Heart Bypass Surgery


Sarah Lewis, PharmD

What is heart bypass surgery?

Heart bypass surgery, also called coronary artery bypass graft (CABG) surgery, is a treatment for coronary artery disease or atherosclerosis. Heart bypass surgery involves the creation of a new route for blood to flow around narrowed or blocked coronary arteries. 

Your coronary arteries are the blood vessels that supply your heart muscle with blood. The newly created route is made with a graft. A graft is a healthy blood vessel taken from other places in your body.

Atherosclerosis is a common cause of narrowed or blocked coronary arteries. In atherosclerosis, fatty deposits build up on coronary artery walls and harden into a substance called plaque. As plaque builds on coronary artery walls, the artery narrows and hardens. A serious blockage can eventually occur. This reduces blood flow through the coronary artery. 

Atherosclerosis can also cause a blood clot to form. A blood clot can completely block the coronary artery (heart attack). 

Heart bypass surgery is a common but major surgery with significant risks and potential complications. You may have less invasive treatment options. Consider getting a second opinion about all your treatment choices before having heart bypass surgery. 

Types of heart bypass surgery

Heart bypass surgery is named by the number of coronary arteries that are bypassed. Bypassing two coronary arteries is a double bypass. Bypassing three arteries is a triple bypass. Bypassing four arteries is a quadruple bypass.

The types of heart bypass surgery include:

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  • On-pump surgery uses a heart-lung machine (cardiopulmonary bypass). This machine temporarily takes over the heart’s job of pumping oxygen-rich blood to the organs and tissues. This is the traditional type of heart bypass surgery. It allows your surgeon to operate on a heart that is not beating and has no blood traveling through it.

  • Beating heart or off-pump surgery does not use a heart-lung machine. Your surgeon operates on an actively beating heart. Your surgeon will slow your heart rate with medication or a device. This procedure can be used to bypass any of the coronary arteries.

  • Robot-assisted surgery allows your surgeon to use a special computer to control robotic arms that perform the surgery. The surgeon sees a three-dimensional view of the surgery on a monitor. This type of surgery is very precise and uses small, keyhole-size incisions.

The types of heart bypass grafts include:

  • Artery grafts most commonly use an internal mammary artery for the graft. This artery is inside your chest, close to your heart. Arteries are blood vessels that carry blood out to your body’s organs and tissues. Artery grafts are less likely than vein grafts to become blocked over time.

  • Vein grafts most commonly use a saphenous vein for the graft. It is a very long vein located in your leg, but it is not required for normal blood flow from your leg. Veins are blood vessels that carry blood from your tissues and organs back to your heart. Vein grafts are more likely than artery grafts to become blocked over time.

Other surgical procedures that may be performed

Your surgeon may also perform other procedures in addition to heart bypass surgery. These include:

  • Aortic aneurysm surgery to fix an aortic aneurysm. An aortic aneurysm is a weakened, dilated area in your aorta, the major blood vessel in your body.

  • Heart valve repair or replacement to treat or replace diseased valves. Heart valves keep blood flowing in one direction through the four chambers of your heart. They open to allow blood to flow forward to the body. They then close tightly so blood does not leak backwards into the heart.

  • Percutaneous coronary intervention or angioplasty to widen or open a blocked or narrowed artery.

  • Stenting to insert a mesh tube (stent) inside the coronary artery. The stent expands to keep the artery open after angioplasty. Stents remain in place to keep your coronary artery open.

Why is heart bypass surgery performed? 

Your doctor may recommend heart bypass surgery to treat narrowed or blocked coronary arteries. Your surgeon may only consider heart bypass surgery for you if other treatment options with less risk of complications have failed. Ask your doctor about all of your treatment options and consider getting a second opinion before deciding on heart bypass surgery.

Your doctor may recommend heart bypass surgery to reduce your risk of heart attack when angioplasty and s