Heart bypass surgery Health Article

Definition

Heart bypass surgery is performed to route blood flow around clogged arteries supplying the heart.

Alternative Names

Bypass surgery - heart; CABG; Coronary artery bypass graft

Description

Coronary arteries are the small blood vessels that supply the heart muscle with oxygen and nutrients. Fat and cholesterol can build up inside these small arteries. The arteries can gradually become clogged. This buildup of fat and cholesterol plaque is called atherosclerosis.

When one or more of the coronary arteries becomes partially or totally blocked, the heart does not get enough blood. This is called ischemic heart disease or coronary artery disease (CAD). It can cause chest pain (angina).

Sometimes CAD does not cause pain until the blood supply to the heart becomes critically low, and the muscle begins to die. The first symptom of CAD in this case may be a potentially deadly heart attack. Symptomless CAD is especially common in diabetics.

OVERVIEW OF THE PROCEDURE

Heart bypass surgery creates a detour or "bypass" around the blocked part of a coronary artery to restore the blood supply to the heart muscle. The surgery is commonly called Coronary Artery Bypass Graft, or CABG (pronounced "cabbage").

You will receive anesthesia and be completely free from pain. Then the heart surgeon makes a surgical cut in the middle of the chest and separates the breastbone.

Through this cut, the surgeon can see the heart and aorta (the main blood vessel leading from the heart to the rest of the body). After surgery, the breastbone will be rejoined with wire and the opening will be sewn closed.

ARTERY AND VEIN GRAFTS

If the saphenous vein in the leg is to be used for the bypass, an incision is made in the leg and the vein is removed. The vein is located on the inside of the leg. It runs from the ankle to the groin.

The saphenous vein normally does only about 10% of the work of circulating blood from the leg back to the heart. Therefore, it can be taken out without harming you or or the leg.

The internal mammary artery (IMA) can also be used as the graft. This has the advantage of staying open for many more years than the vein grafts, but there are some situations in which it cannot be used.

The left IMA, or LIMA, is an artery that runs next to the sternum on the inside of the chest wall. It can be disconnected from the chest wall without affecting the blood supply to the chest. It is commonly connected to the artery on the heart that supplies most of the muscle.

Other arteries are also now being used in bypass surgery. The most common of these is the radial artery. This is one of the two arteries that supply the hand with blood. It can usually be removed from the arm without affecting the blood supply to the hand.

TRADITIONAL APPROACH

In the traditional surgery, you are connected to the heart-lung machine, or bypass pump. This machine adds oxygen to the blood and circulates blood during the surgery. This is necessary because the heart muscle must be stopped before the graft can be done.

One end of the graft is stitched to an opening below the blockage in the coronary artery. If the grafted vessel is the saphenous vein or the radial artery, its other end is stitched to an opening made in the aorta. If the grafted vessel is the mammary artery, its other end is already connected to the aorta.

The entire surgery can take 4-6 hours. After the surgery, you will be taken to the Intensive Care Unit. For a few days after the surgery, you will be connected to monitors and tubes.

OTHER TECHNIQUES

Other surgical techniques for this procedure are being used more frequently. One popular method is to avoid the use of the heart-lung machine. This is called off-pump coronary artery bypass or OPCAB. This operation allows the bypass to be created while the heart is still beating.

The advantage is that use of the heart-lung machine can lead to some loss of memory and mental clarity. With OPCAB, that risk is reduced because the heart isn't stopped, and oxygen isn't added to the blood outside the body.

Another alternative is the use of smaller incisions that avoid splitting the breastbone. This is referred to as Minimally Invasive Direct Coronary Artery Bypass or MIDCAB.

Coronary bypass surgery can now be performed with the aid of a robot. This robot allows the surgeon to perform the operation without being in the same room as the patient.