VORTEX DYNAMICS OF RETROGRADE VENO-ARTERIAL EXTRACORPOREAL CIRCULATION: A COMPUTATIONAL FLUID DYNAMICS STUDY

Abstract

Veno-Arterial Extra Corporeal Membrane Oxygenation (VA-ECMO) is used for patients with both heart and lung failure. The retrograde supply of oxygenated blood from VA-ECMO leads to reduction in cerebral perfusion, lower limb ischemia, and thrombosis. Very recently, studies have emerged on computational modeling of ECMO, but none have investigated the complex flow environment during VA-ECMO. Hence, we develop an in-silico framework using computational fluid dynamics by implementing two idealized full body aorta models with in-plane and out of plane curvature to investigate the effects of aortic geometry and ECMO support levels. We studied the formation of secondary flow features and vortices and showed that streamwise vorticity and aortic arch geometry significantly influence mixing zone. We also demonstrated that location and complexity of secondary flows and vortical structures is affected by variation in ECMO support levels and aortic geometry. To investigate the effects of pulsatility on VA-ECMO, we employed three pulsatile flow waveforms and found that the position of supra-aortic branches, aortic arch curvature and pulse period influence the mixing zone and cause the formation of hairpin-like vortical structures in the abdominal aorta. Together, we believe that this three-dimensional computational framework will provide useful information to clinicians and improve patient care.