Optimization of Blalock-Taussig Shunt and Anastomotic Geometry for Vascular Access Fistula Using a Genetic Algorithm
Date of Award
Master of Science (MS)
Blalock-Taussig (BT) shunts are used for defects that affect the flow of blood from the right ventricle, through the pulmonary artery, and to the lungs. Arteriovenous (AV) fistula is one type of vascular access which is a surgically created vein used to remove and return blood during hemodialysis. Plastic grafts used in the above two reconstructions may result in areas of non-physiologic flow in the grafts leading to risk of stenosis (blocked area) and thrombosis, which is the single major cause for access morbidity. The focus of this thesis is to study BT shunts and anastomoses models using Computational Fluid Dynamics (CFD) and optimize their shapes to reduce the possibility of the formation of stenosis. A single-objective genetic algorithm (SOGA) is employed to optimize the curvature distributions of grafts to minimize the maximum wall shear stress (WSS). The commercially available software ANSYS Fluent is used to calculate the flow field. The mesh is generated by the commercial mesh generating software ICEM CFD. The flow field is calculated using the Navier-Stokes equations in conjunction with a three-equation transitional k-kl-ω turbulence model. The process is continued for a number of generations until the minimum value of maximum WSS converges. The results show significant improvement in reducing the maximum WSS of the optimized BT shunt and anastomoses compared to the original shapes.
Ramesh K Agarwal
David Peters, Kenneth Jerina
Permanent URL: https://doi.org/10.7936/K7PZ571B