The Hemodynamics Study Of Thoracic Aorta Based On Fluid-structure Interaction Analysis

Objective: To study the thoracic aorta special hemodynamic characteristics,carrying on the fluid-structure interaction analysis on individualized digital model ofthe thoracic aorta and thoracic aortic aneurysm digital model, which can provide moremechanical reference on the develepment of aortic dissection, blunt aortic injury andthoracic aortic aneurysm.Methods:(1) An individualized thoracic aorta and thoracic aortic aneurysmsdigital model were established from CT data of2patients who came from PLA generalhospital vascular surgery department by medical Digital reconstruction softwareMimics.(2) The2digital models were imported into reverse engineering softwareGeomagics and Solidworks to generate the fluid and solid parts.(3) The CFX moduleand Transient Structural module were combined into fluid-structure interactionanalysis system in finite element analysis software Ansys14.5. The2models wereimported into it to carry on fluid-structure interaction analysis by the uniform boundaryconditions.(4) The hemodynamic parameters of thoracic aorta in one cardiac cyclewere displayed in contours visually.Results:(1) The fluid-structure interaction analysis method was applied toindividualized thoracic aorta model for finite element analysis. It is concluded thehemodynamic parameters of individualized model in one cardiac cycle, especially theoverall distribution of the wall stress and displacement.Wall stress change curves of12points on the thoracic aorta were used to compare the wall stress variation in thegreater curvature side and lesser side.(2) The fluid-structure interaction analysismethod was applied to thoracic aortic aneurysm model for finite element analysis. It isconcluded the wall stress and displacement distribution, which displayed that wall stress is most concentrated in the junction of aneurysm and normal artery. Wall stresschange curve was also obtained.Conclusion:(1) The fluid-structure interaction analysis method not only canprovide all kinds of fluid related hemodynamic parameters like the rigid models, butalso can accurately provide wall stress and displacement distribution of the bloodvessel, which is helpful for the study of mechanical properties of blood vessels and thedevelopment of aortic dissection and aneurysm.(2) In ascending aorta of thoracic aorta,the wall stress and displacement are all concentrated in the lesser curvature side.In thedescending aorta, the wall stress is concentrated in the lesser curvature side and thedisplacement is concentrated in the greater side.(3) Wall stress is most concentrated inthe junction of aneurysm and normal artery. While the displacement is concentrated inthe greater curvature side of the aneurysm bottom.