Coronary artery bypass graft (CABG) surgery is one of the most common major surgeries performed in the United States. This is a method of surgery that works to improve blood flow to the heart by creating alternate pathways around arteries that have become blocked or narrowed due to coronary artery disease. Without this surgery, oxygen and nutrients are generally not able to reach the heart in sufficient amounts which increases the patient's chances of experiencing a heart attack. According to the American Heart Association, approximately 448,000 CABGs were performed in 2006. Three times as many men (323,000) as women (125,000) had this surgery.

Atherosclerosis is the primary reason for coronary artery bypass surgery. This is a condition where plaque builds up on the walls of the treaties. The passageways become narrow and the arteries themselves harden reducing flexibility. Accumulation of the plaque is usually due to high cholesterol levels and is aggravated by other conditions, such as high blood pressure, and unhealthy habits, like smoking. When a patient's arteries becomes sufficiently narrow enough to reduce the free flow of the blood supply to the heart (approximately 50% to 70%), the muscle becomes starved of oxygen which can lead to tissue damage.

Most patients experience chest pain when the heart is not getting enough oxygen. Typically, a doctor will recommend medication and lifestyle changes to bring the patient's atherosclerosis under control. However, if sufficient blockage occurs, the doctor may recommend coronary artery bypass surgery to improve blood flow and prevent further damage to the heart. The surgery takes approximately four hours and consist of the heart surgeon making an incision in the chest and sawing through the breastbone. Pulmonary bypass is established so that the heart can be stopped. The surgeon then drafts venous material, usually taken from the saphenous vein in the legs, around the blockage. One end is attached to the blocked vein and the other directly into the aorta.

The risks associated with coronary artery bypass surgery are fairly low. Approximately 4% die as a result of the surgery. The main cause of death is heart attack which occurs in 5% to 10% of patients during or after the bypass surgery. However, there are factors that increase your risk of experiencing complications. This includes age, diabetes, lung disease, chronic kidney failure, poor heart muscle function, and diseases that affect the left main coronary artery. It is best to consult with a knowledgeable medical professional to determine if this treatment option is best for you.