A total of 495 patients underwent treatment with excimer laser angioplasty for 545 saphenous vein graft stenoses. Clinical success was achieved in 455 of 495 patients (92%), as indicated by < or = 50% residual stenosis at every target lesion and no complication during hospitalization. At least 1 in-hospital complication occurred in 30 of 495 patients (6.1%): death (1.0%), bypass surgery (0.6%), and Q-wave (2.4%) or non-Q-wave (2.2%) myocardial infarction. Relative risk analysis showed that ostial lesions (n = 65) tended to have higher clinical success (success rate = 95%, adjusted odds ratio [OR] = 2.1 [95% confidence interval (CI) 0.62, 6.88]; p = 0.24) and lower complications (complication rate = 0%, OR = 0.10 [CI 0.01, 0.79]; p = 0.03) than lesions in the body of the vein graft. Lesions > 10 mm (n = 131) had lower success (success rate = 84%, OR = 0.30 [CI 0.16, 0.56]; p = 0.001) and higher complications (complication rate = 12%, OR = 3.3 [CI 1.6, 6.6]; p = 0.004) than discrete lesions. Lesions in small vein grafts < 3.0 mm (n = 76) tended to have increased success (success rate = 94%, OR = 1.55 [CI 0.70, 3.44]; p = 0.39) and lower complications (complication rate = 2.2%, OR = 0.31 [CI 0.10, 0.94]; p = 0.03). Thus, excimer laser-facilitated angioplasty has the most favorable outcome for discrete lesions located at the ostium of all grafts and in the body of smaller saphenous vein grafts.(ABSTRACT TRUNCATED AT 250 WORDS)