Numerical Simulation of Compliant Artery Bypass Grafts Using Fluid–Structure Interaction Framework

Abstract

Early researches on the artery bypass graft (ABG) generally took the assumption of rigid vessel wall that ignored the wall compliancy. To obtain more realistic and physiological hemodynamic parameters, a fluid structure interaction study on a complete ABG was carried out. It was concluded: (1) a compliant vessel is able to expand its vessel diameter and decrease its anastomosis angle to achieve a buffer for the blood, thereby helping to reduce endothelial cell injury. (2) The vessel walls experienced their maximum deformation at the time of peak pressure while the deformation could be ignored during diastole. However, the consideration of wall compliance did not quantitatively change the flow characters compared to those of rigid walls. (3) Generally, the hemodynamic priority of helical-type ABG over a conventional one was further strengthened by adopting compliant vessel wall. (4) The consideration of the wall deformation revealed a hidden fact by the rigid wall assumption: Helical ABG aggravated the risk of intimal hyperplasia at its toe region due to its geometry and flow asymmetry. The present study may be useful for surgeons and graft designers to optimize the current and future ABG configurations and selection of materials.

Precise plan of hybrid treatment for thoracoabdominal aortic aneurysm: Hemodynamics of retrograde reconstruction visceral arteries from the iliac artery

“…Wall compliance is neglected in this study, which is not true in vivo; however, previous studies have indicate that the wall elasticity may be of considerable significance in, for example, transport mechanisms, but of somewhat lesser importance as far as the gross features of the flow are concerned[ 27 ].…”