Saphenous vein bypass grafts: Long-term patency and effect on the native coronary circulation.

The long-term durability of saphenous vein bypass grafts and their effect on existing intrinsic coronary artery disease remain ill defined. Therefore, sequential catheterization studies were performed in patients selected for study solely on the basis of documentation of a patent graft at an earlier study performed three to nine months postoperatively; at that time 29 patent grafts were demonstrated in 20 patients. Fifteen to 36 months postoperatively (average 22 months), 27 grafts were unchanged, 1 manifested minimal luminal irregularities and 1 was occluded. In one additional patient, studied 4 months and 4 1/2 years postoperatively, the graft was widely patent and had good distal runoff at the second study. Sequential coronary arteriograms revealed that progression of disease to complete occlusion occurred in 24 percent of vessels with severe lesions proximal to a patent graft, whereas progression of disease distal to a graft anastomosis was uncommon. Of 25 vessels not receiving grafts, disease progressed in 5 (20 percent). Grafts that are patent 3 months after operation appear to remain patent for at least 2 to 3 years, and their presence does not unduly accelerate the disease process involving the native coronary arteries.