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 surgical procedure. It involves the circumvention of blood vessels that supply the heart with its own blood supply, called the coronary arteries.

In some people, the coronary arteries may become blocked. If a blockage is severe, it can completely stop blood flow to the area of the heart and trigger a heart attack. This blockage is commonly known as coronary artery disease (CAD).

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, surgery may be needed. This surgery is known as coronary artery bypass surgery (CABG).

Double Bypass Procedure

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.

Before the Surgery

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

General anesthesia means that the muscles of the body are paralyzed. In order to breathe, the patient will be provided an endotracheal breathing tube connected to a mechanical ventilator.

During the Surgery

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 perform a bypass, the heart will need to be stopped so that the surgeon can accurately place the resected blood vessel. During the time, the patient will be placed 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 patient's 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. 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 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.

Another surgical variation is the "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 for complications from regular bypass surgery, such as those with liver cirrhosis, poor lung or kidney function, or extensive calcification (calcium deposits) of the aortic valve.

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Article Sources

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