Coronary artery bypass grafting

What it is

Open-heart surgery that routes blood around blocked coronary arteries using the patient's own vessels: the internal mammary artery from inside the chest wall is joined beyond the blockage in the left anterior descending artery, and lengths of leg vein or radial artery bridge from the aorta to the other vessels. Usually done on a heart-lung machine with the heart stopped.

Why it is done

• Left main stem or three-vessel coronary disease, particularly with diabetes or a weak ventricle
• Angina not controlled by medication where anatomy is unsuitable for stents
• Failed or complicated angioplasty
• Combined with valve surgery when both are needed

Before the procedure

• Coronary angiography and echocardiogram; carotid ultrasound; lung function, bloods, dental review
• Stop clopidogrel a few days before; continue aspirin
• General anaesthetic; arterial and central venous lines; urinary catheter

Step by step

1. The sternum is split lengthways and the internal mammary artery harvested from the chest wall while the vein is taken from the leg
2. Heparin is given and the heart-lung machine takes over circulation; the aorta is clamped and the heart arrested with cold potassium solution
3. Each graft is sewn with fine sutures to the coronary artery beyond its blockage; vein grafts are then joined to the aorta
4. The heart is restarted, the machine weaned off, and pacing wires and chest drains placed
5. The sternum is closed with steel wires and the skin closed

Afterwards

• Intensive care overnight on a ventilator for a few hours, then the ward; 5-8 days in hospital
• Chest drains out in a day or two; pain from the sternum and leg wound
• Aspirin, statin, beta blocker; cardiac rehabilitation from about six weeks

Recovery

Six to twelve weeks off work, no driving for four weeks, no heavy lifting for three months while the sternum knits; full benefit at about three months. Arterial grafts last decades; vein grafts about half are narrowed by ten years.