A numerical analysis of the aortic blood flow pattern during pulsed cardiopulmonary bypass

Area of Science:

• Cardiovascular Science
• Biomedical Engineering
• Fluid Dynamics

Background:

• Stroke is a significant complication following cardiac surgery, often linked to cardiopulmonary bypass (CPB) techniques.
• Despite advancements in CPB, reducing the incidence of postoperative stroke remains a critical clinical challenge.

Purpose of the Study:

• To numerically investigate the impact of intra-aortic balloon pump (IABP) assistance on blood flow dynamics in the aorta and epiaortic vessels during standard and pulsed CPB.
• To evaluate the hemodynamic alterations induced by IABP during CPB and their potential to mitigate stroke risk.

Main Methods:

• Development of a validated multi-scale model coupling 3D computational fluid dynamics (CFD) with a 0D model.
• Numerical simulation of blood flow in the aorta and epiaortic vessels under standard and pulsed CPB conditions with and without IABP.
• In vivo data were utilized for model validation.

Main Results:

• The presence of IABP demonstrated an improvement in the blood flow pattern directed towards the epiaortic vessels.
• A mean flow increase of 6.3% was observed in the epiaortic vessels with IABP assistance.
• IABP usage was associated with a reduction in flow vorticity within the aorta and epiaortic arteries.

Conclusions:

• IABP-assisted CPB can positively alter hemodynamics, enhancing flow to critical epiaortic vessels.
• The observed improvements in flow pattern and reduced vorticity suggest a potential mechanism for decreasing stroke incidence after cardiac surgery.
• Numerical modeling provides valuable insights into optimizing CPB strategies for stroke prevention.