Postoperative coronary arteriography
Postoperative coronary arteriography involves saphenous vein grafting and internal mammary artery opacification as well as coronary arteriography. In our institution, these examinations have been carried out prospectively in two series of near-consecutive patients at three separate times after surgery (Table 1). The first series represents patients operated on at the onset, whereas patients of the second series were operated on after 2 years of experience and improvement in surgical techniques.
Saphenous vein graft patency
The cumulative graft patency is detailed in Table 2. A significant improvement is observed in patients of the second series at 6 to 18 months and between 54 and 88 months. Graft closure was rarely observed after the first year particularly in the second series, its average yearly rate being recorded at 0.7%.
These were first noted at the 6- to 18-month evaluation and consisted of diffuse and localized narrowing, which at pathologic examination were found to be caused primarily by fibrous intimal proliferation. Moderate to marked narrowing (>40%) was observed less frequently in the second series (Table 3). Diffuse narrowing did not progress after the first year and it did not appear to lead to late graft occlusion. Grafts with localized stenoses, however, became occluded in 21.6% of cases (8 of 37), as compared to 8.1% (9 of 102) without this alteration (p < 0.02)
Other obstructive changes were noted in 8.8% of the grafts at the 5- to 7-year examination and appeared to be of atherosclerotic origin (histologic proof in three patients). . .