Coronary Bypass Surgery

Definition

This is an operation in which cardiac surgeons remove part of the blood vessel (graft) from somewhere else in the body, and attach it to a narrowed or blocked coronary artery so the heart muscle ordinarily supplied by that coronary artery can be nourished again. It is also known as Coronary Artery Bypass Grafting (CABG, often pronounced "cabbage").

Description

More than 20 years ago, bypass graft surgery was introduced as a way of treating coronary artery disease. For many people who suffer from unremitting angina, CABG can provide dramatic relief. It is a major operation done under general anesthesia.

The principle of bypass graft surgery is to construct a new channel so blood can get around the atherosclerotic blockages in the coronary arteries. Therefore, instead of trying to scrape out the plaques, the surgeon uses a segment of a vessel from another part of the body to transport blood to the far side of the obstruction.

Usually the grafts are fashioned from one of the large, accessible saphenous veins that run down the inside of the leg, although recently there has been a trend toward using the internal mammary arteries located under the chest wall.

During the operation, your heart will be temporarily stopped, and you will be placed on a heart-lung bypass machine which will oxygenate and warm your blood while the surgeon works on your heart.

Sewing these grafts into place requires considerable skill. In essence, the surgeon must join two tubes that are only slightly larger than spaghetti. The juncture must be tight enough to keep blood under high pressure from leaking out. But if the stitches are even a fracture of a millimeter off the mark, movement of the blood through the tubes will be compromised.

In addition, the tubes must be placed quickly, since complications are more likely the longer the heart is arrested. As intricate as this procedure is, placement of each bypass graft usually takes 15 to 30 minutes, while the entire operation may take 2 to 4 hours. Many patients undergo multi-vessel bypass if more than one coronary artery is narrowed or blocked.

CABG can be accomplished with a very low mortality rate (1 to 3 percent) in otherwise healthy patients with preserved heart function. However, the mortality rate rises to 4 to 8 percent in older patients and in those who have had a prior CABG.

Angioplasty - Alternative to CABG

Each year more than 500,000 Americans will be given a new lease on life in the form of coronary artery bypass surgery or balloon angioplasty. These two techniques are the primary medical weapons against coronary heart disease, an insidious process that chokes off the blood supply to the heart.

Of course, the wisest approach is to prevent heart disease in the first place by following a low-fat diet, stopping smoking, controlling high blood pressure, losing weight if necessary and getting regular exercise.

CABG reroutes the blood past potentially deadly blockages, while angioplasty opens blocked arteries by stretching open obstructions in vessel walls. If a physician suspects heart disease, the patient usually undergoes an exercise test to evaluate heart activity and to see whether chest pain occurs. If the stress test indicates a potential problem, the patient will then undergo angiography, an x-ray procedure used to study blood vessels.

In angiography, a small catheter is passed from an arm or leg to the heart. Dye is then injected into the arteries of the heart to detect the location and severity of any blockages. If angiography reveals one or more severe blockages, the physician will recommend either bypass surgery or the balloon angioplasty technique.

Beyond some general guidelines, the decision over which technique to use may be open to considerable discussion. When the disease affects more than one coronary artery and when there are multiple blockages in the same artery, the balance tends to shift in favor of bypass surgery.

Recovery

Your physician and surgeon will help determine the most appropriate recovery regimen for you. For people who have sedentary office jobs, four to six weeks is the average. People who must perform heavy work will have to wait longer. In some cases, a person may not be able to return to his or her former job. Patients should follow these general guidelines:

Arise at a normal hour.
Bathe or shower if possible.
Always dress in street clothes and never stay in sleeping clothes during the day.
Take a mid-morning and mid-afternoon rest following periods of activity.
Rest periods are helpful following activity, so after taking a morning walk of a few blocks, come home and take a short nap.

You'll be able to perform more activities as more time passes, so be patient. And walking is particularly good exercise and will speed your recovery. Aside from walking, you should have no problem doing any of the following: helping with light work around the house; going to the theater, restaurant, store or church; visiting friends; or going for a ride in the car. In some instances, your doctor may prescribe a more formal, graded activity schedule. If you have questions, ask your doctor.

Recent Developments

Two new surgical approaches are being used more frequently:

Minimally invasive CABG" uses small incisions in the chest to perform the surgery, rather than the classic "median sternotomy" incision, a longer incision down the middle of the chest.
Direct coronary artery bypass" avoids the heart-lung machine, and the grafts are sewn directly to the beating but stabilized heart. Avoiding the bypass machine reduces recovery time.

These two surgical approaches are usually not suitable for more than two grafts and to date, do not have established durability.