An evaluation of the long-term patency of the aortocoronary bypass graft anastomosed to a vascular prosthesis

Abstract

OBJECTIVES: Although concomitant surgery for coronary artery disease (CAD) and thoracic aortic aneurysm is performed often, the long-term patency of the coronary artery bypass grafting (CABG) anastomosed to a vascular prosthesis has not been fully investigated. Here, we explored the long-term patency of the graft in comparison with the proximal anastomosis site on the native ascending aorta or vascular prosthesis. METHODS: A total of 84 patients with concomitant CABG who underwent surgery for thoracic aortic aneurysm at 3 Osaka Cardiovascular Research Group institutes were retrospectively investigated for this study. The patency of 109 aortocoronary bypasses using saphenous vein grafts was evaluated with computed tomography angiography or coronary angiography, comparing the grafts anastomosed on the vascular prosthesis (group P, n = 75) to those anastomosed on the native ascending aorta (group N, n = 34). RESULTS: During 45.9 ± 39.7 months follow-up, significantly worse patency of the grafts in group P was revealed when compared with those in group N (100% vs 77.6% in 12 months, 100% vs 52.7% in 36 months and 100% vs 31.6% in 57 months, log rank P < 0.001). The poor patency of the grafts was confirmed in each target lesions (left anterior descending artery: P = 0.050, right coronary artery: P = 0.045, left circumflex artery: P = 0.051) and regardless of the severities of the target coronary vessels (severe stenosis: P = 0.013, mild-to-moderate stenosis: P = 0.029). Furthermore, an analysis of graft occlusion risk factors using the univariate Cox proportional hazards model revealed that the proximal anastomosis site on the vascular prosthesis was the sole risk factor for graft occlusion (P < 0.001). CONCLUSIONS: In the simultaneous surgery for CAD and thoracic aortic aneurysm, CABG design from vascular prosthesis to coronary artery should be avoided if possible, although further studies are warranted.