Correlation of Hemodynamic Parameters to Endothelial Cell Proliferation in an End to Side Anastomosis

A strong correlation between the localization of atherosclerotic lesions with abnormal wall shear stress (WSS) has long been recognized at the distal anastomosis of a peripheral bypass where disturbed flow occurs. Identification of a WSS variable that significantly contributes to disease formation at this site has been elusive to date, as endothelial cell (EC) response to the abnormal hemodynamics at this anastomotic junction has yet to be quantitatively characterized. In vitro experiments were performed exposing human aortic ECs to pulsatile flow variables appropriate to a distal bypass graft junction using a novel in vitro device. Computational fluid dynamics was employed to detail the hemodynamic variables of this flow chamber. These variables were then correlated to EC proliferation which was used as an indicator of intimal hyperplasia (IH) development. Under pulsatile flow, maximum absolute temporal WSS gradient was found to be the parameter that most significantly correlated to EC proliferation (p = 0.0001, r = 0.8947). This metric can be utilized as an indicator to detect arterial segments prone to the initiation and localization of IH, it may also be used to help optimize the surgical construction of coronary artery bypass, peripheral bypass and arteriovenous anastomotic junctions to improve patient outcomes.