Aortocoronary bypass saphenous vein graft atherosclerosis. Anatomic study of 99 vein grafts from normal and hyperlipoproteinemic patients up to 75 months postoperatively

In this anatomic study of 99 saphenous vein grafts recovered at autopsy from 55 patients who survived aortocoronary bypass for 0 to 75 months, a comparison was made between patients with normal and elevated lipid levels in regard to the severity of vein graft intimai proliferation and the prevalence of true atherosclerosis. Although progression of intimai proliferation with time occurred in both patient groups, a greater proportion of hyperlipemic patients had high grade luminal narrowing of vein grafts as the interval after aortocoronary bypass increased. True atherosclerosis did not develop before 12 months in any of the 59 vein grafts from the 27 normolipemic and 5 hyperlipemic patients who survived aortocoronary bypass, but it occurred in 3 of 26 vein grafts (11.5 percent) from normolipemic and 11 of 14 vein grafts (78.6 percent) from hyperlipemic patients who survived 13 to 75 months after aortocoronary bypass. The observation that microscopic changes of atherosclerosis may occur in saphenous vein grafts in some patients without hyperlipemia also emphasizes the importance of effective control not only of blood lipids but also of the other recognized risk factors for atherosclerosis.