Off-pump coronary artery bypass surgery (OPCAB) is an operation that treats blocked coronary arteries. By dramatically improving the flow of oxygen-rich blood to the heart (a process called revascularization), an off-pump bypass greatly reduces the risk of angina and heart attack.

Off-pump bypass involves the same two procedures that are performed during traditional bypass surgery. In the first, the surgeon removes (harvests) one of the patient’s blood vessels – usually the saphenous vein in the leg or the mammary artery. In the second procedure, the surgeon uses the blood vessel to create a detour (bypass graft) around the blockages in the coronary arteries.