The surgery reroutes, or "bypasses," blood around clogged arteries to improve blood flow and oxygen to the heart. Coronary bypass surgery remains one of the gold standard surgical treatments for coronary artery disease.

The aim of CABG is to reduce the chance of heart attack, increase life expectancy and improve quality of life. Every year more than one million CABG performed world wide. Last year over 7 thousands CABG were done in Bangladesh.

Your heart needs blood and oxygen to perform its job. Left and right coronary arteries through their branches deliver a constant supply of much-needed blood and oxygen to the heart muscle. When one or more of these arteries becomes narrowed or clogged, blood and oxygen are reduced and heart muscle is damaged.

According to American heart Association and American College of Cardiologists, there are many indications for CABG. CABG may not be suitable for all patients with angina (pain in the chest caused by inadequate supply of blood to the heart muscles, following exercise or eating, because of narrowing of the arteries).

We need to access the patient individually. There are following indications, when we consider patients for CABG. When you have debilitating chest pain caused by narrowing of several of the arteries that supply your heart muscle; you have more than one diseased coronary artery and the heart's main pump (left ventricle) is functioning poorly; your left main coronary artery is severely narrowed or blocked; you have an artery blockage for which angioplasty is not appropriate; you have had a previous angioplasty or stent placement has not been successful; or you have had angioplasty but the artery has narrowed again (restenosis).

CABG generally takes between three and six hours and requires general anesthesia. On an average, surgeons repair two to four coronary arteries. Surgeons take a segment of a healthy blood vessel from another part of the body and make a detour around the blocked part of the coronary artery. An artery may be detached from the chest wall and the open end attached to the coronary artery below the blocked area. A piece of a long vein in your leg may be taken. One end is sewn onto the large artery leaving your heart - the aorta. The other end of the vein is attached or "grafted" to the coronary artery below the blocked area.

Either way, blood can use this new path to flow freely to the heart muscle. Cardiopulmonary bypass with a pump oxygenator (heart-lung machine) is used for most coronary bypass graft operations.

During the past several years, more surgeons have started performing off-pump coronary artery bypass surgery (OPCAB or Beating heart Surgery). In this case, the heart continues beating while the bypass graft is sewn in place. It is not an option for everyone.

In the USA , the UK and Australia, approximately 20 percent of CABG are done on beating heart. In India this procedure is done in about 40 percent of all CABG.

The long-term outcome of this type of procedure is not yet known. In Minimally invasive cardiac surgery, a surgeon performs coronary bypass through several smaller incisions in the chest. This technique is usually used only when certain conditions exist.

If multiple coronary arteries need to be worked on, it is best to use a conventional approach. Variations of minimally invasive surgery may be called port-access or keyhole surgery.

Lifestyle changes are still necessary and an integral part of treatment after CABG. Lifestyle changes - especially smoking cessation - are crucial to reduce the chance of future blockages and heart attacks, even after successful bypass surgery.

In addition, you will likely need to make other lifestyle changes, such as reducing certain types of fat in your diet, increasing physical activity, and controlling high blood pressure, diabetes, stress, obesity and other risk factors for heart disease.

Medications are routine after heart surgery to lower your blood cholesterol, reduce the risk of developing a blood clot and help your heart function as well as possible.

Most people with sedentary office jobs can return to work in four to six weeks. Those with physically demanding jobs will have to wait longer.

Dr Md Habibe Millat, MBBS, FRCS is a Consultant Cardiac Surgeon at Square Hospital, Dhaka. [E-mail: mhmillat@hotmail.com]