Swirling flow can suppress monocytes adhesion in end-to-end arterial anastomosis

To test the hypothesis that the monocytes adhesion would be suppressed by intentionally inducing swirling flow in end-to-end arterial anastomosis to inhibit the flow disturbance, the comparing experimental and numerical investigation under both normal flow condition and swirling flow condition were executed, in which the sudden expanded tube and U-937 cells were used. The numerical results reveal that, comparing to normal flow, the swirling flow could reduce the size of flow disturbed zones and enhance the wall shear stress (WSS) in the closed downstream of sudden expanded tube. The experimental results show that there are disturbed flow zones in the sudden expanded tube, where the adhesion number of U-937 cells is larger than other zones. More importantly, comparing to the normal flow, the swirling flow could reduce the adhesion of U-937 cells, in which the adhesion number become smaller with the increasing of the swirling intensity. Therefore, the present study suggests that intentionally introducing swirling flow in end-to-end arterial anastomosis may be a solution to solve the problem of intimal hyperplasia (IH) by suppressing the flow disturbance and restraining the adhesion of monocytes to keep the favorably unimpeded flow.