During a coronary artery bypass graft (CABG), blood flow is rerouted through a new artery or vein that is grafted around diseased sections of your coronary arteries to increase blood flow to the heart muscle tissue. This procedure is also called coronary artery bypass surgery.
A bypass typically requires open-chest surgery and the use of a heart-lung bypass machine to circulate the blood and add oxygen.
There are several newer, less invasive techniques for bypass surgery that can be used instead of open-chest surgery in some cases. In some procedures, the heart is slowed with medication but is still beating during the procedure. For these types of surgery, a heart-lung bypass machine is not needed.
Other techniques use keyhole procedures or minimally invasive procedures instead of open-chest surgery. Keyhole procedures use several smaller openings in the chest and may or may not require a heart-lung machine. While these techniques are growing in popularity, they have not been well studied and may not be available in all medical centers.
This information will focus on traditional open-chest bypass surgery. For the bypass grafts, your surgeon will use either an artery or a vein from your body.
A vein may be removed from your leg. One end of it is attached to the aorta and the other end to the diseased coronary artery just past the blocked area.
One end of a mammary artery or another artery in the chest may be detached and reattached to the coronary artery just past the blocked area.
- A portion of the radial artery in your forearm may be used.
In either case, blood is redirected through the artery or vein graft, detouring the blocked or narrowed artery and increasing blood flow to that region of the heart.
What To Expect After Surgery
After surgery, there will be a short stay (1 to 2 days if there are no complications) in the intensive care unit (ICU). In the ICU, you will likely have:
- Continuous monitoring of your heart activity.
- A tube to temporarily help with breathing.
A central line, which is a thin plastic tube inserted into a vein in the neck and threaded down into the heart and pulmonary artery. It is used to monitor pressures and blood flow within the heart.
- A tube to remove stomach secretions until you start eating again.
- A tube (catheter) to drain the bladder and measure urine output.
Tubes connected to veins in the arms (intravenous, or IV, lines) through which fluids, nutrition, and medication can be given.
An arterial line to measure blood pressure. An arterial line is a short, soft, plastic tube (a catheter) that is placed directly into an artery. The arterial line leads to a monitor, which continuously displays your blood pressure.
Chest tubes to drain the chest cavity of fluid and blood (which is temporary and normal) after surgery.
Recovery includes physical therapy, respiratory therapy, occupational therapy, and diet counseling. You will typically stay in the hospital from 3 to 8 days after open-chest bypass surgery. The amount of time you stay varies and will depend on your health before bypass surgery and whether complications develop from the surgery.
Your doctor may have you take aspirin right after your surgery. Starting aspirin therapy shortly after having this procedure can help prevent complications that can affect the heart, brain, kidneys, and intestines.
After you are released from the hospital, your recovery at home takes 4 to 6 weeks. Exercise and driving may be resumed after about 2 to 3 weeks. People who are able to return to work can usually do so within 1 to 2 months, depending on the type of work they do. Some people find that they experience heightened emotions (such as a greater tendency to cry or otherwise show emotion in ways that are unusual compared with before the procedure) for up to a year following the surgery.
Why It Is Done
Bypass surgery is usually performed for heart attack only when other treatments, such as medication and angioplasty with or without stenting, are not useful because of the location or extent of the blockage. See an illustration of the coronary arteries.
Although new techniques have allowed doctors to use angioplasty and/or stenting increasingly over bypass surgery, some types of heart attack may not be effectively treated with angioplasty with or without stenting. Bypass may be a better option for people with diabetes. It may also be a better option when certain areas of the heart are damaged or when angioplasty is not possible for technical reasons.
How Well It Works
Although the immediate risks of coronary artery bypass graft surgery are greater than those of angioplasty, long-term outcomes are similar for both procedures. CABG surgery offers the advantages of greater durability and more complete revascularization. Generally, the greater the extent of coronary atherosclerosis, the greater the benefits of bypass surgery over angioplasty.
Bypass surgery may be considered a better option for some people who have:
- Disease of the left main coronary artery.
Bypass surgery often relieves symptoms of chest pain (angina), improves exercise performance, and reduces the risk of a future heart attack.
People with severe coronary artery disease (CAD) have an increased risk of death within a year when they are treated with bypass surgery rather than medicines alone. However, 5 to 10 years after bypass surgery, the risk of death from CAD is less for those who had surgery compared with those treated with medicine. Factors that affect these results include the number of coronary arteries that are diseased, the severity of the disease, and the location of the plaque in the coronary arteries.
The most common problem after surgery is the return of chest pain (angina). Research shows that 98% of people typically do not have recurring angina 1 year after CABG surgery. However, 10 to 12 years after surgery, only about half of those remain free of angina. Angina probably returns because plaque continues to build up in the grafted arteries and the other coronary arteries.
After 5 years, 2% to 3% of people need another operation. People who have vein grafts tend to need repeat CABG surgeries more than those with artery grafts.
Other risks of bypass surgery may include:
- Risks associated with anesthesia.
- Heart attack.
- Excessive bleeding.
- Subtle problems in long-term memory, comprehension, calculation skills, and concentration.
What To Think About
When bypass surgery is clearly needed, surgery improves symptoms and in some cases prolongs life. However, in many situations the reasons for doing bypass surgery as opposed to other treatments are less clear.
Bypass surgery is often recommended in people with diabetes. Studies show that bypass surgery reduces the rate of death in people who have diabetes and heart attack when compared with angioplasty or thrombolytic therapy.
People are encouraged to ask their doctors what they can expect from bypass surgery compared with other forms of treatment. Bypass surgery does not cure coronary artery disease and does not affect the process of hardening and narrowing of the arteries (atherosclerosis). A person can still develop new blockages in the new blood vessels that are used to bypass blocked arteries, as well as in the original coronary arteries. Reducing risk factors and slowing the rate of atherosclerosis are vital to successful long-term results. Lowering cholesterol when it is high, quitting smoking, and controlling high blood pressure and diabetes are important in anyone who receives bypass surgery.
In each case, the cardiac surgeon or cardiologist should be able to clearly explain why bypass surgery is preferred over medicine or angioplasty. Sometimes a second opinion can be helpful when it is not clear that surgery needs to be done.