Endothelial cell seeding and the thrombogenicity of vascular grafts

Abstract: ABSTRACT In humans, synthetic vascular grafts heal with a limited ingrowth of endothelium. This fact might be responsible for inferior performance of synthetic grafts compared with native artery.Endothelial cells can be autotransplanted (seeded) into the graft in an effort to improve graft function. The attachment of endothelial cells to different graft materials was investigated in vitro (I). In order of decreasing attachment the grafts were albumin-coated dacron, pre-clotted dacron, gelatin-coated dacron, gelatin-coated polyurethane, collagen-coated dacron and preclotted PTFE. The loss of seeded cells was studied in sheep (II). A low blood flow velocity did not improve cell retention. The early thrombogenicity was studied in arterial (III) and venous (IV) conduits in sheep. No difference in the attachment platelets, leukocytes and fibrinogen could be demonstrated. The conduit in the vein caused an activation and attachment of platelets on the vein wall downstream from the graft. Seeded and unseeded grafts were implanted in sheep for three (V) or twelwe (VI) weeks. After three weeks seeded grafts had a higher endoluminal release of prostacyclin and a higher endothelial coverage. After twelwe weeks this difference was no longer obvious. In human aorto-bifemoral grafts, one graft limb was seeded (VII). No difference could be demonstrated in platelet scintigraphy two months postoperatively. The long-term outcome did not seem to be affected.