Coronary artery bypass grafts

The heart needs a constant supply of blood to provide oxygen and other nutrients. There are 2 large blood vessels called the left and right coronary arteries. The artery on the right supplies the right and under surface of your heart (Right Coronary Artery) and the artery on the left divides to supply the front of your heart (Left Anterior Descending Artery) and left side of your heart (Circumflex Artery).

Over time, these arteries can become narrowed and hardened by the build-up of fatty deposits called plaques. This process is known as atherosclerosis. People with atherosclerosis of the coronary arteries are said to have coronary heart disease. When all three vessels of your main heart vessels are involved, this is termed triple vessel disease.

Your chances of developing coronary heart disease increase with age.

There are also a number of risk factors that may affect development of atherosclerosis:

• Smoking
• Hypertension
• Being overweight
• Diabetes
• A family history of heart disease

Coronary heart disease can cause angina, which is chest pain that occurs when the supply of oxygen-rich blood to the heart becomes restricted. While many cases of angina can be treated with medication, severe angina may require a coronary artery bypass graft to improve the blood supply to the heart. Another risk associated with coronary heart disease is the possibility of one of the plaques in the coronary artery rupturing (splitting), creating a blood clot. If the blood clot blocks the blood supply to the heart, it can trigger a heart attack.

A coronary artery bypass graft may be recommended to reduce your chances of having a heart attack.

Almost all operations on the heart will be performed under general anaesthetic. Your anaesthetist will review you before the operation and discuss the anaesthesia and the risks involved. The anaesthetist will outline what lines will be used for the procedure but usually these involve:

• A drip in your arm to put you to sleep
• A radial artery pressure monitoring line in your wrist
• An endotracheal tube (breathing tube) to help your breathing under anaesthesia
• A line in your neck to administer drugs
• A Transoesophageal (TOE) probe to assess your heart during surgery
• A catheter in your bladder
• Pad protection for your eyes

To perform the procedure, surgeons usually make a cut down the middle of the breastbone to reach your heart. 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 (saphenous vein) and sometimes an artery from your arm (radial artery) 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 surgeon often uses a heart-lung machine (cardiopulmonary bypass machine) to take over the work of the heart and lungs whilst the heart vessel bypass surgery is being performed. The 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.

The breastbone is put back together with steel wire until the bone heals itself in 4-6 weeks.

But in some operations the breastbone doesn't need to be cut. This is called keyhole surgery or minimally invasive surgery. This can be performed in some centres where the procedure is performed regularly. It most of the cases it is offered when only the main artery (Left Anterior Descending Artery) is involved and needs bypassing.

Some surgeons may also offer the surgery without the need for using the heart lung bypass machine. This is called off-bypass surgery or OPCAB (Off-Bypass Coronary Artery Bypass Surgery). The surgeon will explain the pros and cons of doing the procedure this way

After your operation you will be moved to intensive care for close monitoring until you wake up. The intensive care staff will only wake you once they are satisfied that you are stable. When you wake up you will notice that you still have the various lines inserted by the anaesthetist at the start of the operation but not the TOE probe.

Pain is usually controlled with strong painkillers in the first 24-48 hours after the operation, but most patients find that the chest wound is comfortable after that with only paracetamol required to ease the discomfort.

You will also notice some drains at the bottom of your wound that help monitor any bleeding that invariably happens to a degree after heart surgery as the blood can be very thin and may not clot (stop bleeding) properly after surgery. Occasionally if there is excessive drainage from the tubes before you wake up, then the surgeon may decide to take you back to theatre to reopen the wound and wash out the area around your heart. Whilst the surgeon hopes not to have to do this, it is always safer to do this if needed. The drains are usually removed on the first or second day after the operation.

You may also notice thin wires near the drains called pacing wires. These are often placed onto the surface of your heart at the end of the operation to help regulate the heart rate. They are attached to a device called a pacing box which provides the electrical stimulus to regulate the heart rate during recovery. If they are no longer needed, then they are removed on the third or fourth day after surgery. Occasionally, if they are still needed after four or five days, a permanent pacemaker will be fitted before you leave for home. Your heart surgeon and cardiologist will discuss this with you if needed.

Once your condition is stable, you will be moved to the high dependency unit or the cardiac ward. You should be out of bed in a day or two and return home after a week, with full recovery after two or three months depending on your fitness, age and how complex the operation was.

Most people get excellent relief from angina and improved quality of life. The operation will hopefully prevent your heart function from deteriorating in the near future and can often improve function if there has been a reduction in your heart pump function.

The risks of heart bypass surgery are different from person to person, depending on the severity of heart disease, type of operation, age, and current state of health. You can visit our risk page on this website to help you understand these risks.

In many hospitals, after a heart bypass operation, 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.

Surgery is not a cure - so it's important to look after your heart health long term.

There are 3 main ways to deal with coronary artery disease.

1. Medication – this can often be very effective in controlling angina and helping the function of your heart. Drugs include:
   • Blood thinners or Antiplatelets – (Aspirin or Clopidogrel)
   • Blood lowering drugs – (Beta blockers, ACE-inhibitors, or calcium channel blockers)
   • Cholesterol lowering drugs – statins
   • Diuretics (water tablets)
2. Stents – These are thin tubes that are placed inside your coronary arteries and are placed by the Cardiologist when you have an angiogram. Generally, the more stents that are required, the less effective they are than surgery.
3. Open heart surgery – Coronary artery bypass grafts.

Your Cardiologist and Heart Surgeon will have a discussion (MDT – Multi-disciplinary Team meeting) to discuss which is the most appropriate treatment for you and will discuss this with you – explain the risks and benefits of each 3 options.

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