Human endothelial cell seeding: evaluation of its effectiveness by platelet parameters after one year

Platelet parameters were assessed in patients after implantation of polytetrafluoroethylene (PTFE) grafts, either nonseeded or seeded with autologous endothelial cells or reversed saphenous vein grafts, during the follow-up period of 1 year. The objective of this investigation was to compare the sensitivity of different noninvasive platelet parameters with the assessment of the result of endothelial cell seeding. Scanning electron microscopic investigation of circulating blood platelets showed a significantly higher incidence of activated platelets in patients with seeded or nonseeded PTFE grafts, compared with patients after reversed vein graft implantation. "Shape-changed" platelets, as well as membrane-perforated thrombocytes, were found exclusively in the circulating blood of patients after seeded or nonseeded PTFE graft implantation, indicative of platelet trauma by the artificial graft surface. Plasma levels of platelet factor IV and beta-thromboglobulin, as well as the uptake of indium-111-labeled platelets, failed to show statistically significant differences after 1 year of follow-up. The similar results for seeded and nonseeded grafts indicate the failure of endothelial cell seeding to induce the development of a nontraumatizing surface, comparable to that of saphenous vein grafts.