Mesothelial seeding of knitted Dacron.

Bilateral superficial femoral artery replacement using knitted Dacron was performed in 38 dogs. One side was seeded with omental mesothelium and the other acted as an unseeded control. 111In-labelled platelet accumulation on grafts was measured at 5 days and 2 months and the thrombogenicity index of seeded and unseeded grafts calculated. Patency was monitored for 2 months, at which time grafts were removed and luminal thrombus, ultrastructural cell cover and prostacyclin release were measured. Cell seeding did not influence the mean(s.e.m.) thrombogenicity index of 0.95(0.25) and 0.88(0.24) at 5 days in control and seeded grafts respectively; nor was there any difference between the groups at 2 months. Occlusion occurred in six control and four seeded grafts. Seeding did not significantly improve the percentage thrombus-free area or luminal cell cover. Neither did it enhance mean(s.e.m.) luminal 6-keto-prostaglandin F1 alpha release of 2.58(0.80) pg cm-2 in controls and 2.63(0.78) pg cm-2 in seeded grafts. Further studies demonstrated that only a mean(s.e.m.) of 4.4(1.9) per cent of the seeded inoculum was present on grafts 48 h after implantation, providing too few cells to achieve confluent cover. Mesothelial cell seeding might be useful in promoting a healed graft surface but critical levels of seeding density must be achieved before the technique can be properly evaluated.