[Angiographic studies of atherosclerotic changes in coronary vein grafts after operation].

A total of 230 vein grafts were studied angiographically in 116 unselected survivors of 260 coronary bypass operations performed from May 1977 through October 1989 in order to investigate atherosclerotic changes in coronary vein grafts after operation. These patients were divided into three groups according to the interval from operation to angiography. In group A (30 patients) the interval was less than one year (mean interval 8.2 months), in group B (73 patients) from one to five years (mean interval 19.2 months) and in group C (13 patients) more than 5 years (mean interval 96.6 months). Fifty-five vein grafts were in group A, 153 vein grafts in group B and 22 vein grafts in group C. The graft patency rate of each group was 83.6%, 89.5% and 90.9% respectively (N.S.). To classify angiographic appearances we believe to be caused by atherosclerosis, we devised a grading system. Category I indicated that the graft outline was completely smooth without any irregularity; Category II indicated that less than 50% of the estimated surface area of the graft intima was irregular; Category III indicated that more than 50% of the intima was involved. Significant stenosis indicated narrowing reducing the lumen to less than 50% of the graft. Of the 203 patent grafts 181 grafts (89%) were in Category I, 22 grafts (11%) in Category II, but no graft in Category III. In group A of the 46 patent grafts 45 grafts (98%) were classified as Category I and 1 graft (2%) was classified as Category II.(ABSTRACT TRUNCATED AT 250 WORDS)