ALTHOUGH THE recent Nobel prizes in medicine attest to the possibility, it still remains tough to fool Mother Nature. Artificial hearts, kidneys, and joints can't compare with the tissues they replace. But some vascular surgeons are trying a new disguise for that simplest of artificial organs, the synthetic vascular graft, in hopes of deceiving the lady to the patient's advantage.
Of the approximately 180 000 vascular grafts placed in the extremities each year, one quarter fail, especially the small-caliber, low-flow conduits. Most of these grafts thrombose.
Native blood vessels normally do not clot because of their antithrombotic endothelial cell lining. To decrease the thrombogenicity of a vascular graft, then, it would seem logical to cover it with endothelial cells. In humans, this does not happen spontaneously; endothelial cells only grow a short distance into the anastomotic ends of a prosthetic vessel.
Lining vascular grafts with endothelial cells became more than