Overview of Double Bypass Heart Surgery

Double bypass surgery is a serious and fairly common open-heart surgical procedure. It involves the circumvention of blood vessels that supply the heart muscle, called the coronary arteries.

Doctor using a touchscreen in the operating room
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In some people, the coronary arteries may develop a disease that's commonly called coronary artery disease (CAD). This can cause symptoms such as fatigue, shortness of breath, and chest pain.

When the disease is severe, the arteries can become blocked, which can cause a heart attack. 

In many cases, CAD can be treated with medications, lifestyle changes, or the placement of stents in the coronary arteries during a heart catheterization. For patients with severe arterial blockages, coronary artery bypass surgery (CABG) may be needed to place new vessels that reroute blood flow in the heart muscle.

Double Bypass Procedure

A double bypass procedure is performed by a cardiothoracic surgeon. Before surgery, you would need tests to determine which vessels are affected. For example, the left coronary artery, the right coronary artery, the posterior interventricular artery, or other coronary arteries might be involved.

Before the Surgery

The procedure begins with general anesthesia, which is administered by an anesthesiologist, or in some cases, a CRNA—an advanced practice nurse who provides general anesthesia. 

General anesthesia means that you cannot feel pain, the muscles of the body are paralyzed, and you are fully asleep. In order to breathe, you will have an endotracheal breathing tube placed into your throat and connected to a mechanical ventilator.

During the Surgery

Your skin on your chest and on another area of your body (usually the leg) will be prepared for surgery. Blood vessels are taken from another area of the body, typically the leg, and grafted onto the existing heart vessel to reroute blood flow around the blockage.

In some cases, the surgeon will be working on the chest and an assistant will be obtaining the blood vessels from the leg. This combined effort helps shorten the duration of your surgery and makes the process more efficient.

The rerouted blood vessel makes it possible for the heart muscle to receive the blood it needs and helps prevent heart damage. 

In order to perform a bypass, the heart sometimes will need to be stopped so that the surgeon can accurately place the blood vessel. During this time, you would be placed on a heart-lung bypass machine.

The heart-lung bypass machine temporarily takes over the function of the heart and lungs during surgery, maintaining blood circulation and the oxygen content in the body.

After the Surgery

Once the bypasses are complete, the heart-lung machine is turned off and the heart is restarted. The sternum (breastbone) is wired back together and the skin incision is closed. 

Chest tubes are usually placed. These tubes are connected to gentle suction or gravity drainage to prevent the build-up of blood around the heart.

Once your surgery is over, you will be taken to an ICU or similar cardiac area to recover. 

Unlike most procedures, the anesthesia is not reversed with medication.  Instead, the anesthesia is allowed to slowly wear off over the course of four or more hours, allowing you to slowly and gently wake up

Other Bypass Surgeries

If two vessels are blocked and need to be bypassed, the surgery is referred to as a double bypass because two grafts are performed. If three vessels are bypassed, the surgery is called a triple bypass, four bypasses are called a quadruple bypass, and so on. The quintuple bypass, which is 5 bypass grafts to the heart, is fairly rare.

Sometimes the procedure is done as "off-pump bypass" in which the heart continues to beat during the procedure rather than utilizing a heart-lung bypass machine. 

An off-pump bypass may be suitable for people who are at increased risk of complications from having a pump during surgery, such as those with liver cirrhosis, poor lung or kidney function, or extensive calcification (calcium deposits) of the aortic valve.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. MedlinePlus. Heart bypass surgery. Reviewed February 28, 2018.

  2. Cleveland Clinic. Coronary artery bypass surgery: Procedure details. Reviewed June 21, 2019.

By Jennifer Whitlock, RN, MSN, FN
Jennifer Whitlock, RN, MSN, FNP-C, is a board-certified family nurse practitioner. She has experience in primary care and hospital medicine.