Morphological study of flow surface of glutaraldehyde pre-treated vascular substitutes.

90 grafts were inserted as arterial and shunt conduits in 31 dogs. Human saphenous veins and umbilical veins were either fresh or treated with 0.2% v/v glutaraldehyde. 72 samples from these grafts were studied morphologically. Macroscopic inspection, and light, scanning and transmission microscopy was used. The insertion time of the grafts were kept in place for periods up to 6.0 months. The tanning procedure with glutaraldehyde destroyed all normal endothelial structures. However, the new vascular interface appeared to be quite thrombo-resistant, because only slight changes were found on the flow surface following surgery. Multiple collagen fibres were seen with fibrin like deposits predominating. In those grafts which were thrombosed the thrombus had its origin at the anastomotic site and the graft itself was free of thrombus. No endothelium could be seen in any case studied. Fresh untreated saphenous vein grafts studied as controls showed clear degenerative changes and thrombus accumulation on the inner surface. The same kind of changes were found also in the anastomosing artery.