ACUTE THROMBOGENICITY OF INTACT AND INJURED NATURAL BLOOD CONDUITS VERSUS SYNTHETIC CONDUITS - NEUTROPHIL, PLATELET, AND FIBRIN(OGEN) ADSORPTION UNDER VARIOUS SHEAR-RATE CONDITIONS

We investigated the acute thrombogenicity of synthetic arterial prosth eses compared to biological arterial surfaces in contact with flowing nonanticoagulated blood. The acute events following blood/surface inte ractions were quantified using Cr-51-platelet deposition, In-111-neutr ophil adhesion, and (125)-fibrin(ogen) adsorption on expanded polytetr afluoroethylene (ePTFE) synthetic arterial surfaces (Goretex(R) and Im pra(R)) and on intact and injured biological arterial surfaces in ex v ivo superfusion flow chambers at low (424/sec) and high (3397/sec) she ar rates for 5 min at 37 degrees C. The hematological parameters were determined, and surface analysis was assessed by scanning electron mic roscopy. At low shear rate, the retention on intact arterial surfaces averaged 3.7 +/- 0.7 x 10(6) platelets/cm(2), 26.5 +/- 4.2 x 10(3) neu trophils/cm(2), and 10.7 +/- 2.2 cpm of fibrin(ogen)/cm(2); retention remained statistically similar at the high shear rate on both Goretex( R) and Impra(R) ePTFE surfaces. In contrast, the deposition of platele ts and neutrophils on injured arterial surfaces was significantly high er and increased with shear rate, although the significant increase in fibrin(ogen) adsorption was not influenced by the shear rate. At shea r rates characterized by patent and stenosed arteries, ePTFE arterial prostheses demonstrated a low level of thrombogenicity compared to inj ured arteries. This favorable comparison can be considered as the firs t requirement for their successful use in arterial substitution. (C) 1 997 John Wiley & Sons, Inc.