The Nuts and Bolts of Bypass Surgery

Sept. 3, 2004 -- Coronary bypass surgery is a procedure intended to reroute, or bypass, blood around clogged arteries and improve blood flow and oxygen to the heart, according to the American Heart Association's Web site.

Chest pains or heart attacks result when a buildup of fat, cholesterol and other substances, known generically as plaque, slows blood flow and clogs coronary arteries, which carry blood to the heart muscle. The bypass procedure is a way to increase the flow of blood to the heart, alleviate pain and reduce the risk of a heart attack.

In the procedure, surgeons take a segment of a healthy blood vessel from another part of the body and attach it to the blocked artery to reroute or detour the blood around the blocked portion of the artery. This can be done in two ways.

An artery may be detached from the patient's chest wall. The surgeon then reattaches the open end of the detached artery below the blocked area of the coronary artery, making a new path for blood to flow to the heart muscle.

Or a piece of a long vein in the patient's leg may be taken out and sewn on to the aorta, the large artery leaving the heart. The other end of the vein is attached or "grafted" to the coronary artery below the blocked area, creating a new path for blood flow.

Depending on how many of the coronary arteries are blocked, a patient can undergo one, two, three or more bypasses.

After surgery, the patient is moved to a cardiac intensive care unit, where the patient's heart rate and blood pressure are monitored for the next 12 to 14 hours. Medications that regulate circulation and blood pressure may be given intravenously, and an endotracheal breathing tube is used until doctors are confident the patient is ready to breath on his or her own.