Experimental study of fibrin embolization under shear flow

Arterial thrombi consist mainly of platelets and fibrin, the biopolymer pro duced in the final step of the coagulation cascade. Thrombus fragmentation may result in occlusion of smaller distal vessels (embolization), a serious and often fatal event. The objective of this study is to investigate the r ole of the fibrin polymer network on the resistance of a clot to fragmentat ion under shear flow. For that purpose, a fibrin clot model representative of native clots is submitted to a shear flow that reproduces the pathophysi ological range of sheer stress. The adhesion force due to specific fibrin/fibrin interactions is determined from the measurement of the shear stress producing 50% detachment of model particles of blood platelets embedded in the clot. This force was found to be several orders higher than the nonspecific colloidal forces between sur faces, which can, thus, be neglected. Influence of the number of fibrin mon olayers in the clot model on adhesion force is investigated.