The effect of pulsatile shear flow on thrombus formation and hemolysis

The hydrodynamic effects of periodically fluctuating shear rate on clot growth and on erythrocyte destruction have been investigated in vitro to study quantitatively thrombus formation and hemolysis in pulsatile flow. Sinusoidally fluctuated uniform shear rates in the Couette flow were applied to the blood, which filled the space in the concave-convex cones or in the parallel-discs-type of rheoscope systems. The results show that clot growth is controlled so as not to occupy a large space when the time of application of lower (<100 s^-1) shear rates are modified by the wash-out effect of intermittent application of higher (>500 s^-1) shear rates, and that erythrocyte destruction including sub-lethal damage decreases when the exposure time of larger (>500 s^-1) shear rates is interspersed with smaller (<300 s^-1) shear rates. This study demonstrates that pulsatile flow plays an important role in controlling thrombus formation and hemolysis