As we enter the 1970s, it is cogent to review the experience of the two decades that have passed since techniques of arterial reconstruction were first introduced. As with any surgical act, results must be viewed against the background of answers to three questions: (1) Can it be done at all? (2) Can it be done with acceptable risk to life and limb? and (3) What are the late consequences and are they acceptable?
In the field of vascular replacement, the answers to the first two questions are both "yes," provided we pay careful heed to hard-earned lessons in the selection of methods and patients. The answer to the third one is, even at this late date, not so clear. This is because of late degenerative changes that take place in arterial substitutes to varying degrees depending on the site of implantation and the nature of the substitute. Mural thrombus,