel dilation. Eccentric flow beam, local high WSS accompany with vessel dilation are formed above the banding ring in all banding models because of the banding operation compared with normal model. More concentrated flow beam with bigger velocity, higher local WSS and more obvious expansion deformation above the banding ring are prone to happen in the middle segment banding with 60% banding severity and banding angle of 30 degree.Conclusion: According to the results, a higher position, relatively severe banding, and an acute banding angle are more favor to promote the generation of ascending aortic aneurysm.