Pulsatile extracorporeal circulation during on-pump cardiac surgery enhances aortic wall shear stress.
Controversy on superiority of pulsatile versus non-pulsatile extracorporeal circulation in cardiac surgery still continues. Stroke as one of the major adverse events during cardiopulmonary bypass is, in the majority of cases, caused by mobilization of aortic arteriosclerotic plaques that is inducible by pathologically elevated wall shear stress values. The present study employs computational fluid dynamics to evaluate the aortic blood flow and wall shear stress profiles under the influence of antegrade or retrograde perfusion with pulsatile versus non-pulsatile extracorporeal circulation. While, compared to physiological flow, a non-pulsatile perfusion resulted in generally decreased blood velocities and only moderately increased shear forces (48 Pa versus 20 Pa antegradely and 127 Pa versus 30 Pa retrogradely), a pulsatile perfusion extensively enhanced the occurrence of turbulences, maximum blood flow speed and maximum wall shear stress (1020 Pa versus 20 Pa antegradely and 1178 Pa versus 30 Pa retrogradely). Under these circumstances arteriosclerotic embolism has to be considered. Further simulations and experimental work are necessary to elucidate the impact of our findings on the scientific discourse of pulsatile versus non-pulsatile extracorporeal circulation.
Clinic for Cardiovascular Surgery, Heinrich Heine University Medical School, Moorenstr. 5, D-40225 Duesseldorf, Germany. alexander.assmann@med.uni-duesseldorf.de
Alexander
A
Assmann
Ali Cemal
AC
Benim
Fethi
F
Gül
Philipp
P
Lux
Payam
P
Akhyari
Udo
U
Boeken
Franz
F
Joos
Peter
P
Feindt
Artur
A
Lichtenberg
D000368:Aged; D001011:Aorta / Q000502:physiology*; D001161:Arteriosclerosis / Q000601:surgery; D001783:Blood Flow Velocity / Q000502:physiology*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000379:methods; D002315:Cardiopulmonary Bypass / Q000009:adverse effects / Q000379:methods; D003198:Computer Simulation; D004617:Embolism / Q000150:complications; D005112:Extracorporeal Circulation / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006801:Humans; D011673:Pulsatile Flow / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology*; D033081:Shear Strength / Q000502:physiology*; D013314:Stress, Mechanical; D020521:Stroke / Q000209:etiology