BALLOON ANGIOPLASTY FOR THE TREATMENT OF LESIONS IN SAPHENOUS-VEIN BYPASS GRAFTS

Objectives. The purpose of this review is to assess the value and limitations of balloon angioplasty for the treatment of saphenous vein bypass graft obstructions. The potential efficacy of new interventional techniques is discussed. Background. Treatment of ischemia due to saphenous vein bypass graft obstructions poses a difficult problem that will be encountered more often as the pool of surgically treated patients continues to accumulate. Reoperation is technically demanding and is associated with high mortality and morbidity rates. Balloon angioplasty may provide a suitable alternative. Methods. The review proposes a classification of patients with attempted saphenous vein graft angioplasty according to expected early and late outcome based on the data obtained from the relevant published data and personal experience. Results. Angioplasty of a nonocclusive obstruction in a saphenous vein bypass graft has an initial success rate of approximately 90% and is a safe procedure (procedural death rate <1%, myocardial infarction rate <4%). The overall average restenosis rate is 42%. Surgical standby is limited and technically difficult. Angioplasty of chronic total occlusions in old grafts is associated with poor initial and long-term results. The long-term clinical results are unfavorable because of the continuing progression of disease in nontreated vein graft segments and native coronary arteries, in addition to the high restenosis rate. New techniques, although promising, have shown neither better initial results nor reduction of restenosis. Stent placement may be useful in longer graft lesions containing friable material. Conclusions. Patients may be classified into three groups according to expected early and late outcome on the basis of 1) unfavorable graft anatomy, 2) risk of cardiogenic shock in event of acute graft closure, and 3) age of grafts. The three groups are 1) those with an initial high success, low procedural risk and low restenosis rate; 2) those with an initial high success but high procedural risk and moderate to high restenosis rate; and 3) those with a low success, high risk and high restenosis rate. Balloon angioplasty to treat lesions in venous bypass grafts should be considered a palliative procedure, not a long-term solution, for ongoing progression of coronary artery and vein graft disease. The induced high restenosis rate remains a significant problem.