Fibrinolysis Profiles and Platelet Activation After Endothelial Cell Seeding of Prosthetic Vascular Grafts

There is no convincing evidence that endothelial cell seeding of prosthetic grafts in humans confers any of the advantages seen in animals. However, partial endothelial coverage might exert a subtle effect not detectable with indirect end points such as patency or scintigraphy. This study examined seeded cell function by measuring fibrinolytic and platelet activation markers in patients receiving seeded and control prosthetic grafts. Thirty-two patients were randomly assigned to seeded (n=15) and control (n=17) groups. Preoperatively and 3, 6, and 12 months postoperatively, plasma levels of fibrinopeptide A (FPA), Bβ1–42 fragment, cross-linked fibrin degradation products (XL-FDP), thromboxane A2 (TXA2), platelet factor 4 (PF4), and β-thromboglobulin (sTG) were measured. Patients with seeded grafts had significantly lower levels of FPA at 6 and 12 months (p <0.05) and a significant overall group effect (p <0.05). These patients also tended to have higher levels of XL-FDP (p <0.1). No other significant differences were seen. The lower rate of conversion of fibrinogen to fibrin and the trend toward increased fibrinolysis seen in seeded grafts may be due to the metabolic effects of viable retained seeded cells. Although comparable platelet activation indicates that endo-thelial coverage remains limited, seeding may exert an antithrombotic influence at the graft surface.