Factors Involved in Success or Failure of Arterial Grafts

Fig. 1.  —This illustration is concerned with the role of the elastica. Besides its normal functions, its strength role and its ultimate fate in implants are discussed. The first series of curves represents a theoretical concept (Burton) of relative tensile properties of elastic tissue and collagen. One notes that there is little limitation to stretch when tension is applied to the elastic fiber short of its breaking point. Collagen, on the other hand, shows limited extension and considerably greater resistance to stress.The next three tracings represent experimental findings on the tensile properties of an untreated artery and on tubes which are predominantly composed of either elastin or collagen. The last two materials mentioned were derived from arteries by chemical and enzymatic treatment. Their tension-elongation curves coincide remarkably well with the theoretical stress curves previously shown.The two photomicrographs, below, deal with the fate of elastic tissue in an initially