Computational Analysis of the Mechanical Behaviors of Hemiarch and Total Arch Replacements.

Surgery for aortic dissections or aneurysms can be extended into the aortic arch by hemiarch replacement (HAR) or total arch replacement (TAR). Although cardiovascular surgeons have been performing HAR and TAR for decades, the mechanical properties of HAR and TAR are not well understood. This study investigates the mechanical behaviors and stress distributions in HAR and TAR using a hybrid fluid-structure interaction analysis that combines computational fluid dynamics and structural static analysis. Geometrical information on the aortas of 11 subjects was extracted from contrast-enhanced computed tomography (CT) scan data. The CT images were imported into medical image processing software to reconstruct 3D models of the aortas. A 3D finite element model was employed to simulate aortas that receive HAR or TAR. The deformation of the great vessels and the stress distributions at both the vessels and the aortic grafts were calculated. The numerical results revealed that the aortas following TAR exhibited a lower level of stress than those following HAR. Higher stresses may cause arterial wall injury and increase the risk of rupture. Finite element analysis of the aortas and the aortic grafts provides useful information that helps physicians better understand the potential problems that may arise after various surgical procedures.