摘要
BACKGROUND: In the past decade, the radial artery has frequently been used for coronary bypass surgery despite concern regarding the possibility of graft spasm. Graft patency is a key predictor of long-term survival. We therefore sought to determine the relative patency rate of radial-artery and saphenous-vein grafts in a randomized trial in which we controlled for bias in the selection of patients and vessels. METHODS: We enrolled 561 pa tients at 13 centers. The left internal thoracic artery was used to bypass the anterior circulation. The radial-artery graft was randomly assigned to bypass the major vessel in either the inferior(right coronary)territory or the lateral(circumflex) territory, with the saphenous-vein graft used for the opposing territory(control). The primary end point was graft occlusion, determined by angiography 8 to 12 months postoperatively. RESULTS: Angiography was performed at one year in 440 patients: 8.2 percent of radial-artery grafts and 13.6 percent of saphenous-vein grafts were completely occluded(P=0.009). Diffuse narrowing of the graft(the angiographic “string sign”)was present in 7.0 percent of radial-artery grafts and only 0.9 percent of saphenous-vein grafts(P=0.001). The absence of severe native-vessel stenosis was associated with an increased risk of occlusion of the radial-artery graft and diffuse narrowing of the graft. Harvesting of the radial artery was well tolerated. CONCLUSIONS: Radialartery grafts are associated with a lower rate of graft occlusion at one year than are saphenous-vein grafts. Because the patency of radial-artery grafts depends on the severity of native-vessel stenosis, such grafts should preferentially be used for target vessels with highgrade lesions.
BACKGROUND: In the past decade, the radial artery has frequently been used for coronary bypass surgery despite concern regarding the possibility of graft spasm. Graft patency is a key predictor of long-term survival. We therefore sought to determine the relative patency rate of radial-artery and saphenous-vein grafts in a randomized trial in which we controlled for bias in the selection of patients and vessels. METHODS: We enrolled 561 pa tients at 13 centers. The left internal thoracic artery was used to bypass the anterior circulation. The radial-artery graft was randomly assigned to bypass the major vessel in either the inferior(right coronary)territory or the lateral(circumflex) territory, with the saphenous-vein graft used for the opposing territory(control). The primary end point was graft occlusion, determined by angiography 8 to 12 months postoperatively. RESULTS: Angiography was performed at one year in 440 patients: 8.2 percent of radial-artery grafts and 13.6 percent of saphenous-vein grafts were completely occluded(P=0.009). Diffuse narrowing of the graft(the angiographic “string sign”)was present in 7.0 percent of radial-artery grafts and only 0.9 percent of saphenous-vein grafts(P=0.001). The absence of severe native-vessel stenosis was associated with an increased risk of occlusion of the radial-artery graft and diffuse narrowing of the graft. Harvesting of the radial artery was well tolerated. CONCLUSIONS: Radialartery grafts are associated with a lower rate of graft occlusion at one year than are saphenous-vein grafts. Because the patency of radial-artery grafts depends on the severity of native-vessel stenosis, such grafts should preferentially be used for target vessels with highgrade lesions.
