I am thinking how thrombus (veins, arteries and heart) can move.
Secondary mechanisms come to my mind only: some enzyme which lyses it, probably adhesion mechanism. Blood circulation (flow rate) is one secondary measure, I think. I am not sure if there exist any primary mechanisms. In veins, there are valves which probably can help trombus go forward by pushing. Veins can also dilate so dilation of vessel can help.
Arteries do net dilate their diameter. So aim would be there to maximise laminar flow, and decrease turbulence.
So probably the question is related somehow to the laminar flow which could help thrombus to move.
How can thrombus move in veins, arteries and heart?