Overview of Double Bypass Heart Surgery

Cardiologist doctor in the operation room
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Double bypass surgery is a serious but common open heart surgery procedure. To understand a double bypass, you first need to understand some things about the anatomy of the heart and heart disease.

How the Heart Works

The blood vessels that supply the heart with its own blood supply are called the coronary arteries. In some people, the coronary arteries become blocked. If a blockage is severe, it can completely stop blood flow to the area of the heart that is fed by that particular blood vessel. This blockage can then cause a heart attack. This blockage is commonly known as coronary artery disease.

Treatments for Coronary Artery Disease

In many cases, coronary artery disease can be treated with medication, lifestyle changes and alternative procedures such as the placement of stents in the coronary arteries during a heart catheterization.

For patients with blockages that are severe, surgery may be necessary to make sure the heart continues to receive adequate blood flow. This surgery is known as coronary artery bypass surgery (CABG).

What Happens During a Double Bypass

A double bypass procedure is performed by a cardiothoracic surgeon, a surgeon who is trained in the surgical treatment of chest issues. In this case, surgery will be performed by a surgeon specializing in heart issues.

The procedure begins with general anesthesia being provided by an anesthesiologist, or in some cases, a CRNA—an advanced practice nurse who provides anesthesia. General anesthesia means that the muscles of the body are paralyzed and the patient will have a breathing tube placed so a ventilator can provide air.

Once anesthesia is given, the patient's skin is prepared for surgery, both on the chest and on the leg. This is because blood vessels are taken from another area of the body, typically the leg, and grafted onto the existing heart vessel before and after the blockage. The blood is literally being rerouted around the blockage in the vessel. In some cases, the surgeon will be working on the chest and an assistant will be recovering the blood vessels from the leg. This combined effort helps shorten the length of the surgery and makes the process more efficient.

This rerouted blood vessel, the bypass, makes it possible for the heart to receive the blood it needs and helps prevent heart damage. In order to do this bypass, the most common procedure requires the heart to be stopped so that the surgeon isn't working on a moving beating heart. When the heart is stopped, a heart-lung bypass machine is used to supply oxygen and blood to the body while the heart is still.

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. Most individuals will have chest tubes, which are often connected to gentle suction or gravity drainage, to prevent the build-up of blood around the heart.

Once the surgery is over, the patient will be taken to an ICU or similar cardiac area to recover. Unlike most procedures, the anesthesia is not reversed with medication to wake the patient up. Instead, the anesthesia is allowed to slowly wear off over the course of four or more hours, allowing the patient to slowly and gently wake rather than abruptly.

Other Common Heart Bypass Surgeries

As you already know, 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.

The other variation on the heart bypass surgery is the "off-pump bypass" which is a procedure where the heart continues to beat during the procedure, rather than utilizing a heart-lung bypass machine. Fewer patients are good candidates for this procedure than the more common on-pump procedure.

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Article Sources

  • What Is Coronary Artery Bypass Grafting? National Heart Lung and Blood Institute.