Coronary artery bypass graft (CABG)

Your heart is a muscle the size of your fist and consequently needs a constant supply of oxygen (via the blood) to function properly. The blood vessels that carry the oxygen to the heart are called the Coronary arteries and any narrowing of these can result in problems. If your doctor suspects for any reason that you may have narrowed or blocked arteries then they will suggest you have an Angiogram (See section on Angiography).

Angiography may well show that you have Coronary Artery Disease and you may therefore by a candidate for a CABG (heart bypass) or a smaller procedure known as a Angioplasty (see section on angioplasty).

Coronary Heart Disease occurs when the coronary arteries that supply the blood to the heart become blocked due to a build up fatty plaques on the inside of the blood vessel wall. This build up of material is called Atheroma / Atherosclerosis:

Atheroma: Build up of fatty deposits, calcium, cholesterol and other cellular substances that form plaques on inside of blood vessel walls thus narrowing it. The exact reason for the build up of Atheroma is not fully understood but the following are known risk factors:

• Diet high in fat and cholesterol (LDL-bad cholesterol)
• High blood pressure.
• Smoking.
• Higher prevalence in men.
• If you are overweight
• Diabetes.

To prevent the build up of Atheroma the following advice is recommended:

• Healthy and varied diet.
• Stop smoking.
• Lose weight.
• Increase exercise.
• Control B/P and diabetes.

If the blockage of the coronary artery is severe then chest pain may be experienced (angina) and a heart attack is more likely. Angina happens when you heart isn’t getting enough oxygen and is often only present during exercise as this is when your heart needs more blood.

CABG is an extremely common procedure and is carried out on over 500,000 people in the US each year. CABG aims to improve the flow of blood to the heart ensuring it receives the oxygen it needs to function properly. As many as 4 blocked major coronary arteries can be treated by the surgery which would be termed a quadruple heart bypass.

When is CABG surgery indicated?

• You still get chest pain even though you are taking medication for angina.
• Chest pain with any physical exertion.
• Angiograms show that you have narrowing of the arteries of the heart.
• If 3 or more of your arteries are narrowed/blocked.
• Lifestyle changes or medication fail to reduce your symptoms.
• Arteries can’t be widened with an Angioplasty (see Angioplasty section).

Patients with high BP or high cholesterol will need to continue taking their medication following the heart bypass. By losing weight and stopping smoking you are more likely to benefit form the operation.
 
 Goals of CABG:

• Reduce angina and other symptoms of Coronary Artery Disease.
• Enable you to have a more active life style.
• Reduce your chance of getting a heart attack therefore increasing your life expectancy.
• 85% of patients have significantly reduced symptoms following surgery.

The procedure: CABG:

In order to treat your blocked coronary artery your surgeon needs to take a graft of a healthy blood vessel (normally from your leg) and use that to bypass (go around) your damaged artery. This therefore means your heart will receive the required amount of blood and oxygen. The surgeon may bypass as many as 4 arteries.

The surgery is carried out under a general anaesthetic and takes between 3 – 5 hours depending on how many grafts are being done. The procedure:

• A vein from the leg or arm is removed.
• An incision (approx 25 cm) is made down the sternum (breast bone) and your rib cage is opened so your surgeon can access your heart.
• The surgeon attaches the new grafts (bypass) either whilst the heart is still beating or more commonly the heart is stopped.
• If the heart is stopped (using medication) then you are attached to a heart and lung machine to add oxygen to your blood and maintain your circulation.
• The grafts are attached to bypass the blocked arteries then the heart is restarted using controlled electric shocks.
• Your breast bone is closed and held together with wire and your skin is stitched up.

Minimal Invasive Surgery/keyhole: CABG

This is a less common procedure and involves making smaller incisions through the rib cage and using special equipment to enable the surgeon to view what is going on inside your chest via a TV monitor. This is not suitable for all patients and it is best to discuss this with your surgeon.

Recovery period: CABG

• Following the surgery you will be in the intensive care unit (ICU) for      1 – 2 days.
• When you wake up you will be connected to machines that monitor the heart and lung activity.
• You may be attached to a ventilator machine to help your breathing.
• Pain killers are given for any pain.
• Your physiotherapy will start as soon as possible.
• The wires holding the sternum together remain there permanently and the bone usually heals in about 6 weeks.
• Stitches in the skin dissolve naturally.
• Check with your surgeon when you can drive. Normally at least 4 weeks but depends on your recovery.
• Full recovery normally takes 2 – 3 months.
• Increase exercise slowly.

The risks:CABG:

• Heart attack.
• Stroke.
• Abnormal heart beat.
• Death – 2 %

It is important to mention that if you have been advised that a CABG is necessary then you are already at risk of a heart attack.

‘This information is intended as a guide only and should not be used as a substitute for medical information from your own doctor’