Coronary Artery Bypass Grafting

When arteries that feed oxygen to the heart are blocked, the heart muscle is at risk for damage – called a heart attack – and even death. In an operation known as coronary artery bypass grafting (CABG), an artery or vein from another part of the body is used to reroute blood flow around the blockage. Surgeons use chest wall arteries (known as internal mammary arteries) and segments of the patient’s own veins to construct new pathways for blood and oxygen to reach the heart. The veins used for this reconstruction are usually taken from the patient’s legs, using a minimally invasive technique that leaves only a few tiny incisions. By restoring blood flow to the heart, CABG can relieve symptoms and potentially prevent a heart attack. Coronary bypass operations are performed half a million times a year with an overall success rate of almost 98 percent.

There are two types of CABG operations currently available: on-pump and off-pump surgery. On-pump procedures require the surgeon to open the chest bone (sternum), stop the patient's heart, and place the patient on a heart-lung machine. This machine takes over the function of the patient's heart—delivering oxygenated blood through out the body and brain—while the bypass is performed.

Dr. Craig Smith – What is an off-pump coronary artery bypass surgery?

Dr. Craig Smith – Who is a candidate for off-pump coronary artery bypass?

Off-Pump CABG

A new, minimal access procedure, the off-pump method eliminates the need for the surgeon to stop the heart and to place the patient on bypass. The surgeon operates directly on the beating heart, reducing the risk for perioperative bleeding and stroke associated with the on-pump procedure. Selection of an on- versus off-pump procedure partly depends on the health of the individual patient.

An important issue in CABG surgery is selection of an appropriate conduit (vein or artery) to bring the new blood supply to the heart. Most often, the internal mammary artery, which is located on the inside of the chest wall, serves as the best conduit because it has been shown to last the longest. In 90% of cases, this conduit will last for the rest of the patient's life. During the bypass procedure, the surgeon will take the internal mammary vessel down from inside the chest wall and attach it to the front of the heart. Alternatively, the saphenous vein in the leg may be used as a conduit.

Postoperative care depends on both the type of bypass procedure received and the pace of the patient's recovery. One possible complication is atrial fibrillation, or irregular heartbeats, which occur in about 25% of all heart surgery patients. Typically not dangerous, this condition typically happens in older patients. Other complications include fevers, pain, and drainage from your wounds.

During your postoperative stay, patient education about medications and risk factors is vital in order to ensure a full recovery. These modifications include the permanent cessation of cigarette smoking, appropriate dietary modifications, careful management of diabetes and high blood pressure, and an overall approach to life that results in a less stressful and happier existence.

About Coronary Artery Bypass Surgery

An estimated 170,000 Americans undergo coronary artery bypass surgery each year. This operation, once considered a difficult achievement, is now almost routine in many medical centers.

Studies have conclusively demonstrated that the operation prolongs life in patients who have severe blockages in the three major coronary arteries, in severe disease, in patients with low ejection fraction, and in patients with diabetes. There is less agreement about when it is appropriate for other patients. In general, it is recommended for people with disabling angina that cannot be controlled by conventional therapy and who are also good candidates for surgery.

The operation itself is relatively simple. For "on-pump" procedures, circulation is maintained by a heart-lung machine. In an "off-pump" operation, the surgeon operates directly on the beating heart. Most people who undergo the operation report feeling vastly better afterward. Very often, the patient may have suffered from disabling angina or other cardiac limitations before the operation. With an increased blood supply to the heart muscle, these problems should be eliminated or minimized.

The skill and experience of the surgical and recovery teams also are important considerations. Patients considering coronary bypass surgery always should determine whether the surgeon performs this particular operation regularly (at least 2 or 3 times per week) and whether there is a skilled recovery team and a special recovery unit.

Although bypass surgery greatly improves the way most patients feel, it is not a cure for heart disease. Unless other preventive steps are taken, the processes that caused the artery disease will continue. In fact, the grafts seem to become diseased even faster than the natural coronary arteries. Therefore, it is particularly important for bypass patients to follow a prudent lifestyle following the operation.