Guide to Coronary Artery Bypass Grafting (CABG)
Reviewed by the physicians of Columbia’s Heart Surgery Team, May 2024
Who Is It For? | Types of Bypass | Recovery & Outlook | Choosing A Surgeon | Next Steps
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, an artery or vein from another part of the body is used to reroute blood flow around the blockage.
Coronary artery bypass grafting may also be referred to as simply "bypass" or "CABG" for short (which is sometimes spoken out loud and pronounced like "cabbage").
In a bypass procedure, surgeons use arteries (like the the internal mammary arteries from the chest wall) 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.
Who Is a Candidate for 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 patients with severe disease, in patients with weak hearts (based on 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 chest pain (angina) that cannot be controlled by conventional therapy and who are also good candidates for surgery.
What Are the Types of Bypass Surgery?
There are two types of CABG operations currently available: on-pump and off-pump surgery.
On-Pump CABG
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.
Off-Pump CABG
A newer, minimal-access procedure, the off-pump method eliminates the need for the surgeon to stop the heart and to place the patient on bypass. In an off-pump CABG, the surgeon operates directly on the beating heart, reducing the risk for bleeding and stroke associated with the on-pump procedure. Selection of an on-pump versus off-pump procedure partly depends on the health of the individual patient.
Choosing a Graft Conduit
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.
Another conduit option is the radial artery, which feeds the arm and hands. The advantage of using radial arteries is that they are much more durable than venous grafts and have been associated with better patient survival. The choice of conduits will depend on the patient’s risk profile and availability of radial artery for grafting.
Alternatively, the saphenous vein in the leg may be used as a conduit.
Robotic Surgery for CABG
Most bypass surgery is performed using either an open-heart or minimally invasive approach. Newer robotic techniques have been shown to be a safe and accurate alternative for certain surgical candidates.
In open-heart surgery (or just “open surgery”), an incision is made through the breastbone (sternum), which is then spread apart.
In minimally-invasive heart surgery, special surgical instruments (including high-tech cameras), are inserted through tiny incisions in the chest or rib cage.
In the robotic surgery approach, incisions are not made in the breastbone or between the ribs. Instead, small puncture wounds, are made in the right and/or left sides of the chest. These small punctures allow the arms of a machine (the surgical robot) to access the heart. The surgeon then controls the machine’s movements from a console.
By avoiding even the limited incisions used in other minimally invasive approaches, this totally endoscopic approach results in even less trauma. The patient’s body size and shape, previous surgery, and other medical conditions will help determine whether this approach is possible.
What Happens After the Procedure?
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 is seen more often in older patients. Other complications include fevers, pain, and drainage from your wounds.
During the 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.
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.
At the same time, it's important to remember that bypass surgery 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.
How Do I Choose a Bypass Surgeon?
The skill and experience matter when it comes to getting good, safe results from bypass surgery. Patients considering coronary bypass surgery should always look for:
- Whether the surgeon performs this particular operation regularly (at least 2 or 3 times per week)
- Whether there is a skilled recovery team and a special recovery unit for post-procedure care
Next Steps
If you have heart disease and need help, we’re here for you. To get started today, call (212) 305-2633 or use our appointment request form.
