Why Do Bypasses Fail?

About 40 percent of vein grafts

experience such a failure within 18 months of the operation. Boehm and his colleagues examined veins from mouse models of bypass surgery, and discovered that a process known as an endothelial-to-mesenchymal transition, or EndoMT, causes the inside of the vein to over-thicken.

What happens if bypass surgery fails?

Third, patients presenting with bypass graft failure are often old (mean age was 68–70 years in this study) and have worse baseline left ventricular function, hence may be at increased risk for heart failure or arrhythmias, and for developing noncardiac disease, such as infections and cancer.

Can a bypass graft fail?

Approximately 50% of saphenous vein grafts (SVGs) fail by 5 to 10 years post-coronary artery bypass grafting (CABG) and between 20–40% fail within the first year (1,2). While SVG failure can sometimes be silent, when symptomatic events occur, SVG percutaneous coronary intervention (PCI) is often performed.