Can autologous vascular endothelial cell seeding increase the patency rate of small-diameter No-React-treated bovine internal mammary arteries? An in vivo study in juvenile sheep.

Background: This study was performed to evaluate the possibility of seeding No-React (R)-treated bovine small-diameter internal mammary arteries (SIMAs) and to record any improvement in patency rate. Material/Methods: During the in vitro study, 12 seeded SIMAs were divided into two groups; group I (n=6) was endothelial cell (EC) seeded and group II (n=6) EC seeded after pie-coating with fibrin glue to evaluate the binding capacity. Dining the in vivo part of the study, eight juvenile sheep received either a seeded or a non-seeded SIMA. In the seeded group (n=3), a piece of jugular vein was harvested to culture autologous ECs. SIMA grafts were coated and seeded in a special bioreactor. In the. con trol group (n=5), non-seeded SIMA grafts were implanted. No anti-coagulation was administered. Explantation was performed at three and six months post-implantation. Grafts were evaluated by gross examination, histology, and immunohistochemistry. Results: By inserting two million ECs in the vitro study, the seeding density in group I was 1.29 +/- 0.09x 10(5) Cells/cm(2) and 2.27 +/- 0.17x10(5) cells/cm(2) in group II (p < 0.003). In the in vivo study the mean EC density of the implanted seeded grafts was 2.35 +/- 0.04x 10(5) cell/cm(2). At explantation, the seeded grafts showed less inflammatory reaction and a higher patency rate compared with the non-seeded grafts. Histology showed a monolayer of ECs oil the inner surface of seeded SIMAs at follow-up. Conclusions: Seeding of No-React (R)-treated SIMA arterial grafts with autologous ECs increases the patency rate.