Role of Saphenous Vein Grafts in CABG

Primary Conduit Strategy

The American College of Cardiology recommends the left internal mammary artery (LIMA) to the left anterior descending artery (LAD) as the gold standard, with >90% patency at 10-15 years, compared to only 25-50% for SVGs at the same timepoint 1, 2, 3
Bilateral internal mammary artery (BIMA) grafting should be strongly considered in patients ≤60 years with few comorbidities (Class 2a recommendation) 1, 3

The American Heart Association suggests that SVGs should be used when arterial conduits are unavailable, unsuitable, or insufficient to achieve complete revascularization 1
SVGs should be used when multiple grafts are needed beyond available arterial options 2
The American College of Cardiology recommends that SVGs should be used when the patient has limited life expectancy where long-term patency is less critical 2

10-25% of SVGs occlude within the first year after CABG 1, 2
Additional 1-2% of SVGs occlude annually during years 1-5 1, 2
4-5% of SVGs occlude annually during years 6-10 1, 2
At 10 years, only 50-60% of SVGs remain patent, and only half of these are free of atherosclerosis 1, 2

Endothelial damage during harvesting and exposure to arterial pressure leads to platelet aggregation and acute thrombosis 1, 2
Intimal hyperplasia develops from platelet adherence and smooth muscle cell migration 1, 2
Accelerated atherosclerosis unique to SVGs, with friable plaques occurring in 44% of SVGs versus 0% in native arteries 7, 5

Perioperative aspirin and dipyridamole administration improves early (1 month) and 1-year SVG patency 1, 2
SVGs should target vessels with adequate size and distal runoff 2

Up to 20% of UA/NSTEMI patients have prior CABG, and conversely 20% of post-CABG patients develop UA/NSTEMI within 7.5 years 7, 5
Maintain a low threshold for angiography in post-CABG patients presenting with ischemia given multiple potential anatomic culprits 7, 5
For early ischemia (<30 days post-CABG), urgent angiography is indicated as this typically reflects acute graft thrombosis requiring PCI 6
For multiple SVG stenoses, repeat CABG is reasonable, especially with significant stenosis of a graft supplying the LAD 7, 5
For focal SVG stenosis, PCI is reasonable but carries higher risk of embolization from friable atherosclerotic material 7, 5

Do not use SVGs as first-line conduits when arterial grafts are available and suitable 3, 4
Do not bypass vessels with inadequate stenosis severity as this promotes graft failure through competitive flow 1