Effect of Negative Angle Cannulation during Cardiopulmonary Bypass - A Computational Fluid Dynamics Study

Abstract

Creation of emboli in the aortic root and changes in flow distribution between supra-aortic arteries and descending aorta can lead to stroke and perfusion related tissue damage during cardiopulmonary bypass. A thorough understanding of how the angle of cannulation affects the overall success of cardiopulmonary bypass during cannulation of the ascending aorta is needed. Previous simulation research has observed the effect of outflow cannula position by changing the location of the cannulation site to the subclavian artery and other vessels, as well as positions for innovative cannula designs. The purpose of this study is to evaluate the success of the procedure while using a straight cannula, modulating the angle of cannulation below horizontal in the frontal plane. A simplified geometry of the aorta was used. The success of the procedure was quantified by observing wall shear stress, normal stress, intra-fluid shear stress, and flow distribution. A numerical study was performed to solve the Reynolds Averaged Naiver Stokes governing equations, which were used in conjunction with a constant density fluid to simulate blood, and a realizable two-layer k-ε turbulence model.

Effect of aortic cannulation depth on air emboli transport during cardiopulmonary bypass: A computational study

“…1,30 In contrast, current numerical CFD cannula studies use a constant pump flow rate in the range of 4-5 L/min. 29,[31][32][33] Therefore, to determine the interaction of pump flow, two extreme differential non-pulsatile flows of 2 L/min and 5 L/min were arbitrarily chosen.…”