Dispersive Aortic Cannulas Reduce Aortic Wall Shear Stress Affecting Atherosclerotic Plaque Embolization

• Published in: Artificial organs Vol. 39; no. 3; pp. 203 - 211
• Main Authors: Assmann, Alexander, Gül, Fethi, Benim, Ali Cemal, Joos, Franz, Akhyari, Payam, Lichtenberg, Artur
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.03.2015; Wiley Subscription Services, Inc
• Subjects: Aorta - physiopathology; Aortic blood flow; Aortic cannula; Blood Flow Velocity; Cardiac Catheterization - instrumentation; Cardiac Catheterization - methods; Computational fluid dynamics; Coronary vessels; Extracorporeal circulation; Extracorporeal Circulation - adverse effects; Extracorporeal Circulation - methods; Hemodynamics - physiology; Humans; Medical research; Models, Cardiovascular; Plaque embolization; Plaque, Atherosclerotic - physiopathology; Plaque, Atherosclerotic - surgery; Pulsatile Flow; Reference Values; Reproducibility of Results; Shear Strength - physiology; Shear stress; Stress, Mechanical; Wall shear stress; Wall shear stress; Computational fluid dynamics; Aortic blood flow; Plaque embolization; Aortic cannula; Extracorporeal circulation
• ISSN: 0160-564X; 1525-1594
• DOI: 10.1111/aor.12359

Neurologic complications during on‐pump cardiovascular surgery are often induced by mobilization of atherosclerotic plaques, which is directly related to enhanced wall shear stress. In the present study, we numerically evaluated the impact of dispersive aortic cannulas on aortic blood flow characteristics, with special regard to the resulting wall shear stress profiles. An idealized numerical model of the human aorta and its branches was created and used to model straight as well as bent dispersive aortic cannulas with meshlike tips inserted in the distal ascending aorta. Standard cannulas with straight beveled or bent tips served as controls. Using a recently optimized computing method, simulations of pulsatile and nonpulsatile extracorporeal circulation were performed. Dispersive aortic cannulas reduced the maximum and average aortic wall shear stress values to approximately 50% of those with control cannulas, while the difference in local values was even larger. Moreover, under pulsatile circulation, dispersive cannulas shortened the time period during which wall shear stress values were increased. The turbulent kinetic energy was also diminished by utilizing dispersive cannulas, reducing the risk of hemolysis. In summary, dispersive aortic cannulas decrease aortic wall shear stress and turbulence during extracorporeal circulation and may therefore reduce the risk of endothelial and blood cell damage as well as that of neurologic complications caused by atherosclerotic plaque mobilization.