Dynamics of Platelet Interaction With Surfaces in Steady Flow Conditions

Platelet adhesion and consumption

“…This has been demonstrated with especially constructed flow chambers and videotape recordings. Platelets which are removed from the surface after a variable period of adhesion, leave a "footprint" on the surface, as some of these sites are preferred for further platelet adhesion (Richardson et al, 1979).…”

“…In a living organism, or in a functioning device, the deposition of platelets takes place from flowing blood in the presence of other blood cells and is influenced by it (Goldsmith et al, 1975). Under these circumstances, a turnover of the platelets at the surface has been described (Richardson et al, 1979), and more importantly, platelets, groups of platelets and small thrombi may be removed from the surface and enter the blood stream as thromboemboli. Clinically, thromboembolism may have disastrous consequences, depending on the blood vessels in which the embolus gets stuck as it enters smaller blood vessels during the transport with the flowing blood.…”

Rheological factors in platelet — vessel wall interactions

“…Evidence is now growing that degrees of reaction can occur between platelets and walls that are intermediate between simple collision and permanent adhesion and aggregation. Richardson et al (1979) have studied the adhesion of platelets to foreign surfaces and have observed that many platelets depart after adhesions lasting 2 -3 min, and moreover that sites previously occupied by platelets were preferred for adhesion by platelets (passing subsequently) compared with unused adhesion sites. Adams & Feuerstein (1980) observed fluorescently labelled platelets in shear flow over a wall and reported that there were transient adhesions lasting up to 0.5 s, but that platelets adhering longer than that tended to remain for a relatively long time.…”

“…Adams & Feuerstein (1980) observed fluorescently labelled platelets in shear flow over a wall and reported that there were transient adhesions lasting up to 0.5 s, but that platelets adhering longer than that tended to remain for a relatively long time. Richardson et al (1979) have observed that individual platelets that a then come free often adhere again downstream, and that circumstances can prevail with this turnover process that the platelet adhesion density (platelets per unit area) becomes progressively larger downstream, suggesting that platelets can become more adhesive as they progress downstream after adhesion-detachment events. It is not clear whether repeated adhesions and detachments are necessary to augment the adhesiveness, or whether it occurs with the passage of time after a damaging event as illustrated by the results of Feuerstein et al (1980) for sero tonin release from the mechanically injured platelet.…”