Since the first successful coronary artery bypass operation in 1964, coronary artery bypass grafting (CABG) has helped create new coronary arteries for patients with severely clogged arteries. Narrowing of the arteries—atherosclerosis—occurs when arteries become clogged with fat, cholesterol and other substances. Atherosclerosis can slow or stop the flow of blood through the heart’s blood vessels, increasing the risk for heart attack. To prevent this, about 400,000 people annually undergo CABG, which uses harvested blood vessels from other parts of the body to reroute, or “bypass,” blood around clogged arteries and improve the supply of blood and oxygen to the heart.
While not a cure for atherosclerosis, CABG improves symptoms in 90 percent of people who have it. CABG relieves angina (chest pain caused by inadequate blood flow in the coronary arteries) and helps people with severe coronary heart disease live longer.
If you or someone you love requires CABG, read on for answers to some common questions about the procedure.
CABG is performed in cases where patients have severe blockages in the coronary arteries that can’t be remedied by medication (such as beta-blocking drugs that lower blood pressure and slow heart rate), balloon angioplasty (a nonsurgical procedure that uses a balloon-tipped catheter to inflate and reopen arteries) or keyhole bypass (a relatively recent, minimally invasive procedure). It’s especially appropriate for patients who have debilitating angina; multi-vessel disease (narrowing or blockages in two or more arteries); significant narrowing of the left main artery (the primary path for blood to reach the heart); or poor function of the left ventricle, the heart’s main pump.
Before undergoing bypass surgery, candidates will undergo testing to assess the extent and severity of their condition. The results of an electrocardiogram (ECG) and a coronary angiography can help determine whether CABG is necessary.
During traditional surgery, which is performed under general anesthesia, the patient is placed on a heart-lung machine that takes over the work of pumping blood throughout the body. A surgeon then makes a small incision in one of the patient’s legs to remove a length of vein. Another incision is made down the center of the patient’s chest, and the rib cage is opened to expose the heart.
The bypass is achieved by sewing the “harvested” vein from the leg into place by the aorta, the main artery that leads from the heart, and attaching it to the coronary artery beyond the point of blockage. Using the length of vein from the patient’s leg, the surgeon makes one or more grafts to bypass the blockages in the coronary artery, restoring blood flow to the newly grafted section. The grafted section resumes the work of the narrowed or blocked artery.
Instead of harvesting a leg vein, CABG also may be performed using an artery from the chest wall—called the internal mammary artery—and attaching the open end to the coronary artery below the blocked area. Another alternative procedure, called off-pump bypass grafting, allows surgery to be performed on a beating heart without using the heart-lung machine.
After successful traditional surgery, the patient is taken off the heart-lung machine and the heart resumes functioning. Patients can expect to spend a few days in intensive care, where fluids, nutrition and medications are administered intravenously and the heart rhythms can be monitored. Drainage tubes are placed in the patient’s chest cavity to remove excess fluid or blood from around the heart. A breathing tube also may remain until the patient can breathe unaided.
In the past, patients were often hospitalized as many as 12 days following bypass surgery. Today, many patients go home just four days after bypass surgery of multiple arteries. Patients still need to convalesce at home for six to eight weeks. A physician advises the patient on necessary dietary modifications to reduce fat and cholesterol as well as how to safely resume physical activity.