The underfilled coronary artery: some pre- and post-operative observations on recipient arterial quality and left ventricular function after coronary artery surgery.

In a series of 141 saphenous vein aortocoronary bypass grafts in 59 patients undergoing routine restudy of the coronary arteries within four weeks of operation, an overall graft occlusion rate of 12% was found. A trend towards a higher occlusion rate was seen in arteries that were small (19%), that had a limited run-off (15%), significant distal disease (24%) or severe atheroma at the graft site (22%). Statistically, these occlusion rates are not significantly different from the overall failure rate and do not give absolute contra-indications to grafting. A particular group of arteries which seemed underfilled in the pre-operative angiogram (1.5 mm or less in diameter but apparently healthy with smooth walls and supplying a larger area of myocardium than would be expected from their apparent size) was identified. These arteries showed a significant increase in diameter in the post-operative angiograms and had a low occlusion rate (1 of 15 grafts; 7%). When all grafts were patent, the mean post-operative left ventricular ejection fraction showed a significant increase over the pre-operative valve, but when one or more grafts were occluded there was no significant change.