Endothelialization of vascular prosthetic surfaces after seeding or sodding with human microvascular endothelial cells.

The rapid establishment of an endothelial cell (EC) monolayer on the luminal surface of small-diameter vascular grafts may be necessary to prevent early thrombosis and failure. We have studied procedures used to promote EC coverage of vascular grafts and have compared preclotting prosthetic surfaces with ECs in platelet-rich plasma (seeding) with plating ECs onto a preestablished clot (sodding). We evaluated the rate of monolayer formation, the subsequent resistance to shear stress, and the effects of EC growth factors (ECGF and heparin) on these functions. Woven Dacron was seeded or sodded at a density of 2 x 10(5) cells/cm2 with human adult microvessel ECs derived from adipose tissue. In the presence of ECGF-heparin, the immediate establishment of an EC layer after sodding was observed, whereas seeded grafts required almost 48 hours for cells to reach the surface. In the absence of ECGF-heparin, sodded grafts still exhibited a complete monolayer of EC, whereas ECs were not observed at the surface of seeded grafts after 48 hours. After exposure to shear stress (up to 20 dynes/cm2) for 2 hours, most freshly sodded EC remained attached; however, the loss of loosely adherent cells did occur. EC seeded grafts remained covered with fibrin matrix after exposure to shear stress. We conclude that the use of a microvessel sodding technique as an alternative to previously reported seeding techniques is necessary for the immediate formation of an EC monolayer before implantation.