Thrombogenic potential

Lacoste L, Lam JY, Hung J, Letchacovski G, Solymoss CB, Waters D. Hyperlipidemia and coronary disease. Correction of the increased thrombogenic potential with cholesterol reduction. Circulation 1995 92 3172-3177. 

A material with a critical surface tension around 25 dyn/cm will have a low thrombogenic potential. 

High water content materials have a low thrombogenic potential due to the lowered free energy of the hydrated interface. 

H-bonding groups in a surface lead to strong interactions with biological species and therefore endow a surface with a high thrombogenic potential. 

A surface with a high apolar/polar ratio is desirable for low thrombogenic potential. 

Flexible (as opposed to stiff) polymer chain ends and loops in the material interface lower the thrombogenic potential of the foreign surface. 

Fibrinogen dominates the initial protein layer on most foreign materials, and fibrinogen adsorption leads to high thrombogenic potential for that surface. 

Thus, the actual substances produced as segmented polyurethanes (Scheme I and Table II) that were tested for thrombogenic potential, are peculiarly complicated in molecular structure. 

Liotta (12) constructed his artificial heart from a combination of different materials - Lucite, teflon, polyester urethane, and silk. It is difficult to evaluate the thrombogenic potential of this combination of materials because the longest survival was 13 hours in dogs. The principle cause of death in these animals was low cardiac output secondary to inadequate venous return. The following year in a different series of experiments Liotta (13) tried a different combination of materials. Here, although the experiments were acute in scope, thrombus formation at the blood-plastic interface was a major problem. The left ventricular assist device (LVAD) was a tube-type with the housing and valves constructed of Estane. The internal elastic tube was made of either natural rubber. Silastic, or natural rubber covered externally with Silastic. 

---