Numerical investigation of a novel aortic cannula aimed at reducing cerebral embolism during cardiovascular bypass surgery

Abstract

The generation of emboli during cardiopulmonary bypass (CPB) is profoundly affected by the hemodynamic properties of the aortic cannula used in the current study. The aim of the current work was to numerically investigate the hemodynamic efficiency and feasibility of a novel, backward suction cannula (BSC), designed to drastically reduce the potential risk for cerebral emboli (CEP). In line with the standard cannulae, the BSC provides oxygenated blood from the CPB machine through its primary lumen. However, the unique feature of the BSC lies in its secondary lumen, which is used to suck blood and embolic matter back from the surgical field to the CPB machine for filtration. Analysis included a numerical investigation of the hemodynamic characteristics of 44 different models, encompassing various anatomic orientations, cannula types, cannula orientations and flow conditions. Hemodynamic efficacy and CEP were assessed via trajectories of particle released from the surgical region, while the cannula feasibility was evaluated through potential for atheroembolism (AP) and index for hemolysis (IH). Differences between the investigated cannulae in terms of these measures were tested using analyses of variance tests (ANOVAs). Results indicate that the BSC exhibited a significant improvement of the cannula performance in terms of CEP with no significant change in the risk for other hemodynamic complications, such as hemolysis or atheroembolism (AP and IH). These findings suggest the advantageous use of the BSC in the clinical setting for its potential to diminish the risk for cerebral emboli, which presents the most pertinent cause of noncardiac complications following open heart surgery.