Long-term fate of the internal mammary artery and saphenous vein grafts.

Thirty-four patients, each receiving internal mammary artery (IMAG) as well as saphenous vein grafts (SVGs), returned with symptoms 3 to 12 years after operation and underwent angiographic studies. At a mean follow-up period of 6.8 years, two (6%) IMAGs were occluded and 33 (94%) were in excellent condition. Of the 57 SVGs, 28 (48%) were totally occluded, 12 (22%) had severe atherosclerosis, and only 17 (30%) were in good condition. Seven patients (20%) had new significant lesions in the ungrafted coronary arteries. Failure of SVGs was the predominant cause of symptoms in this group of patients. Late failure of the SVGs appears to be due to progressive atherosclerosis in the grafts. The IMAGs tend to remain free from atherosclerosis and perform much better than the SVGs in the long run.