HEMOCOMPATIBILITY STUDIES OF SURFACE-TREATED POLYURETHANE-BASED CHRONIC INDWELLING CATHETERS

The objectives of this research were to evaluate and compare the inter actions of several polyurethane-based central venous catheter material s with blood. Specifically, measurements of fibrinogen adsorption, pla telet adhesion, kallikrein generation, and fibrinopeptide A (FPA) rele ase were performed. The catheter materials examined in this study incl uded: platinum-cured, 50 shore A durometer, barium sulfate-filled, sil icone (SI); Tecoflex EG85A-B20 polyurethane (PU); PU catheters whose o uter surface had been impregnated with ion beam-deposited silver atoms (AgI and AgII); PU catheters coated with a hydrophilic, polyacrylic a cid polymer (UC); PU catheters coated with an air-cured PTFE emulsion (CS); and PU catheters coated with an aminofunctional dimethylsiloxane copolymer (JG). The time course of fibrinogen adsorption from plasma to the SI, JG, PU, and CS materials was similar, with CS exhibiting th e least amount of adsorbed fibrinogen after 1 h (65 +/- 4.7 ng cm(-2)) and PU the greatest (144 +/- 16.5 ng cm(-2)). After 90 min of contact , AgI and AgII exhibited the greatest number of adherent platelets, le vels that were approximately two to three times higher than those on t he other catheter materials. With the exception of UC and PU, which ca used kallikrein generation levels approximately half that of the posit ive (glass) control, little kallikrein formation was observed for any of the materials relative to the negative control. Finally, FPA genera tion was greatest using the SI: CS, and PU materials, with the latter causing the production of almost four times the amount of FPA as the n egative control. This preliminary assessment of the hemocompatibility of the various catheters suggests that the surface treatments did not adversely affect their interactions with blood components; further inv estigations of these materials are therefore warranted in order to com pletely characterize their behavior prior to use in clinical situation s.