Bacterial adherence to endothelial-seeded polytetrafluoroethylene grafts

Since infections of an arterial prosthesis pose a serious threat to life and limb, efforts to produce a graft that is resistant to hematogenous bacteremia continue. We studied the effect of endothelial seeding on bacterial adherence to polytetrafluoroethylene grafts in a canine model. Enzymatically derived venous endothelial cells were seeded in 10 cm long, 4 mm inner diameter polytetrafluoroethylene grafts, which were then implanted as carotid interpositions opposite contralateral unseeded controls. After 4 to 8 weeks, each dog received an intravenous infusion of 3 x 10⁸ radiolabeled Staphylococcus aureus. Seeded grafts had significantly fewer adherent viable bacteria than had control grafts (mean, 432 versus 989; p < 0.05) and significantly fewer radiolabeled bacteria (mean, 2 x 10⁵ versus 8 x 10⁵; p < 0.05). Seeded grafts also had significantly more thrombus-free, luminal surface area than had control grafts (mean, 72% versus 40.6%; p < 0.05). Scanning electron microscopy and autoradiography of seeded grafts confirmed that the sites of bacterial adherence largely corresponded to accumulations of surface thrombus. In this experiment, endothelial seeding appeared to protect against bacterial adherence after a hematologous challenge 4 to 8 weeks after inplantation by reducing luminal thrombi.