When the coronary arteries are blocked too much with plaque and angioplasty cannot be performed, your cardiologist may recommend a major operation called coronary artery bypass grafting (CABG) to lower your likelihood of a heart attack. More than 250,000 people a year undergo bypass surgery. In this procedure, the surgeon redirects the flow of blood so it travels around the narrowed portions of the coronary arteries, allowing blood to reach the heart unimpeded.

Bypass surgery is typically recommended over angioplasty if you have blockages in all three major coronary arteries or if the left main coronary artery is severely obstructed. People with diabetes are frequently considered better candidates for bypass surgery than for angioplasty.

Here are the major steps in a bypass operation:

  • In the operating room, you are given general anesthesia.
  • The surgeon makes an incision in your chest and opens your rib cage to access your heart and coronary arteries. The surgeon then removes a segment of a healthy artery from your chest wall or a vein from your leg or arm. (If the surgeon uses an artery from the wall of your chest, one end remains attached to its blood source.) You may also be placed on a heart-lung machine, which will perform the functions of your heart and lungs during the surgery.
  • One end of the surgically removed vein is sewn onto your aorta (the artery that carries oxygenated blood from your heart to the other arteries); the other end is attached to a healthy section of the coronary artery downstream from the blockage site. If your surgeon uses an artery from the chest, the free end is attached to a section of coronary artery beyond the blockage while the other end remains attached to its blood supply in the chest wall.
  • Once the transplanted vessels are in place, blood flows unimpeded, detouring around (bypassing) the obstructed area of the artery. If more than one coronary artery is obstructed, the surgeon can perform multiple bypasses during the same operation.
  • Bypass surgery lasts an average of three to six hours. There's a 1 to 2% chance of dying and a 2 to 10% chance of experiencing a major complication such as a blood clot that could cause a heart attack or stroke. Once the surgery is completed, you can leave the hospital in about three to five days, although it takes another six to 12 weeks to fully recover. A successful operation dramatically reduces chest pain and significantly decreases the risk of having a heart attack.

Today, more and more surgeons are performing bypass operations on a beating heart. Called off-pump bypass, the procedure does not require a heart-lung machine. Some doctors perform a minimally invasive direct coronary artery bypass (MIDCAB) surgery. In the procedure, the surgeon gains access to the heart and coronary arteries through a small incision between the ribs, rather than sawing through the breastbone as is done in traditional bypass surgery.

Publication Review By: Roger S. Blumenthal, M.D. and Simeon Margolis, M.D., Ph.D.

Published: 14 Mar 2011

Last Modified: 03 Jul 2013