Coronary artery bypass graft

Coronary artery bypass grafting, called CABG for short (pronounced 'cabbage'), is a heart operation. It is also called coronary artery bypass surgery.

A CABG is used to treat coronary artery disease. In coronary artery disease, the arteries supplying the heart become narrowed and blocked, affecting blood flow to the heart. A CABG is an operation which diverts blood around a narrowed or blocked artery.

CABG procedures are a type of major heart surgery. They are usually done in people who have angina that isn't treated well enough with medicines, and in some people who have had a heart attack.

The aim of the surgery is to improve blood flow to the heart. This can improve symptoms of angina, and may reduce the risk of having a heart attack in future. In some cases, this can be life-saving.

Heart triple bypass

Before a CABG is offered, you will have a coronary angiogram. This is a technique for taking special X-rays. A small tube (catheter) is inserted via your wrist or groin and dye is injected to look at your arteries in greater detail. The procedure is used to look for the location and amount of narrowing in the coronary arteries.

A different procedure - angioplasty and stenting (percutaneous coronary intervention, or PCI) - is usually preferred for treating coronary artery disease because it has fewer risks and a much quicker recovery time.

However, a CABG is recommended in some situations, such as:

• If PCI hasn't worked.

• If there is a narrowing or blockage in the left main coronary artery - a large artery which provides blood supply to the left side of the heart.

• If there is significant narrowing or blockage in several different coronary arteries.

• If the left side of the heart is not pumping blood properly.

• If someone has diabetes.

Cases are usually discussed at a cardiac multidisciplinary team meeting, which consists of cardiologists, anaesthetists, cardiac nurses and cardiac surgeons. Other illnesses you have and surgical risk will also be discussed and be important in deciding on whether surgery is the right approach.

Some people, particularly people who have had a recent heart attack, may need a hospital stay to wait for urgent surgery.

Coronary artery bypass graft procedure

• You will be anaesthetised with a general anaesthetic (fully asleep).

• A mid-sternal incision (vertical incision through the breastbone) is made.

• The grafts are commonly taken from your leg veins. Sometimes, a graft may be taken from the internal mammary artery, an artery that runs inside the chest.

• Most people will need three or more grafts (common terms used are 'triple bypass' and 'quadruple bypass').

• During a CABG procedure, your heart and lungs are temporary stopped and the blood bypassed through a heart-lung bypass machine to allow the grafts to be stitched in place:

  • A technique using a smaller incision has also been used - called minimally invasive direct coronary artery bypass (MIDCAB); however, it is only appropriate for certain cases and is not routinely available.

• Operating without bypass is possible but CABG with temporary bypass is the standard.

• You will usually need to be on the intensive care unit for 24 hours after the procedure.

• You will usually have a chest drain inserted - a tube draining fluid from around the lungs. This will usually be removed 2-3 days later. You will also have a urinary catheter.

• People can be ready for discharge after five days provided no complications occur.

Outcome

• CABG improves symptoms of angina, quality of life and exercise capacity.

• Around 10% of people will need a repeat CABG procedure after 10 years.

• The chance of needing repeat surgery can be lessened by controlling the development of heart disease. This means stopping smoking, lowering blood pressure and cholesterol levels and controlling diabetes mellitus.

Complications

• Heart attack (myocardial infarction).

• Acute kidney injury- kidney problems.

• Ventricular arrhythmias - abnormal heart rhythms which can sometimes be serious.

• Blood clots developing in the legs (deep vein thrombosis) or lungs (pulmonary embolism).

• Stroke occurs in 1-2%. An ultrasound scan of the neck arteries is sometimes done before the operation. In some people with significant 'furring' (plaque disease) of the main neck vessels, carotid artery revascularisation surgery at the same time as a CABG procedure may be performed.

• Cognitive decline following CABG surgery has been reported in various studies. Most changes are mild and thought to reverse within the first few months after the operation.

• Localised infection at the site of veins taken from the legs.

What follow-up is needed after coronary artery bypass graft?

There will be surgical follow-up after discharge and then ongoing care with your doctor unless there are complications. Most people will be referred on to cardiac rehabilitation.

Prevention of coronary heart disease is very important and will include:

• Stopping smoking.

• Use of long-term aspirin.

• Use of an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin-II receptor antagonist (AIIRA) - also called an angiotensin receptor blocker.

• Use of beta-blockers.

• Use of statins to achieve target cholesterol levels.

• Control of blood pressure and diabetes mellitus.

• Exercise and a healthy diet.