Coronary By-pass Grafting (CABG)

Coronary Artery By-pass Grafts

Coronary artery bypass grafting is a surgical technique to try and provide new routes around the narrowings and blockages in the coronary arteries to improve the blood supply to the muscle past those narrowings and blockages.

This is a major operation carried out by cardiothoracic surgeons under a general anaesthetic.

Several different types of blood vessel can be used as the bypass grafts.

Sometimes this involves removing whole sections of blood vessels from a different site in the body to use as new routes around the diseased coronary arteries. Often veins will be taken out of the leg. (Usually the long saphenous vein). Sometimes the radial artery from the lower part of the arm is used. One end of the vessel used as the graft will be attached to the aorta (the big blood vessel that comes out of the top of the heart) and the other end attached to the coronary artery past the narrowed or blocked section.

Sometimes arteries from within the chest are used and in this case the proximal end of the artery (that is the end nearest to its origin) is left attached to its feeding artery but the distal end (that is the end which is running into the muscle of the chest wall) is separated from its normal distribution and is then attached into the coronary artery past the blockage. The artery most often used is the left internal mammary artery (LIMA) but the right internal mammary artery (RIMA) can also be used, as sometimes can arteries that usually run onto the stomach (gastro-epiploic vessels).

These grafts provide new and undamaged routes down which the blood can flow from the aorta into the muscle wall of the heart bypassing the narrowed sections of the diseased coronary arteries and thereby improving the blood supply to the heart muscle (myocardium). This has the benefit in potentially reducing or curing angina and also protecting the muscle past a narrowed section should it block off making it less likely that a heart attack will occur.

Patients most likely to benefit from CABG's fall into two categories. First, those with very troublesome angina despite treatment with adequate medications (particularly if they are not suitable for an angioplasty procedure). Second, patients who are at high risk of future (and potentially fatal) heart attacks. In this latter group surgery may be recommended even though they feel well as in certain circumstances we know that CABG's significantly improve longterm survival rates as compared with medical therapy. Patients who are particularly likely to benefit are those with significant narrowings in the proximal portion of all three main coronary arteries (right, left anterior descending and circumflex arteries) and those with a tight narrowing in the left mainstem artery (this is the short common origin of the left anterior decending artery and the circumflex artery).

It is important to understand that CABG's (and angioplasty and stenting) do not cure coronary artery disease. They will hopefully relieve at least some of the symptoms and may also make future heart attacks less likely to occur, but it is very important to continue to take medications that help to reduce future disease progression (particularly statins and aspirin), to try to maintain the blood pressure and lipids within the recommended targets, to refrain from smoking and to have a healthy diet and regular physical exercise.


Patients with a personal driving license (Group1; cars and motorcycles) can resume driving after four weeks (although most doctors recommend at least six weeks to allow the scars from surgery to have completely healed). Those with a professional license (Group 2: HGV and PSV) are disqualified for three months and must satisfy the criteria of having an ejection fraction of 40% - see heart failure section Heart Failure or greater and passing a DVLA exercise test. DVLA

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