Long-term freedom from angina and ischemic events after coronary artery bypass graft (CABG) surgery is limited by degeneration of saphenous vein grafts. Vein graft stenosis may begin within the first year after surgery, but becomes increasingly prevalent after the first five years following a bypass operation. Stenosis results from intimal hyperplasia, atherosclerotic plaque build-up, and graft remodeling similar to that observed in native coronary arteries. In fact, only 80 percent of vein grafts remain patent five years after surgery, versus 50 to 60 percent at 7 to 10 years. The outcome is better with internal mammary grafts. The optimal management of saphenous vein stenosis is uncertain. Angioplasty for vein graft disease results in even higher restenosis rates (40 to 70 percent) than seen in native coronary vessels. Stenting results in lower restenosis rates and is usually used for vein graft interventions. Re-do CABG may be necessary in certain cases, however, it is associated with increased perioperative mortality and with less complete revascularization and control of symptoms when compared to the first CABG. Stenting usind Drug Eluting stents is very effective in the treatment of saphenous vein graft lesions.
A major problem in saphenous vein graft interventions is distal embolization resulting in no-reflow following successful intervention leading to elevated cardiac enzymes and Q non-Q wave myocardial infarctions. This is particularly worrisome in older degenerated grafts. In fact using distal protection devices, plaque debris can be retrieved which would otherwise go distally. In addition, older grafts tend to redevelop ischemia due to new disease in the unstented segment of the saphenous vein graft as well as restenosis.
Revascularization of totally occluded saphenous vein graft is associated with a lower initial success rate and higher complication rate. However, when no other options are available, these can be achieved. Interventionalists at BIDMC have recently started taking a step approach to these totally occluded vein grafts with recanalization.