Vein graft failure.

Saphenous vein graft failure is one of the primary reasons for coronary artery bypass reoperation. The economic impact alone in this country is staggering in an era of intensive cost cutting. The fact that some vein grafts remain free of disease for years while the sibling vein develops extensive atherosclerosis remains an enigma. Saphenous vein valves have recently attracted interest. Repeated angiograms show that vein graft disease invariably is accentuated around valves. Studies show that the segment of saphenous vein distal to the valves have more accelerated and intense atherosclerosis. Early results of saphenous vein bypass grafting may be predicted with some degree of certainty by saphenous vein graft biopsy. Attention is now being turned to the hypercoagulable state as a cause of graft failure, as this has not been previously addressed. Research into pharmacologic agents for maintaining open grafts has had disappointing results and aspirin alone is still the single drug of choice to promote patency. Preparation of the graft continues to be important because there is direct evidence that surgical injury during preparation leads to neointimal thickening and vascular smooth muscle proliferation. Although there are some exciting new modalities for preventing graft disease, the difficulty in transposing animal data to humans and the uncertainty of the biologic similarities of in vitro and in vivo endothelial cell biochemistry makes any immediate solution unlikely. Therefore an even greater increase in the use of arterial grafts in the near future seems likely, even with their associated problems.