Endothelial cell seeding has been proposed as a method of iinproving potency rates in small-calibre prosthetic vascular gr-afis. In vivo, endothelid cells norrnallj, produce prostacyclin (PGI,), a potent antiplatelet agent. The aini of' this stud?' was to deterniine whether seeded grclfis show signijicctnt PGI, production qfter in vivo iniplantation. Grafts were seeded with either autologous canine venous endothelial cells or autologous naicrovascular endotlielial cells. After 12 weeks, PGI, production was assessed under basal and stiniulated conditions. Seeded grufis nwe compared with non-seeded controls and the corresponding aorta. The overall paienc?, rate in seeded grafts was 80 per cent compared wiih 10 per cent in non-seeded grqfts (P t0.01). Grafts seeded witli cells froni either source produced signijicantlj, more PGI, than unseeded grafis in both basal cind stiniulated states (P < 0.05). The aorto produced significanrljinore PG12 tlian seeded grafts under both conditions ( P < 0.01). Endothelial cell seeding produces a .functional yruft and leads to an improved patencji rate.
Endothelial cells produce a number of substances with either thrombotic or antithrombotic activity; the balance i t ] vii:o is normally in favour of the antithrombotic properties. This activity is brought a b o u t by a number of mechanisms, b u t one t h a t is thought to be particularly important is t h e production of prostacyclin (PG12)'. This potent inhibitor of platelet aggregation is released by normal endothelial cells in varying quantities depending on t h e vascular bed in question. It has ,previously been shown t h a t endothelial cell seeding, using a preformed confluent layer of endothelial cells on prosthetic grafts, reduces graft thrombogenicity a n d improves patency rate'. T h e present study was designed t o investigate t h e functional properties of grafts seeded with either autologous venous endothelial or microvascular endothelial cells.