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Coronary Artery Bypass Grafting

What Is Coronary Artery Bypass Grafting?

Coronary artery bypass grafting (CABG) is a way to revascularize the coronary vessels to improve blood flow to the heart muscle. Cardiothoracic surgeons use CABG to treat people with coronary heart disease that need bypass surgery as a revascularization technique.

CABG is one of the treatments for coronary artery disease. During CABG, a relatively healthy artery or vein from the body is connected, or grafted, to the blocked coronary artery. The grafted artery or vein bypasses (that is, goes around) the blocked portion of the coronary artery. This creates a new path for oxygen-rich blood to flow to the heart muscle. Surgeons can bypass multiple coronary arteries during one surgery.

CABG or angioplasty (putting stents into the coronary vessels) may be options if you have severe blockages in your large coronary arteries. CABG also may be an option if you have blockages in the heart that can’t be treated with angioplasty. In certain cases, CABG will be the preferred treatment option especially if your heart’s pumping action has already grown weak. In this situation, CABG may work better than other types of treatment.

The goals of CABG may include:

  • Improving your quality of life and reducing angina and other coronary heart disease symptoms
  • Allowing you to resume a more active lifestyle
  • Improving the pumping action of your heart if it has been damaged by a heart attack
  • Lowering the risk of a heart attack (in some patients, such as those who have diabetes)
  • Improving your chance of survival

What happens during bypass surgery?

Bypass surgery

A schematic diagram of your heart after bypass surgery.(http://www.bhf.org.uk/images/bypass_surgery_diagram_fullsize.jpg)

Your arteries get narrowed when fatty deposits build up on the inner walls of your arteries. The aim of coronary bypass surgery is to bypass – or ‘get around’ – the narrowed sections of your coronary arteries.The cardiothoracic surgeon does this by grafting a blood vessel between the aorta (the main blood vessel leaving the heart) and a point along the coronary artery, past the narrowed area.

In most cases, at least one of the blood vessels used as a bypass graft is an artery from your chest called the internal mammary artery.

Blood vessels such as a vein from your legs and sometimes an artery from your arms are used for the other grafts. You can have one graft, but it’s more common to have two, three or four (often called double, triple or quadruple bypasses).

The operation

Surgeons usually make a cut down the middle of the breastbone to reach your heart. You will have a long wound down the middle of your chest. If you have had a vein graft from your leg or an artery graft from your arm, you will have a wound in these places too.

A heart-lung bypass machine circulates the blood around your body while the surgeon operates on your heart (on pump bypass). Some surgeons carry out coronary bypass operations without this machine, this is called beating heart surgery (off pump bypass).

Traditional Coronary Artery Bypass Grafting

Traditional CABG is used when at least one major artery needs to be bypassed. During the surgery, the chest bone is opened to access the heart.

Medicines are given to stop the heart; a heart-lung bypass machine keeps blood and oxygen moving throughout the body during surgery. This allows the surgeon to operate on a still heart.

After surgery, blood flow to the heart is restored. Usually, the heart starts beating again on its own. Sometimes mild electric shocks are used to restart the heart.

Off-Pump Coronary Artery Bypass Grafting

This type of CABG is similar to traditional CABG because the chest bone is opened to access the heart. However, the heart isn’t stopped, and a heart-lung bypass machine isn’t used. Off-pump CABG sometimes is called beating heart bypass grafting.

Minimally Invasive Direct Coronary Artery Bypass Grafting

This type of surgery differs from traditional CABG because the chest bone isn’t opened to reach the heart. Instead, several small cuts are made on the left side of the chest between the ribs. This type of surgery mainly is used to bypass blood vessels at the front of the heart.

Minimally invasive bypass grafting is a fairly new procedure. It isn’t right for everyone, especially if more than one or two coronary arteries need to be bypassed.

After your operation you will be moved to intensive care for close monitoring until you wake up. Once your condition is stable, you will be moved to the high dependency unit or the cardiac ward.

The benefits

Most people get excellent relief from angina and improved quality of life. Average CABG with artery graft will last 10-15 years for the patient, provided the risk factors are well controlled.

The risks

The risk of CABG surgery will differ from person to person, depending on the severity of heart disease, condition of the heart muscle and its strength, type of operation, age, and other associated illness at time of operation.

Complications of heart bypass surgery

Some of the possible complications of heart bypass surgery include:

  • Haemorrhage
  • Infection of the wound
  • Heartbeat irregularities (arrhythmia)
  • Kidney failure
  • Fluid build-up in the lungs (pleural effusion)
  • Blood clots in the leg veins (thrombosis)
  • Stroke.


Out of bed in a day or two, return home after a week, full recovery after two or three months, depending on your fitness, age and how severe the problem was.

Taking care of yourself at home

Be guided by your doctor, but general suggestions include:

  • Take all prescribed medications strictly as directed by your doctor.
  • Activities such as sneezing and coughing could cause some discomfort around your wound site. Don’t be alarmed, as this is normal.
  • Watch for any possible complications. Some of the symptoms of infection (for example) may include redness, drainage of pus, heat, or increasing pain at your wound site. Other symptoms that may indicate problems include difficulty breathing, or a swollen and tender calf muscle.
  • You will need to wear an elastic support stocking on the leg that the vein was removed from. Raise your leg regularly to reduce swelling.
  • Your breastbone needs at least three months to properly heal. Strictly avoid lifting, pulling or pushing heavy objects for at least six to eight weeks after the operation.
  • Follow your doctor’s recommendations on diet and exercise.
  • Eat a wide variety of fresh fruit and vegetables, wholegrain cereals and deep sea fish (such as salmon, tuna, sardines, mackerel).
  • In particular, avoid saturated fats found in animal products (including dairy foods) and hidden fats in pastries, biscuits, fried foods, snack foods.
  • Don’t smoke.

Long-term outlook after heart bypass surgery

Your wellbeing in the long term depends on your commitment to healthier lifestyle changes. For example, if you continue to smoke and eat a high-fat diet, your bypass graft may eventually become clogged with fatty plaques. You will need to regularly consult with your health professionals (including your doctor and surgeon) to ensure proper cardiac rehabilitation.

Some common experiences for patients in the weeks and months following heart surgery include:

  • Constipation caused by medications, inactivity and the impact of surgery on the body.
  • Excessive sweating, particularly at night.
  • Emotional problems, including stress, depression and reduced self-esteem.
  • Thinking difficulties, such as reduced concentration and shortened attention span

What should I do when I go home?

In many hospitals a member of the cardiac rehabilitation team will see you on the ward to give you information about your condition and the treatment you have had.

They will talk to you about making lifestyle changes and how to reduce your risk factors (the things that increase your risk of heart disease) to help protect your heart in the future. You can also ask the rehabilitation staff any questions about your recovery. CABG surgery is not a cure – so it’s important to look after your health long term.

Who can I talk to?

As the day of your surgery gets closer, you may be feeling a whole range of emotions. You may feel anxious, afraid, angry, worried about the future or glad that you are about to have treatment. It’s natural to have these feelings and it’s important to talk about them with your partner, a friend, relative or healthcare professional.


Last Reviewed : 12 May 2014
Writer : Dr. Siti Khairani bt. Zainal Abidin