Fluid-structure interaction simulation of aortic valve closure with various sinotubular junction and sinus diameters

This study was designed to investigate the effect of sinotubular junction and sinus diameters on aortic valve closure to prevent the regurgitation of blood from the aorta into the left ventricle during ventricular diastole. The 2-dimensional geometry of a base aortic valve was reconstructed using the geometric constraints and modeling dimensions suggested by literature as the reference model A (aortic annulus diameter (DAA) = 26, diameters of sinotubular junction (DSTJ) = 26, sinus diameter (DS) = 40), and then the DSTJ and DS were modified to create five geometric models named as B (DSTJ = 31.2, DS = 40), C (DSTJ = 20.8, DS = 40), D (DSTJ = 26, DS = 48), E (DSTJ = 26, DS = 32) and F (DSTJ = 31.2, DS = 48) with different dimensions. Fluid structure interaction method was employed to simulate the movement and mechanics of aortic root. The performance of the aortic root was quantified in terms of blood flow velocity through aortic valve, annulus diameter as well as leaflet contact pressure. For comparison among A, B and C, the differences of annulus diameter and leaflet contact pressure do not exceed 5% with DSTJ increased by 1.2 times and decreased by 0.8 times. For comparison among A, D and E, annulus diameter was increased by 6.92% and decreased by 7.87%, and leaflet contact pressure was increased by 8.99% and decreased by 12.14% with DS increased by 1.2 times and decreased by 0.8 times. For comparison between A and F, annulus diameter was increased by 5.10%, and leaflet contact pressure was increased by 13.54% both with DSTJ and DS increased by 1.1 times. The results of leaflet contact pressure presented for all models were consistent with those of aortic annulus diameters. For the Ross operation involves replacing the diseased aortic valve, aortic valve closure function can be affected by various sinotubular junction and sinus diameter. Compared with the sinus diameters, sinotubular junction diameters have less effect on the performance of aortic valve closure, when the diameter difference is within a range of 20%. So surgical planning might give sinus diameter more consideration.