Questions and answers

At what percentage the failure rate of vein graft will be within one year?

At what percentage the failure rate of vein graft will be within one year?

Accepted for publication Feb 22, 2019. 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).

Why do saphenous vein grafts fail?

Saphenous vein graft failure during the first year of surgery is due to technical errors, thrombosis, and intimal hyperplasia. All saphenous vein grafts experience endothelial damage during harvesting and initial exposure to arterial pressure.

What happens when bypass grafts fail?

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.

What is graft occlusion?

Acute graft occlusion is the occlusion (blockage) of a vascular bypass graft shortly after the bypass is performed. Its causes, which are distinct from those of chronic graft occlusion, include technical failure (e.g. anastomotic stricture, incomplete valve lysis in non-reversed vein) and thrombosis.

What percentage of bypass grafts 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.

How long do vein grafts last?

After grafting, implanted veins remodel to become more arterial. However, the remodeling can go awry and the vein can become too thick, resulting in clogged blood flow. About 40% of vein grafts fail within 18 months of the operation.

Why is the greater saphenous vein used for a bypass graft?

The saphenous vein (SPV) is a commonly used conduit for bypass due to the ease of harvest, which can generally be done through minimally invasive procedures, with less scarring and faster recovery.

Can a bypass graft be stented?

After a bypass, the graft may narrow or close up over time. And it’s not uncommon for bypass recipients to develop narrowings in other arteries. Both problems can be treated with stents. But neither a stent nor bypass surgery stops atherosclerosis, the disease process that clogs coronary arteries in the first place.

Why do grafts fail?

After grafting, the implanted vein remodels to become more arterial, as veins have thinner walls than arteries and can handle less blood pressure. However, the remodeling can go awry and the vein can become too thick, resulting in a recurrence of clogged blood flow.

How long does a vascular graft last?

Despite the advances in endovascular surgery and its increased popularity over recent decades, vascular bypass grafting remains commonplace and is believed to be the optimal choice for patients requiring long-term revascularization solutions (life expectancy >2 years).

What causes a bypass graft to fail?

Late (beyond 1 year) graft failure is primarily due to progressive atherosclerosis, which occurs over the already injured endothelium. Compared to native coronary artery atheroma, SVG atherosclerosis is more diffuse and concentric, yet less calcified [25].