Coronary Artery Bypass Grafting (CABG) is performed using arteries and saphenous veins from patients to bypass blocked arteries in the heart. Over 400,000 are performed in the US annually. It is shown to be effective to prolong life and decrease angina. One disadvantage of the use of saphenous vein grafts in CABG procedures is the risk of decrease flow in the vein due to neointimal hyperplasia that could lead to graft failure. To address this issue, a new clinical trial is investigating the use of the VEST device – an external metal sleeve used around the vein graft – that could potentially improve the long-term patency of these common grafts.