Late Results of Saphenous Vein Bypass Grafting for Myocardial Revascularization

Abstract Data from three large groups of patients undergoing aorta-to-coronary artery saphenous vein bypass grafting with follow-up angiograms between 0 and 32 months and postoperative clinical evaluation for up to 46 months enable us to say there is an early saphenous vein closure rate of 9%. These closures are probably related to technical judgment difficulties and lend themselves to improvement in results. The documented late closure rate in 92 patients followed a mean of 31.7 months was 13%. This is a rate of one late closure per 171 patient-months. Of the 92 patients, 80 had some effective vein graft functioning in this follow-up period. Histological evaluation has revealed subintimal fibrous hyperplasia to be the predominant factor involved in late closure of the vein bypass. Its manifestations are variable, and the multifactorial etiology is as yet unclear. Since 5% of vein grafts have some significant subintimal fibrous hyperplasia at the time of insertion, only close follow-up with correlation of operative, angiographic, and histological data will provide the answers to the question of etiology of late vein graft closure. Studies on the effect of trauma, vascularity, and nutrition of vein grafts are necessary. The answer to this problem will be necessary to set the coronary vein bypass procedure on a firm footing in the treatment of coronary artery disease.