Numerical Simulation Of Blood Flow In Ascending Aorta Replacement Surgery

In the modern world,cardiovascular disease has become one of the diseases with high incidence and high mortality among middle-aged and elderly people.In recent years,with the advancement of China's aging process,the incidence of thoracic aortic dissection has increased significantly.As one of the cardiovascular diseases,it has seriously threatened people's lives and health.At this stage,a comprehensive treatment plan based on surgery has a good effect on thoracic aortic dissection,and artificial blood vessel replacement is a common clinical treatment.When the body's own blood vessels cannot normally supply blood to the human body due to factors such as disease,trauma,etc.,surgical operations such as repairing,replacing or bypassing the damaged blood vessels should be used for treatment.Artificial blood vessels have become one of the efficient treatment options for these kinds of diseases.Because blood vessel replacement greatly changes the vascular tissue structure in terms of geometry,it has a great change and influence on various mechanical parameters of blood flow in the flow field.However,there are few domestic studies on the impact of artificial blood vessel replacement on the aortic flow field,and there are individual differences in different patients.This article selects a certain artificial blood vessel replacement surgery to treat ascending aortic dissection for simulation analysis,which can provide some guidance effect.Numerical simulation has the advantages of high degree of simulation,fast calculation,and convenient parameter adjustment.Computational fluid dynamics,as an efficient method of in vitro simulation,has great reference value in the research of artificial blood vessel replacement mechanics.Objective: To study the hemodynamics after artificial ascending aortic replacement surgery for Stanford type A aortic dissection,collect clinical CT images,and construct a personalized geometric model of aortic flow field before and after surgery.Numerical simulations were performed on the preoperative model,postoperative model and postoperative ascending aorta segments to obtain the flow wall pressure distribution,the flow section velocity distribution,the Tresca equivalent stress distribution and the artificial blood vessel elastic strain distribution,so as to analyze the flow law.Methods: Collect the patient's preoperative and postoperative CT image DICOM files,and use the image post-processing software MIMICS to perform three-dimensional reconstruction and optimization,and obtain the preoperative and postoperative geometric models of the aortic drainage area and postoperative ascending aortic segment geometry Model,and then import the geometric model into the meshing software for meshing,and finally import the mesh file into ABAQUS for multi-period transient simulation.Results: Through simulation calculation,the simulation results of the mechanical parameter distribution of the preoperative and postoperative aorta and the postoperative part ascending aorta at different times of the cardiac cycle were obtained.Conclusion: After the comparative analysis of model geometry and mechanical parameters,it is believed that: 1.Artificial blood vessel replacement has a positive therapeutic effect on this case of Stanford A type aortic dissection.2.Hemodynamic parameters are closely related to boundary conditions.3.There is a certain connection between the complex flow field environment in the aorta and cardiovascular disease.Numerical simulation can provide a reference for the treatment of the disease after artificial blood vessel replacement.