The Impact of Blood Shear Rate On Arterial Thrombus Formation

Figures & data

Figure 1.  Artery parabolic blood flow velocity profile.

Velocity is maximal in the central part of the vessel and gradually diminishes as blood approaches the vessel wall.

Figure 2.  Vessel wall shear rates and corresponding shear stresses under normal physiological and pathological (stenosis) conditions.

Figure 3.  Blood flow properties and thrombus formation at an atherosclerotic/stenotic lesion.

Figure 4.  Distribution of platelets and erythrocytes in arterial flowing laminar blood.

The rotating and deforming erythrocytes increase the concentration of platelets at the vessel wall.

Figure 5.  Human ex vivo parallel-plate blood perfusion device.

Blood is drawn from an antecubital vein by the pump. Ex vivo studies of therapeutic agents not requiring in vivo metabolism can be injected upstream to the perfusion chamber with the reactive surface. Blood sampling for biomarker analysis can be collected downstream to the perfusion chamber.

Reproduced with permission from [19] © Future Medicine (2007).

Figure 6.  Typical blood flow velocity profile in the parallel-plate blood perfusion chamber.

The shear rate and shear stress profiles would basically be related to the slope of the velocity profile – zero at center and maximal at the wall where the velocity is zero. Formulas for calculation of wall shear rate (Y) and shear stress (u) are indicated above the figure.

Table 1.  Selected ex vivo perfusion chamber models of human thrombosis.

Chamber type	Wall shear rate (s^-1) at 10 ml/min	Corresponding vessel condition
Parallel	100	Venous
Parallel	650	Average-sized arteries
Parallel	2600	Diffuse atherosclerosis
Stenosis^†	2600	Moderate arterial stenosis
Stenosis^†	10,500	Severe arterial stenosis
Stenosis^†	32,000	Very severe arterial stenosis

† Thrombus formation at the stenosis apex.

Sakariassen KS . Thrombus formation on apex of arterial stenoses: the need for a fluid high shear diagnosis device. Future Cardiol.3(2), 193–201 (2007).

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