In our experience—and insofar as the record shows, in the experience of others as well—the results of surgical procedures utilizing homologous arterial grafts in the surgical management of aneurysmal and occlusive arterial disease deteriorate as the postoperative follow-up period lengthens. The worsening of the results is not uniform in all anatomical areas and in all forms and degrees of disease. After four years' experience, from the point of view of technical excellence alone, the results of operations for aortic lesions appear best, although the long-term survival rate of patients with these lesions is unfavorably affected by the intercurrent manifestations of arteriosclerosis, mainly coronary thrombosis. Late deterioration of the results is commonest in patients with femoral and, especially, popliteal obliteration, a fact particularly disquieting, since this group of patients is the most numerous and generally has the best survival outlook. As a recent study1 shows, the commonest factor in the