| Objective: This paper is intended to apply computational fluid mechanics methods to simulate the blood flow in the ascending aorta and aortic root of David patients in turn:(1)observe the hemodynamic characteristics of David surgery patients with aortic root aneurysms before(2)calculate the hydrodynamic characteristics of David surgery patients with central ejection and eccentric ejection,and(3)further analyze the disease after comparison to clarify the David surgery patients Impact and to evaluate the impact of postoperative eccentric ejection from a hemodynamic perspective.Methods: A total of 16 patients with aortic root aneurysms with severe aortic regurgitation who underwent David surgery at our institution between January 2020 and January 2021 in the Department of cardiac surgery,the First Affiliated Hospital of China Medical University were included.A three-dimensional aortic model was constructed by reading the CTA data of the aorta obtained from the patients preoperatively and at the time of reexamination within the first half postoperative year using the medical simulation engineering software mimics 20.0.The reconstructed 3D aortic model was imported into the sys fluent12020r2 software combined with computational fluid dynamics numerical simulation of the blood flow field,and the hemodynamic parameter changes of each patient postoperatively and before operation were counted,after which the conclusions were drawn.Results: 1.In the contraction acceleration phase: the preoperative wall pressure was concentrated at the sinotubular junction,the postoperative central type had a relatively uniform pressure distribution,there was a high-pressure zone in a small area of the artificial vessel section,and in other periods,the wall pressure in the font vessel section was not significantly different between the preoperative and postoperative central types,and the wall pressure changed more in the central type model than in the preoperative groupsmooth.2.In the arterial sinus before the operation during the whole contraction there is a obvious sinus low-speed vortex region except for the central region,the direction of vortex is composed of the aortic valve orifice to the sinotubular junction and then turns to the aortic valve,after the operation the velocity streamline is relatively uniform and the flow rate is overall faster than the preoperative model,the root vortex is relatively uniform,no obvious gyral change.3.The coronary flow rate of the preoperative model during the flow velocity trough phase was significantly lower than that of the postoperative central type,and there was no significant difference between the two in the wall shear force of the coronary 4.The wall pressure map showed that the eccentric group had high pressure in the artificial vessel area where the eccentric direction was located throughout the systole,especially in the eccentric valve area to form high-pressure vortex reflux.5 the presence of regurgitation from the ascending aorta to the aortic valve in the flow velocity Valley region,while substantial turbulence in the artificial vessel region,regardless of eccentricity,occurs.However,there are regular vortices at low pressure in the autogenous vascular region,and the high-speed region is mainly concentrated at the greater curvature gyri of the ascending aorta.6.Blood velocity in the coronary artery during the initial diastolic phase is greater than in the preoperative model,regardless of the direction of blood flow.Conclusions: The 1.David operation can effectively reduce the hemodynamic contained vortex,kinetic energy loss and other negative effects of aortic valve regardless of the direction of blood flow,and can reduce the burden on the heart,reduce the aortic root ineffective ejection and ineffective work,and can improve the blood perfusion of the coronary artery in diastole without changing the wall shear force and then less coronary atherosclerosis in patients Ossification possible.2.Eccentric flow contrast central type flow persists in systole containing wall hypertension,regurgitant impingement and other adverse effects,we must try to pursue the establishment of central type flow also in surgery,while affirming David surgery has excellent effects on aortic root reconstruction,... |
PDF Full Text Request